Cancer in Patients With Gabapentin (GPRD)

• ClinicalTrials.gov Identifier: NCT01236053
• Recruitment Status: Completed
• First Posted: November 7, 2010
• Results First Posted: August 4, 2011
• Last Update Posted: July 6, 2017
• Sponsor: GlaxoSmithKline
• Information provided by (Responsible Party): GlaxoSmithKline

Study Description

Brief Summary:

High doses of gabapentin are associated with pancreatic acinar cell tumors in rats, but there has been no post marketing pancreatic carcinogenicity signal with gabapentin as reported by spontaneous reports in AERS or in the published literature. In a published case-control screening study of the association of gabapentin with 55 cancers, the only cancer that met the screening criteria for possibly increased cancer risk with gabapentin exposure was renal (including renal pelvis) cancer. This association was judged to be likely due to or substantially accentuated by confounding by cigarette smoking, hypertension, and lifestyle (Cancer Causes Control 2009;20:1821-1835).

The relationship between gabapentin exposure and pancreatic cancer and renal cancer is studied in NCT01138124, and supplemental analyses for these cancers are performed in the current study. The FDA recommended GSK also study the relationship between gabapentin and all-cancer sites, as well as cancer at the following specific sites: 1) stomach, 2) anus, anal canal, and anorectum, 3) lung and bronchus, 4) bones and joints, 5) breast, 6) penis, 7) urinary bladder, and 8) other nervous system.

The primary objective of this study is to determine whether exposure to gabapentin is associated with an increased risk of developing all-cancer, and these specific cancers in the United Kingdom (UK) General Practice Research Database (GPRD). Each member of the UK population is registered with a General Practice, which centralizes the medical information not only from the general practitioners themselves but also from specialist referrals and hospital attendances. Over 487 General Practices contribute data to the GPRD.

The study cohort from which cases and controls are drawn is all subjects in the GPRD 1993-2008. Gabapentin was approved in the UK in May 1993. Entry into the study cohort begins Jan 1, 1993 for all those who are registered in GPRD before that time, and at the time of registration if later than Jan 1, 1993. Subjects are excluded from the GPRD cohort if they have a cancer diagnosis or a history of cancer prior to the cohort entry date. Patients with a first diagnosis of the respective cancer 1995-2008 are risk set matched with up to 10 controls within the same General Practice for age at cohort entry (within two years), sex, and year of entry into the study cohort (within one year). For cases, the index date is the date of first diagnosis of the respective cancer. The index date for controls is set as the date at which the follow-up time from cohort entry is the same as the case. The index date is chosen so as to give the control equal follow-up time to that of the case for ascertainment of use of gabapentin. Cases and controls will be required to have at least 2 years of follow-up in the study cohort before their index date. Cases must have no history of any other cancer diagnosis prior to the index date. Controls are required to be free of cancer diagnosis in the database up to the control's index date.

Data on gabapentin prescriptions are obtained for cases and controls from study cohort entry to the index date. Gabapentin exposure will be assessed as ever/never, number of prescriptions, cumulative dose, and cumulative duration, with a 2 year lag period incorporated to control for protopathic bias (gabapentin prescription for initial pain symptoms of undiagnosed cancer) and latency (time between cancer onset and specific GPRD cancer diagnosis).

Crude and adjusted odds ratios and 95% confidence intervals (CI) will be produced from conditional logistic regression models, with additional analyses evaluating for dose-response. Covariates include indications for gabapentin use and risk factors for each cancer.

Condition or disease	Intervention/treatment
Pain, Neuropathic; Epilepsy; Renal Pelvis Cancer; Pancreatic Cancer; Breast Cancer; Nervous System Cancer; Chronic Pancreatitis; Stomach Cancer; Renal Cell Carcinoma; Diabetes; Bladder Cancer; Bone and Joint Cancer; Penis Cancer; Anal Cancer; Cancer; Renal Cancer	Drug: Gabapentin prescriptions

Detailed Description:

Actual number of patients may be less, as it is possible for a patient to be represented in more than one of the 22 arms (See "Participant Flow: Overall Study" Table) because of the risk set sampling.

Study Design

• Study Type: Observational
• Actual Enrollment: 2323608 participants
• Observational Model: Case-Control
• Time Perspective: Retrospective
• Official Title: Risk of Cancer in Patients Exposed to Gabapentin in the GPRD
• Study Start Date: June 2010
• Actual Primary Completion Date: September 2010
• Actual Study Completion Date: September 2010

Groups and Cohorts

Group/Cohort

Intervention/treatment

UK GPRD 1993-2008; The study cohort from which cases and controls are drawn is all subjects in the United Kingdom (UK) General Practice Research Database (GPRD) 1993-2008. Each member of the UK population is registered with a General Practice, which centralizes the medical information not only from the general practitioners themselves but also from specialist referrals and hospital attendances. Over 487 General Practices contribute data to the GPRD. Entry into the study cohort begins Jan 1, 1993 for all those who are registered in GPRD before that time, and at the time of registration if later than Jan 1, 1993. Subjects are excluded from the GPRD cohort if they have a cancer diagnosis or a history of cancer prior to the cohort entry date.

Drug: Gabapentin prescriptions; The exposure of interest is gabapentin use as defined by prescriptions recorded by the GPRD general practitioner (British National Formulry codes). Data on prescriptions for gabapentin will be extracted for each case and control from entry into the study cohort up to two years prior to the index date (the exposure window). A two year lagged exposure is incorporated to account for latency between cancer onset and GPRD diagnosis, and for protopathic bias (gabapentin prescription for initial pain symptoms of undiagnosed cancer). Gabapentin exposure will be parameterized as follows: (1) Ever versus never exposed; (2) Number of prescriptions; (3) Duration of exposure; and (4) Cumulative dose.

Outcome Measures

Primary Outcome Measures :

1. Number of All-Cancer Cases and Matched Controls With the Indicated Exposure to Gabapentin [ Time Frame: The case index date was the date of incident cancer diagnosis ascertained in the GPRD study cohort 1995-2008. The matched control index date was the date at which the follow-up time from his/her cohort entry was the same as that for the case. ]
   Incidence of all cancers. Gabapentin Exposure Description: Without 2 year lag = Gabapentin prescription from cohort entry to index date. With 2 year lag = Gabapentin prescription from cohort entry to 2 years prior to index date (to control for prediagnostic prescribing for pain symptoms possibly related to cancer).
2. Number of All-Cancer Cases and Matched Controls With the Indicated Number of Gabapentin Prescriptions [ Time Frame: The case index date was the date of incident cancer diagnosis ascertained in the GPRD study cohort 1995-2008. The matched control index date was the date at which the follow-up time from his/her cohort entry was the same as that for the case. ]
   Incidence of all cancers. Gabapentin Exposure Description: With 2 year lag = Gabapentin exposure from cohort entry to 2 years prior to index date (to control for prediagnostic prescribing for pain symptoms possibly related to cancer). Without 2 year lag = Gabapentin exposure from cohort entry to index date. Tertile's with 2 year lag: Tertile 1 (1-2 prescriptions), Tertile 2 (3-7 prescriptions), Tertile 3 (8-298 prescriptions). Tertiles without 2 year lag: Tertile 1 (1-2 prescriptions), Tertile 2 (3-7 prescriptions), and Tertile 3 (8-388 prescriptions).
3. Number of All-Cancer Cases and Matched Controls With the Indicated Duration of Exposure to Gabapentin [ Time Frame: The case index date was the date of incident cancer diagnosis ascertained in the GPRD study cohort 1995-2008. The matched control index date was the date at which the follow-up time from his/her cohort entry was the same as that for the case. ]
   Incidence of all cancers. Gabapentin Exposure Description: With 2 year lag = Gabapentin exposure from cohort entry to 2 years prior to index date (to control for prediagnostic prescribing for pain symptoms possibly related to cancer). Without 2 year lag = Gabapentin exposure from cohort entry to index date. Tertile's with 2 year lag: Tertile 1 (0.01 - 1.38 months), Tertile 2 (1.39 - 5.56 months), and Tertile 3 (5.57 - 105.82 months). Tertile's without 2 year lag: Tertile 1 (0.01 - 1.38 months), Tertile 2 (1.39 - 5.72 months), and Tertile 3 (5.73 - 123.70 months).
4. Number of All-Cancer Cases and Matched Controls With the Indicated Long Duration of Exposure to Gabapentin [ Time Frame: The case index date was the date of incident cancer diagnosis ascertained in the GPRD study cohort 1995-2008. The matched control index date was the date at which the follow-up time from his/her cohort entry was the same as that for the case. ]
   Incidence of all cancers. Gabapentin Exposure Description: With 2 year lag = Gabapentin exposure from cohort entry to 2 years prior to index date (to control for prediagnostic prescribing for pain symptoms possibly related to cancer). Without 2 year lag = Gabapentin exposure from cohort entry to index date.
5. Number of All-Cancer Cases and Matched Controls With the Indicated Cumulative Dose of Gabapentin [ Time Frame: The case index date was the date of incident cancer diagnosis ascertained in the GPRD study cohort 1995-2008. The matched control index date was the date at which the follow-up time from his/her cohort entry was the same as that for the case. ]
   Incidence of all cancers. Gabapentin Exposure Description: With 2 year lag = Gabapentin exposure from cohort entry to 2 years prior to index date (to control for prediagnostic prescribing for pain symptoms possibly related to cancer). Without 2 year lag = Gabapentin exposure from cohort entry to index date. Tertile's with 2 year lag: Tertile 1 (0.1 - 30.0 grams), Tertile 2 (30.1 - 189.0 grams), and Tertile 3 (189.1 - 9600.0 grams). Tertile's without 2 year lag: Tertile 1 (0.1 - 30.0 grams), Tertile 2 (30.1 - 189.0 grams), and Tertile 3 (189.1 - 11610.0 grams).
6. Number of Stomach Cancer Cases and Matched Controls With the Indicated Exposure to Gabapentin [ Time Frame: The case index date was the date of incident stomach cancer diagnosis ascertained in the GPRD study cohort 1995-2008. The matched control index date was the date at which the follow-up time from his/her cohort entry was the same as that for the case ]
   Incident stomach cancer. Gabapentin Exposure Description: With 2 year lag = Gabapentin prescription from cohort entry to 2 years prior to index date (to control for prediagnostic prescribing for pain symptoms possibly related to cancer). Without 2 year lag = Gabapentin prescription from cohort entry to index date.
7. Number of Stomach Cancer Cases and Matched Controls With the Indicated Number of Gabapentin Prescriptions [ Time Frame: The case index date was the date of incident stomach cancer diagnosis ascertained in the GPRD study cohort 1995-2008. The matched control index date was the date at which the follow-up time from his/her cohort entry was the same as that for the case ]
   Incident stomach cancer. Gabapentin (Gaba.) Exposure Description: With 2 year (yr) lag=Gaba. exposure from cohort entry to 2 yr prior to index date (to control for prediagnostic prescribing for pain symptoms possibly related to cancer). Without 2 yr lag=Gaba. exposure from cohort entry to index date. Tertiles (T) with 2 yr lag: T 1 (1-2 prescriptions [prescrip]), T 2 (3-7 prescrip), T 3 (8-298 prescrip). Tertiles without 2 yr lag: T 1 (1-2 prescrip), T 2 (3-7 prescrip), and T 3 (8-388 prescrip). Inestimable OR and 95% CI when no gaba.-exposed cancer cases or controls at the exposure level.
8. Number of Stomach Cancer Cases and Matched Controls With the Indicated Duration of Exposure to Gabapentin [ Time Frame: The case index date was the date of incident stomach cancer diagnosis ascertained in the GPRD study cohort 1995-2008. The matched control index date was the date at which the follow-up time from his/her cohort entry was the same as that for the case ]
   Incident stomach cancer. Gabapentin (Gaba.) Exposure Description: With 2 year (yr) lag=Gaba. exposure from cohort entry to 2 yr prior to index date (to control for prediagnostic prescribing for pain symptoms possibly related to cancer). Without 2 yr lag=Gaba. exposure from cohort entry to index date. Tertiles (T) with 2 yr lag: T 1 (0.01-1.38 months [mo.]), T 2 (1.3-5.56 mo.), and T 3 (5.57-105.82 mo.). Tertiles without 2 yr lag: T 1 (0.01-1.38 m.), T 2 (1.39-5.72 mo.), and T 3 (5.73-123.70 mo.). Inestimable OR and 95% CI when no gaba.-exposed cancer cases or controls at the exposure level.
9. Number of Stomach Cancer Cases and Matched Controls With the Indicated Long Duration of Exposure to Gabapentin [ Time Frame: The case index date was the date of incident stomach cancer diagnosis ascertained in the GPRD study cohort 1995-2008. The matched control index date was the date at which the follow-up time from his/her cohort entry was the same as that for the case ]
   Incident stomach cancer. Gabapentin Exposure Description: With 2 year lag = Gabapentin exposure from cohort entry to 2 years prior to index date (to control for prediagnostic prescribing for pain symptoms possibly related to cancer). Without 2 year lag = Gabapentin exposure from cohort entry to index date.
10. Number of Stomach Cancer Cases and Matched Controls With the Indicated Cumulative Dose of Gabapentin [ Time Frame: The case index date was the date of incident stomach cancer diagnosis ascertained in the GPRD study cohort 1995-2008. The matched control index date was the date at which the follow-up time from his/her cohort entry was the same as that for the case ]
    Incident stomach cancer. Gabapentin (Gaba.) Exposure Description: With 2 year (yr) lag=Gabapentin exposure from cohort entry to 2 years prior to index date (to control for prediagnostic prescribing for pain symptoms possibly related to cancer). Without 2 yr lag=Gaba. exposure from cohort entry to index date. Tertiles (T) with 2 yr lag: T 1 (0.1-30.0 grams [g]), T 2 (30.1-189.0 g), and T 3 (189.1-9600.0 g). Tertiles without 2 yr lag: T 1 (0.1-30.0 g), T 2 (30.1-189.0 g), and T 3 (189.1-11610.0 g). Inestimable OR and 95% CI when no gaba.-exposed cancer cases or controls at the exposure level.
11. Number of Anal Cancer Cases and Matched Controls With the Indicated Exposure to Gabapentin [ Time Frame: The case index date was the date of incident anal cancer diagnosis ascertained in the GPRD study cohort 1995-2008. The matched control index date was the date at which the follow-up time from his/her cohort entry was the same as that for the case. ]
    Incident Anal cancer. Gabapentin Exposure Description: With 2 year lag = Gabapentin prescription from cohort entry to 2 years prior to index date (to control for prediagnostic prescribing for pain symptoms possibly related to cancer). Without 2 year lag = Gabapentin prescription from cohort entry to index date.
12. Number of Anal Cancer Cases and Matched Controls With the Indicated Number of Gabapentin Prescriptions [ Time Frame: The case index date was the date of incident anal cancer diagnosis ascertained in the GPRD study cohort 1995-2008. The matched control index date was the date at which the follow-up time from his/her cohort entry was the same as that for the case. ]
    Incident anal cancer. Gabapentin (Gaba.) Exposure Description: With 2 year (yr) lag=Gaba. exposure from cohort entry to 2 yr prior to index date (to control for prediagnostic prescribing for pain symptoms possibly related to cancer). Without 2 yr lag=Gaba. exposure from cohort entry to index date. Tertiles (T) with 2 yr lag: T 1 (1-2 prescriptions [prescrip.]), T 2 (3-7 prescrip.), T 3 (8-298 prescrip.). Tertiles without 2 yr lag: T 1 (1-2 prescrip.), T 2 (3-7 prescrip.), and T 3 (8-388 prescrip.). Inestimable OR and 95% CI when no gaba.-exposed cancer cases or controls at the exposure level.
13. Number of Anal Cancer Cases and Matched Controls With the Indicated Duration of Exposure to Gabapentin [ Time Frame: The case index date was the date of incident anal cancer diagnosis ascertained in the GPRD study cohort 1995-2008. The matched control index date was the date at which the follow-up time from his/her cohort entry was the same as that for the case. ]
    Incident anal cancer. Gabapentin (Gaba.) Exposure Description: With 2 year (yr) lag=Gaba. exposure from cohort entry to 2 yr prior to index date (to control for prediagnostic prescribing for pain symptoms possibly related to cancer). Without 2 yr lag=Gaba. exposure from cohort entry to index date. Tertiles (T) with 2 yr lag: T 1 (0.01-1.38 months [mo.]), T 2 (1.39-5.56 mo.), and T 3 (5.57 -105.82 mo.). Tertiles without 2 yr lag: T 1 (0.01-1.38 mo.), T 2 (1.39-5.72 mo.), and T 3 (5.73-123.70 mo.). Inestimable OR and 95% CI when no gaba.-exposed cancer cases or controls at the exposure level.
14. Number of Anal Cancer Cases and Matched Controls With the Indicated Long Duration of Exposure to Gabapentin [ Time Frame: The case index date was the date of incident anal cancer diagnosis ascertained in the GPRD study cohort 1995-2008. The matched control index date was the date at which the follow-up time from his/her cohort entry was the same as that for the case. ]
    Incident anal cancer. Gabapentin Exposure Description: With 2 year lag = Gabapentin exposure from cohort entry to 2 years prior to index date (to control for prediagnostic prescribing for pain symptoms possibly related to cancer). Without 2 year lag = Gabapentin exposure from cohort entry to index date.
15. Number of Anal Cancer Cases and Matched Controls With the Indicated Cumulative Dose of Gabapentin [ Time Frame: The case index date was the date of incident anal cancer diagnosis ascertained in the GPRD study cohort 1995-2008. The matched control index date was the date at which the follow-up time from his/her cohort entry was the same as that for the case. ]
    Incident anal cancer. Gabapentin (Gaba.) Exposure Description: With 2 yr lag=Gaba. exposure from cohort entry to 2 yr prior to index date (to control for prediagnostic prescribing for pain symptoms possibly related to cancer). Without 2 yr lag=Gaba. exposure from cohort entry to index date. Tertiles (T) with 2 yr lag: T 1 (0.1-30.0 grams [g]), T 2 (30.1-189.0 g), and T 3 (189.1-9600.0 g). Tertiles without 2 yr lag: T 1 (0.1-30.0 g), T 2 (30.1-189.0 g), and T 3 (189.1-11610.0 g). Inestimable OR and 95% CI when no gaba.-exposed cancer cases or controls at the exposure level.
16. Number of Lung Cancer Cases and Matched Controls With the Indicated Exposure to Gabapentin [ Time Frame: The case index date was the date of incident lung cancer diagnosis ascertained in the GPRD study cohort 1995-2008. The matched control index date was the date at which the follow-up time from his/her cohort entry was the same as that for the case. ]
    Incident lung cancer. Gabapentin Exposure Description: With 2 year lag = Gabapentin prescription from cohort entry to 2 years prior to index date (to control for prediagnostic prescribing for pain symptoms possibly related to cancer). Without 2 year lag = Gabapentin prescription from cohort entry to index date.
17. Number of Lung Cancer Cases and Matched Controls With the Indicated Number of Gabapentin Prescriptions [ Time Frame: The case index date was the date of incident lung cancer diagnosis ascertained in the GPRD study cohort 1995-2008. The matched control index date was the date at which the follow-up time from his/her cohort entry was the same as that for the case. ]
    Incident lung cancer. Gabapentin Exposure Description: With 2 year lag = Gabapentin exposure from cohort entry to 2 years prior to index date (to control for prediagnostic prescribing for pain symptoms possibly related to cancer). Without 2 year lag = Gabapentin exposure from cohort entry to index date. Tertile's with 2 year lag: Tertile 1 (1-2 prescriptions), Tertile 2 (3-7 prescriptions), Tertile 3 (8-298 prescriptions). Tertiles without 2 year lag: Tertile 1 (1-2 prescriptions), Tertile 2 (3-7 prescriptions), and Tertile 3 (8-388 prescriptions).
18. Number of Lung Cancer Cases and Matched Controls With the Indicated Duration of Exposure to Gabapentin [ Time Frame: The case index date was the date of incident lung cancer diagnosis ascertained in the GPRD study cohort 1995-2008. The matched control index date was the date at which the follow-up time from his/her cohort entry was the same as that for the case. ]
    Incident lung cancer. Gabapentin Exposure Description: With 2 year lag = Gabapentin exposure from cohort entry to 2 years prior to index date (to control for prediagnostic prescribing for pain symptoms possibly related to cancer). Without 2 year lag = Gabapentin exposure from cohort entry to index date. Tertile's with 2 year lag: Tertile 1 (0.01 - 1.38 months), Tertile 2 (1.39 - 5.56 months), and Tertile 3 (5.57 - 105.82 months). Tertile's without 2 year lag: Tertile 1 (0.01 - 1.38 months), Tertile 2 (1.39 - 5.72 months), and Tertile 3 (5.73 - 123.70 months).
19. Number of Lung Cancer Cases and Matched Controls With the Indicated Long Duration of Exposure to Gabapentin [ Time Frame: The case index date was the date of incident lung cancer diagnosis ascertained in the GPRD study cohort 1995-2008. The matched control index date was the date at which the follow-up time from his/her cohort entry was the same as that for the case. ]
    Incident lung cancer. Gabapentin Exposure Description: With 2 year lag = Gabapentin exposure from cohort entry to 2 years prior to index date (to control for prediagnostic prescribing for pain symptoms possibly related to cancer). Without 2 year lag = Gabapentin exposure from cohort entry to index date.
20. Number of Lung Cancer Cases and Matched Controls With the Indicated Cumulative Dose of Gabapentin [ Time Frame: The case index date was the date of incident lung cancer diagnosis ascertained in the GPRD study cohort 1995-2008. The matched control index date was the date at which the follow-up time from his/her cohort entry was the same as that for the case. ]
    Incident lung cancer. Gabapentin Exposure Description: With 2 year lag = Gabapentin exposure from cohort entry to 2 years prior to index date (to control for prediagnostic prescribing for pain symptoms possibly related to cancer). Without 2 year lag = Gabapentin exposure from cohort entry to index date. Tertile's with 2 year lag: Tertile 1 (0.1 - 30.0 grams), Tertile 2 (30.1 - 189.0 grams), and Tertile 3 (189.1 - 9600.0 grams). Tertile's without 2 year lag: Tertile 1 (0.1 - 30.0 grams), Tertile 2 (30.1 - 189.0 grams), and Tertile 3 (189.1 - 11610.0 grams).
21. Number of Bone/Joint Cancer Cases and Matched Controls With the Indicated Exposure to Gabapentin [ Time Frame: The case index date was the date of incident bone/joint cancer diagnosis ascertained in the GPRD study cohort 1995-2008. The matched control index date was the date at which the follow-up time from his/her cohort entry was the same as for the case. ]
    Incident bone/joint cancer. Gabapentin Exposure Description: With 2 year lag = Gabapentin prescription from cohort entry to 2 years prior to index date (to control for prediagnostic prescribing for pain symptoms possibly related to cancer). Without 2 year lag = Gabapentin prescription from cohort entry to index date. Inestimable OR and 95% CI when no gabapentin-exposed cancer cases or no gabapentin-exposed controls at the exposure level.
22. Number of Bone/Joint Cancer Cases and Matched Controls With the Indicated Number of Gabapentin Prescriptions [ Time Frame: The case index date was the date of incident bone/joint cancer diagnosis ascertained in the GPRD study cohort 1995-2008. The matched control index date was the date at which the follow-up time from his/her cohort entry was the same as for the case. ]
    Incident bone/joint cancer. Gabapentin (Gaba.) Exposure Description: With 2 year (yr) lag=Gaba. exposure from cohort entry to 2 yr prior to index date (to control for prediagnostic prescribing for pain symptoms possibly related to cancer). Without 2 yr lag=Gaba. exposure from cohort entry to index date. Tertiles (T) with 2 yr lag: T 1 (1-2 prescriptions [prescrip.]), T 2 (3-7 prescrip.), T 3 (8-298 prescrip.). Tertiles without 2 yr lag: T 1 (1-2 prescrip.), T 2 (3-7 prescrip.), and T 3 (8-388 prescrip.). Inestimable OR and 95% CI when no gaba.-exposed cases or controls at the exposure level.
23. Number of Bone/Joint Cancer Cases and Matched Controls With the Indicated Duration of Exposure to Gabapentin [ Time Frame: The case index date was the date of incident bone/joint cancer diagnosis ascertained in the GPRD study cohort 1995-2008. The matched control index date was the date at which the follow-up time from his/her cohort entry was the same as for the case. ]
    Incident bone/joint cancer. Gabapentin (Gaba.) Exposure Description: With 2 year (yr) lag=Gaba. exposure from cohort entry to 2 yr prior to index date (to control for prediagnostic prescribing for pain symptoms possibly related to cancer). Without 2 yr lag=Gaba. exposure from cohort entry to index date. Tertiles (T) with 2 yr lag: T 1 (0.01-1.38 months [mo.]), T 2 (1.39-5.56 mo.), and T 3 (5.57-105.82 mo.). Tertiles without 2 yr lag: T 1 (0.01-1.38 mo.), T 2 (1.39-5.72 mo.), and T 3 (5.73-123.70 mo.). Inestimable OR and 95% CI when no gaba.-exposed cases or controls at the exposure level.
24. Number of Bone/Joint Cancer Cases and Matched Controls With the Indicated Long Duration of Exposure to Gabapentin [ Time Frame: The case index date was the date of incident bone/joint cancer diagnosis ascertained in the GPRD study cohort 1995-2008. The matched control index date was the date at which the follow-up time from his/her cohort entry was the same as for the case. ]
    Incident bone/joint cancer. Gabapentin Exposure Description: With 2 year lag = Gabapentin exposure from cohort entry to 2 years prior to index date (to control for prediagnostic prescribing for pain symptoms possibly related to cancer). Without 2 year lag = Gabapentin exposure from cohort entry to index date.
25. Number of Bone/Joint Cancer Cases and Matched Controls With the Indicated Cumulative Dose of Gabapentin [ Time Frame: The case index date was the date of incident bone/joint cancer diagnosis ascertained in the GPRD study cohort 1995-2008. The matched control index date was the date at which the follow-up time from his/her cohort entry was the same as for the case. ]
    Incident bone/joint cancer. Gabapentin (Gaba.) Exposure Description: With 2 year (yr) lag=Gaba. exposure from cohort entry to 2 yr prior to index date (to control for prediagnostic prescribing for pain symptoms possibly related to cancer). Without 2 yr lag=Gaba. exposure from cohort entry to index date. Tertiles (T) with 2 yr lag: T 1 (0.1-30.0 grams [g]), T 2 (30.1-189.0 g), and T 3 (189.1-9600.0 g). Tertiles without 2 yr lag: T 1 (0.1-30.0 g), T 2 (30.1-189.0 g), and T 3 (189.1-11610.0 g). Inestimable OR and 95% CI when no gaba.-exposed cancer cases or controls at the exposure level.
26. Number of Breast Cancer Cases and Matched Controls With the Indicated Exposure to Gabapentin [ Time Frame: The case index date was the date of incident breast cancer diagnosis ascertained in the GPRD study cohort 1995-2008. The matched control index date was the date at which the follow-up time from his/her cohort entry was the same as that for the case. ]
    Incident breast cancer. Gabapentin Exposure Description: With 2 year lag = Gabapentin prescription from cohort entry to 2 years prior to index date (to control for prediagnostic prescribing for pain symptoms possibly related to cancer). Without 2 year lag = Gabapentin prescription from cohort entry to index date.
27. Number of Breast Cancer Cases and Matched Controls With the Indicated Number of Gabapentin Prescriptions [ Time Frame: The case index date was the date of incident breast cancer diagnosis ascertained in the GPRD study cohort 1995-2008. The matched control index date was the date at which the follow-up time from his/her cohort entry was the same as that for the case. ]
    Incident breast cancer. Gabapentin Exposure Description: With 2 year lag = Gabapentin exposure from cohort entry to 2 years prior to index date (to control for prediagnostic prescribing for pain symptoms possibly related to cancer). Without 2 year lag = Gabapentin exposure from cohort entry to index date. Tertile's with 2 year lag: Tertile 1 (1-2 prescriptions), Tertile 2 (3-7 prescriptions), Tertile 3 (8-298 prescriptions). Tertiles without 2 year lag: Tertile 1 (1-2 prescriptions), Tertile 2 (3-7 prescriptions), and Tertile 3 (8-388 prescriptions).
28. Number of Breast Cancer Cases and Matched Controls With the Indicated Duration of Exposure to Gabapentin [ Time Frame: The case index date was the date of incident breast cancer diagnosis ascertained in the GPRD study cohort 1995-2008. The matched control index date was the date at which the follow-up time from his/her cohort entry was the same as that for the case. ]
    Incident breast cancer. Gabapentin Exposure Description: With 2 year lag = Gabapentin exposure from cohort entry to 2 years prior to index date (to control for prediagnostic prescribing for pain symptoms possibly related to cancer). Without 2 year lag = Gabapentin exposure from cohort entry to index date. Tertile's with 2 year lag: Tertile 1 (0.01 - 1.38 months), Tertile 2 (1.39 - 5.56 months), and Tertile 3 (5.57 - 105.82 months). Tertile's without 2 year lag: Tertile 1 (0.01 - 1.38 months), Tertile 2 (1.39 - 5.72 months), and Tertile 3 (5.73 - 123.70 months).
29. Number of Breast Cancer Cases and Matched Controls With the Indicated Long Duration of Exposure to Gabapentin [ Time Frame: The case index date was the date of incident breast cancer diagnosis ascertained in the GPRD study cohort 1995-2008. The matched control index date was the date at which the follow-up time from his/her cohort entry was the same as that for the case. ]
    Incident breast cancer. Gabapentin Exposure Description: With 2 year lag = Gabapentin exposure from cohort entry to 2 years prior to index date (to control for prediagnostic prescribing for pain symptoms possibly related to cancer). Without 2 year lag = Gabapentin exposure from cohort entry to index date.
30. Number of Breast Cancer Cases and Matched Controls With the Indicated Cumulative Dose of Gabapentin [ Time Frame: The case index date was the date of incident breast cancer diagnosis ascertained in the GPRD study cohort 1995-2008. The matched control index date was the date at which the follow-up time from his/her cohort entry was the same as that for the case. ]
    Incident breast cancer. Gabapentin Exposure Description: With 2 year lag = Gabapentin exposure from cohort entry to 2 years prior to index date (to control for prediagnostic prescribing for pain symptoms possibly related to cancer). Without 2 year lag = Gabapentin exposure from cohort entry to index date. Tertile's with 2 year lag: Tertile 1 (0.1 - 30.0 grams), Tertile 2 (30.1 - 189.0 grams), and Tertile 3 (189.1 - 9600.0 grams). Tertile's without 2 year lag: Tertile 1 (0.1 - 30.0 grams), Tertile 2 (30.1 - 189.0 grams), and Tertile 3 (189.1 - 11610.0 grams).
31. Number of Penile Cancer Cases and Matched Controls With the Indicated Exposure to Gabapentin [ Time Frame: The case index date was the date of incident penile cancer diagnosis ascertained in the GPRD study cohort 1995-2008. The matched control index date was the date at which the follow-up time from his/her cohort entry was the same as that for the case. ]
    Incident penile cancer. Gabapentin Exposure Description: With 2 year lag = Gabapentin prescription from cohort entry to 2 years prior to index date (to control for prediagnostic prescribing for pain symptoms possibly related to cancer). Without 2 year lag = Gabapentin prescription from cohort entry to index date.
32. Number of Penile Cancer Cases and Matched Controls With the Indicated Number of Gabapentin Prescriptions [ Time Frame: The case index date was the date of incident penile cancer diagnosis ascertained in the GPRD study cohort 1995-2008. The matched control index date was the date at which the follow-up time from his/her cohort entry was the same as that for the case. ]
    Incident penile cancer. Gabapentin (Gaba.) Exposure Description: With 2 year (yr) lag=Gaba. exposure from cohort entry to 2 yr prior to index date (to control for prediagnostic prescribing for pain symptoms possibly related to cancer). Without 2 yr lag=Gaba. exposure from cohort entry to index date. Tertiles (T) with 2 yr lag: T 1 (1-2 prescriptions [prescrip.]), T 2 (3-7 prescrip.), T 3 (8-298 prescrip.). Tertiles without 2 yr lag: T 1 (1-2 prescrip.), T 2 (3-7 prescrip.), and T 3 (8-388 prescrip.). Inestimable OR/95% CI when no gaba.-exposed cancer cases or controls at the exposure level.
33. Number of Penile Cancer Cases and Matched Controls With the Indicated Duration of Exposure to Gabapentin [ Time Frame: The case index date was the date of incident penile cancer diagnosis ascertained in the GPRD study cohort 1995-2008. The matched control index date was the date at which the follow-up time from his/her cohort entry was the same as that for the case. ]
    Incident penile cancer. Gabapentin (Gaba.) Exposure Description: With 2 year (yr) lag=Gaba. exposure from cohort entry to 2 yr prior to index date (to control for prediagnostic prescribing for pain symptoms possibly related to cancer). Without 2 yr lag=Gaba. exposure from cohort entry to index date. Tertiles (T) with 2 yr lag: T 1 (0.01-1.38 months [mo.]), T 2 (1.39-5.56 mo.), and T 3 (5.57-105.82 mo.). Tertiles without 2 yr lag: T 1 (0.01-1.38 mo.), T 2 (1.39-5.72 mo.), and T 3 (5.73-123.70 mo.). Inestimable OR and 95% CI when no gaba.-exposed cancer cases or controls at the exposure level.
34. Number of Penile Cancer Cases and Matched Controls With the Indicated Long Duration of Exposure to Gabapentin [ Time Frame: The case index date was the date of incident penile cancer diagnosis ascertained in the GPRD study cohort 1995-2008. The matched control index date was the date at which the follow-up time from his/her cohort entry was the same as that for the case. ]
    Incident penile cancer. Gabapentin Exposure Description: With 2 year lag = Gabapentin exposure from cohort entry to 2 years prior to index date (to control for prediagnostic prescribing for pain symptoms possibly related to cancer). Without 2 year lag = Gabapentin exposure from cohort entry to index date.
35. Number of Penile Cancer Cases and Matched Controls With the Indicated Cumulative Dose of Gabapentin [ Time Frame: The case index date was the date of incident penile cancer diagnosis ascertained in the GPRD study cohort 1995-2008. The matched control index date was the date at which the follow-up time from his/her cohort entry was the same as that for the case. ]
    Incident penile cancer. Gabapentin (Gaba.) Exposure Description: With 2 year (yr) lag=Gaba. exposure from cohort entry to 2 yr prior to index date (to control for prediagnostic prescribing for pain symptoms possibly related to cancer). Without 2 yr lag=Gaba. exposure from cohort entry to index date. Tertiles (T) with 2 yr lag: T 1 (0.1-30.0 grams [g]), T 2 (30.1-189.0 g), and T 3 (189.1-9600.0 g). Tertiles without 2 yr lag: T 1 (0.1-30.0 g), T 2 (30.1-189.0 g), and T 3 (189.1-11610.0 g). Inestimable OR and 95% CI when no gaba.-exposed cancer cases or controls at the exposure level.
36. Number of Bladder Cancer Cases and Matched Controls With the Indicated Exposure to Gabapentin [ Time Frame: The case index date was the date of incident bladder cancer diagnosis ascertained in the GPRD study cohort 1995-2008. The matched control index date was the date at which the follow-up time from his/her cohort entry was the same as that for the case ]
    Incident bladder cancer. Gabapentin Exposure Description: With 2 year lag = Gabapentin prescription from cohort entry to 2 years prior to index date (to control for prediagnostic prescribing for pain symptoms possibly related to cancer). Without 2 year lag = Gabapentin prescription from cohort entry to index date.
37. Number of Bladder Cancer Cases and Matched Controls With the Indicated Number of Gabapentin Prescriptions [ Time Frame: The case index date was the date of incident bladder cancer diagnosis ascertained in the GPRD study cohort 1995-2008. The matched control index date was the date at which the follow-up time from his/her cohort entry was the same as that for the case ]
    Incident bladder cancer. Gabapentin Exposure Description: With 2 year lag = Gabapentin exposure from cohort entry to 2 years prior to index date (to control for prediagnostic prescribing for pain symptoms possibly related to cancer). Without 2 year lag = Gabapentin exposure from cohort entry to index date. Tertile's with 2 year lag: Tertile 1 (1-2 prescriptions), Tertile 2 (3-7 prescriptions), Tertile 3 (8-298 prescriptions). Tertiles without 2 year lag: Tertile 1 (1-2 prescriptions), Tertile 2 (3-7 prescriptions), and Tertile 3 (8-388 prescriptions).
38. Number of Bladder Cancer Cases and Matched Controls With the Indicated Duration of Exposure to Gabapentin [ Time Frame: The case index date was the date of incident bladder cancer diagnosis ascertained in the GPRD study cohort 1995-2008. The matched control index date was the date at which the follow-up time from his/her cohort entry was the same as that for the case ]
    Incident bladder cancer. Gabapentin Exposure Description: With 2 year lag = Gabapentin exposure from cohort entry to 2 years prior to index date (to control for prediagnostic prescribing for pain symptoms possibly related to cancer). Without 2 year lag = Gabapentin exposure from cohort entry to index date. Tertile's with 2 year lag: Tertile 1 (0.01 - 1.38 months), Tertile 2 (1.39 - 5.56 months), and Tertile 3 (5.57 - 105.82 months). Tertile's without 2 year lag: Tertile 1 (0.01 - 1.38 months), Tertile 2 (1.39 - 5.72 months), and Tertile 3 (5.73 - 123.70 months).
39. Number of Bladder Cancer Cases and Matched Controls With the Indicated Long Duration of Exposure to Gabapentin [ Time Frame: The case index date was the date of incident bladder cancer diagnosis ascertained in the GPRD study cohort 1995-2008. The matched control index date was the date at which the follow-up time from his/her cohort entry was the same as that for the case ]
    Incident bladder cancer. Gabapentin Exposure Description: With 2 year lag = Gabapentin exposure from cohort entry to 2 years prior to index date (to control for prediagnostic prescribing for pain symptoms possibly related to cancer). Without 2 year lag = Gabapentin exposure from cohort entry to index date.
40. Number of Bladder Cancer Cases and Matched Controls With the Indicated Cumulative Dose of Gabapentin [ Time Frame: The case index date was the date of incident bladder cancer diagnosis ascertained in the GPRD study cohort 1995-2008. The matched control index date was the date at which the follow-up time from his/her cohort entry was the same as that for the case ]
    Incident bladder cancer. Gabapentin Exposure Description: With 2 year lag = Gabapentin exposure from cohort entry to 2 years prior to index date (to control for prediagnostic prescribing for pain symptoms possibly related to cancer). Without 2 year lag = Gabapentin exposure from cohort entry to index date. Tertile's with 2 year lag: Tertile 1 (0.1 - 30.0 grams), Tertile 2 (30.1 - 189.0 grams), and Tertile 3 (189.1 - 9600.0 grams). Tertile's without 2 year lag: Tertile 1 (0.1 - 30.0 grams), Tertile 2 (30.1 - 189.0 grams), and Tertile 3 (189.1 - 11610.0 grams).
41. Number of Other Nervous System Cancer Cases and Matched Controls With the Indicated Exposure to Gabapentin [ Time Frame: The case index date was the date of incident other nervous system cancer diagnosis ascertained in the GPRD study cohort 1995-2008. The matched control index date was the date at which the follow-up time from his cohort entry was the same as case. ]
    Incident other nervous system cancer. Gabapentin Exposure Description: With 2 year lag = Gabapentin prescription from cohort entry to 2 years prior to index date (to control for prediagnostic prescribing for pain symptoms possibly related to cancer). Without 2 year lag = Gabapentin prescription from cohort entry to index date. Inestimable OR and 95% CI when no gabapentin-exposed cancer cases or no gabapentin-exposed controls at the exposure level.
42. Number of Other Nervous System (ONS) Cancer Cases and Matched Controls With the Indicated Number of Gabapentin Prescriptions [ Time Frame: The case index date was the date of incident other nervous system cancer diagnosis ascertained in the GPRD study cohort 1995-2008. The matched control index date was the date at which the follow-up time from his cohort entry was same as for case. ]
    Incident ONS cancer. Gabapentin (Gaba.) Exposure Description: With 2 year (yr) lag=Gaba. exposure from cohort entry to 2 yr prior to index date (to control for prediagnostic prescribing for pain symptoms possibly related to cancer). Without 2 yr lag=Gaba. exposure from cohort entry to index date. Tertiles (T) with 2 yr lag: T 1 (1-2 prescriptions [prescrip.]), T 2 (3-7 prescrip.), T 3 (8-298 prescrip.). Tertiles without 2 yr lag: T 1 (1-2 prescrip.), T 2 (3-7 prescrip.), and T 3 (8-388 prescrip.). Inestimable OR and 95% CI when no gaba.-exposed cancer cases or controls at the exposure level.
43. Number of Other Nervous System (ONS) Cancer Cases and Matched Controls With the Indicated Duration of Exposure to Gabapentin [ Time Frame: The case index date was the date of incident other nervous system cancer diagnosis ascertained in the GPRD study cohort 1995-2008. The matched control index date was the date at which the follow-up time from his/her cohort entry was same as for case ]
    Incident ONS cancer. Gabapentin (Gaba.) Exposure Description: With 2 yr lag=Gaba. exposure from cohort entry to 2 yr prior to index date (to control for prediagnostic prescribing for pain symptoms possibly related to cancer). Without 2 yr lag=Gaba. exposure from cohort entry to index date. Tertiles (T) with 2 yr lag: T 1 (0.01-1.38 months [mo.]), T 2 (1.39-5.56 mo.), and T 3 (5.57-105.82 mo.). Tertiles without 2 yr lag: T 1 (0.01-1.38 mo.), T 2 (1.39-5.72 mo.), and T 3 (5.73-123.70 mo.). Inestimable OR and 95% CI when no gaba.-exposed cancer cases or controls at the exposure level.
44. Number of Other Nervous System Cancer Cases and Matched Controls With the Indicated Long Duration of Exposure to Gabapentin [ Time Frame: The case index date was the date of incident other nervous system cancer diagnosis ascertained in the GPRD study cohort 1995-2008. The matched control index date was the date at which the follow-up time from his/her cohort entry was same as for case ]
    Incident other nervous system cancer. Gabapentin Exposure Description: With 2 year lag = Gabapentin exposure from cohort entry to 2 years prior to index date (to control for prediagnostic prescribing for pain symptoms possibly related to cancer). Without 2 year lag = Gabapentin exposure from cohort entry to index date.
45. Number of Other Nervous System (ONS) Cancer Cases and Matched Controls With the Indicated Cumulative Dose of Gabapentin [ Time Frame: The case index date was the date of incident other nervous system cancer diagnosis ascertained in the GPRD study cohort 1995-2008. The matched control index date was the date at which the follow-up time from his/her cohort entry was same as for case ]
    Incident ONS cancer. Gabapentin (Gaba.) Exposure Description: With 2 year (yr) lag=Gaba. exposure from cohort entry to 2 yr prior to index date (to control for prediagnostic prescribing for pain symptoms possibly related to cancer). Without 2 yr lag=Gaba. exposure from cohort entry to index date. Tertiles (T) with 2 yr lag: T 1 (0.1-30.0 grams [g]), T 2 (30.1-189.0 g), and T 3 (189.1-9600.0 g). Tertiles without 2 yr lag: T 1 (0.1-30.0 g), T 2 (30.1-189.0 g), and T 3 (189.1-11610.0 g). Inestimable OR and 95% CI when no gaba.-exposed cancer cases or controls at the exposure level.
46. Number of Pancreatic Cancer Cases and Matched Controls With the Indicated Exposure to Gabapentin [ Time Frame: The case index date was the date of incident pancreatic cancer diagnosis ascertained in the GPRD study cohort 1995-2008. The matched control index date was the date at which the follow-up time from his/her cohort entry was the same as for the case. ]
    Incident pancreatic cancer. Gabapentin Exposure Description: With 2 year lag = Gabapentin prescription from cohort entry to 2 years prior to index date (to control for prediagnostic prescribing for pain symptoms possibly related to cancer). Without 2 year lag = Gabapentin prescription from cohort entry to index date.
47. Number of Pancreatic Cancer Cases and Matched Controls With the Indicated Number of Gabapentin Prescriptions [ Time Frame: The case index date was the date of incident pancreatic cancer diagnosis ascertained in the GPRD study cohort 1995-2008. The matched control index date was the date at which the follow-up time from his/her cohort entry was the same as for the case. ]
    Incident pancreatic cancer. Gabapentin Exposure Description: With 2 year lag = Gabapentin exposure from cohort entry to 2 years prior to index date (to control for prediagnostic prescribing for pain symptoms possibly related to cancer). Without 2 year lag = Gabapentin exposure from cohort entry to index date. Tertile's with 2 year lag: Tertile 1 (1-2 prescriptions), Tertile 2 (3-7 prescriptions), Tertile 3 (8-298 prescriptions). Tertiles without 2 year lag: Tertile 1 (1-2 prescriptions), Tertile 2 (3-7 prescriptions), and Tertile 3 (8-388 prescriptions).
48. Number of Pancreatic Cancer Cases and Matched Controls With the Indicated Duration of Exposure to Gabapentin [ Time Frame: The case index date was the date of incident pancreatic cancer diagnosis ascertained in the GPRD study cohort 1995-2008. The matched control index date was the date at which the follow-up time from his/her cohort entry was the same as for the case. ]
    Incident pancreatic cancer. Gabapentin Exposure Description: With 2 year lag = Gabapentin exposure from cohort entry to 2 years prior to index date (to control for prediagnostic prescribing for pain symptoms possibly related to cancer). Without 2 year lag = Gabapentin exposure from cohort entry to index date. Tertile's with 2 year lag: Tertile 1 (0.01 - 1.38 months), Tertile 2 (1.39 - 5.56 months), and Tertile 3 (5.57 - 105.82 months). Tertile's without 2 year lag: Tertile 1 (0.01 - 1.38 months), Tertile 2 (1.39 - 5.72 months), and Tertile 3 (5.73 - 123.70 months).
49. Number of Pancreatic Cancer Cases and Matched Controls With the Indicated Long Duration of Exposure to Gabapentin [ Time Frame: The case index date was the date of incident pancreatic cancer diagnosis ascertained in the GPRD study cohort 1995-2008. The matched control index date was the date at which the follow-up time from his/her cohort entry was the same as for the case ]
    Incident pancreatic cancer. Gabapentin Exposure Description: With 2 year lag = Gabapentin exposure from cohort entry to 2 years prior to index date (to control for prediagnostic prescribing for pain symptoms possibly related to cancer). Without 2 year lag = Gabapentin exposure from cohort entry to index date.
50. Number of Pancreatic Cancer Cases and Matched Controls With the Indicated Cumulative Dose of Gabapentin [ Time Frame: The case index date was the date of incident pancreatic cancer diagnosis ascertained in the GPRD study cohort 1995-2008. The matched control index date was the date at which the follow-up time from his/her cohort entry was the same as for the case. ]
    Incident pancreatic cancer. Gabapentin Exposure Description: With 2 year lag = Gabapentin exposure from cohort entry to 2 years prior to index date (to control for prediagnostic prescribing for pain symptoms possibly related to cancer). Without 2 year lag = Gabapentin exposure from cohort entry to index date. Tertile's with 2 year lag: Tertile 1 (0.1 - 30.0 grams), Tertile 2 (30.1 - 189.0 grams), and Tertile 3 (189.1 - 9600.0 grams). Tertile's without 2 year lag: Tertile 1 (0.1 - 30.0 grams), Tertile 2 (30.1 - 189.0 grams), and Tertile 3 (189.1 - 11610.0 grams).
51. Number of Renal Cancer Cases and Matched Controls With the Indicated Exposure to Gabapentin [ Time Frame: The case index date was the date of incident pancreatic cancer diagnosis ascertained in the GPRD study cohort 1995-2008. The matched control index date was the date at which the follow-up time from his/her cohort entry was the same as for the case. ]
    Incident renal cancer. Gabapentin Exposure Description: With 2 year lag = Gabapentin prescription from cohort entry to 2 years prior to index date (to control for prediagnostic prescribing for pain symptoms possibly related to cancer). Without 2 year lag = Gabapentin prescription from cohort entry to index date.
52. Number of Renal Cancer Cases and Matched Controls With the Indicated Number of Gabapentin Prescriptions [ Time Frame: The case index date was the date of incident renal cancer diagnosis ascertained in the GPRD study cohort 1995-2008. The matched control index date was the date at which the follow-up time from his/her cohort entry was the same as that for the case. ]
    Incident renal cancer. Gabapentin Exposure Description: With 2 year lag = Gabapentin exposure from cohort entry to 2 years prior to index date (to control for prediagnostic prescribing for pain symptoms possibly related to cancer). Without 2 year lag = Gabapentin exposure from cohort entry to index date. Tertile's with 2 year lag: Tertile 1 (1-2 prescriptions), Tertile 2 (3-7 prescriptions), Tertile 3 (8-298 prescriptions). Tertiles without 2 year lag: Tertile 1 (1-2 prescriptions), Tertile 2 (3-7 prescriptions), and Tertile 3 (8-388 prescriptions).
53. Number of Renal Cancer Cases and Matched Controls With the Indicated Duration of Exposure to Gabapentin [ Time Frame: The case index date was the date of incident renal cancer diagnosis ascertained in the GPRD study cohort 1995-2008. The matched control index date was the date at which the follow-up time from his/her cohort entry was the same as that for the case. ]
    Incident renal cancer. Gabapentin Exposure Description: With 2 year lag = Gabapentin exposure from cohort entry to 2 years prior to index date (to control for prediagnostic prescribing for pain symptoms possibly related to cancer). Without 2 year lag = Gabapentin exposure from cohort entry to index date. Tertile's with 2 year lag: Tertile 1 (0.01 - 1.38 months), Tertile 2 (1.39 - 5.56 months), and Tertile 3 (5.57 - 105.82 months). Tertile's without 2 year lag: Tertile 1 (0.01 - 1.38 months), Tertile 2 (1.39 - 5.72 months), and Tertile 3 (5.73 - 123.70 months).
54. Number of Renal Cancer Cases and Matched Controls With the Indicated Long Duration of Exposure to Gabapentin [ Time Frame: The case index date was the date of incident renal cancer diagnosis ascertained in the GPRD study cohort 1995-2008. The matched control index date was the date at which the follow-up time from his/her cohort entry was the same as that for the case. ]
    Incident renal cancer. Gabapentin Exposure Description: With 2 year lag = Gabapentin exposure from cohort entry to 2 years prior to index date (to control for prediagnostic prescribing for pain symptoms possibly related to cancer). Without 2 year lag = Gabapentin exposure from cohort entry to index date.
55. Number of Renal Cancer Cases and Matched Controls With the Indicated Cumulative Dose of Gabapentin [ Time Frame: The case index date was the date of incident renal cancer diagnosis ascertained in the GPRD study cohort 1995-2008. The matched control index date was the date at which the follow-up time from his/her cohort entry was the same as that for the case. ]
    Incident renal cancer. Gabapentin Exposure Description: With 2 year lag = Gabapentin exposure from cohort entry to 2 years prior to index date (to control for prediagnostic prescribing for pain symptoms possibly related to cancer). Without 2 year lag = Gabapentin exposure from cohort entry to index date. Tertile's with 2 year lag: Tertile 1 (0.1 - 30.0 grams), Tertile 2 (30.1 - 189.0 grams), and Tertile 3 (189.1 - 9600.0 grams). Tertile's without 2 year lag: Tertile 1 (0.1 - 30.0 grams), Tertile 2 (30.1 - 189.0 grams), and Tertile 3 (189.1 - 11610.0 grams).

Eligibility Criteria

• Ages Eligible for Study: Child, Adult, Older Adult
• Sexes Eligible for Study: All
• Accepts Healthy Volunteers: No
• Sampling Method: Probability Sample

Study Population

The study cohort from which cases and controls are drawn is all subjects in the UK GPRD 1993-2008. Entry into the study cohort begins Jan 1, 1993 for all those who are registered in GPRD before that time, and at the time of registration if later than Jan 1, 1993. Subjects are excluded from the GPRD cohort if they have a cancer diagnosis or a history of cancer prior to the cohort entry date. Follow-up ends Dec 31, 2008, or earlier if the subject leaves the GPRD for any reason including death. There are several advantages to the GPRD dataset for this study. It is a large dataset with detailed longitudinal prescription data, and long term follow-up (mean 7 years) to allow for latency in carcinogenicity. It provides good representation of the elderly who are disproportionately affected by cancer, and routinely includes data recorded by general practitioners on potential risk factors such as smoking, alcohol consumption and body mass index.

Criteria

Inclusion Criteria:

• The study cohort from which cases and controls are drawn is all subjects in the UK GPRD 1993-2008. Entry into the study cohort begins Jan 1, 1993 for all those who are registered in GPRD before that time, and at the time of registration if later than Jan 1, 1993. Follow-up ends Dec 31, 2008, or earlier if the subject leaves the GPRD for any reason including death.

Exclusion Criteria:

• Subjects are excluded from the GPRD cohort if they have a cancer diagnosis or a history of cancer prior to the cohort entry date. Cases and controls will be required to have at least 2 years of follow-up in the study cohort before their index date (For cases, the index date is the date of first diagnosis of the respective cancer. The index date for controls is set as the date at which the follow-up time from cohort entry is the same as the case.) Cases must have no history of any other cancer diagnosis prior to the index date. Controls are required to be free of cancer diagnosis in the database up to the control's index date.

Contacts and Locations

Sponsors and Collaborators

GlaxoSmithKline

Investigators

• Study Director: GSK Clinical Trials; GlaxoSmithKline

More Information

• Responsible Party: GlaxoSmithKline
• ClinicalTrials.gov Identifier: NCT01236053
• Other Study ID Numbers: 114790; WEUSRTP4931 ( Other Identifier: GSK )
• First Posted: November 7, 2010
• Results First Posted: August 4, 2011
• Last Update Posted: July 6, 2017
• Last Verified: June 2017

Keywords provided by GlaxoSmithKline:

renal cancer; pancreatic cancer; epidemiology; renal cell carcinoma; nervous system cancer; lung cancer; breast cancer; case-control; GPRD; Gapabentin; cancer; anal cancer; bone and joint cancer; renal pelvis cancer; penis cancer; stomach cancer; bladder cancer

Additional relevant MeSH terms:

Pancreatic Neoplasms; Urinary Bladder Neoplasms; Carcinoma, Renal Cell; Anus Neoplasms; Kidney Neoplasms; Stomach Neoplasms; Pelvic Neoplasms; Nervous System Neoplasms; Penile Neoplasms; Pancreatitis; Pancreatitis, Chronic; Neuralgia; Carcinoma; Neoplasms, Glandular and Epithelial; Neoplasms by Histologic Type; Neoplasms; Neoplasms by Site; Digestive System Neoplasms; Endocrine Gland Neoplasms; Digestive System Diseases; Pancreatic Diseases; Endocrine System Diseases; Nervous System Diseases; Urologic Neoplasms; Urogenital Neoplasms; Urinary Bladder Diseases; Urologic Diseases; Adenocarcinoma; Kidney Diseases; Rectal Neoplasms