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Exemestane in Preventing Cancer in Postmenopausal Women at Increased Risk of Developing Breast Cancer

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ClinicalTrials.gov Identifier: NCT00083174
Recruitment Status : Completed
First Posted : May 17, 2004
Results First Posted : May 20, 2013
Last Update Posted : April 25, 2018
Sponsor:
Collaborators:
Grupo Espanol de Investigacion del Cancer de Mama
UNICANCER
Information provided by (Responsible Party):
Canadian Cancer Trials Group ( NCIC Clinical Trials Group )

Study Type: Interventional
Study Design: Intervention Model: Single Group Assignment;   Masking: None (Open Label);   Primary Purpose: Prevention
Condition: Breast Cancer
Intervention: Drug: exemestane

  Participant Flow

Recruitment Details
Key information relevant to the recruitment process for the overall study, such as dates of the recruitment period and locations
Between February 11, 2004, and March 23, 2010, 4560 women were recruited in medical clinics.

Pre-Assignment Details
Significant events and approaches for the overall study following participant enrollment, but prior to group assignment
Eligibility of women was first checked before the randomization to the trial.

Reporting Groups
  Description
Randomization Period: Exemestane one 25 mg tablet daily in am
Randomization Period: Placebo one tablet daily in am
Open-label Extension: Exemestane one 25 mg tablet daily in am

Participant Flow for 2 periods

Period 1:   Randomization Period
    Randomization Period: Exemestane   Randomization Period: Placebo   Open-label Extension: Exemestane
STARTED   2285   2275   0 
COMPLETED   2285 [1]   2275 [1]   0 
NOT COMPLETED   0   0   0 
[1] All women randomized were included in the analysis based on intent-to-treat principle.

Period 2:   Open-label Extension
    Randomization Period: Exemestane   Randomization Period: Placebo   Open-label Extension: Exemestane
STARTED   0   0   2831 
COMPLETED   0   0   2831 
NOT COMPLETED   0   0   0 



  Baseline Characteristics

Population Description
Explanation of how the number of participants for analysis was determined. Includes whether analysis was per protocol, intention to treat, or another method. Also provides relevant details such as imputation technique, as appropriate.
No text entered.

Reporting Groups
  Description
Randomization Period: Exemestane one 25 mg tablet daily in am
Randomization Period: Placebo one tablet daily in am
Total Total of all reporting groups

Baseline Measures
   Randomization Period: Exemestane   Randomization Period: Placebo   Total 
Overall Participants Analyzed 
[Units: Participants]
 2285   2275   4560 
Age 
[Units: Participants]
Count of Participants
     
<=18 years      0   0.0%      0   0.0%      0   0.0% 
Between 18 and 65 years      1458  63.8%      1481  65.1%      2939  64.5% 
>=65 years      827  36.2%      794  34.9%      1621  35.5% 
Age 
[Units: Years]
Mean (Standard Deviation)
 63.1  (7.2)   63.1  (7.0)   63.1  (7.1) 
Sex: Female, Male 
[Units: Participants]
Count of Participants
     
Female      2285 100.0%      2275 100.0%      4560 100.0% 
Male      0   0.0%      0   0.0%      0   0.0% 
Region of Enrollment 
[Units: Participants]
     
United States   1416   1408   2824 
France   9   10   19 
Canada   643   642   1285 
Spain   217   215   432 


  Outcome Measures

1.  Primary:   Percentage of Women With Serious Adverse Events   [ Time Frame: 5 years open-label extension period ]

2.  Primary:   Invasive Breast Cancer Incidence (Breast Cancer-Free Survival)   [ Time Frame: Over randomization period of study (median follow-up 35 months) ]
  Hide Outcome Measure 2

Measure Type Primary
Measure Title Invasive Breast Cancer Incidence (Breast Cancer-Free Survival)
Measure Description Invasive breast cancer incidence was estimated from the breast cancer-free survival (BCFS) which was calculated for all women from the day of the randomization to the earliest date of diagnosis for invasive breast cancer. Women who died from other causes were censored at the time of death. If a woman did not develop an invasive breast cancer, or died, BCFS was censored on the date of the last day the woman was known alive (LKA), which was the latest of the date of assessment. Women who had breast cancer before study entry were also censored at the time of randomization.
Time Frame Over randomization period of study (median follow-up 35 months)  

Population Description
Explanation of how the number of participants for analysis was determined. Includes whether analysis was per protocol, intention to treat, or another method. Also provides relevant details such as imputation technique, as appropriate.
intention to treat (ITT)

Reporting Groups
  Description
Randomization Period: Exemestane 25 mg of exemestane tablet daily
Randomization Period: Placebo Placebo tablet daily

Measured Values
   Randomization Period: Exemestane   Randomization Period: Placebo 
Participants Analyzed   2285   2275 
Invasive Breast Cancer Incidence (Breast Cancer-Free Survival) 
[Units: Percentage of cases/follow-up person-yr]
Number (95% Confidence Interval)
 0.19 
 (0.08 to 0.30) 
 0.55 
 (0.36 to 0.73) 


Statistical Analysis 1 for Invasive Breast Cancer Incidence (Breast Cancer-Free Survival)
Groups [1] All groups
Statistical Test Type [2] Superiority or Other
Statistical Method [3] Log Rank
P Value [4] 0.002
Hazard Ratio (HR) [5] 0.35
95% Confidence Interval 0.18 to 0.70
[1] Additional details about the analysis, such as null hypothesis and power calculation:
  The null hypothesis was no difference between two groups. The sample size estimate was based on an assumption of annual invasive breast cancer rate of 0.60% in the placebo group and 0.21% in exemestane group, a relative reduction of 65% with exemestane. To detect this with a two-sided 5% level and 90% power, a total of 38 cases of invasive breast cancer were required, projected to occur when 4560 women were randomly assigned in a 3-year period and then followed for an additional 1.2 years.
[2] Details of power calculation, definition of non-inferiority margin, and other key parameters:
  No text entered.
[3] Other relevant method information, such as adjustments or degrees of freedom:
  No text entered.
[4] Additional information, such as whether or not the p-value is adjusted for multiple comparisons and the a priori threshold for statistical significance:
  No text entered.
[5] Other relevant estimation information:
  No text entered.



3.  Secondary:   Total Incidence of Invasive and Non-invasive (DCIS) Breast Cancer   [ Time Frame: Over randomization period of study (median follow-up 35 months) ]

4.  Secondary:   Incidence of Lobular Carcinoma in Situ, Atypical Ductal Hyperplasia and Atypical Lobular Hyperplasia Events   [ Time Frame: Over randomization period of study (median follow-up 35 months) ]

5.  Secondary:   Number of Clinical Breast Biopsies   [ Time Frame: Over randomization period of study (median follow-up 35 months) ]

6.  Secondary:   Incidence of All Clinical Fractures   [ Time Frame: During protocol treatment over randomization period of study (up to 5 years) ]

7.  Secondary:   Incidence of Clinically Relevant Cardiac Events   [ Time Frame: During protocol treatment in randomization period (up to 5 years) ]

8.  Secondary:   Incidences of Other Malignancies   [ Time Frame: Over randomization period of study (median follow-up 35 months) ]


  Serious Adverse Events


  Other Adverse Events


  Limitations and Caveats

Limitations of the study, such as early termination leading to small numbers of participants analyzed and technical problems with measurement leading to unreliable or uninterpretable data
No text entered.


  More Information