The Role of Serotonin in Hot Flashes After Breast Cancer
|Breast Cancer||Dietary Supplement: Acute tryptophan depletion Dietary Supplement: Half-strength tryptophan depletion (Control)|
|Study Design:||Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: Double (Participant, Outcomes Assessor)
Primary Purpose: Basic Science
|Official Title:||The Role of Serotonin in Hot Flashes After Breast Cancer|
- Serum Tryptophan Levels [ Time Frame: baseline, 1 hour, 2 hours, 3 hours, 4 hours, 5 hours, 6 hours, 7 hours, 8 hours ]Mean serum tryptophan levels (blood draw) at the end of the nadir period.
- Objective Subject Hot Flash Frequency [ Time Frame: One 24 hour monitoring session per week for 8 weeks ]Mean of the 24 hour monitoring sessions for each patient based on one 24 hour monitoring session after each intervention using an electronic monitor.
|Study Start Date:||July 2005|
|Study Completion Date:||November 2008|
|Primary Completion Date:||October 2007 (Final data collection date for primary outcome measure)|
Experimental: Acute tryptophan depletion
Full-strength tryptophan depletion
Dietary Supplement: Acute tryptophan depletion
L-alanine (5.5g), L-arginine (4.9g), L-cysteine (2.7g), glycine (3.2g), L-histidine (3.2g), L-isoleucine (8.0g), L-leucine (13.5g), L-lysine (11.0g), L-methionine (3.0g), L-phenylalanine (5.7g), L-proline (12.2g), L-serine (6.9g), L-threonine (6.9g), L-tyrosine (6.9g), L-valine (8.9g)
Active Comparator: Control
Half-strength tryptophan depletion drink used as a control
Dietary Supplement: Half-strength tryptophan depletion (Control)
L-alanine (1.4g), L-arginine (1.2g), L-cysteine (0.7g), glycine (0.8g), L-histidine (0.8g), L-isoleucine (2.0g), L-leucine (3.4g), L-lysine (2.8g), L-methionine (0.8g), L-phenylalanine (1.4g), L-proline (3.1g), L-serine (1.7g), L-threonine (1.7g), L-tyrosine (1.7g), L-valine (2.2g), and fillers (7.95g).
Among women with breast cancer, hot flashes are a frequent, severe and bothersome symptom. For this group, hot flashes are negatively related to mood, affect, and daily activities and can compromise compliance with life-saving medications (e.g., tamoxifen). Over 60% of breast cancer survivors report hot flashes, with 59% stating they are extremely severe and 44% reporting them to be extremely bothersome. Unfortunately, limitations in our understanding of hot flash physiology limit clinicians' abilities to fully treat this symptom. Although the current non-hormonal treatment of choice for hot flashes after breast cancer targets the central serotonin system (e.g., paroxetine, venlafaxine), the role of serotonin in hot flashes has not been directly tested. Because the effectiveness of these agents has been based largely on improvement in subjective reporting of hot flashes, it is not clear whether benefits are due to physiological effects on hot flashes or due to improvements in mood or other related symptoms. In addition, these and other currently available treatments are not acceptable, appropriate, or effective for all women with breast cancer. Understanding the physiological mechanisms involved in hot flashes after breast cancer will enable us to develop more targeted behavioral and/or pharmacological therapies to be used in lieu of, or in addition to, currently available therapies so that we can eradicate hot flashes and improve the quality of life for women with breast cancer.
Results implicating direct effects of tryptophan and serotonin on objective hot flashes will help guide the development of improved interventions for alleviating hot flashes in women with breast cancer. These interventions may target the central serotonin system either behaviorally (e.g., diet) or pharmacologically (e.g., alternative drug therapeutics). If direct manipulation of tryptophan and serotonin does not affect hot flashes, these findings will be equally as useful in guiding future research on non-serotonin related etiologies and interventions. Findings from this study will ultimately be used to eradicate hot flashes as a frequent, severe and bothersome breast cancer treatment related condition, thereby, improving quality of life for all women with breast cancer.
Please refer to this study by its ClinicalTrials.gov identifier: NCT00228943
|United States, Indiana|
|Indiana University Cancer Center|
|Indianapolis, Indiana, United States, 46202|
|Principal Investigator:||Janet S Carpenter, PhD||Indiana University School of Medicine|