Trial Information

The Role of Serotonin in Hot Flashes After Breast Cancer

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.