Up to 80 percent of women taking tamoxifen report problems with hot flashes, which can severely limit their quality of life, says Vered Stearns, M.D., associate professor at the Kimmel Cancer Center and leader of the research.
Hormone therapy taken for short periods can alleviate symptoms in healthy women, but it is not recommended for breast cancer patients whose tumors may grow in response to hormones.
For the study, Stearns
focused on a gene encoding small proteins, called receptors, which bind to the hormone estrogen, making breast cancer cells grow.In patients, tamoxifen targets such estrogen receptors to dampen the effects of hormones on the cells.But at the same time, the drug may be blocking hormone receptors in central nervous tissues that, the investigators believe, could influence hot flashes.The genes for these estrogen receptors vary widely in their quantity and code. Stearns
found that premenopausal women with two exact copies of the gene had, on average, more than 17 monthly hot flashes, as compared to women missing one gene copy (with approximately five hot flashes).Postmenopausal women with two specific versions of the gene recorded close to 60 monthly hot flashes compared to those with other gene types (at approximately 12.5).
Tamoxifen-takers who are plagued by hot flashes may get some relief from certain classes of antidepressants and chronic pain drugs, says Stearns
.In addition to estrogen receptor gene status, she
also reported that postmenopausal status and prior chemotherapy experience may increase hot-flash occurrence.