Hot flashes are the most prominent side effect of
tamoxifen, the most frequently prescribed
antitumor agent in the world. Little detailed information is available to predict who will develop
hot flashes on
tamoxifen, to describe the natural history of these
hot flashes, and/or to predict who will request
therapy for such a side effect. This current trial was developed to address these items. Women who were about to begin adjuvant
tamoxifen for locally treated
breast cancer were approached for this trial. Before initiating
tamoxifen, patients completed a short questionnaire designed to inquire about potential prognostic factors. Upon starting
tamoxifen, women were asked to complete a hot flash diary daily for 3 months, and then daily for 1 week of each of the subsequent 9 months. Fifty patients, aged 51-83 years, provided data for this report. Approximately half of the women reported that they did not have any substantial
hot flashes while the other half reported
hot flashes of variable intensity. On average, these
hot flashes gradually increased over 3 months and then plateaued. Baseline factors that appeared to predict for subsequent hot flash problems included a prior history of moderate to severe
hot flashes with menopause and a history of prior
estrogen therapy use. Overall, 16% of the women reported the desire for
therapy for their
hot flashes. Thirty-seven and one-half percent of the women (6/16) had a history of both prior
estrogen use and moderate to severe
hot flashes with menopause as compared to none (0/14) of the women without either of these factors. The data from this study can be utilized to better identify and educate women as to their probability of developing
hot flashes after starting
tamoxifen, to describe the average time frame for these
hot flashes, and to predict the likelihood of whether resultant
hot flashes will be substantial enough to have a woman request
therapy for them.