Study shows chemo-induced menopause may provide benefit

June 3, 2010

A study of different chemotherapy schedules uncovered a surprise finding - premenopausal women with breast cancer who experienced amenorrhea (no menstruation) for more than six months during the two years following chemotherapy treatment had statistically significant improvements in overall survival and disease free survival, irregardless of estrogen receptor status.

Researchers From the National Surgical Adjuvant Breast and Bowel Project randomly assigned 5351 patients with operable, node-positive, early-stage breast cancer to receive four cycles of doxorubicin and cyclophosphamide followed by four cycles of docetaxel (sequential ACT); four cycles of doxorubicin and docetaxel (doxorubicin–docetaxel); or four cycles of doxorubicin, cyclophosphamide, and docetaxel (concurrent ACT).  The main purpose of the study was to examine whether concurrent ACT was more effective than sequential ACT, but a secondary aim was to look at the relationship of amenorrhea to outcomes in premenopausal women.

According to the study results published in the New England Journal of Medicine, after 73 months, overall survival was improved in the sequential-ACT group (8-year overall survival, 83%) as compared with the doxorubicin–docetaxel group (overall survival, 79%; P=0.03) and the concurrent-ACT group (overall survival, 79%; P=0.09).

In addition, overall survival was improved in patients with amenorrhea for 6 months or more across all treatment groups, independent of estrogen-receptor status. Of the 2445 premenopausal patients who were eligible for the menstrual history study, follow-up menstrual history was available for 2343 (97%). Both overall survival (relative risk, 0.76; P=0.04) and disease-free survival (relative risk, 0.70; P<0.001) were significantly increased among patients who had amenorrhea as compared with those who did not.