Menstrual influence on surgical cure of breast cancer.

In a retrospective study of 44 premenopausal women who underwent resection of a primary breast cancer and were followed for 5 to 12 years, disease recurrence and metastasis were more frequent and more rapid in women who had been operated upon during the perimenstrual period (days 0-6 and 21-36 of the menstrual cycle). By multivariate analysis, the time of resection in relation to the menstrual cycle is an independent predictor of the likelihood of future metastatic disease. Patients who underwent resection during the perimenstrual period had a more than quadrupled risk of recurrence and death compared with women operated upon during days 7 to 20 of the menstrual cycle.