BREAST-CANCER DETECTION DEMONSTRATION PROJECT DATA CAN DETERMINE WHETHER THE PROGNOSIS OF BREAST-CANCER IS AFFECTED BY THE TIME OF SURGERY DURING THE MENSTRUAL-CYCLE

The purpose of this study was to determine the feasibility of using Br east Cancer Detection Demonstration Project (BCDDP) data to ascertain whether the prognosis of breast cancer in premenopausal women is affec ted when surgery is performed relative to the different phases of the menstrual cycle. In the Louisville BCDDP only 40 cases were available for study, but even with this small number, the data indicate that sur vivorship was superior when the surgery was performed between days 7-2 0 of the menstrual cycle (P < 0.06). One thousand eighty-seven premeno pausal women underwent surgery for breast cancer during the first 5 ye ars of the national BCDDP, beginning in 1972. This large number of cas es, plus the long period of follow-up should provide sufficient statis tical power for us to evaluate if there is any relationship between th e day of the menstrual cycle, the day surgery was performed, and progn osis. This feasibility study indicates that these women should be foll owed up and the appropriate statistical studies should be done.