Correlation of menstrual cycle at time of breast cancer surgery to disease-free and overall survival.

The timing of surgery during the menstrual cycle of premenopausal breast cancer patients was correlated with their disease-free survival (DFS) and overall survival (OS). The study included 150 premenopausal patients treated for breast cancer between 1977 and 1992. The data were analyzed using three different menstrual cycle phase categorization schemes: (1) days 0 to 6 and 21 to 32 vs 7 to 20; (2) days 0 to 2 and 13 to 32 vs 3 to 12; and (3) days 0 to 14 vs 14 to 32. Two different surgery dates used for analysis were biopsy date and definitive surgery date. There was no association of the timing of surgery with OS. Only one categorization scheme correlated with DFS (scheme No. 2), and this correlation was significant using either surgery or biopsy dates. Thus, premenopausal breast cancer patients who have biopsy and/or definitive surgery during their perimenstrual phase (days 0 to 2 or after day 13) of the menstrual cycle may have a longer DFS than patients operated on during their midcycle phase (days 3 to 13); however, this may not affect overall survival.