The effect of surgical timing within the fertility cycle on breast cancer outcome

Murine studies have documented the relationship between surgical curability of a breast cancer and fertility cycle stage at the time of primary surgical resection. In a retrospective study of 41 premenopausal women with primary breast cancer followed for 6 to 14 years, disease recurrence was more frequent and more rapid in women whose initial tumor resection was performed during the perimenstrual period (days 0-6 and 21-36) than during the periovulatory period (days 7-20) of the menstrual cycle. Patients in both groups had disease of equal severity as measured by size of primary tumor, extent of lymph node involvement, estrogen and progesterone receptor assay determination, flow cytometry, and HER-2/neu gene amplification. To date, with 100% follow-up, 7 of the 19 perimenstrual patients (37%) have relapsed and 6 (32%) have died of metastatic disease. Only 3 of the 22 periovulatory patients (14%) have relapsed and only 1 (5%) has died of metastatic disease. These results, predicted by a murine experimental model, suggest that the endocrine milieu at the time of primary tumor resection impacts upon breast cancer prognosis.