124 o - Does timing of surgery for breast cancer affect prognosis?

It has been claimed that premenopausal women with breast cancer have worse prognosis if the surgery is performed during the follicular phase of the menstrual cycle (days 3–12.) compared to other days. Previous studies on this subject have relayed on clinical data for placing women in the menstrual cycle. We wanted to estimate the accuracy of that, and study the relationship between the hormonal profile and prognosis. Blood samples were taken at the day of surgery from all women diagnosed from 1988-90, younger than 55 years old, and registrated at the Icelandic Cancer Registry. Diagnosed women were 106, but eligible were 66 women. Clinical data and hormonal mesurements were collected. The follow-up time was on average 32 months. Women who had surgery during the follicular phase had less overall survival (p=0,03). High testosterone level was a profound prognostic marker in a multivatiate analysis (RR=6,7). Inconsistency was in placing the women in the menstrual cycle, i.e. 30% of the women who were in follicular phase according to hormonal profile were expected to be on other days of the menstrual cycle according to clinical data.