Timing of surgery influences survival in receptor-negative as well as receptor-positive breast cancer.

Analysis of oestrogen and progesterone receptor (ER, PR) status was interpreted in relation to menstrual phase at the time of surgery and survival in 84 women diagnosed with breast cancer between 1975 and 1988. We showed previously (Br J Surgery 1994, 81, 217-220) that long-term survival was significantly poorer when surgery was performed during the follicular phase of the menstrual cycle compared to luteal phase; we now demonstrate that this effect on survival is at least as important in receptor-negative as receptor-positive patients. At 10 years, overall survival (OS) of ER-positive patients who had their biopsy during the follicular phase was significantly poorer than for those whose biopsy was performed during the luteal phase of their menstrual cycle (52 versus 88%, P = 0.02). OS for the ER-negative follicular phase group was also significantly poorer than that for the ER-negative luteal phase group (33 versus 76%, P = 0.009). The OS difference between the PR-positive follicular phase group and PR-positive luteal phase group was of borderline significance (60 versus 87%, P = 0.06), while the difference in OS between the PR-negative follicular phase group and that of the PR-negative luteal phase group was highly significant (13 versus 76%, P = 0.001). Disease-free survival for these groups followed a similar trend. The survival differences in receptor-negative women suggest that hormonal fluctuations at the time of surgery may have complex indirect effects on tumour growth and metastasis. The mechanism, if indeed independent of the tumour steroid receptors, could also apply in other cancers.