The hormonal milieu and prognosis in operable breast cancer.

Evidence is presented from those studies which have shown that the timing of surgery affects the prognosis of premenopausal women with operable breast cancer. Those undergoing surgery at a time of unopposed oestrogen (days 3-12) had a significantly worse prognosis than those who had operations at other phases of the menstrual cycle. This was also borne out by another study that indicated that progesterone levels at the time of surgery had prognostic significance, with node positive patients in the luteal phase (progesterone > 1.5 ng/ml) having a significantly better outcome. A meta-analysis has shown a highly significant heterogeneity of results, which do not overall show an effect. Possible reasons for this heterogeneity are discussed together with the need for prospective studies.