12. Timing of surgery for breast cancer.

Several studies have now shown that premenopausal women with early breast cancer have a significantly better prognosis if their tumours are excised during the luteal phase of the cycle. The 10-year survival for node positive cases undergoing follicular phase surgery was 33% compared with 78% in those having surgery at other times of the menstrual cycle. Further work has shown that there is an improved survival in those with plasma progesterone levels >4 ng/ml(-1), associated with the luteal phase. Luteal phase surgery is also associated with a decreased risk of vascular invasion, implying that the tumour is more cohesive at that time. Similarly, in the heaviest quartile of postmenopausal patients, with the highest endogenous oestrogen levels, there was vascular invasion around tumours in 45% compared with only 11% of the lightest quartile. Changing the hormonal milieu at the time of surgery for breast cancer may have the ability to improve the prognosis for some patients with early breast cancer.