Cyclical tumour variations in premenopausal women with early breast cancer

The hormonal milieu at the time of tumour excision may have a significant impact on survival in premenopausal patients with breast cancer, with those undergoing surgery between days 3 and 12 of the menstrual cycle having a worse prognosis. To investigate possible mechanisms which might explain this finding,, histological features of tumours from 363 patients included in two studies from Guy's Hospital have been reviewed. Axillary nodal involvement occurred in 71/115 (62%) of patients whose primary tumour was excised between days 3 and 12 of the cycle, compared with 116/248 (47%) of patients undergoing surgery at other phases of the cycle (chi(2) = 7.04, P < 0.01). Vascular invasion was observed in 54/115 (47%) of primary tumours removed between days 3 and 12 and 82/248 (33%) of tumours removed at other times (chi(2) = 6.47, P < 0.02). Multivariate analysis of factors influencing survival indicated that both axillary nodal status and phase of the cycle were highly significant independent predictors of prognosis.