Lack of correlation between timing of surgery in relation to the menstrualcycle and prognosis of premenopausal patients with early breast cancer

In a retrospective cohort of a randomised study of adjuvant endocrine, chem otherapy and chemoendocrine therapy, we investigated the correlation betwee n timing of mastectomy and relapse-free survival (RFS) and overall survival (OS) in 721 premenopausal patients with early breast cancer. The median fo llow-up was 10.1 years (range: 6.1-19.1 years). We grouped the patients by three kinds of classification according to Badwe, Senie, and Hrushesky. The logrank test after the Kaplan-Meier curves showed that there were no signi ficant differences between the categorised menstrual phase in cycle and RFS or OS, except for RFS using Badwe's classification, where the patients who se timing of operation was in the follicular phase had a better RFS compare d with those in the luteal phase. These were confirmed by the Cox proportio nal hazard model. These results suggest that a positive result might be a c hance finding, dependent upon the cut-off levels in the menstrual cycle. (C ) 1999 Elsevier Science Ltd. All rights reserved.