Sauerbrei W, Blettner M, Schmoor C, Bojar H, Schumacher M
Institute of Medical Biometry and Informatics, Albert-Ludwigs-University, Freiburg, Germany.
Eur J Cancer. 1998 Aug;34(9):1348-51. doi: 10.1016/s0959-8049(98)00139-7.
The effect of oral contraceptive (OC) use as a risk factor for breast cancer was recently assessed in a large meta-analysis, but currently available data on the prognostic effect are still insufficient. We investigated the relationship between OC use and standard prognostic factors and the effect of OC use on recurrence-free survival (RFS) and overall survival (OS) in 422 premenopausal pT1a-3aN + M0 patients from two trials of the German Breast Cancer Study Group (GBSG). 137 patients (32.5%) were OC users. They were younger on average (mean age 41.5 years versus 45 years for non-OC users) and the percentage of patients with smaller tumours was higher in the group of OC users. Based on 163 events for RFS and 103 events for OS, no significant effect of OC use on RFS and OS could be demonstrated in univariate and multivariate analyses. In our study of node positive breast cancer cases, OC users were younger and had smaller tumours. This may be an effect of earlier detection of breast cancer, but OC users did not have a better prognosis, both before and after adjustment for tumour size and other prognostic factors.
