S-phase fraction and menopausal status as the most important prognostic factors of disease-free survival for node negative patients with breast cancer. A prospective study.

The aim of our study was to determine a prognostic value of DNA flow cytometry measurements performed on fresh breast cancer tissues, separately for patients' groups defined by nodal status, with special attention to histological type of tumor. Between 1993 and 1996 samples from 677 patients were analyzed and 457 cases were included in the survival analysis. Two-hundred and nine patients from them were node negative (N0). The median time of follow-up was 74 months. In multivariate analysis of disease-free survival (DFS), S-phase fraction (SPF) and menopausal status were found to be independent prognostic parameters for N0 group. A combination of this factors allowed us to distinguish three groups different in respect of the risk of recurrence. Our results showed that: 1. SPF and menopausal status could be prognostically valuable factors for DFS in N0 breast cancer patients; 2. prognostic value of SPF and ploidy should be evaluated separately for each histological type of breast cancer.