Searching for new prognostic factors, we investigated the influence of cyclin expression on breast cancer prognosis. A total of 273 archival tumor specimens from patients with pT1/pT2 N0 breast cancers treated by surgery and local irradiation were immunostained for cyclins E, A and B. Outcome was evaluated as metastasis-free (MFS) and disease-specific survival (DSS) over a median observation period of 99 months. In postmenopausal women, DSS was significantly predicted by cyclin E, and in premenopausal patients by cyclin B. No statistical significance was found for cyclin A. When the prognostic impact of cyclins was compared to that of standard prognostic indicators in a multivariate analysis, both cyclin E and cyclin B were selected as independent predictors of survival in postmenopausal and premenopausal patients, respectively. After inclusion of Ki-67 in the model, cyclin E lost its significance, whereas cyclin B remained the only independent prognostic factor with a hazard ratio of 4.5 (p = 0.026) for tumor-related death. Assessment of cyclin expression may, therefore, refine current prognostic models if considered in relation to menopausal status. The prognostic relevance of cyclins is likely attributable to an influence on proliferation, cell survival and genetic instability. Awareness of the molecular mechanisms leading to deregulated cyclin expression may guide decisions for risk-adapted therapy regimens.
Copyright 2003 Wiley-Liss, Inc.