DNA ploidy, S-phase fraction and mitotic indices as prognostic predictors of female breast cancer.

DNA ploidy, S-phase fraction (SPF), mitotic index (MI), volume corrected mitotic index (M/V index) and standard prognostic factors were related to disease outcome in a series of 363 women with breast cancer followed-up for over 10 years in our clinic. DNA ploidy and SPF were significantly related to histological type, tumour grade and mitotic indices (p < 0.001). In univariate survival analysis, pN status (p < 0.0001), tumour diameter (p < 0.0001), MI (p = 0.001), M/V index (p = 0.0003) and SPF (p = 0.015) predicted survival. In pN(-) tumours. MI (p = 0.059) was related to survival. In pN(+) tumours, tumour diameter (p = 0.0004), M/V index (p = 0.023) and SPF (p = 0.045) predicted survival. In multivariate survival analysis, tumour diameter (p < 0.001). M/V index (p < 0.007), pN status (p = 0.014) and patient age (p = 0.09) were independently related to survival. In pN(-) tumours, tumour diameter independently predicted survival (p = 0.033). In pN(+) tumours, tumour diameter (p < 0.001), M/V index (p = 0.006) and the year of treatment (p = 0.08) were independent predictors. The results show that tumour diameter, pN status and proliferative activity of cancer cells are important prognostic factors in breast cancer. Of the proliferation indices, M/V index and SPF are equally powerful predictors, and the use of M/V index is advocated due to simplicity of the assessment.