Flow cytometry in primary breast carcinomas: prognostic impact of multiploidy and hypoploidy

The aims of the present work were to study the prognostic impact of multiploidy and/or hypoploidy in breast cancers and their relation to other classic clinicopathologic prognostic factors (T, grade, receptors, and lymph node status).

From 3 January 1990 to 7 January 1999, 1984 previously untreated, invasive breast carcinoma samples were snap frozen for flow-cytometry.

Multiploid tumors had the same prognosis as the aneuploid ones, and those with one hypoploid peak had a better prognosis than did the other aneuploid tumors. However, the presence of both multiploid and hypoploid peaks was correlated with a poor outcome, even after multivariate analysis. In this series after quality control, 93.4% of the histograms could be evaluated concerning ploidy; of these 81.6% could be assessed concerning S-phase fraction (SPF) in the entire population and 77.1% in the multiploid population. In the entire population, we performed a multivariate analysis including all relevant prognostic factors remaining after monovariate analysis by using a compound factor (proliferative activity) regrouping SPF and mitotic activity. This analysis showed that lymph node status and proliferative activity correlates with every type of survival, whereas receptor status correlates with all types of survival except recurrence free survival size, correlated with non-metastasis and overall survival. Grade and age correlated only with overall survival and vascular permeations only with disease-free survival.

SPF is a valuable predictor of survival, can be confidently assessed in multiploid histograms, and thus improves the yield of flow cytometry. When combined with mitotic activity, the prognostic impact of SPF is the same as that of lymph node status. Tumors that are hypoploid and multiploid have a significantly worse prognosis.