The prognostic significance of ploidy analysis in operable breast cancer

The nuclear DNA content of 98 operable breast cancers was determined by flow cytometric analysis using paraffin-embedded tissue. All patients were on follow-up and failure of treatment or recurrences were identified. DNA ploidy data in the form of ploidy status and DNA index (DI) has been correlated with various clinical and histopathologic factors. The only significant correlation using univariate analysis exists between the histologic grade and DI (P less than 0.025), recurrence of the disease and ploidy status (P less than 0.005), and recurrence of the disease and DI (P less than 0.005). The absence of correlation of ploidy status with other tumor derived factors indicates the independent nature of ploidy as a prognostic factor. Multivariate analysis showed that in the whole-group ploidy (P less than 0.01), tumor margin (P less than 0.01), and menopausal status (P less than 0.01) were significant factors in the order mentioned. DI with a cut of at 1.29 is not found to be a significant factor in the multivariate analysis. The maximum prognostic value of ploidy status was observed in the postmenopausal group (P less than 0.0005). In the node-negative group ploidy status (P less than 0.05) is the only independent significant factor predicting for early relapse. It is concluded that ploidy status is an independent prognostic factor predicting for recurrence of the disease. In the node-negative subgroup this could be used to identify the subset of patients who may benefit from adjuvant treatment.