Flow cytometric DNA and cytomorphometric analysis in renal cell carcinoma: Its correlation with histopathology and prognosis

Cell material from 49 cases of archival paraffin-embedded tumor specimens of newly diagnosed renal cell carcinoma (RCC) was studied retrospectively using rapid flow cytofluorometric (propidium iodide) DNA analysis. The degree of ploidy (DNA index), percentage of cells in the S-phase (SPF), and modal nuclear size were determined from histograms. The tumors were classified as diploid (DNA index = 0.9-1.1) or aneuploid. Proliferative activities of the tumors were assessed from the proportion of S-phase cells. The aneuploid occurrence was 77.6% in our series. Univariate and multivariate logistic regression analyses of DNA ploidy and associated parameters showed that DNA ploidy was correlated with SPF of cells (P = 0.0061) as no correlation was seen between DNA ploidy, sex, age, histological type, tumor size, stage, and nuclear size (P = 0.0697). Multiple aneuploid stem lines had no influences on ploidy and prognosis. Comparison of survival data using the multivariate stepwise hazard rate and Lee-Desu statistics showed that patient prognosis was closely related to tumor size (P = 0.006) and staging (P <0.0001). DNA ploidy had marginal correlation to progression and disease-specific death (P = 0.064). Nevertheless, flow cytometric analysis in conjunction with conventional histopathology may have a potential role for the management of patients with RCC.