The prognostic significance of flow cytometric cellular DNA content determination in patients with colorectal carcinoma

Abstract

Paraffin-embedded tumor specimens from 55 patients with operable colorectal carcinoma were studied by flow cytometry in order to determine the prognostic value of DNA ploidy and S-phase fraction. Twenty-two patients (40%) had aneuploid and 33 (60%) had diploid tumors. Mean S-phase fraction was calculated as 10.1% (range: 1.2%-34.8%) in all patients. There was no significant correlation between DNA ploidy and the other clinical and histological parameters. S-phase fraction was found to be significantly higher in aneuploid and rectal tumors. Histologic grade, age and S-phase fraction were significant factors for overall survival in univariate analysis. Adjuvant chemotherapy group and patients $\legq$60 years of age had better disease-free survival rates in univariate analysis. While age and the histologic grade of the tumor were independent significant factors for overall survival, DNA ploidy and histologic grade of the tumor were independent prognostic factors for disease-free survival. In conclusion, DNA ploidy status may be a weak prognostic for patients with colorectal carcinoma, whereas S-phase fraction seems to be more important than DNA ploidy in the assessment of prognosis. [Turk J Cancer 1998;28(2):51-8]