Flow cytometric DNA and clinicopathologic analysis of Dukes' A&B colonic adenocarcinomas: a retrospective study

We retrospectively evaluated DNA content flow cytometrically in a series of 124 colonic adenocarcinomas selected for uniformity of stage (A and B), anatomical location (right or transverse colon), and treatment (surgical only) in order to precisely define the significance of ploidy. Aneuploid populations were detected in 43% overall and more commonly with advancing stage (31% Stage A versus 45% Stage B), although this trend did not reach statistical significance (P = 0.16). Overall, as well as stage corrected, 5-yr patient survival was higher for patients with diploid range tumors, but not significantly (71% diploid range versus 60% aneuploid, P = 0.19). Dukes' stage, in contrast, was strongly predictive for 5-yr survival (89% Stage A versus 61% Stage B, P less than or equal to 0.005). Abnormal DNA content was significantly associated with increased patient age (P = 0.02) and presence of angiolymphatic invasion (P = 0.013) but not tumor grade (P = greater than or equal to 0.10). We conclude that flow cytometrically determined abnormal DNA content is weakly related to pathologic features of biologic aggressiveness in colonic adenocarcinoma and is less predictive of patient outcome than conventional Duke's stage.