Prognostic Implications of DNA Ploidy and S-phase Fraction Comparing with Other Prognostic Factors in Advanced Coloretal Adenocarcinomas

Yang, Young Il; Joo, Jong Eun

Abstract

Dukes' stage of colorectal carcinoma has proven to be the most reliable and conventional prognostic indicator, followed by histological grade, lymph node metastases, tumor size, vascular and neural invasion. Flow cytometric analysis of DNA ploidy and S-phase fraciion (SPF) was examined to elucidate the correlations between sex, age, preoperative serum carcinoembryonic antigen (CEA) value, Dukes' stage, tumor site, size, gross features, histologic grade, and survival rate in 117 paraffin-embedded tissues of 68 cases of colorectal adenocarcinoma in Dukes' stage and 39 cases of colorectal adenoma and 10 cases of normal colonic mucosa. DNA aneuploidy was detected in 30 cases(44%) in adenocarcinomas and 6 cases (15%) in adenomas. Although the DNA ploidy and SPF did not show any correlation with sex, age, preoperative serum CEA level, Dukes' stage, tumor size, site and gross features, the incidence of DNA aneuploidy in the moderately differentiated adenocarcinomas was significantly higher than that of the well differentiated adenocarcinomas (p=0.0127) An apparent correlation was found between survival rate and DNA ploidy, Dukes' stage, histologic grade and preoperative serum CEA value. Dukes' stage was the most reliable prognostic indicator (p=0.0106), followed by histologic grade (p=0.0230), DNA aneuploidy (p=0.0251) and preoperative serum CEA level. (p=0.0369) In the patients with Dukes' stage C, DNA aneuploidy was more important than histologic grade as a prognostic indicator (p=0.0202). Although high SPF, greater than 21% in adenocarcinoma, was associated with the lower 5-year survival rate (12.0%), it was not statistically significant. These results suggest that DNA aneuploidy is regarded as biologic aggressiveness and considered as independent and/or dependent prognostic indicator along with Dukes' stage. However, prognostic utility of the SPF was not significant.