Prognostic significance of DNA content in large bowel carcinoma: a retrospective flow cytrometric study

Flow cytometric (FCM) determination of DNA content was performed on surgical specimens from 44 patients with previously untreated colonic carcinoma. For each tumor, cell suspensions were prepared from 2-4 40-μm thick sections obtained from formalin-fixed and paraffin embedded tissue samples. Aneuploidy was found in 47.2% of all the tumors and the aneuploid clone had a median DNA index of 1.49 (range: 1.24-1.93). Aneuploidy was found in 26.7% of highly differentiated tumors (WHO histologic classification), in 53.8% of moderately differentiated tumors and in 100% of poorly differentiated tumors (P = 0.04). The 33.3% of stages 1 + 2 (TNM) and the 70.6% of stages 3 + 4 tumors were aneuploid (P = 0.002). Median survival from surgery was 46.4 months for all patients. It was 18.8 months for patients with aneuploid tumors and 85.7 months for those with diploid tumors (P = 0.0002). FCM determination of DNA in colon carcinomas can easily be performed on archival histological material and provides prognostic information.