DNA Image cytometry as a prognostic tool in stage II and stage III colorectal cancer

13565 Background: We assessed the prognostic value of nuclear DNA content measured in the primary tumors of 123 patients with stage II or stage III colorectal cancer (CRC). Methods: Isolated nuclei from paraffin sections were stained with Feulgen and DNA was measured using a computer-assisted image analysis cytometry system (Ahrens ACAS). We applied 4 different approaches in analysis of DNA histograms: ABCDE approach, histogram range, peak evaluation, and DNA cut-off values. Results: Using the histogram range, narrow range was rare (3.7%) in patients who died of disease as compared with 16.4% among those alive (p=0.017). Modal peak evaluation was a significant predictor of disease free survival (DFS) (Kaplan-Meier log-rank p=0.0235). In the range evaluation, the first set (low-start gates) was a significant predictor of DFS (log-rank p=0.0121), where disease recurrence was closely associated the widest range (1.8c->10c) gates. Recurrence-free survival was markedly better among patients with narrow gate hi...