The Influence of DNA Ploidy, Index and Lymph Node Status on Disease Free Survival in Patients with Colorectal Cancer

ABSTRACT

The DNA flow cytometric analysis in colorectal cancer has been studied for more than 10 years as an independent prognostic factor or a factor correlated with other preexistent prognostic factors, such as the depth of invasion, lymph node status, histologic differentiation, etc. To clarify the influence of DNA contents (DNA ploidy, DNA index) and lymph node status on disease free survival in colorectal cancer, we investigated the relationship between them, retrospectively. METHODS: This study included 198 patients with curatively resected Dukes' stage A, B, and C colorectal cancer who had taken DNA flow cytometric analysis from June of 1996 to March of 1999 at Department of Surgery, Inha University Hospital. RESULTS: In over all twelve-month disease free survival, there were 92.5% in DNA diploid and 74.3% in DNA aneuploid tumors. And so forth, there were 78.0% in positive and 91.9% in negative lymph node tumors. In the event of a DNA index greater and lesser than 1.15, the twelve-month disease free survival was 72.9% and 92.7%, respectively. These results were statistically significant (p<0.05). Therefore, patients with a negative lymph node, diploid colorectal cancer or DNA index lesser than 1.15 had a longer disease free survival than those with a positive lymph node, aneuploid one or DNA index greater than 1.15. CONCLUSIONS: In conclusion, there seems to be a significant relationship between DNA contents and lymph node status on disease free survival. Thus, these factors are considered to be valuable in predicting the recurrence of colorectal cancer.