Survival analysis for colon subsite and rectal cancers: Experience from a single surgeon

Purpose: The survival rates of patients with colorectal cancers have been well documented in many studies.Some studies have shown that proximal colon cancers have inferior survival rates when compared with distal colon cancers.However, the prognostic significance of tumor location with respect to survival remains controversial.By using data from a single physician, we analysed patient survival rates based on colon cancer subsite location, including rectal cancers.Methods: We retrospectively analysed 881 patients with colorectal cancers between 1987 and 2008.Colon subsite locations were defined as cecum, ascending colon, transverse colon, descending colon, sigmoid colon, and rectum.Subsite-specific survival analyses were performed using Kaplan-Meier analysis and Cox proportional hazards ratios.The median follow-up time was 93 months.Results: A total of 689 colorectal cancer cases were included in our analysis, of which 14 were cecum (2.0%), 95 were ascending colon (13.8%),21 were transverse colon (3.0%), 25 were descending colon (3.6%), 129 were sigmoid colon (18.7%), and 405 were rectum (58.8%) cancers.The 5-year overall survival rates were 77.8% for all colorectal cancers, which consisted of 92.9% for cecal cancer, 69.5% for ascending colon cancer, 76.2% for transverse colon cancer, 84.0% for descending colon cancer, 82.2% for sigmoid colon cancer, and 77.5% for rectal cancer.Conclusion: Ascending colon cancer was associated with the poorest survival outcome, whereas descending colon cancer was associated with the best survival outcome except cecal cancer.Moreover, the survival rate associated with left colon cancer was better than the survival for right colon and rectal cancer.