Comparison of Clinicopathological and Survival Features of Right and Left Colon Cancers: Experience of the Medical Oncology Department of Fez

Abstract

Right-sided colon cancers (RCC) and left-sided colon cancers (LCC) have different epidemiological, physiological, pathological, genetic, and clinical characteristics, which result in differences in the course, prognosis, and outcome of disease. The objective of our study is to compare right-sided colon cancers and left-sided colon cancers regarding clinicopathological and survival characteristics. This is a retrospective study of 664 patients with colon cancer treated at the medical oncology department of Fez over a period from December 2009 to September 2020. Rectosigmoid, descending colon, and splenic flexure tumors were considered left-sided colon cancers, whereas ascending colon tumors were considered right-sided colon cancers. The Kaplan Meier method was used to estimate median survival. The study included 664 patients (female, 47%) having colon cancer with a median age of 60 years (23 - 83). Of the patients, 78.5% (n = 519) had LCC and 19.36 % (n = 128) had RCC. The rate of patients aged ≥ 65 years and the rate of patients with a family history of colon cancer was higher in the LCC patients. The proportion of poorly differentiated adenocarcinomas represented 3%, of which 63% had cancer of the right colon. There was a significantly higher proportion of higher T stage (T3-4: 62% vs 38%) in right sided tumors as compared to left sided tumors. The rate of metastatic patients was 64.1% in the RCC group and 43% in the LCC group. The median follow-up period was 14 months in the RCC group and 19 months in the LCC group with higher median overall survival in the LCC group (32 vs 21 months). We found histopathological differences between right and left sided colon cancer. Tumors on the right colon were found to be more aggressive, as expressed by poorer differentiation, higher T stage associated with a median overall survival better in left colon cancer.