Pathologic factors are more important than tumor location in long-term survival in colon cancer.

ABSTRACT

PURPOSE: Proximal and distal colon cancers differ in terms of epidemiology, clinical presentation, and pathologic features. The aim of our study was to evaluate the impact of right-sided (RC), transverse (TC), and left-sided (LC) colon cancer on morbidity rates and oncological outcomes. METHODS: A retrospective analysis of patients with resected colon cancer between 2004 and 2014 was conducted. Cox proportional hazard models were used to assess predictors of overall (OS), and disease-specific survival (DSS), as well as disease-free survival (DFS). RESULTS: A total of 1189 patients were included. RC patients (n = 618) were older, predominantly women, and had a higher comorbidity rate. LC (n = 454) was associated with symptomatic presentation and increased rates of laparoscopic surgery. Multivisceral resections were more frequently performed in TC tumors (n = 117). This group was admitted 1 day longer and had a higher complication rate (RC 35.6% vs. TC 43.6% vs. LC 31.1%, P0.032). Although the incidence of abscess/leak was similar between the groups, the necessity of readmission and subsequent reoperation for a leak was significantly higher in LC patients. Pathology revealed more poorly differentiated tumors and microsatellite instability in RC. Kaplan-Meier curves demonstrated worse 5-year OS for right-sided tumors (RC 73.0%; TC 76.2%. LC 80.8%, P0.023). However, after adjustment, no differences were found in OS, DSS, and DFS between tumor location. Only pathological features were independently correlated with prognosis, as were baseline characteristics for OS. CONCLUSION: Tumor location in colon cancer was not associated with survival or disease recurrence. Pathological differences beyond tumor stage were significantly more important.