Stage-related impact of body mass index on long-term outcomes in patients with colorectal cancer: 5-year and 10-year survival after curative surgery

Purpose: The prognostic role of body mass index (BMI) on colorectal cancer (CRC) is unclear. The aim of this study is to assess the impact of BMI on stage-related survival in patients with CRC. Methods: Data of patients who underwent surgical resection for CRC between January 2008 and December 2013 were retrospectively analyzed. Patients were divided into two groups according to a BMI <30 (group A) or ≥30 kg/m 2 (group B), respectively. Overall and stage-related survival were analyzed at 5 and 10 years and compared between the two groups. Cancer-specific survival was analyzed only at 5 years. Results: A total of 377 patients were enrolled in the study, 316 in group A (83.8%) and 61 in group B (16.2%). Five-year survival was similar between the two groups in Dukes stage A ( P = 0.5926) and B ( P = 0.1842). Conversely, in stage C, obese patients showed a significantly higher 5-year survival when compared with nonobese patients ( P = 0.0134). Furthermore, obese patients showed 10-year survival rates lower in stage A ( P = 0.0492), similar in stage B ( P = 0.8707), and higher in stage C ( P = 0.0425). Conclusion: These results suggest that high BMI offers a paradoxical protective effect in advanced-stage CRC.