Clinicopathological Characteristics and Population-Level Survival Outcomes of Mucinous Adenocarcinoma Across Different Colon Segments: An Analysis Using the Surveillance Epidemiology and End Result Database

Abstract

Aim: To determine population-level survival differences for patients undergoing curative resection for mucinous adenocarcinoma (MAC) based on specific anatomical colon segment and stage over the last two decades. Method: The study was conducted using the Surveillance Epidemiology and End Result program. Patients who underwent curative colectomy for MAC between 2004 and 2019 were identified. Demographics and clinical and histopathologic factors were compared for different colon segments, stages, and time periods. Kaplan-Meier survival analysis was conducted for each colon subsite location and stage, and curves were compared using the log-rank test. Results: A total of 19,427 patients met the inclusion criteria. Patients with proximal colon cancers were significantly older (70.6±12.6 years) and more likely to be female (56.5%) than those with distally located tumor sites (p<0.001). The incidence of MAC was higher in the cecum (30.8%) and ascending colon (27.9%) than at distal sites (3.4-14.6%). The 3-year and 5-year overall survival rates were similar among the different colon sites (3-year survival rate: 66.7-69.9%, 5-year overall survival rate: 54.7-58.7%) for patients at stage 2, 3, and 4. Only patients at stage 1 exhibited significantly different outcomes among colon sites (p=0.018). Patients at stage 1 with MAC in the sigmoid colon exhibited a significantly improved overall survival rate compared with other colon sites (p<0.001). Multivariable Cox regression analysis revealed that age [hazard ratio (HR): 2.2, p<0.001], stage (p<0.001), degree of differentiation (p<0.001), and greater tumor diameter (HR: 1.05, p=0.007) were independently associated with less favorable survival. Conclusion: In contrast to previous literature, our study revealed that the results of long-term population-level stage-by-stage survival analysis for MAC were similar across seven different colon sites, except for patients at stage 1, who exhibited significantly improved survival for MAC in the sigmoid colon.

Keywords

• surveillance epidemiology and end result data
• colon cancer
• mucinous adenocarcinoma