Revisiting the rationale for radical resection in low-risk early rectal cancer: a population-level perspective

Aim: Management of early rectal cancer is influenced by the risk of nodal involvement. High-risk pathologic features (lymphovascular and/or perineural Invasion, poor differentiation) confer a significantly increased risk of nodal positivity. Traditionally, T2 disease is thought to represent a high-risk feature, but supporting evidence is weak. This study aimed to determine whether T2 disease alone should be considered high-risk disease by evaluating the risk of nodal disease and long-term survival. Methods: Retrospective population-level cohort study was performed. Individuals with pT1-2N0-2 rectal cancer without other high-risk features undergoing radical resection were included. Logistic regression was used to explore associations between T stage, nodal involvement and demographics. Survival was assessed using Cox regression. Results: Of 716 low-risk early stage patients, most were male (65%), aged over 60 (75%) with T2 disease (69%). Nodal involvement was higher but not statistically significant in those with T2 disease (T1 12% vs. T2 18%, p = 0.085). On multivariable analysis, T stage was not associated with N+ disease (T1 Ref, T2 OR 1.55 (95%CI 0.98 - 2.50), p = 0.066). Five-year overall survival was high in both T1 and T2 (84% and 81%). T stage was not associated with survival on univariable (T1 Ref, T2 HR 1.08 (95% CI 0.80 - 1.45), p = 0.63) or multivariable (T1 Ref, T2 HR 1.03 (95% CI 0.76 - 1.39), p = 0.87) analysis. Conclusion: In this population cohort, nodal involvement was not associated with inferior survival in low-risk T2 early rectal cancer treated by radical resection.