Impact of Preoperative Chemoradiotherapy on Clinical Outcomes in Elderly Patients With Locally Advanced Rectal Cancer

Background Preoperative treatment is central to rectal cancer, but its benefit in elderly patients remains unclear. This study evaluated its impact on clinical outcomes in elderly patients undergoing surgery. Methods This cohort included 5,533 patients aged ≥65 years with newly diagnosed locally advanced rectal cancer (LARC) who underwent surgical resection between January 1, 2008, and December 31, 2017. Patients were stratified into the neoadjuvant chemoradiotherapy (nCRT) group (n = 1,086) and the upfront surgery group (n = 4,447). Cox proportional hazards models were used to estimate the overall survival (OS) and disease-free survival (DFS) between groups. Stratified analyses were further performed according to relevant prognostic factors. Results Elderly LARC patients who received nCRT were more likely to be male, younger (65–75 years), have stage III disease (clinically node-positive), and have no comorbidities (CCI = 0). These patients were also more likely to achieve significant tumor downstaging (p < 0.05), as reflected by higher rates of ypT0 and ypN0 status, along with a lower lymph node yield. nCRT was associated with improved OS in univariable analysis (p=0.0002), but this association was no longer significant after multivariable adjustment (p=0.5645). No significant associations were observed for DFS. Consistent with the adjusted analysis, stratified analyses across relevant prognostic factors showed no significant associations between nCRT and either OS or DFS. Conclusions The use of nCRT was associated with increased pathological tumor downstaging but not improved survival outcomes in elderly patients with locally advanced rectal cancer. Individualized treatment decisions are therefore warranted.