Assessment of Local Recurrence and Distant Metastasis After Curative Resection of Rectal Tumors: A Retrospective...

Background Rectal cancer remains a significant global health burden, with rising incidence in younger populations and substantial risk of recurrence despite curative-intent resection. This study aimed to assess rates of local recurrence and distant metastasis following curative resection of rectal tumors and identify clinical and pathological predictors of oncologic outcomes. Methods This single-center retrospective study analyzed 289 patients who underwent curative resection for non-metastatic rectal adenocarcinoma at Shaukat Khanum Memorial Cancer Hospital and Research Center, Lahore, between 2013 and 2017. Demographic, clinicopathological, and treatment data were collected from medical records. Patients were followed for a median of 60 months according to a standardized surveillance protocol. Kaplan-Meier survival analysis and multivariate Cox proportional hazards regression were performed to identify predictors of local recurrence and distant metastasis. Results The cohort had a mean age of 44.3 ± 14.8 years with a male predominance (71.6%). Neoadjuvant chemoradiotherapy was administered to 78.9% of patients, and 55.4% received adjuvant chemotherapy. Local recurrence occurred in 17.6% (n=51) and distant metastasis in 22.8% (n=66), with lung (5.2%) and liver (4.5%) being the most common metastatic sites. The one-year, three-year, and five-year recurrence-free survival rates were 83.5% (95% CI: 79.2-87.8%), 66.6% (95% CI: 60.9-72.3%), and 52.8% (95% CI: 46.5-59.1%), respectively, with a mean recurrence-free survival of 76.3 months (95% CI: 71.05-81.08 months). On multivariate analysis, independent predictors of local recurrence included signet ring cell histology (HR 3.42, 95% CI 1.98-5.91; p<0.001), ypN2 nodal status (HR 2.85, 95% CI 1.62-5.01; p<0.001), positive circumferential resection margin (HR 2.14, 95% CI 1.28-3.58; p=0.004), poor tumor differentiation (HR 1.96, 95% CI 1.18-3.26; p=0.009), and extra-levator abdominoperineal resection (HR 3.67, 95% CI 1.95-6.91; p<0.001). Predictors of distant metastasis included ypN2 status (HR 3.21, 95% CI 1.88-5.48; p<0.001), signet ring histology (HR 2.76, 95% CI 1.61-4.73; p<0.001), and positive circumferential resection margin (CRM) (HR 1.98, 95% CI 1.19-3.29; p=0.008). Conclusions Signet ring cell histology, advanced nodal disease (ypN2), positive circumferential resection margin, poor tumor differentiation, and low rectal tumors requiring extralevator abdominoperineal resection (ELAPR) are independent predictors of recurrence following curative resection of rectal cancer. These findings support risk-stratified postoperative surveillance and individualized adjuvant therapy strategies to improve long-term outcomes, particularly in high-risk patient populations.