Clinico-Pathological Outcome of Neoadjuvant Chemoradiation in Rectal Cancer: A Retrospective Study

Abstract

Background: Rectal cancer continues to pose a significant oncological challenge due to its high global incidence, heterogeneous biological behaviour, and the intricacies involved in its multidisciplinary management. The incorporation of neoadjuvant chemoradiation (NACRT) has emerged as a cornerstone in the treatment of locally advanced rectal cancer, with the dual objectives of achieving tumor downstaging and enhancing resectability while maximizing the potential for sphincter preservation. This approach has been shown to improve locoregional control, reduce recurrence rates, and ultimately contribute to better overall survival outcomes. Materials and Methods: Forty patients with histologically proven rectal cancer who had received neoadjuvant chemoradiation with prescribed dose of 50.4 Gy delivered in 28 fractions,1.8Gy per fraction along concurrent Capecitabine 825mg/m2 BD on days of radiation, were included in this study. Patient demographics, clinical staging, chemoradiation details, treatment response based on radiological and clinical assessment, surgical procedures performed and postoperative pathological outcomes were retrieved from electronic medical records and analysed using appropriate statistical tests. Proportions are reported with 95% confidence intervals (CI). Results: Pathological complete response was achieved in 27.5% of patients (95% CI: 13.7–41.3%), and partial response in 67.5%. T-stage and N-stage downstaging occurred in 45% (95% CI: 29.6–60.4%) and 75% (95% CI: 61.6–88.4%) of patients, respectively. A longer interval between radiotherapy and surgery (>8 weeks) was significantly associated with higher pCR rates (p = 0.04). Smaller tumor size (<3 cm) and earlier clinical stage demonstrated favorable response trends without reaching statistical significance. Advanced radiotherapy techniques showed numerically higher response rates. Conclusion: Neoadjuvant chemoradiation resulted in clinically meaningful pathological response and nodal downstaging in LARC. Surgical timing appears to influence tumor regression, supporting individualized treatment sequencing. Larger prospective studies incorporating survival, toxicity, and multivariate analyses are warranted.