Exploring treatment outcomes in Stage II-III rectal cancer patients undergoing neoadjuvant therapy at a tertiary care center in Pakistan: a comprehensive analysis of pathological outcomes.

BACKGROUND: Rectal cancer treatment has transformed in recent years, with neoadjuvant treatment (NT) and total neoadjuvant treatment (TNT) aiming to enhance pathological responses. This pioneering study in our country delves into rectal cancer management, offering crucial insights by examining pathological outcomes in patients treated with the NT and TNT approach, shaping the evolving landscape.

METHODS: In this retrospective-cohort study spanning January 2017 to December 2022 at a tertiary care hospital in Pakistan, ethical approval was obtained to examine outcomes of two treatments. Patients were divided into TNT (chemoradiation and pre-surgery 5 FU-based chemotherapy) and NT (chemoradiation, surgery, and subsequent 5 FU-based chemotherapy). The primary end-point was response rates-no response, pathological complete response (pCR), near complete response (near CR), and partial response (PR). The Chi-Square Test for Independence assessed the association between treatment response and type (TNT or NT). Data analysis used STATA MP 64; significance was set at p < 0.05 for all two-tailed tests.

RESULTS: We analyzed 77 patients, 60 underwent standard neoadjuvant chemoradiation, and 17 followed the total neoadjuvant approach. Predominantly male, most were > 65 with ECOG 0-1. The TNT group showed higher response rates (76% vs 62%, p = 0.039), with 40.38% achieving pCR. In the overall population, pCR and near-CR were similar (27.2% vs 26%), while PR were 14%. Treatment characteristics correlated significantly with chemotherapy type, concurrent chemoradiation, LVI, PNI, and T, N, M staging (p < 0.05). Median overall survival was not reached, and mean survival was 89.1 months (CI: 95.0 to 83.3). Side effects varied, with notable differences in neuropathy, diarrhea, oral mucositis, and thrombocytopenia between NT and TNT groups.

CONCLUSION: Our study adds to evidence favoring neoadjuvant approaches in managing rectal cancer in pakistan. Demonstrating a favorable pcr rate, ongoing research with extended follow-up is essential, given the dynamic landscape of rectal cancer treatment for improved patient outcomes.