A single-institution retrospective analysis of outcomes for locally advanced rectal cancer treated with neoadjuvant chemoradiotherapy

Abstract

Background: Neoadjuvant chemoradiotherapy (NACTRT) is an established standard of care for the management of locally advanced rectal cancer (LARC). A retrospective analysis was conducted to assess the results of treatment and predictors of overall survival (OS) for patients treated in a tertiary care hospital in India from 2013 to 2019. Materials and Methods: Biopsy-proven 79 patients of LARC were included in the analysis. Clinical and treatment parameters were assessed. Prognostic factors associated with OS and pathologic response were studied. Treatment toxicities and sphincter preservation rates were documented. Results: There were 55(69.6%) patients with Stage III rectal cancer. Majority of the patients, i.e., 74 (93.7%), received long-course radiation therapy by intensity-modulated radiation therapy–volumetric modulated arc therapy technique after computed tomography + magnetic resonance imaging fusion-based simulation. Pathological complete response (pCR) was achieved in 20 (25.3%) while 45 (57%) showed tumor downstaging post-NACTRT. Time interval (TI) to surgery of ≤8 weeks was significantly associated with higher pCR and tumor downstaging. Actuarial 5-year OS rate was 64.4% and local recurrence-free survival (LRFS) rate of 72.2%. Both OS and LRFS were significantly higher in patients who showed pCR and tumor downstaging. Long-term gastrointestinal and genitourinary toxicities were seen in 11 (15%) and 15 (21.5%) patients, respectively. Conclusions: This study reaffirms the efficacy of preoperative NACTRT as an upfront standard of care in LARC in the Indian population. TI to surgery to the tune of ≤8 weeks yielded optimal pCR and tumor downstaging which translated into significantly better survival.