Neoadjuvant Chemoradiation for Rectal Cancer Achieves Satisfactory Tumour Regression and Local Recurrence – Result of a Dedicated Multi-Disciplinary Approach from a South Asian Centre

Abstract

Abstract Background Pre-operative long-course chemoradiotherapy (CRT) for rectal cancer has resulted in improvement in rates of restorative rectal resection and local recurrence by inducing tumour downstaging and down-sizing. Total mesorectal excision (TME) is a standardised surgical technique of low anterior resection aimed at prevention of local tumour recurrence. The purpose of this study was to evaluate tumour response following CRT in a standardised group of patients with rectal cancer. Methods One hundred and thirty-one patients (79 male; 52 female, median age 57; interquartile range 47 – 62 years) with rectal cancer underwent pre-operative long-course CRT followed by standardised open low anterior resection at a median of 10weeks post-CRT. Median follow up at the time of analysis was 15 months (interquartile range 6 – 45 months). Pathology reports were analysed based on AJCC-UICC classification using the TNM system. Data recorded were overall/sub-grades of tumour regression; good, moderate or poor, lymph node harvest, local recurrence, disease-free and overall survival using standard statistical methods. Results Seventy eight percent showed tumour regression post CRT; 43% displayed good tumour regression/response while 22% had poor tumour regression/response. All patients had a pre-operative T-stage of either T3 or T4. Post-operation, those classified as good responders had a median T stage of T2 vs. T3 in poor responders (P=0.0002). Overall, median lymph node harvest was less than 12. There was no difference in the number of nodes harvested in good responders vs. poor responders (Good/moderate-6 nodes vs. Poor- 8; P=0.31). Good responders tended to have a lesser number of malignant nodes vs. poor responders (P=0.31). Overall, local recurrence was 6.8% and there was no significant difference in predicted 5-year disease-free or overall survival between good and poor responders. Conclusion The use of pre-operative long-course CRT results in satisfactory tumour regression and enables consideration for safe, sphincter resection in rectal cancer. A dedicated multi-disciplinary team approach achieved a global benchmark for local recurrence. Further research will be aimed at methods to improve overall lymph node harvest in irradiated patients with rectal cancer having low anterior resection.