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

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 downsizing. Total mesorectal excision (TME) is a standardised surgical technique of low anterior resection aimed at the 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) of 153 with rectal cancer who underwent pre-operative long-course CRT were treated by standardised open low anterior resection at a median of 10 weeks post-CRT. Sixteen of 131 (12%) were 70 years or older. 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/subgrades of tumour regression; good, moderate or poor, lymph node harvest, local recurrence, disease-free and overall survival using standard statistical methods.

Results: 78% 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, good responders had a median T stage of T2 vs. T3 in poor responders (P = 0.0002). Overall, the median lymph node harvest was < 12. There was no difference in the number of nodes harvested in good 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 the anal sphincter preservation rate was 89%. Predicted 5-year disease-free and overall survival were similar between good and poor responders.

Conclusion: Long-course CRT resulted in satisfactory tumour regression and enabled consideration for safe, sphincter-saving resection in rectal cancer. A dedicated multi-disciplinary team approach achieved a global benchmark for local recurrence in a resource-limited setting.

Keywords: Chemoradiation; Local recurrence; Lymph node harvest; Rectal cancer; Tumour regression.