Surgical timing after radiotherapy for rectal cancer

INTERVENTION: 12 weeks: surgery for rectal cancer performed following 12‐week delay from completion of neo‐adjuvant long‐course chemoradiotherapy 6 weeks: surgery for rectal cancer performed following 6‐week delay from completion of neo‐adjuvant long‐course chemoradiotherapy. Follow Up Length: 1 month(s) CONDITION: Topic: National Cancer Research Network, Generic Health Relevance and Cross Cutting Themes; Subtopic: Colorectal Cancer, Rectum, Surgery ; Cancer ; Malignant neoplasm of rectum PRIMARY OUTCOME: Operative Technical Complexity measured at time of surgical intervention SECONDARY OUTCOME: 1. Down‐staging of disease as assessed on magnetic resonance imaging (MRI) measured at 6 weeks following completion of neo‐adjuvant therapy +/‐ at 12 weeks; 2. In‐hospital surgical complications measured at time of discharge & also at 30‐days post‐operatively; 3. Length of hospital inpatient admission measured by counting day of surgery as day 0 until day of discharge; 4. Mortality measured 30 days from operation; 5. Oncological clearance of tumour ("R0 resection") ‐ Histopathological analysis of surgical resection specimen; 6. Quality of life: EORTC QLQ‐CR29 & C30 and EQ‐5D‐5L questionnaires measured pre‐operatively; 7. Post‐operative on day of discharge from hospital measured 2‐weeks after discharge in clinic; 8. Quality of resected specimen assessed from high‐definition photography of resected tumour specimens; 9. Rates of sphincter preservation measured following surgery; 10. Re‐admission rates measured 30‐days following operation; 11. Surgeon‐Reported Operative Complexity measured at using questionnaire completed by the operating surgeon at the end of each procedure; 12. Tumour response to chemoradiotherapy measured using operative resection specimen assessed using standard histopathological techniques INCLUSION CRITERIA: 1. Age 18 years or over 2. Completing neo‐adjuvant long‐course 3. Chemoradiotherapy for rectal cancer 4. Fit for surgical resection by open or laparoscopic anterior resection or abdominoperineal excision (APE) 5. American Society of Anaesthesiology (ASA) grades I, II and III 6. Able and willing to provide written consent 7. Target Gender: Male & Female