Preoperative short-course radiotherapy with delayed surgery in primary rectal cancer.

BACKGROUND: Short-course radiotherapy (SRT) with immediate surgery and long-course chemoradiotherapy (CRT) are currently the standard preoperative treatment options for rectal cancer. SRT with surgery delayed for 4-8 weeks (SRT-delay) is an option described for patients with locally advanced tumours who are not fit for CRT. This study examined early toxicity, response to radiotherapy (RT) and short-term outcomes of SRT-delay.

METHODS: Patients in the Stockholm region diagnosed with rectal cancer between January 2002 and December 2008, who received SRT (25 Gy over 5-7 days) and had surgery with resection of the primary tumour more than 4 weeks after the start of RT, were identified from a prospective register. Additional data were obtained by retrospective review of clinical records.

RESULTS: A total of 112 patients had SRT and delayed surgery. The reasons given for SRT included primary unresectable disease and co-morbidities. Severe RT-induced toxicity was noted in six patients (5·4 per cent). Signs of tumour regression were seen on magnetic resonance imaging in 74 per cent of patients reassessed after RT. Pathological stage (44·9 versus 60·7 per cent stage 0-II; P < 0·001), tumour category (11·9 versus 29·4 per cent T0-T2; P < 0·001) and node category (45·8 versus 63·6 per cent N0; P = 0·014) were significantly lower than those at initial assessment. Nine patients (8·0 per cent) had a complete pathological response.

CONCLUSION: The SRT-delay schedule was a feasible alternative with low toxicity. The study indicated a downstaging effect of SRT if surgery was delayed.