Phase II trial of short-course radiotherapy followed by delayed surgery for locoregionally advanced rectal cancer

AimA prospective phase II study to investigate the feasibility and the rate of complete pathological response (ypT0) after short-course radiotherapy (SCRT) followed by surgery at 8weeks. MethodOperable patients with localized rectal cancer staged T3-4N0/+ or T2N+ were eligible and received 25Gy (in one-third of patients, the gross tumor volume received a simultaneous integrated boost up to a total of 30Gy) in five consecutive fractions to the posterior pelvis followed by surgery 8weeks later. Pathological response and surgical toxicity were assessed in all patients. ResultsFifty-two patients (median age 68years) completed the study. The median distance of the tumour from the anal verge was 6.5cm. The median interval to surgery was 52days. Three-quarters of patients underwent a low anterior resection. All underwent complete surgical resection and 100% had pathological negative margins. Ten per cent had stage ypT0 after radiotherapy. The median length of hospital stay was 8days. Toxicity was comparable with the rates reported in the literature. ConclusionIn this study, SCRT followed by delayed surgery was feasible and had acceptable toxicity. All patients underwent complete surgical resection and 100% had negative pathological margins. The rate of ypT0 was 10%.