Surgery for rectal cancer after high-dose radiotherapy for prostate cancer: is sphincter preservation relevant?

Aim The feasibility and outcome of sphincter-saving resection for rectal cancer were assessed in patients previously treated by high-dose radiotherapy for prostate cancer. Method Between 2000 and 2012, 1066 patients underwent rectal excision for rectal cancer. Of these, 236 were treated by conventional radiotherapy (45Gy) and sphincter-saving resection (Group A) and 12 were treated by external-beam radiotherapy (EBRT) for prostate cancer (70Gy) and sphincter-saving resection (Group B) of whom five had a metachronous and seven a synchronous cancer. The end-points were surgical morbidity, pelvic sepsis, reoperation and definitive stoma. Results Tumour characteristics were similar in both groups. Surgical morbidity (67% vs 25%, P=0.004), anastomotic leakage (50% vs 10%, P=0.001, and reoperation (50% vs 17%, P=0.011) were significantly higher in Group B. Multivariate analyses showed that EBRT for prostate cancer was the only independent factor for anastomotic leakage (OR=5.12; 95% CI 1.45-18.08; P=0.011) and definitive stoma (OR=10.56; 95% CI 3.02-39.92; P<0.001). Conclusion High-dose radiotherapy for prostate cancer increases morbidity from rectal surgery and the risk of a permanent stoma. This suggests that a delayed coloanal anastomosis or a Hartmann procedure should be proposed as an alternative to low anterior resection in this population.