Can preoperative radiotherapy of rectal cancer convert a radical abdomino-perineal resection into a sphincter preserving surgery?

Randomized trials published in the literature do not demonstrate definitively that preoperative radiotherapy increases the chance of sphincter preservation in rectal cancer. A long interval (four to six weeks) between radiotherapy and surgery may increase in selected cases of low rectal cancer the chance of sphincter preservation. Such an improvement must not lead to an increased rate of local recurrence and must preserve a good functional sphincter. Ongoing trials of dose escalation and concurrent radio-chemotherapy will provide interesting data regarding this complex question. (author)