UC Irvine

Locally advanced rectal cancer is usually treated with chemotherapy, radiation therapy, and total mesorectal excision. Although effective, this trimodality therapy is arduous and associated with treatment-related toxicity. It has become clear that some patients may not need to undergo all three modalities of treatment and can thus avoid some of the treatment-associated morbidity. Two such approaches include selective use of preoperative radiation and nonoperative management. Limiting radiation can reduce treatment related toxicity and eliminate radiation-induced toxicity, fibrosis, and bowel and urogenital dysfunction. As an alternative to radical surgery, nonoperative management offers the considerable advantage of organ preservation. Efforts are under way to identify genetic markers that could be used to predict treatment response and better individualize treatment.