Sphincter preservation in rectal cancer. External-beam radiation therapy alone

Surgery with or without adjuvant radiation therapy and chemotherapy is the standard treatment for patients with resectable rectal carcinoma. Many patients, however, are medically unfit or simply refuse surgery that could result in a colostomy. This article reviews the results of external-beam radiation therapy alone for selected patients with rectal carcinoma and its role in preserving anorectal function. For patients with mobile tumors, a 5-year survival and local relapse-free rate of 30% and 25%, respectively, can be expected after external-beam radiation therapy alone, and 60% remain colostomy free. Results of radiation therapy alone in patients with fixed or unresectable tumors are poor. Although more than a third of patients remain colostomy-free, only 5% of patients survive 5 years. In patients with mobile rectal carcinomas that are not amenable to sphincter-preserving surgery, who are unfit medically for radical surgery, or who refuse a colostomy, external-beam radiation therapy offers the reality of sphincter preservation and the possibility of long-term tumor control.