Adjuvant therapy for rectal cancer.

Patients with stage II and III rectal cancer benefit from a multidisciplinary approach to treatment. Studies of postoperative adjuvant therapy consistently demonstrate decreases in locoregional recurrence with the use of radiation therapy. The use of postoperative chemotherapy results in improved disease-free survival and overall survival in certain studies. Preoperative radiation therapy decreases locoregional recurrence and in one study demonstrated an improvement in survival. The addition of chemotherapy to preoperative radiation results in improved locoregional control, but not survival. Preoperative chemoradiation is the standard of care for patients with clinical stage II and III rectal cancer in the United States due to improved local recurrence, acute and late toxicity, and sphincter preservation compared with postoperative chemoradiation. Promising approaches include the incorporation of new chemotherapeutic and biologic agents into chemoradiation and adjuvant chemotherapy regimens; new radiation techniques, such as the use of intraoperative radiation therapy and an accelerated concomitant radiation boost; and gene and protein expression profiling, to better predict response to treatment and prognosis.