Clinicopathological staging and management of colorectal cancer. Perioperative radiation therapy.

Abstract

The use of radiotherapy, as a complementary procedure prior to surgery for immobile, nonresectable, rectal cancers or as an adjuvant treatment in patients with mobile rectal cancer is discussed. Locally nonresectable rectal cancer can be resected after prolonged preoperative radiotherapy. The proportion of patients possible to cure after this prolonged treatment is not precisely known, mainly due to differences in the criteria for nonresectability. Literature data show that between 35% and 80% can undergo resection for cure, and 25% to 40% can be long-term disease-free survivors. Moreover, the role of chemotherapy in combination with radiotherapy in this group is not yet settled owing to the lack of convincing data from randomized trials. Data from the literature clearly indicate that preoperative radiotherapy in patients with mobile rectal cancer is superior to postoperative irradiation. Provided the dose is sufficiently high, a relative reduction in the local recurrence rate of 60% in combination with "standard surgery" is to be expected, and this reduction increases long-term survival. An important question is the role of adjuvant radiotherapy together with "more optimized surgery." It is likely that the local recurrence rate will decrease with the same magnitude, indicating that local recurrent rectal cancer in patients with mobile rectal cancer can be more or less eradicated if optimized surgery is combined with preoperative radiotherapy. With proper timing and treatment technique, the adverse effects on surrounding tissues, both immediate and late, can be kept acceptably low.