Surgery, radio- and chemotherapy for multimodal treatment of rectal cancer

Abstract

The possibilities and results of multimodal treatment in rectal cancer were reviewed with respect to the results of surgical treatment only. Based on the results of 4 studies, reducing local relapse rates and increasing long term survival rates significantly, postoperative radiochemotherapy (RCT) + chemotherapy (CT) should remain the recommended standard for R0 resected UICC II and III rectal cancers. The addition of RT to adjuvant CT reduces local relapses without significant impact on survival (NSABP R-02). Vice versa, the addition of CT to RT or an improved CT in the RCT-concept prolongs survival. Preoperative neoadjuvant radiotherapy (RT) reduced local relapse rates in 9 studies, and extended survival in one study that evaluated all eligible patients. Preoperative RT reduced local relapse rates in addition to total mesorectal excision (TME) but did not extend survival. The preoperative RCT + CT downstages resectable and nonresectable tumors and induces a higher sphincter preservation rate. Phase III data justifying its routine use in all UICC II + III stages are not yet available. This treatment may be routinely applied in nonresectable primary tumors or local relapses. Preoperative RCT (or RT) may evolve as standard, if the patient selection is improved and postoperative morbidity and long term toxicity reduced. Intraoperative RT could be added to this concept or be used together with preoperative/postoperative RT at the same indications. Postoperative adjuvant RT reduced local relapses significantly in a single trial, and no impact on survival time is reported. Since postoperative RT is inferior to preoperative RT, this treatment cannot be recommended, if RT is chosen as a single treatment modality in adjunction to surgery. The results of local tumor excisions may be improved with pre- or postoperative RCT + CT. In the future, multimodal treatment of rectal cancer might be more effective, if individualized according to prognostic factors.