Present indications for adjuvant therapy in resectable rectal cancer

Combined modality therapy is an effective adjuvant therapy for many patients with clinically resectable rectal cancer. The indications for adjuvant therapy for rectal cancer are based on the pattern of failure after surgery. Despite radical surgery, local-regional failure frequently occurs in patients with transmural or node-positive rectal cancers. The incidence of treatment failure in the pelvis is directly correlated with the extent of transmural penetration (microscopic vs gross) and the additional risk of lymph node metastases. In the post-operative setting its use is dictated by pathologic stage and the type of operation (i.e. conventional surgery or a local excision). The choice of which post-operative adjuvant regimen to recommend in the non-protocol setting remains controversial. If 5-FU alone is used, then it is best administered by continuous infusion. In the preoperative setting, the use of adjuvant therapy depends on the clinical stage and the need for sphincter preservation. Phase I/II trials examining the use of newer chemotherapeutic agents such as Tomudex, UFT/leucovorin, CPT-11, oxaliplatin, eniluracil and capecitabine with preoperative radiation therapy are in progress. This review examines both the selection criteria and results of adjuvant combined modality therapy for patients with clinically resectable rectal cancer.