Patient selection for neoadjuvant therapy of rectal adenocarcinoma

Rectal adenocarcinomas are typically treated with a combination of radiotherapy, chemotherapy, and surgical resection. Risk factors for local recurrence include tumor stage, nodal stage, tumor location, circumferential resection margin status, and surgical technique. Most patients receive pre-operative therapy based on staging evaluations using endorectal ultrasound and/or pelvic MRI. Pre-operative therapy is recommended for any patient with T3-4 disease or nodal involvement. Subgroups of patients defined by combinations of stage and tumor location are at very low risk for local recurrence after surgery alone and may benefit from initial surgery followed by selective post-operative therapy based on pathologic results. Prospective studies are needed to validate therapy de-intensification approaches.