Predicting the node-negative mesorectum after preoperative chemoradiation for locally advanced rectal carcinoma

Preoperative chemoradiation therapy (CRT) in patients with locally advanced rectal cancer allows for radical surgery with sphincter preservation in many patients. To determine whether patients downsized with preoperative CRT may be potential candidates for local excision, we investigated residual disease patterns after neoadjuvant treatment. A retrospective analysis was carried out of patients with T3 or T4 rectal adenocarcinoma who were treated with neoadjuvant CRT. Clinical and pathologic data were analyzed to (1). determine the response rates to preoperative CRT in the tumor bed and regional nodal basin and (2). identify the incidence of residual disease in the mesorectum in patients downsized to