The impact of capecitabine and oxaliplatin in the preoperative multimodality treatment in patients with carcinoma of the rectum: NSABP R-04.

3503 Background: The optimal chemotherapy regimen to be given concurrently with preop radiation therapy (RT) in patients with resectable adenocarcinoma of the rectum is unknown. NSABP R-04 compared the efficacy of 4 chemotherapy regimens administered concomitantly with preop RT. Methods: Patients with clinical stage II or III rectal cancer undergoing preop RT (4,500cGy in 25 fractions over 5 wk + boost of 540cGy-1080cGy in 3-6 daily fractions) were randomly assigned to one of the following chemotherapy regimens: continuous IV infusion (CVI) 5-FU (225mg/m2 5 days/wk), with or without IV oxaliplatin (OX) (50mg/m2 /wk x 5); oral capecitabine (CAPE) (825 mg/m2 BID 5 days/wk), with or without OX (50mg/m2/wk x 5). Prior to random assignment the surgeon indicated if the patient was eligible for sphincter-saving surgery (SSS) based on clinical staging. The endpoints were complete pathologic response (pCR), SSS, and surgical downstaging (SD, conversion to SSS). Results: From July 2004 to August 2010, 1,608 patient...