Complete Neoadjuvant Treatment For Rectal Cancer: A Single Institution Experience

148 Background: Full dose adjuvant chemotherapy following preoperative chemoradiation and surgery is poorly tolerated in stage II and III rectal cancer. We reviewed our institution’s experience with complete neoadjuvant treatment for rectal cancer since publication of the BrUOG R-224 trial results. Methods: After obtaining IRB approval, Data on patients with stage II and III rectal cancer who underwent complete neoadjuvant therapy were collected.. Patients who were planned to receive 8 cycles of modified FOLFOX6, chemoradiation with capecitabine 825 mg/m2 twice daily and 50.4 Gy intensity-modulated radiation therapy, then surgery were included. Results: Thirty-five patients were treated with complete neoadjuvant therapy between January 2014 and December 2017. Median age was 58 years (27 to 75 y); 1 patient (3%) was clinical stage II and 34 (97%) stage III. Twenty-seven patients (77%) received all 8 cycles of mFOLFOX6, of whom 24 completed subsequent chemoradiation. Therefore 69% of patients completed therapy according to the BrUOG R-224 protocol. Pathologic complete response (ypT0N0) was observed in 9 patients (26%). Treatment related toxicities resulted in dose reductions or treatment interruption in 57% and 29% of patients receiving chemotherapy and chemoradiation respectively. Conclusions: Complete neoadjuvant therapy for clinical stage II to III rectal cancer is well-tolerated in routine practice and offers an alternative to preoperative chemoradiation, surgery, then adjuvant full dose chemotherapy.