Rectal cancer is a common cancer in the country and in the world. The rates of T3, T4 lower rectal cancer patients are high
therefore, neoadjuvant chemoradiotherapy is needed to downstage for easier surgery. In Vietnam, the method of radiation therapy combined with capecitabine for locally advanced low rectal cancer (LALRC) patients has been used since 2009. Aims: Evalate the tumor regression after neoadjuvant chemoradiation for locally advanced low rectal cancer. Subjects and Methods: Clinical intervention study without control on 87 LALRC patients who were treated by neoadjuvant radiotherapy 46Gy + capecitabine 82Smg/m2, p.o, twice a day at The Center of Nuclear Medicine and Oncology, Bach Mai Hospital and Department of Radiation 4, K Hospital from 6/2009-12/2012. Results: 90.8 percent of patients achieved response after treatment and 9.2 percent of them had complete response. 79.3 percent patients underwent surgery in which 67.8 percent patients with radical surgery, 12.6 percent patients underwent anal sphincter preserving surgery. 62.1 percent of patients assessed response rate on postoperative histopathology and the tumor regression grade after treatment: grade 0: 0 percent
grade 1: 38.9 percent, grade 2:,29.6 percent, grade 3: 16.7 percent, grade 4: 14.8 percent. There are no factors that significantly influence on tumor regression. Conclusion: After preoperative chemoradiotherapy for rectal cancer patients, the tumor regression mainly were 50 percent.