Mi Joo Chung1, Joo Hwan Lee2, Jong Hoon Lee3, Sung Hwan Kim2, Jin Ho Song4, Songmi Jeong5, Mina Yu6, Taek Keun Nam7, Jae Uk Jeong7, Hong Seok Jang8. 1. Department of Radiation Oncology, Kyung Hee University Hospital at Gangdong, Seoul, Republic of Korea. 2. Center for Colorectal Cancer, St. Vincent's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea. 3. Center for Colorectal Cancer, St. Vincent's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea. Electronic address: koppul@catholic.ac.kr. 4. Department of Radiation Oncology, Gyeongsang National University School of Medicine and Gyeongsang National University Hospital, Jinju, Republic of Korea. 5. Department of Radiation Oncology, Ewha Woman's University School of Medicine, Seoul, Republic of Korea. 6. Department of Radiation Oncology, Bucheon St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea. 7. Department of Radiation Oncology, Chonnam National University Hospital, Hwasun, Republic of Korea. 8. Department of Radiation Oncology, Seoul St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea.
Abstract
PURPOSE: The role of adjuvant chemotherapy after preoperative chemoradiation therapy (CRT) and curative surgery in rectal cancer has yet to be definitely determined. We performed a retrospective and multicenter study to evaluate whether adjuvant chemotherapy (AC) could reduce recurrence and improve survival in locally advanced rectal cancer. METHODS AND MATERIALS: We analyzed data from 8 tertiary institutions for 1442 patients with rectal cancer who underwent preoperative CRT and total mesorectal excision. Patients were classified into 2 groups: the AC group (patients who received chemotherapy after surgery) and the observation group (those who did not receive chemotherapy after surgery). Propensity-score matching was used to assess the exact role of AC. The AC group was then subdivided to investigate the impact of adding oxaliplatin to 5-fluorouracil (5-FU). Group 1 was treated with 5-FU/folinic acid or capecitabine without oxaliplatin, and group 2 received 5-FU/folinic acid or capecitabine with oxaliplatin. RESULTS: The 3-year relapse-free survival rates in the AC and observation groups were 85.9% and 84.3%, respectively (P = .532). The 3-year overall survival rates in the AC and observation groups were 94.9% and 89.9%, respectively (P = .123). The rates of locoregional recurrence (2.2% vs 3.2%, P = .294) and distant metastasis (12.4% vs 12.9%, P = .927) at 3 years were not significantly different between the two groups. The 3-year relapse-free survival rates of group 1 and group 2 were 71.5% and 74.8%, respectively (P = .426). The 3-year overall survival rates of group 1 and group 2 were 89.9% and 96.5%, respectively (P = .102). CONCLUSIONS: This multicenter study found insufficient evidence to support the use of 5-FU-based AC after preoperative CRT and curative surgery in rectal cancer.
PURPOSE: The role of adjuvant chemotherapy after preoperative chemoradiation therapy (CRT) and curative surgery in rectal cancer has yet to be definitely determined. We performed a retrospective and multicenter study to evaluate whether adjuvant chemotherapy (AC) could reduce recurrence and improve survival in locally advanced rectal cancer. METHODS AND MATERIALS: We analyzed data from 8 tertiary institutions for 1442 patients with rectal cancer who underwent preoperative CRT and total mesorectal excision. Patients were classified into 2 groups: the AC group (patients who received chemotherapy after surgery) and the observation group (those who did not receive chemotherapy after surgery). Propensity-score matching was used to assess the exact role of AC. The AC group was then subdivided to investigate the impact of adding oxaliplatin to 5-fluorouracil (5-FU). Group 1 was treated with 5-FU/folinic acid or capecitabine without oxaliplatin, and group 2 received 5-FU/folinic acid or capecitabine with oxaliplatin. RESULTS: The 3-year relapse-free survival rates in the AC and observation groups were 85.9% and 84.3%, respectively (P = .532). The 3-year overall survival rates in the AC and observation groups were 94.9% and 89.9%, respectively (P = .123). The rates of locoregional recurrence (2.2% vs 3.2%, P = .294) and distant metastasis (12.4% vs 12.9%, P = .927) at 3 years were not significantly different between the two groups. The 3-year relapse-free survival rates of group 1 and group 2 were 71.5% and 74.8%, respectively (P = .426). The 3-year overall survival rates of group 1 and group 2 were 89.9% and 96.5%, respectively (P = .102). CONCLUSIONS: This multicenter study found insufficient evidence to support the use of 5-FU-based AC after preoperative CRT and curative surgery in rectal cancer.