Adjuvant Chemotherapy in Rectal Cancer Patients Treated with Preoperative Chemoradiation and Total Mesorectal Excision : A Multicenter and Retrospective Propensity-Score Matching Study
Menée à partir de données portant sur 1 442 patients atteints d'un cancer rectal de stade localement avancé, cette étude multicentrique évalue, du point de vue notamment des taux de survie sans récidive et de survie globale à trois ans, l'intérêt d'ajouter une chimiothérapie adjuvante à un traitement comportant une chimioradiothérapie suivie d'une exérèse mésorectale totale
Purpose : The role of adjuvant chemotherapy after preoperative chemoradiotherapy (CRT) and curative surgery in rectal cancer has not to be definitely determined yet. 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 1,442 patients with rectal cancer from 8 tertiary institutions who underwent preoperative CRT and total mesorectal excision. Patients were classified into two groups; the AC group consisted of patients who received chemotherapy after surgery while the observation group consisted of those who did not. 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. Group I was treated with 5-FU/folinic acid or capecitabine without oxaliplatin and group II received 5-FU/folinic acid or capecitabine with oxaliplatin. Results : The 3-year relapse-free survival (RFS) rates in the AC and observation groups were 85.9% and 84.3%, respectively (P = 0.532). The 3-year overall survival (OS) rates in the AC and observation groups were 94.9% and 89.9%, respectively (P = 0.123). The rates of locoregional recurrence (2.2% vs. 3.2%, P = 0.294) and distant metastasis (12.4% vs. 12.9%, P = 0.927) at 3 years were not significantly different between the two groups. The 3-year RFS rates of group I and group II were 71.5% and 74.8%, respectively (P = 0.426). The 3-year OS rates of group I and group II were 89.9% and 96.5%, respectively (P = 0.102). Conclusion : This multicenter study found an insufficient evidence to support the use of 5-FU-based AC after preoperative CRT and curative surgery in rectal cancer.