Which is the best postoperative chemotherapy regimen in patients with rectal cancer after neoadjuvant therapy?
Menée à partir des données des registres américains des cancers et de la base Medicare portant sur 1 535 patients atteints d'un carcinome primitif du rectum de stade I à III traité par chimioradiothérapie néoadjuvante et chirurgie curative (âge : plus de 65 ans), cette étude compare, du point de vue de la survie spécifique et en fonction du stade de la maladie, l'efficacité d'une chimiothérapie adjuvante à base de 5-fluorouracile en combinaison ou non avec l'oxaliplatine
Background : There is no general agreement about whether patients who have already received neoadjuvant chemoradiotherapy need further postoperative chemotherapy based on 5-fluorouracil(5-FU) or 5-FU plus oxaliplatin. Methods : Medicare beneficiaries from 1992 to 2008 with Union for International Cancer Control ypStages I to III primary carcinoma of the rectum who underwent 5-FU-based neoadjuvant chemoradiotherapy and surgery for curative intent were identified through the Surveillance, Epidemiology, and End Results (SEER)-Medicare-linked database. A Cox proportional hazards model and propensity score-matched techniques were used to evaluate the effect of treatment on survival. Results : For patients with resected rectal cancer who have already received 5-FU-based neoadjuvant chemoradiotherapy, postoperative 5-FU-based chemotherapy did not prolong cancer-specific survival (CSS) in ypStage I (P = 0.960) and ypStage II (P = 0.134); however, it significantly improved the CSS in ypStage III (hazard ratio = 1.547, 95% CI = 1.101-2.173, P = 0.012). No significant differences in survival between the 5-FU group and oxaliplatin group were observed. Conclusions : For patients with resected rectal cancer who have already received 5-FU-based neoadjuvant chemoradiotherapy, postoperative 5-FU-based chemotherapy prolongs the CSS of groups in ypStage III. Adding oxaliplatin to fluoropyrimidines in the postoperative chemotherapy did not improve the CSS for patients who received neoadjuvant chemoradiotherapy.