title: Which is the best postoperative chemotherapy regimen in patients with rectal cancer after neoadjuvant therapy?
abstract: 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.
authors.forename: Peng
authors.initials: P
authors.lastname: Gao
authors.forename: Yong-xi
authors.initials: YX
authors.lastname: Song
authors.forename: Jing-xu
authors.initials: JX
authors.lastname: Sun
authors.forename: Xiao-wan
authors.initials: XW
authors.lastname: Chen
authors.forename: Ying-ying
authors.initials: YY
authors.lastname: Xu
authors.forename: Jun-hua
authors.initials: JH
authors.lastname: Zhao
authors.forename: Xuan-zhang
authors.initials: XZ
authors.lastname: Huang
authors.forename: Hui-mian
authors.initials: HM
authors.lastname: Xu
authors.affiliation: Department of Surgical Oncology and General Surgery, the First Hospital of China Medical University, 155 North Nanjing Street, Heping District, Shenyang 110001, PR China. josieon826@sina.cn.
authors.forename: Zhen-ning
authors.initials: ZN
authors.lastname: Wang
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use*; D003131:Combined Modality Therapy; D066264:Datasets as Topic; D005260:Female; D006801:Humans; D008297:Male; D020360:Neoadjuvant Therapy; D060787:Neoplasm Grading; D009362:Neoplasm Metastasis; D009367:Neoplasm Staging; D012004:Rectal Neoplasms / Q000188:drug therapy* / Q000401:mortality / Q000473:pathology / Q000601:surgery; D018426:SEER Program; D016896:Treatment Outcome