title: Impact of age on efficacy of postoperative oxaliplatin-based chemotherapy in patients with rectal cancer after neoadjuvant chemoradiotherapy.
abstract: BACKGROUND
  Clinical practice guidelines focusing on age-related adjuvant chemotherapy for rectal cancer are currently limited. The present study aimed to explore the impact of age on the efficacy of adjuvant oxaliplatin-based chemotherapy in patients with rectal cancer after neoadjuvant chemoradiotherapy.
  
  
  METHODS
  We performed a retrospective cohort analysis using data from the Surveillance, Epidemiology, and End Results-Medicare-linked database from 1992-2009. We enrolled patients with yp stages I-III rectal cancer who received neoadjuvant chemoradiotherapy and underwent curative resection. The age-related survival benefit of adding oxaliplatin to adjuvant 5-fluorouracil (5-FU) chemotherapy was evaluated using Kaplan-Meier survival analysis with propensity score-matching and Cox proportional hazards models.
  
  
  RESULTS
  Comparing the oxaliplatin group with the 5-FU group, there were significant interactions between age and chemotherapy efficacy in terms of overall survival (OS) (p for interaction = 0.017) among patients with positive lymph nodes (ypN+). Adding oxaliplatin to 5-FU could prolong survival in patients aged < 73 years and ypN+ category, and but did not translate into survival benefits in patients aged ≥ 73 years and ypN+ category. No significant interactions were observed among ypN- patients, and oxaliplatin did not significantly improve OS, regardless of age.
  
  
  CONCLUSIONS
  In patients with rectal cancer who have already received neoadjuvant chemoradiotherapy and undergone curative resection, adding oxaliplatin to 5-FU could prolong OS in patients aged < 73 years and ypN+ category. However, adding oxaliplatin did not translate into survival benefits in patients age ≥ 73 years and ypN+ category, or in ypN- patients.
authors.affiliation: Department of Chemotherapy and Radiotherapy, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Lucheng District, Wenzhou City 325027, P.R. China.|Department of Surgical Oncology and General Surgery, The First Hospital of China Medical University, Heping District, Shenyang City 110001, P.R. China.
authors.forename: Xuan-Zhang
authors.initials: XZ
authors.lastname: Huang
authors.affiliation: Department of Surgical Oncology and General Surgery, The First Hospital of China Medical University, Heping District, Shenyang City 110001, P.R. China.
authors.forename: Peng
authors.initials: P
authors.lastname: Gao
authors.affiliation: Department of Surgical Oncology and General Surgery, The First Hospital of China Medical University, Heping District, Shenyang City 110001, P.R. China.
authors.forename: Yong-Xi
authors.initials: YX
authors.lastname: Song
authors.affiliation: Department of Surgical Oncology and General Surgery, The First Hospital of China Medical University, Heping District, Shenyang City 110001, P.R. China.
authors.forename: Jing-Xu
authors.initials: JX
authors.lastname: Sun
authors.affiliation: Department of Surgical Oncology and General Surgery, The First Hospital of China Medical University, Heping District, Shenyang City 110001, P.R. China.
authors.forename: Xiao-Wan
authors.initials: XW
authors.lastname: Chen
authors.affiliation: Department of Surgical Oncology and General Surgery, The First Hospital of China Medical University, Heping District, Shenyang City 110001, P.R. China.
authors.forename: Jun-Hua
authors.initials: JH
authors.lastname: Zhao
authors.affiliation: Department of Surgical Oncology and General Surgery, The First Hospital of China Medical University, Heping District, Shenyang City 110001, P.R. China.
authors.forename: Bin
authors.initials: B
authors.lastname: Ma
authors.affiliation: Department of Surgical Oncology and General Surgery, The First Hospital of China Medical University, Heping District, Shenyang City 110001, P.R. China.
authors.forename: Jun
authors.initials: J
authors.lastname: Wang
authors.affiliation: Department of Surgical Oncology and General Surgery, The First Hospital of China Medical University, Heping District, Shenyang City 110001, P.R. China.
authors.forename: Zhen-Ning
authors.initials: ZN
authors.lastname: Wang
mesh_terms: D000367:Age Factors; D000368:Aged; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use*; D059248:Chemoradiotherapy; D005260:Female; D005472:Fluorouracil / Q000008:administration & dosage; D006801:Humans; D053208:Kaplan-Meier Estimate; D008207:Lymphatic Metastasis; D008297:Male; D020360:Neoadjuvant Therapy; D009944:Organoplatinum Compounds / Q000008:administration & dosage; D017063:Outcome Assessment, Health Care / Q000379:methods* / Q000706:statistics & numerical data; D000077150:Oxaliplatin; D011184:Postoperative Period; D057216:Propensity Score; D016016:Proportional Hazards Models; D012004:Rectal Neoplasms / Q000473:pathology / Q000628:therapy*
chemical_list: D009944:Organoplatinum Compounds; D000077150:Oxaliplatin; D005472:Fluorouracil
keywords: SEER program; adjuvant chemotherapy; age; elderly; rectal cancer