title: Postoperative adjuvant chemotherapy for stage II colorectal cancer: a systematic review of 12 randomized controlled trials.
abstract: BACKGROUND
  The impact of postoperative adjuvant chemotherapy on the oncological outcomes for stage II colorectal cancer remains controversial.
  
  
  METHODS
  The literature was searched for studies published between 1985 and 2010 in which patients with stage II colorectal cancer were randomly assigned to receive either surgery combined with postoperative adjuvant chemotherapy or surgery alone. End points included 5-year overall survival, 5-year disease-free survival, recurrence, and mortality.
  
  
  RESULTS
  A significant improvement in 5-year overall survival was associated with surgery combined with postoperative adjuvant chemotherapy for stage II colon cancer (hazard ratio, 0.81; 95% confidence interval (CI), 0.71-0.91) and for stage II rectal cancer (hazard ratio, 0.72; 95% CI, 0.61-0.86). The 5-year disease-free survival also favored the group of surgery combined with postoperative adjuvant chemotherapy for stage II colon cancer (hazard ratio, 0.86; 95% CI, 0.75-0.98) and for stage II rectal cancer (hazard ratio, 0.34; 95% CI, 0.22-0.51). For stage II colon cancer, a significant reduction in risk of recurrence was found in favor of postoperative adjuvant chemotherapy (risk ratio, 0.82; 95% CI, 0.71-0.95).
  
  
  CONCLUSIONS
  Postoperative adjuvant chemotherapy for stage II colorectal cancer appears to be associated with improved 5-year overall survival and 5-year disease-free survival, and reduction in risk of recurrence.
authors.affiliation: Department of Colorectal Surgery, The Sixth Affiliated Hospital, Sun Yat-sen University, Guangzhou, 510655, China.
authors.forename: Xiaojian
authors.initials: X
authors.lastname: Wu
authors.forename: Junxiao
authors.initials: J
authors.lastname: Zhang
authors.forename: Xiaosheng
authors.initials: X
authors.lastname: He
authors.forename: Chenliang
authors.initials: C
authors.lastname: Wang
authors.forename: Lei
authors.initials: L
authors.lastname: Lian
authors.forename: Huanliang
authors.initials: H
authors.lastname: Liu
authors.forename: Jianping
authors.initials: J
authors.lastname: Wang
authors.forename: Ping
authors.initials: P
authors.lastname: Lan
mesh_terms: D000970:Antineoplastic Agents / Q000627:therapeutic use*; D017024:Chemotherapy, Adjuvant; D003082:Colectomy; D015179:Colorectal Neoplasms / Q000188:drug therapy* / Q000473:pathology / Q000601:surgery; D006801:Humans; D009367:Neoplasm Staging; D011182:Postoperative Care / Q000379:methods*; D016032:Randomized Controlled Trials as Topic; D016896:Treatment Outcome
chemical_list: D000970:Antineoplastic Agents