title: Complete pathologic response after combined modality treatment for rectal cancer and long-term survival: a meta-analysis.
abstract: BACKGROUND
  Complete pathologic response (CPR) after neoadjuvant chemoradiotherapy (combined modality treatment, CMT) for rectal cancer seems associated with improved survival compared to partial or no response (NPR). However, previous reports have been limited by small sample size and single-institution design.
  
  
  METHODS
  A systematic literature review was conducted to detect studies comparing long-term results of patients with CPR and NPR after CMT for rectal cancer. Variables were pooled only if evaluated by 3 or more studies. Study end points included rates of CPR, local recurrence (LR), distant recurrence (DR), 5-year overall survival (OS), and disease-free survival (DFS).
  
  
  RESULTS
  Twelve studies (1,913 patients) with rectal cancer treated with CMT were included. CPR was observed in 300 patients (15.6%). CPR and NPR patient groups were similar with respect to age, sex, tumor size, distance of tumor from the anus, and stage of disease before treatment. Median follow-up ranged from 23 to 46 months. CPR patients had lower rates of LR [0.7% vs. 2.6%; odds ratio (OR) 0.45, 95% confidence interval (CI) 0.22-0.90, P = 0.03], DR (5.3% vs. 24.1%; OR 0.15, 95% CI 0.07-0.31, P = 0.0001), and simultaneous LR + DR (0.7% vs. 4.8%; OR 0.32, 95% CI 0.13-0.79, P = 0.01). OS was 92.9% for CPR versus 73.4% for NPR (OR 3.6, 95% CI 1.84-7.22, P = 0.002), and DFS was 86.9% versus 63.9% (OR 3.53, 95% CI 1.62-7.72, P = 0.002).
  
  
  CONCLUSIONS
  CPR after CMT for rectal cancer is associated with improved local and distal control as well as better OS and DFS.
authors.affiliation: Department of Surgery, University of Cagliari, Cagliari, Italy.
authors.forename: Luigi
authors.initials: L
authors.lastname: Zorcolo
authors.forename: Alan S
authors.initials: AS
authors.lastname: Rosman
authors.forename: Angelo
authors.initials: A
authors.lastname: Restivo
authors.forename: Michele
authors.initials: M
authors.lastname: Pisano
authors.forename: Giuseppe R
authors.initials: GR
authors.lastname: Nigri
authors.forename: Alessandro
authors.initials: A
authors.lastname: Fancellu
authors.forename: Marcovalerio
authors.initials: M
authors.lastname: Melis
mesh_terms: D000230:Adenocarcinoma / Q000473:pathology* / Q000556:secondary / Q000601:surgery / Q000628:therapy*; D000368:Aged; D059186:Chemoradiotherapy, Adjuvant; D016001:Confidence Intervals; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D020360:Neoadjuvant Therapy; D009364:Neoplasm Recurrence, Local / Q000473:pathology*; D009367:Neoplasm Staging; D016017:Odds Ratio; D012004:Rectal Neoplasms / Q000473:pathology* / Q000601:surgery / Q000628:therapy*; D015996:Survival Rate