title: Meta-analysis of survival based on resection margin status following surgery for recurrent rectal cancer.
abstract: OBJECTIVE
  To determine the presence and duration of survival advantages was investigated for resection margin status (R0, R1 or R2) following surgery for locally recurrent rectal cancer (LRRC).
  
  
  METHODS
  A systematic review of the literature was performed for studies comparing resection margin status for LRRC. Weighted mean differences and meta-analysis of hazard ratios were used as a measure of median and overall cumulative survival.
  
  
  RESULTS
  Twenty-two studies were included, providing outcome for 1460 patients undergoing surgery for LRRC. 57% underwent an R0 resection, 25% an R1 resection and 11% an R2 resection. The most commonly performed operations were abdominoperineal excision (35%), exenteration (23%) and anterior resection (21%). The range of median survival per resection margin was R0 28-92 months, R1 12-50 months, R2 6-17 months. Patients undergoing an R0 resection survived on average for 37.6 (95% confidence interval: 23.5-51.7) months longer than those undergoing R1 resection and 53.0 (31.2-74.8) months longer than those undergoing R2 resection. This correlated to a hazard ratio of 2.03 (1.73-2.38) for R0 vs R1 and 3.41 (2.21-5.25) for R0 vs R2. Patients undergoing R1 resection survived on average 13.3 (7.23-19.4) months longer than those undergoing R2 resection [hazard ratio of 1.68 (1.33-2.12)].
  
  
  CONCLUSIONS
  Patients undergoing R0 resection have the greatest survival advantage following surgery for recurrent rectal cancer. There is a survival advantage for R1 over R2 resection, but there may be no benefit of R2 resection over palliative treatment.
authors.affiliation: Department of Colorectal Surgery, Royal Marsden Hospital, Fulham Road, London, UK.
authors.forename: A
authors.initials: A
authors.lastname: Bhangu
authors.forename: S M
authors.initials: SM
authors.lastname: Ali
authors.forename: A
authors.initials: A
authors.lastname: Darzi
authors.forename: G
authors.initials: G
authors.lastname: Brown
authors.forename: P
authors.initials: P
authors.lastname: Tekkis
mesh_terms: D016001:Confidence Intervals; D006801:Humans; D009364:Neoplasm Recurrence, Local / Q000601:surgery*; D018365:Neoplasm, Residual; D012004:Rectal Neoplasms / Q000601:surgery*; D016019:Survival Analysis