title: A systematic review of cancer related patient outcomes after anterior resection and abdominoperineal excision for rectal cancer in the total mesorectal excision era.
abstract: OBJECTIVE
  It is a widely held view that anterior resection (AR) for rectal cancer is an oncologically superior operation to abdominoperineal excision (APE). However, some centres have demonstrated better outcomes with APE. We conducted a systematic review of high-quality studies within the total mesorectal excision (TME) era comparing outcomes of AR and APE.
  
  
  METHODS
  A literature search was performed to identify studies within the TME era comparing AR and APE with regard to the following: circumferential resection margin (CRM) status, tumour perforation rates, specimen quality, local recurrence, overall survival (OS; 3 or 5 year), cancer-specific survival (CSS) and disease-free survival (DFS). Additional data regarding patient demographics and tumour characteristics was collected.
  
  
  RESULTS
  Twenty four studies fulfilled the eligibility criteria with Newcastle-Ottawa scores of six or greater. Where a significant difference was found, all studies reported lower and more advanced tumours for APE and 4/5 studies observed more frequent use of neoadjuvant and adjuvant therapies in APE patients. Tumour perforation rates and CRM involvement where reported, were significantly greater for APE. 8 out of 10 studies showing significant differences in local recurrence reported higher rates for APE but no differences were observed with distant recurrence. Where differences were noted, AR was reported to have increased DFS, CSS and OS compared to APE.
  
  
  CONCLUSIONS
  Patients treated with AR have lower rates of tumour perforation and CRM involvement and tend to have better outcomes with regard to disease recurrence and survival. However, tumours treated by APE are lower and more locally advanced.
authors.affiliation: Pelican Cancer Foundation, The Ark, Dinwoodie Drive, Basingstoke, RG24 9NN, UK. pd_how@hotmail.com
authors.forename: P
authors.initials: P
authors.lastname: How
authors.forename: O
authors.initials: O
authors.lastname: Shihab
authors.forename: P
authors.initials: P
authors.lastname: Tekkis
authors.forename: Gina
authors.initials: G
authors.lastname: Brown
authors.forename: P
authors.initials: P
authors.lastname: Quirke
authors.forename: R
authors.initials: R
authors.lastname: Heald
authors.forename: B
authors.initials: B
authors.lastname: Moran
mesh_terms: D000005:Abdomen / Q000473:pathology / Q000601:surgery*; D013505:Digestive System Surgical Procedures; D006801:Humans; D011379:Prognosis; D012004:Rectal Neoplasms / Q000401:mortality / Q000473:pathology / Q000601:surgery*; D012007:Rectum / Q000473:pathology / Q000601:surgery*; D012196:Review Literature as Topic; D015996:Survival Rate