title: Preoperative Chemotherapy and Survival for Large Anorectal Gastrointestinal Stromal Tumors: A National Analysis of 333 Cases.
abstract: OBJECTIVE
  Anorectal gastrointestinal stromal tumors (GISTs) are exceedingly rare, and management remains controversial in regard to local resection (LR) and preoperative chemotherapy.
  
  
  METHODS
  The National Cancer Data Base was queried from 1998 to 2012 for cases of GIST resection in the rectum or anus. Patient demographics, type of surgery (LR vs. radical excision [RE]), short-term outcomes, and overall survival (OS) were analyzed. Preoperative chemotherapy was recorded following the US FDA approval of imatinib in 2002.
  
  
  RESULTS
  Overall, 333 patients with resection of anorectal GISTs were included. Mean age at presentation was 62.3 years (range 22-90), and median tumor size was 4.0 cm (interquartile range 2.2-7.0). Five-year OS for all patients was 77.6%. In a multivariable survival analysis, only age and tumor size >5 cm (hazard ratio 2.48, 95% confidence interval 1.50-4.01; p = 0.004) were associated with increased mortality. One hundred and sixty-three (49.0%) patients underwent LR, compared with 158 (47.4%) who underwent RE. For tumors smaller than 5 cm, no difference in 5-year survival by surgical approach was observed (LR 82.3% vs. RE 82.6%; p = 0.71). Fifty-nine patients (17.7%) received preoperative chemotherapy; for patients undergoing RE with tumors >5 cm, there was decreased mortality in the group who received preoperative chemotherapy (5-year OS with chemotherapy 79.2% vs. no chemotherapy 51.2%; p = 0.03).
  
  
  CONCLUSIONS
  Size is the most important determinant in survival following resection. Local excision is common, with resection split between LR and RE. For smaller tumors, LR may be adequate therapy. Preoperative chemotherapy may result in improved survival for large tumors treated with radical resection, but the data are imperfect.
authors.affiliation: Division of General Surgery, Section of Colon and Rectal Surgery, Washington University in St. Louis, St Louis, MO, USA.
authors.forename: Alexander T
authors.initials: AT
authors.lastname: Hawkins
authors.affiliation: Division of General Surgery, Section of Colon and Rectal Surgery, Washington University in St. Louis, St Louis, MO, USA.
authors.forename: Katerina O
authors.initials: KO
authors.lastname: Wells
authors.affiliation: Division of General Surgery, Section of Colon and Rectal Surgery, Washington University in St. Louis, St Louis, MO, USA.
authors.forename: Devi Mukkai
authors.initials: DM
authors.lastname: Krishnamurty
authors.affiliation: Division of General Surgery, Section of Colon and Rectal Surgery, Washington University in St. Louis, St Louis, MO, USA.
authors.forename: Steven R
authors.initials: SR
authors.lastname: Hunt
authors.affiliation: Division of General Surgery, Section of Colon and Rectal Surgery, Washington University in St. Louis, St Louis, MO, USA.
authors.forename: Matthew G
authors.initials: MG
authors.lastname: Mutch
authors.affiliation: Division of General Surgery, Section of Colon and Rectal Surgery, Washington University in St. Louis, St Louis, MO, USA.
authors.forename: Sean C
authors.initials: SC
authors.lastname: Glasgow
authors.affiliation: Division of General Surgery, Section of Colon and Rectal Surgery, Washington University in St. Louis, St Louis, MO, USA.
authors.forename: Paul E
authors.initials: PE
authors.lastname: Wise
authors.affiliation: Division of General Surgery, Section of Colon and Rectal Surgery, Washington University in St. Louis, St Louis, MO, USA. silvieram@wudosis.wustl.edu.
authors.forename: Matthew L
authors.initials: ML
authors.lastname: Silviera
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D000970:Antineoplastic Agents / Q000627:therapeutic use; D001005:Anus Neoplasms / Q000188:drug therapy* / Q000401:mortality / Q000473:pathology / Q000601:surgery*; D017024:Chemotherapy, Adjuvant; D005260:Female; D046152:Gastrointestinal Stromal Tumors / Q000188:drug therapy* / Q000401:mortality / Q000473:pathology / Q000601:surgery*; D006801:Humans; D000068877:Imatinib Mesylate / Q000627:therapeutic use; D008297:Male; D008875:Middle Aged; D020360:Neoadjuvant Therapy; D012004:Rectal Neoplasms / Q000188:drug therapy* / Q000401:mortality / Q000473:pathology / Q000601:surgery*; D015996:Survival Rate; D047368:Tumor Burden; D014481:United States; D055815:Young Adult
chemical_list: D000970:Antineoplastic Agents; D000068877:Imatinib Mesylate