title: Primary localized rectal/pararectal gastrointestinal stromal tumors: results of surgical and multimodal therapy from the French Sarcoma group.
abstract: BACKGROUND
  Rectal and pararectal gastrointestinal stromal tumors (GISTs) are rare. The optimal management strategy for primary localized GISTs remains poorly defined.
  
  
  METHODS
  We conducted a retrospective analysis of 41 patients with localized rectal or pararectal GISTs treated between 1991 and 2011 in 13 French Sarcoma Group centers.
  
  
  RESULTS
  Of 12 patients who received preoperative imatinib therapy for a median duration of 7 (2-12) months, 8 experienced a partial response, 3 had stable disease, and 1 had a complete response. Thirty and 11 patients underwent function-sparing conservative surgery and abdominoperineal resection, respectively. Tumor resections were mostly R0 and R1 in 35 patients. Tumor rupture occurred in 12 patients. Eleven patients received postoperative imatinib with a median follow-up of 59 (2.4-186) months. The median time to disease relapse was 36 (9.8-62) months. The 5-year overall survival rate was 86.5%. Twenty patients developed local recurrence after surgery alone, two developed recurrence after resection combined with preoperative and/or postoperative imatinib, and eight developed metastases. In univariate analysis, the mitotic index (≤5) and tumor size (≤5 cm) were associated with a significantly decreased risk of local relapse. Perioperative imatinib was associated with a significantly reduced risk of overall relapse and local relapse.
  
  
  CONCLUSIONS
  Perioperative imatinib therapy was associated with improved disease-free survival. Preoperative imatinib was effective. Tumor shrinkage has a clear benefit for local excision in terms of feasibility and function preservation. Given the complexity of rectal GISTs, referral of patients with this rare disease to expert centers to undergo a multidisciplinary approach is recommended.
authors.affiliation: Service d'Oncologie Médicale, CHU Timone, AP-HM, Marseille, and Aix-Marseille Université, Marseille, France. thanh-khoa.huynh@mail.ap-hm.fr.
authors.forename: Thanh-Khoa
authors.initials: TK
authors.lastname: Huynh
authors.forename: Pierre
authors.initials: P
authors.lastname: Meeus
authors.forename: Philippe
authors.initials: P
authors.lastname: Cassier
authors.forename: Olivier
authors.initials: O
authors.lastname: Bouché
authors.forename: Sophie
authors.initials: S
authors.lastname: Lardière-Deguelte
authors.forename: Antoine
authors.initials: A
authors.lastname: Adenis
authors.forename: Thierry
authors.initials: T
authors.lastname: André
authors.forename: Julien
authors.initials: J
authors.lastname: Mancini
authors.forename: Olivier
authors.initials: O
authors.lastname: Collard
authors.forename: Michael
authors.initials: M
authors.lastname: Montemurro
authors.forename: Emmanuelle
authors.initials: E
authors.lastname: Bompas
authors.forename: Maria
authors.initials: M
authors.lastname: Rios
authors.forename: Nicolas
authors.initials: N
authors.lastname: Isambert
authors.forename: Didier
authors.initials: D
authors.lastname: Cupissol
authors.forename: Jean-Yves
authors.initials: JY
authors.lastname: Blay
authors.forename: Florence
authors.initials: F
authors.lastname: Duffaud
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003131:Combined Modality Therapy; D005260:Female; D005602:France; D046152:Gastrointestinal Stromal Tumors / Q000175:diagnosis / Q000401:mortality / Q000473:pathology* / Q000628:therapy; D006801:Humans; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local; D009367:Neoplasm Staging; D017063:Outcome Assessment, Health Care; D011379:Prognosis; D012004:Rectal Neoplasms / Q000175:diagnosis / Q000401:mortality / Q000473:pathology* / Q000628:therapy; D012307:Risk Factors