title: Patterns of response after preoperative treatment in gastric cancer.
abstract: OBJECTIVE
  To analyze the rate of pathologic response in patients with locally advanced gastric cancer treated with preoperative chemotherapy with and without chemoradiation at our institution.
  
  
  METHODS
  From 2000 to 2007 patients were retrospectively identified who received preoperative treatment for gastric cancer (cT3-4/ N+) with induction chemotherapy (Ch) or with Ch followed by concurrent chemoradiotherapy (45 Gy in 5 weeks) (ChRT). Surgery was planned 4-6 weeks after the completion of neoadjuvant treatment. Pathologic assessment was used to investigate the patterns of pathologic response after neoadjuvant treatment.
  
  
  RESULTS
  Sixty-one patients were analyzed. Of 61 patients, 58 (95%) underwent surgery. The R0 resection rate was 87%. Pathologic complete response was achieved in 12% of the patients. A major pathologic response (<10% of residual tumor) was observed in 53% of patients, and T downstaging was observed in 75%. Median follow-up was 38.7 months. Median disease-free survival (DFS) was 36.5 months. The only patient-, tumor-, and treatment-related factor associated with pathologic response was the use of preoperative ChRT. Patients achieving major pathologic response had a 3-year actuarial DFS rate of 63%.
  
  
  CONCLUSIONS
  The patterns of pathologic response after preoperative ChRT suggest encouraging intervals of DFS. Such a strategy may be of interest to be explored in gastric cancer.
authors.affiliation: Division of Radiation Oncology, Clínica Universidad de Navarra, Pamplona, Spain. jadiaz@unav.es
authors.forename: Juan A
authors.initials: JA
authors.lastname: Díaz-González
authors.forename: Javier
authors.initials: J
authors.lastname: Rodríguez
authors.forename: José L
authors.initials: JL
authors.lastname: Hernández-Lizoain
authors.forename: Raquel
authors.initials: R
authors.lastname: Ciérvide
authors.forename: Miren
authors.initials: M
authors.lastname: Gaztañaga
authors.forename: Iñigo
authors.initials: I
authors.lastname: San Miguel
authors.forename: Leire
authors.initials: L
authors.lastname: Arbea
authors.forename: J Javier
authors.initials: JJ
authors.lastname: Aristu
authors.forename: Ana
authors.initials: A
authors.lastname: Chopitea
authors.forename: Fernando
authors.initials: F
authors.lastname: Martínez-Regueira
authors.forename: Víctor
authors.initials: V
authors.lastname: Valentí
authors.forename: Jesús
authors.initials: J
authors.lastname: García-Foncillas
authors.forename: Rafael
authors.initials: R
authors.lastname: Martínez-Monge
authors.forename: Jesús J
authors.initials: JJ
authors.lastname: Sola
mesh_terms: D000971:Antineoplastic Combined Chemotherapy Protocols / Q000009:adverse effects / Q000627:therapeutic use*; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D020360:Neoadjuvant Therapy / Q000009:adverse effects / Q000379:methods*; D009367:Neoplasm Staging; D018365:Neoplasm, Residual; D012074:Remission Induction; D012189:Retrospective Studies; D013274:Stomach Neoplasms / Q000188:drug therapy* / Q000473:pathology* / Q000532:radiotherapy / Q000601:surgery; D016896:Treatment Outcome