title: Interim endoscopy results during neoadjuvant therapy for gastric cancer correlate with histopathological response and prognosis.
abstract: BACKGROUND
  Neoadjuvant chemotherapy for locally advanced gastric cancer leads to major histopathological response in less than 30 % of patients. Data on interim endoscopic response assessment do not exist. This exploratory prospective study evaluates early endoscopy after 50 % of the chemotherapy as predictor for later response and prognosis.
  
  
  METHODS
  Forty-seven consecutive patients were included (45 resected; 33 R0 resections). All patients received baseline endoscopy and CT scans, after 50 % of their chemotherapy (EGD-1, CT-1) and after completion of chemotherapy (EGD-2, CT-2). Interim endoscopic response (EGD-1) was assessed after having received 50 % (6 weeks) of the planned 12 weeks of neoadjuvant chemotherapy. Post-chemotherapy response was clinically assessed by a combination of CT scan (CT-2) and endoscopy (EGD-2). Histopathological response was determined by a standardized scoring system (Becker criteria). Endoscopic response was defined as a reduction of >75 % of the tumor mass.
  
  
  RESULTS
  Twelve patients were responders at EGD-1 and 13 at EGD-2. Nine patients (19.1 %) were clinical responders and 7 patients (15.6 %) were histopathological responders after chemotherapy. Specificity, accuracy, and negative predictive value of the interim EGD-1 for subsequent histopathological response were 31/38 (82 %), 36/47 (76 %), and 31/33 (93 %); and for recurrence or death, 28/30 (93.3 %), 38/47 (80.9 %), and 28/35 (80.0 %). Response at EGD-1 was significantly associated with histopathological response (p = 0.010), survival (p < 0.001), and recurrence-free survival (p = 0.009).
  
  
  CONCLUSIONS
  Interim endoscopy after 6 weeks predicts response and prognosis. Therefore, tailoring treatment according to interim endoscopic assessment could be feasible, but the findings of this study should be validated in a larger patient cohort.
authors.affiliation: Department of Surgery, University of Heidelberg, Im Neuenheimer Feld 110, 69120, Heidelberg, Germany.
authors.forename: Ulrike
authors.initials: U
authors.lastname: Heger
authors.forename: Franz
authors.initials: F
authors.lastname: Bader
authors.forename: Florian
authors.initials: F
authors.lastname: Lordick
authors.forename: Maria
authors.initials: M
authors.lastname: Burian
authors.forename: Rupert
authors.initials: R
authors.lastname: Langer
authors.forename: Martin
authors.initials: M
authors.lastname: Dobritz
authors.forename: Susanne
authors.initials: S
authors.lastname: Blank
authors.forename: Thomas
authors.initials: T
authors.lastname: Bruckner
authors.forename: Karen
authors.initials: K
authors.lastname: Becker
authors.forename: Ken
authors.initials: K
authors.lastname: Herrmann
authors.forename: Jörg-Rüdiger
authors.initials: JR
authors.lastname: Siewert
authors.forename: Katja
authors.initials: K
authors.lastname: Ott
mesh_terms: D000328:Adult; D000368:Aged; D000970:Antineoplastic Agents / Q000008:administration & dosage / Q000627:therapeutic use*; D005260:Female; D005773:Gastroscopy / Q000379:methods*; D006801:Humans; D008297:Male; D008875:Middle Aged; D020360:Neoadjuvant Therapy / Q000379:methods*; D009364:Neoplasm Recurrence, Local; D011237:Predictive Value of Tests; D011379:Prognosis; D011446:Prospective Studies; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013274:Stomach Neoplasms / Q000473:pathology / Q000628:therapy*; D015996:Survival Rate; D013997:Time Factors; D014057:Tomography, X-Ray Computed / Q000379:methods; D016896:Treatment Outcome
chemical_list: D000970:Antineoplastic Agents