title: Timing of Adjuvant Chemotherapy and Impact on Survival for Resected Gastric Cancer.
abstract: Because postoperative convalescence often prolongs the interval between surgery and chemotherapy in patients undergoing treatment for advanced gastric cancer, this study assesses the survival impact of timing of adjuvant chemotherapy (AC) in patients undergoing curative resection for gastric cancer.
  
  
  
  The 2003-2012 ACS NCDB was analyzed for patients treated with gastrectomy for stages 1-3 gastric cancer. Treatment groups were stratified by time to initiation of AC: initiation of chemotherapy within 8 weeks postoperatively, between 8 and 12 weeks postoperatively, after 12 weeks postoperatively, and no chemotherapy. Univariate and multivariate analyses were performed.
  
  
  
  Of 7942 patients undergoing gastrectomy, 29 % received AC. Of those who received AC, 58 % initiated AC within 8 weeks, 28 % initiated AC between 8 and 12 weeks, and 14 % received AC after 12 weeks. Among patients who received AC, median survival was not significantly different between time cohorts, even when stratified by pathologic stage. Median survival was longer for chemotherapy cohorts when compared with the no chemotherapy cohort, specifically in patients with pathologic stages 2 and 3 disease. In multivariable analysis, patients who received AC had a 27-29 % lower hazard of death (p < .0001), with administration of AC at any time, compared with patients who did not receive AC, but had no difference in hazard when comparing delayed AC to earlier administration of AC.
  
  
  
  Time to initiation of AC does not impact survival. With improved survival over patients who did not receive AC, even delayed initiation of chemotherapy should be offered, when appropriate.
authors.affiliation: Department of Surgery, College of Medicine, The Pennsylvania State University, Hershey, PA, USA.
authors.forename: Erin K
authors.initials: EK
authors.lastname: Greenleaf
authors.affiliation: Department of Surgery, College of Medicine, The Pennsylvania State University, Hershey, PA, USA.
authors.forename: Afif N
authors.initials: AN
authors.lastname: Kulaylat
authors.affiliation: Department of Surgery, College of Medicine, The Pennsylvania State University, Hershey, PA, USA.|Department of Public Health Sciences, College of Medicine, The Pennsylvania State University, Hershey, PA, USA.
authors.forename: Christopher S
authors.initials: CS
authors.lastname: Hollenbeak
authors.affiliation: Department of Gastrointestinal Oncology, H. Lee Moffitt Cancer Center & Research Institute, Tampa, FL, USA.
authors.forename: Khaldoun
authors.initials: K
authors.lastname: Almhanna
authors.affiliation: Department of Surgery, College of Medicine, The Pennsylvania State University, Hershey, PA, USA. joyce.wong02@gmail.com.
authors.forename: Joyce
authors.initials: J
authors.lastname: Wong
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000970:Antineoplastic Agents / Q000008:administration & dosage*; D017024:Chemotherapy, Adjuvant; D005260:Female; D005743:Gastrectomy; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D012189:Retrospective Studies; D013274:Stomach Neoplasms / Q000473:pathology* / Q000628:therapy*; D015996:Survival Rate; D013997:Time Factors; D055815:Young Adult
chemical_list: D000970:Antineoplastic Agents