title: Role of primary tumor resection among chemotherapy-treated patients with synchronous stage IV colorectal cancer: a survival analysis.
abstract: BACKGROUND
  The benefit of an operation to remove the primary tumor among patients with synchronous stage IV colorectal cancer is controversial. This study analyzed the survival benefits associated with primary tumor resection among chemotherapy-treated stage IV colorectal cancer patients.
  
  
  METHODS
  The study analyzed 11,716 chemotherapy-treated stage IV colorectal cancer patients in the California Cancer Registry between 1996 and 2007, with follow-up through 2009. Patients were stratified into operation and non-operation groups. Estimates of median overall and colorectal cancer-specific survival were generated.
  
  
  RESULTS
  Patients undergoing operation compared to those who are not had higher median overall and colorectal cancer-specific survival, 21 versus 10 months (p < 0.0001) and 22 versus 12 months (p < 0.0001), respectively. Patients who were offered surgery but refused had decreased median overall and colorectal cancer-specific survival when compared to patients who underwent resection, 8 versus 21 months (p < 0.001) and 7 versus 22 months (p < 0.001), respectively. In multivariate regression models, patients who underwent resection of primary tumor had improved overall (hazard ratio (HR), 0.42; 95% confidence interval (CI) 0.40-0.44, p < 0.0001) and colorectal cancer-specific survival (HR, 0.43; 95% CI, 0.41-0.45; p < 0.0001).
  
  
  CONCLUSIONS
  Primary tumor resection is associated with improved survival among stage IV chemotherapy-treated colorectal cancer patients.
authors.affiliation: Chao Family Comprehensive Cancer Center, University of California, Irvine, CA, 92697, USA.
authors.forename: Walter Y
authors.initials: WY
authors.lastname: Tsang
authors.forename: Argyrios
authors.initials: A
authors.lastname: Ziogas
authors.forename: Bruce S
authors.initials: BS
authors.lastname: Lin
authors.forename: Tara E
authors.initials: TE
authors.lastname: Seery
authors.forename: William
authors.initials: W
authors.lastname: Karnes
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Stamos
authors.forename: Jason A
authors.initials: JA
authors.lastname: Zell
mesh_terms: D000230:Adenocarcinoma / Q000188:drug therapy / Q000556:secondary* / Q000601:surgery*; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000970:Antineoplastic Agents / Q000627:therapeutic use; D002140:California; D003082:Colectomy; D015179:Colorectal Neoplasms / Q000188:drug therapy / Q000473:pathology* / Q000601:surgery*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D012042:Registries; D015996:Survival Rate; D055815:Young Adult
chemical_list: D000970:Antineoplastic Agents