title: Survival following synchronous colon cancer resection.
abstract: BACKGROUND
  Synchronous colon cancers, defined as two or more primary colon cancer detected simultaneously at the time of initial diagnosis, account for up to 5% of all colon cancer diagnoses. Management principles and outcomes remain largely undefined.
  
  
  METHODS
  A retrospective institutional review of patients undergoing curative intent resection for colon adenocarcinoma (Stages I-III) from 1995 to 2007 was performed. Hereditary causes or inflammatory bowel disease were excluded. Matching was performed and Kaplan-Meier analysis was used to compare overall survival.
  
  
  RESULTS
  Of 2,387 patients, 100 (4.2%) had synchronous cancers. Patients with synchronous lesions tended to be older (median 77 vs. 72 years, P < 0.001) with more advanced tumors (41.0% vs. 31.4% Stage III, P = 0.04). After matching, there were no differences in demographics or tumor factors (all P > 0.05). Compared to solitary, synchronous cancers demonstrated an inferior 10-year overall survival (53.9% vs. 36.5%, P = 0.009). Subset analysis of patients with synchronous cancers showed no difference in overall survival between those with extended versus segmental resections at 120-months (P = 0.07).
  
  
  CONCLUSIONS
  Synchronous colon cancer is associated with decreased overall survival compared to patients with solitary tumors. Extended resection does not confer a survival benefit in these patients. Further research is needed to determine how to mitigate the poor outcomes. J. Surg. Oncol. 2016;114:80-85. © 2016 Wiley Periodicals, Inc.
authors.affiliation: Department of Surgery, Mayo Clinic, Rochester, Minnesota.|The Robert D. and Patricia E. Kern Center for the Science of Health Care Delivery, Mayo Clinic, Rochester, Minnesota.
authors.forename: Cornelius A
authors.initials: CA
authors.lastname: Thiels
authors.affiliation: Department of Surgery, Mayo Clinic, Rochester, Minnesota.
authors.forename: Nimesh D
authors.initials: ND
authors.lastname: Naik
authors.affiliation: Department of Surgery, Mayo Clinic, Rochester, Minnesota.
authors.forename: John R
authors.initials: JR
authors.lastname: Bergquist
authors.affiliation: Department of Surgery, Mayo Clinic, Rochester, Minnesota.
authors.forename: Blake A
authors.initials: BA
authors.lastname: Spindler
authors.affiliation: The Robert D. and Patricia E. Kern Center for the Science of Health Care Delivery, Mayo Clinic, Rochester, Minnesota.
authors.forename: Elizabeth B
authors.initials: EB
authors.lastname: Habermann
authors.affiliation: Department of Surgery, Mayo Clinic, Rochester, Minnesota.
authors.forename: Scott R
authors.initials: SR
authors.lastname: Kelley
authors.affiliation: Department of Surgery, Mayo Clinic, Rochester, Minnesota.
authors.forename: Bruce G
authors.initials: BG
authors.lastname: Wolff
authors.affiliation: Department of Surgery, Mayo Clinic, Rochester, Minnesota.
authors.forename: Kellie L
authors.initials: KL
authors.lastname: Mathis
mesh_terms: D000230:Adenocarcinoma / Q000401:mortality / Q000473:pathology / Q000601:surgery*; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003082:Colectomy; D003110:Colonic Neoplasms / Q000401:mortality / Q000473:pathology / Q000601:surgery*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D009378:Neoplasms, Multiple Primary / Q000401:mortality / Q000473:pathology / Q000601:surgery*; D012189:Retrospective Studies; D016019:Survival Analysis; D016896:Treatment Outcome
keywords: MSI; colon cancer; solitary lesions; synchronous