title: Is preoperative colonoscopy necessary for patients undergoing gastric cancer surgery?
abstract: OBJECTIVE
  The aim of this study was to evaluate the necessity of preoperative colonoscopy (CS) in gastric cancer (GC) patients and to assess the outcomes of different treatments in patients with synchronous GC and colorectal neoplasms (CRN). We also determined the risk factors influencing the comorbidity of colorectal cancer (CRC) in patients with GC.
  
  
  METHODS
  This retrospective study included 1891 consecutive GC patients who underwent CS before surgery from January 1, 1999, through June 30, 2012.
  
  
  RESULTS
  There was a high prevalence of concurrent CRN (28.4 %) and CRC (3.2 %) in our patients with GC. Sixty-one patients with GC had synchronous CRC. Twenty-three of the 61 tumors were perioperatively treated by endoscopic resection. The other 38 tumors were treated by simultaneous surgery for the GC and CRC. Surgical complications were not found in either the endoscopic or surgical resection group. The multivariate logistic regression analysis indicated that the prevalence of synchronous CRC in patients with GC was significantly associated with the incidence of multiple GCs [P < 0.0001; odds ratio (OR) 15.3], having anemia (P = 0.002; OR 3.0), and having a smoking history (P = 0.021; OR 1.9).
  
  
  CONCLUSIONS
  We recommend preoperative CS screening for GC patients. In particular, preoperative CS screening is indispensable for patients with multiple GCs. In addition, simultaneous treatments for patients with synchronous GC and CRN are safe and feasible procedures.
authors.affiliation: Second Department of Surgery, Wakayama Medical University, Wakayama, Japan.
authors.forename: Toshiyasu
authors.initials: T
authors.lastname: Ojima
authors.forename: Makoto
authors.initials: M
authors.lastname: Iwahashi
authors.forename: Mikihito
authors.initials: M
authors.lastname: Nakamori
authors.forename: Masaki
authors.initials: M
authors.lastname: Nakamura
authors.forename: Masahiro
authors.initials: M
authors.lastname: Katsuda
authors.forename: Takeshi
authors.initials: T
authors.lastname: Iida
authors.forename: Keiji
authors.initials: K
authors.lastname: Hayata
authors.forename: Katsunari
authors.initials: K
authors.lastname: Takifuji
authors.forename: Shunsuke
authors.initials: S
authors.lastname: Yamaguchi
authors.forename: Hiroki
authors.initials: H
authors.lastname: Yamaue
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003113:Colonoscopy / Q000379:methods*; D015179:Colorectal Neoplasms / Q000175:diagnosis* / Q000601:surgery; D015897:Comorbidity; D055088:Early Detection of Cancer; D005260:Female; D005500:Follow-Up Studies; D005743:Gastrectomy; D006801:Humans; D007564:Japan / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D009378:Neoplasms, Multiple Primary / Q000175:diagnosis* / Q000601:surgery; D011300:Preoperative Care; D015995:Prevalence; D011379:Prognosis; D012189:Retrospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D013274:Stomach Neoplasms / Q000601:surgery*