title: Obesity is a risk factor for multifocal disease and recurrence after colorectal cancer surgery: a case-control study.
abstract: BACKGROUND
  Several studies have demonstrated that obesity is a risk factor for colorectal cancer (CRC), but few data are available regarding its role in multifocal disease and postoperative recurrence. The present study aimed to assess the role of obesity as a risk factor for multifocal disease and postoperative recurrence in patients with CRC.
  
  
  METHODS
  The records of 940 consecutive patients with CRC admitted to three surgical centres between January 2006 and January 2011 were retrospectively analysed. The 595 individuals whose preoperative body mass index (BMI) values were available were included in the study. Following WHO guidelines, the patients were stratified into four groups depending on their BMI values. Age at disease onset, clinical presentation, tumor invasiveness, the presence of multiple foci, and the colon cancer recurrence rate in the four groups were assessed and compared.
  
  
  RESULTS
  At multivariate analysis, diagnosis of familial adenomatous polyposis (FAP) and a BMI>30 were found to be independent predictors of synchronous polyps (Odd Ratio [OR]=10.7, 95% Confidence interval (CI)=2-75, p=0.005; and OR=2.2, 95% CI=1.3-3.9, p=0.003, respectively). The cancer recurrence rate in the patients with stage 2 CRC was significantly higher in the obese with respect to the non-obese (p=0.05). At multivariate analysis, BMI>30, FAP, and positivity by the Bethesda criteria were found to be independent predictors of recurrence after CRC surgery.
  
  
  CONCLUSIONS
  Obese patients diagnosed with CRC require thorough colonic exploration prior to surgery and necessitate more frequent postoperative endoscopic examinations with respect to patients without any risk factors.
authors.affiliation: Surgical Oncology Unit, Veneto Institute of Oncology (IOV-IRCCS), Padova, Italy marcoscarpa73@yahoo.it.
authors.forename: Marco
authors.initials: M
authors.lastname: Scarpa
authors.affiliation: Second Department of Surgery (Unit IV), Cà Foncello Regional Hospital, Treviso, Italy.
authors.forename: Cesare
authors.initials: C
authors.lastname: Ruffolo
authors.affiliation: Department of Surgical, Oncological and Gastroenterological Sciences, University of Padova, Padova, Italy.
authors.forename: Francesca
authors.initials: F
authors.lastname: Erroi
authors.affiliation: Second Department of Surgery (Unit IV), Cà Foncello Regional Hospital, Treviso, Italy.
authors.forename: Alain
authors.initials: A
authors.lastname: Fiorot
authors.affiliation: Department of Surgical, Oncological and Gastroenterological Sciences, University of Padova, Padova, Italy.
authors.forename: Silvia
authors.initials: S
authors.lastname: Basato
authors.affiliation: Department of Surgical, Oncological and Gastroenterological Sciences, University of Padova, Padova, Italy.
authors.forename: Anna
authors.initials: A
authors.lastname: Pozza
authors.affiliation: Pathology Unit, Cà Foncello Regional Hospital, Treviso, Italy.
authors.forename: Fabio
authors.initials: F
authors.lastname: Canal
authors.affiliation: Second Department of Surgery (Unit IV), Cà Foncello Regional Hospital, Treviso, Italy.
authors.forename: Marco
authors.initials: M
authors.lastname: Massani
authors.affiliation: Surgical Oncology Unit, Veneto Institute of Oncology (IOV-IRCCS), Padova, Italy.
authors.forename: Francesco
authors.initials: F
authors.lastname: Cavallin
authors.affiliation: Second Department of Surgery (Unit IV), Cà Foncello Regional Hospital, Treviso, Italy.
authors.forename: Michele
authors.initials: M
authors.lastname: Antoniutti
authors.affiliation: Second Department of Surgery (Unit IV), Cà Foncello Regional Hospital, Treviso, Italy.
authors.forename: Nicolò
authors.initials: N
authors.lastname: Bassi
authors.affiliation: Surgical Oncology Unit, Veneto Institute of Oncology (IOV-IRCCS), Padova, Italy.
authors.forename: Carlo
authors.initials: C
authors.lastname: Castoro
mesh_terms: D000368:Aged; D015992:Body Mass Index; D016022:Case-Control Studies; D015179:Colorectal Neoplasms / Q000209:etiology* / Q000401:mortality / Q000473:pathology* / Q000601:surgery; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local; D009367:Neoplasm Staging; D009765:Obesity / Q000150:complications*; D012189:Retrospective Studies; D012307:Risk Factors
keywords: Bethesda criteria; Colorectal cancer; adenoma; obesity