title: Advanced proximal colon cancer.
abstract: BACKGROUND
  Two recent studies have documented that sigmoidoscopy as a screening tool for colorectal cancers may miss advanced proximal colonic neoplasms. The purpose of this study was to assess the prevalence of distal synchronous lesions in patients with proximal colon cancer. We sought to determine if screening sigmoidoscopy would have missed these proximal colon cancers.
  
  
  METHODS
  Data were collected on all patients (n = 305) diagnosed with colorectal cancer over a 6-year period. Patients were stratified by age, sex, tumor location, presenting complaint, AJCC stage, and TNM classification. The colonoscopy results of patients diagnosed with proximal colon cancer were analyzed to determine the incidence of synchronous distal colon lesions.
  
  
  RESULTS
  Proximal colon cancer was diagnosed in 88 patients (29%). Of those studied, 45 (54%) did not have synchronous distal lesions detected by colonoscopy. The patients with proximal colon cancer were elderly (mean age 67), had advanced tumor size [59 patients (67%) T3/T4], and had advanced AJCC stages [37 patients (42%) stage III/IV]. Nearly all patients [84 (95%)] with proximal colon cancer were symptomatic.
  
  
  CONCLUSIONS
  In this study, the majority of patients with proximal colon cancer did not have a synchronous lesion in the distal colon. Current screening methods for colon cancer based on sigmoidoscopy would not have identified these proximal lesions. These findings support the incorporation of screening colonoscopy in protocols designed to identify early colon cancer.
authors.affiliation: Department of Surgery, Veterans Affairs Maryland Health Care System and University of Maryland School of Medicine, Baltimore, MD 21201, USA.
authors.forename: C J
authors.initials: CJ
authors.lastname: Gannon
authors.forename: D L
authors.initials: DL
authors.lastname: Malone
authors.forename: R E
authors.initials: RE
authors.lastname: Royal
authors.forename: M
authors.initials: M
authors.lastname: Schreiber
authors.forename: B L
authors.initials: BL
authors.lastname: Bass
authors.forename: L M
authors.initials: LM
authors.lastname: Napolitano
mesh_terms: D000368:Aged; D003110:Colonic Neoplasms / Q000175:diagnosis* / Q000473:pathology; D006801:Humans; D009378:Neoplasms, Multiple Primary / Q000175:diagnosis* / Q000473:pathology; D012189:Retrospective Studies; D012812:Sigmoidoscopy