title: Identification of Extracolonic Pathologies by Computed Tomographic Colonography in Colorectal Cancer Symptomatic Patients.
abstract: OBJECTIVE
  Symptoms suggestive of colorectal cancer may originate outside the colorectum. Computed tomographic colonography (CTC) is used to examine the colorectum and abdominopelvic organs simultaneously. We performed a prospective randomized controlled trial to quantify the frequency, nature, and consequences of extracolonic findings.
  
  
  METHODS
  We studied 5384 patients from 21 UK National Health Service hospitals referred by their family doctor for the investigation of colorectal cancer symptoms from March 2004 through December 2007. The patients were assigned randomly to groups that received the requested test (barium enema or colonoscopy, n = 3574) or CTC (n = 1810). We determined the frequency and nature of extracolonic findings, subsequent investigations, ultimate diagnosis, and extracolonic cancer diagnoses 1 and 3 years after testing patients without colorectal cancer.
  
  
  RESULTS
  Extracolonic pathologies were detected in 959 patients by CTC (58.7%), in 42 patients by barium enema analysis (1.9%), and in no patients by colonoscopy. Extracolonic findings were investigated in 142 patients (14.2%) and a diagnosis was made for 126 patients (88.1%). Symptoms were explained by extracolonic findings in 4 patients analyzed by barium enema (0.2%) and in 33 patients analyzed by CTC (2.8%). CTC identified 72 extracolonic neoplasms, however, barium enema analysis found only 3 (colonoscopy found none). Overall, CTC diagnosed extracolonic neoplasms in 72 of 1634 patients (4.4%); 26 of these were malignant (1.6%). There were significantly more extracolonic malignancies detected than expected 1 year after examination, but these did not differ between patients evaluated by CTC (22.2/1000 person-years), barium enema (26.5/1000 person-years; P = .43), or colonoscopy (32.0/1000 person-years; P = .88).
  
  
  CONCLUSIONS
  More than half of the patients with symptoms of colorectal cancer are found to have extracolonic pathologies by CTC analysis. However, the proportion of patients found to have extracolonic malignancies after 1 year of CTC examination is not significantly greater than after barium enema or colonoscopy examinations. International Standard Randomised Controlled Trials no: 95152621.isrctn.com.
authors: University College London, London, United Kingdom. Electronic address: s.halligan@ucl.ac.uk.
authors: Steve
authors: S
authors: Halligan
authors: Imperial College London, London, United Kingdom.
authors: Katherine
authors: K
authors: Wooldrage
authors: Imperial College London, London, United Kingdom.
authors: Edward
authors: E
authors: Dadswell
authors: Imperial College London, London, United Kingdom.
authors: Urvi
authors: U
authors: Shah
authors: Imperial College London, London, United Kingdom.
authors: Ines
authors: I
authors: Kralj-Hans
authors: University College London, London, United Kingdom.
authors: Christian
authors: C
authors: von Wagner
authors: Imperial College London, London, United Kingdom.
authors: Omar
authors: O
authors: Faiz
authors: Imperial College London, London, United Kingdom.
authors: Julian
authors: J
authors: Teare
authors: Queen Mary University of London, London, United Kingdom.
authors: Rob
authors: R
authors: Edwards
authors: Bradford Teaching Hospitals National Health Service Foundation Trust, Bradford, United Kingdom.
authors: Clive
authors: C
authors: Kay
authors: University of Southampton, Southampton, United Kingdom.
authors: Guiqing
authors: G
authors: Yao
authors: University of Warwick, Warwick, United Kingdom.
authors: Richard J
authors: RJ
authors: Lilford
authors: University of Birmingham, Birmingham, United Kingdom.
authors: Dion
authors: D
authors: Morton
authors: University College London, London, United Kingdom.
authors: Jane
authors: J
authors: Wardle
authors: Imperial College London, London, United Kingdom.
authors: Wendy
authors: W
authors: Atkin
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001466:Barium Sulfate; D023881:Colonography, Computed Tomographic / Q000379:methods*; D003113:Colonoscopy; D015179:Colorectal Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology; D003287:Contrast Media; D004733:Enema / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010388:Pelvis / Q000000981:diagnostic imaging*; D012680:Sensitivity and Specificity
chemical_list: D003287:Contrast Media; D001466:Barium Sulfate
keywords: Colon Cancer; Detection; Diagnostic; Digestive System