title: [Influences of diagnostic modes on an early diagnosis of colorectal cancer].
abstract: OBJECTIVE
  To explore the influences of diagnostic modes of colorectal cancer (CRC) on an early diagnosis of CRC.
  
  
  METHODS
  A total of 405 cases were randomly collected from 1798 CRC patients registered at our hospital from January 2000 to December 2010. A retrospective chart review was undertaken for all identified cases. Besides the demographics and tumor features, TNM stage was obtained from medical records and pathological forms. Other collected data were as follows: (1) Type of clinical examinations leading to diagnosis. (2) Diagnostic duration: including patient duration (period from initial symptoms to consulting a doctor and hospitalization duration (period from patient first seeing a doctor to a confirmed CRC case). (3) Diagnostic delay and its rate: diagnostic delay was identified as the diagnostic duration of over 30 days. We compared the different delay periods of 31 - 60, 61 - 90, 91 - 150 and > 150 days and its corresponding tumor stages at diagnosis. (4) Misdiagnosis and its rate: that CRC subjects were diagnosed and treated as other diseases for at least 30 days was identified as misdiagnosis. The t and Mann-Whitney U tests were performed for the quantitative data and χ(2) test for the qualitative data.
  
  
  RESULTS
  Among the study subjects, 67.2% (270/402) CRC cases were examined by colonoscopy, 17.4 % (70/402) cases by CT scan or B ultrasound. The median diagnostic duration of CRC was 90 days (25% percentile: 40 days, 75% percentile: 210 days). The median patient duration was 30 days and median hospital duration 10 days. The overall misdiagnostic rate of CRC was 27.9% (112/401), higher (39.7%, 48/121) in right sited CRC than in left sited CRC (22.9%, 63/275) (χ(2) = 11.7, P = 0.00). 77.7% (313/403) cases had > 30 days diagnostic delay, 50.8% (156/307) delay attributable to the patients, while 29.0% (89/307) attributable to hospitals and 20.2% (62/307) attributable to both. The diagnostic duration of early-stage CRC and advanced-stage CRC appeared to be in the same length. On the other hand, no difference of TNM stage at the initial diagnosis was found in groups with different diagnostic durations of 31 - 60, 61 - 90, 91 - 150 and > 150 days (all P > 0.05).
  
  
  CONCLUSIONS
  Colonoscopy is the most effective in the diagnosis of CRC. The median diagnostic time of CRC is 90 days. The phenomenon of its diagnostic delay often occurs. However, the delay is not a major cause for its advanced stage and a poor outcome. Its inherent biological characteristics may be more important.
authors.affiliation: Division of Gastroenterology and Hepatology, Peking University People's Hospital, Beijing, China.
authors.forename: Xuan
authors.initials: X
authors.lastname: Jiang
authors.forename: Yi-ping
authors.initials: YP
authors.lastname: Yuan
authors.forename: Ding-ting
authors.initials: DT
authors.lastname: Xu
authors.forename: Bao
authors.initials: B
authors.lastname: Zhang
authors.forename: Yu-lan
authors.initials: YL
authors.lastname: Liu
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015179:Colorectal Neoplasms / Q000175:diagnosis* / Q000473:pathology; D055088:Early Detection of Cancer / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D012189:Retrospective Studies; D013997:Time Factors; D055815:Young Adult