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Gut 50:43-51 doi:10.1136/gut.50.1.43
  • Cancer

Frequency of hereditary non-polyposis colorectal cancer in Danish colorectal cancer patients

  1. N Katballe1,
  2. M Christensen2,
  3. F P Wikman2,
  4. T F Ørntoft2,
  5. S Laurberg1
  1. 1Surgical Research Unit 900, Department of Surgery L, Aarhus University Hospital, Aarhus Amtssygehus, Aarhus, Denmark
  2. 2Department of Clinical Biochemistry, Aarhus University Hospital, Skejby Sygehus, Aarhus, Denmark
  1. Correspondence to:
    Dr N Katballe, Surgical Research Unit, afd. 900, Department of Surgery L, Aarhus Amtssygehus, Aarhus University Hospital, Tage Hansens Gade 2, 8000 Aarhus C, Denmark
  • Accepted 12 April 2001

Abstract

Background: Hereditary non-polyposis colorectal cancer (HNPCC) is an autosomal dominant cancer syndrome, characterised by familial aggregation of HNPCC related cancers, germline mutations in mismatch repair genes, and/or microsatellite instability (MSI) in tumour tissue.

Aim: To estimate the frequency of HNPCC among non-selected Danish patients with colorectal cancer (CRC), and to evaluate the value of MSI analysis as a pre-screen test.

Methods: This was a prospective population based study on consecutive CRC patients. A family history of malignancy was obtained and suspected HNPCC cases were screened for hMLH1/hMSH2 mutations and subjected to MSI analysis. Patients with germline mutations and/or those with Amsterdam criteria I or II families were categorised as HNPCC patients.

Results: Among 1328 eligible CRC patients, 1200 (90.4%) completed a questionnaire. A total of 1.7% (95% confidence interval (CI) 1.0–2.4) (20 cases) were categorised as HNPCC patients. Amsterdam criteria I or II were met in 18 cases (1.5%), and in another two cases (0.2%) pathogenic hMLH1/hMSH2 mutations were detected without fulfilment of the Amsterdam criteria I or II. Among 77 patients younger than 50 years of age, 11 cases (14.3%) were categorised as HNPCC. The Amsterdam criteria I or II were met in eight of 10 gene carriers (80%). The MSI-high phenotype was demonstrated in all 10 gene carriers.

Conclusion: The frequency of HNPCC was approximately 1.7% among all CRC cases and 14.3% among patients younger than 50 years of age. MSI analysis is a reliable pre-screen test for hMLH1/hMSH2 mutations in families suspected of having HNPCC.

Footnotes