Meer opsporing van erfelijke darmkanker met onderzoek op microsatellietinstabiliteit bij door de patholoog geselecteerde patiënten met een colon-rectumcarcinoom

To determine whether an investigation of microsatellite instability (MSI) in patients with colorectal carcinoma that have been selected by the pathologist could increase the number of detected families with hereditary non-polyposis colorectal carcinoma (HNPCC).

Design

Prospective inventory.

Method

Pathologists selected patients with a newly diagnosed colorectal carcinoma for MSI analysis of their tumour tissue if they met one of the following four criteria: (a) colorectal carcinoma diagnosed below 50 years of age; (b) a second colorectal carcinoma; (c) a combination of colorectal carcinoma and another HNPCC-related cancer; (d) colorectal adenoma with high-grade dysplasia diagnosed below 40 years of age. Patients with a positive MSI-test were referred to a clinical geneticist. The new strategy was introduced and explored in 5 hospitals for a period of 10 months.

Results

The new strategy was adopted and implemented successfully by pathologists and surgeons and accepted with satisfaction by the patients. Of the 55 patients included, 10 had a positive MSI-test. In 8/10 patients, DNA-mutation analysis was started by the clinical geneticist and 3 germline mutations in the MSH2-gene were detected. In 2 of 3 families with a pathogenic mutation, the family history alone did not fulfil the clinical criteria for HNPCC.

Conclusion

Selection by the pathologist for MSI investigation was feasible in daily practice and identified more HNPCC patients than selection based on family history alone.

Ned Tijdschr Geneeskd 2005;149:1792-8