[More hereditary intestinal cancer can be detected if patients with colorectal carcinoma that are selected by the pathologist are examined for microsatellite instability].
OBJECTIVE
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).


METHODS
Prospective inventory.


METHODS
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 to 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.


CONCLUSIONS
Selection by the pathologist for MSI investigation was feasible in daily practice and identified more HNPCC patients than selection based on family history alone.
de Bruin
J H F M
JH
Universitair Medisch Centrum St Radboud, Postbus 9IoI, 6500 HB Nijmegen. j.debruin@antrg.umcn.nl
Kievit
W
W
Ligtenberg
M J L
MJ
Nagengast
F M
FM
Adang
E M M
EM
Ruers
T J
TJ
Kleibeuker
J H
JH
Sijmons
R H
RH
van Krieken
J H J M
JH
Hoogerbrugge
N
N
D000328:Adult; D015179:Colorectal Neoplasms / Q000175:diagnosis; D003123:Colorectal Neoplasms, Hereditary Nonpolyposis / Q000175:diagnosis* / Q000235:genetics* / Q000473:pathology; D003937:Diagnosis, Differential; D005260:Female; D005820:Genetic Testing; D042822:Genomic Instability; D018095:Germ-Line Mutation; D006801:Humans; D008297:Male; D018895:Microsatellite Repeats; D008875:Middle Aged; D009426:Netherlands; D010375:Pedigree; D011237:Predictive Value of Tests; D011446:Prospective Studies