Developing a molecular marker for metachronous colorectal cancer.
OBJECTIVE
To determine the prevalence of microsatellite instability in patients with metachronous colorectal cancer as a potential marker for identification of high risk individuals.


METHODS
Surgical research laboratory, Whittington Hospital, Highgate Hill, London.


METHODS
37 colorectal tumours from 18 individuals with metachronous colorectal cancers were investigated at five microsatellite loci by single stranded conformational polymorphism (SSCP) analysis. A control group of 11 individuals who had developed one sporadic colorectal cancer each were also similarly analysed.


METHODS
Tumour microsatellite instability was defined as the appearance of new polymarase chain reaction (PCR) bands, either larger or smaller than those produced from the normal mucosa.


RESULTS
27 of the total of 37 metachronous cancer specimens PCR amplified successfully. Microsatellite instability was demonstrated in 59.3% (16/27) of individuals with metachronous tumours. None of the tumours in the control group showed microsatellite instability.


CONCLUSIONS
These results suggest that individuals with colorectal cancer with replication errors are at a greater risk of developing metachronous colorectal cancer than those without replication errors.
de Silva
W M
WM
Whittington Hospital, London, UK.
D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor / Q000235:genetics*; D016022:Case-Control Studies; D015179:Colorectal Neoplasms / Q000235:genetics* / Q000473:pathology; D003123:Colorectal Neoplasms, Hereditary Nonpolyposis / Q000235:genetics; D020732:Cytogenetic Analysis; D004252:DNA Mutational Analysis / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D018895:Microsatellite Repeats; D008875:Middle Aged; D016609:Neoplasms, Second Primary / Q000235:genetics* / Q000473:pathology; D016133:Polymerase Chain Reaction; D018807:Polymorphism, Single-Stranded Conformational; D011379:Prognosis
D014408:Biomarkers, Tumor