Assessment of microsatellite instability in colorectal cancer patients from Brazil.
The replication error status analysis of DNA, through microsatellite instability detection, has become an indispensable tool for hereditary non-polyposis colorectal cancer screening. This study investigated the microsatellite instability in Brazilian individuals presenting colorectal cancer. In this study, 66 patients were clinically analyzed according to Amsterdam II and Bethesda guidelines. Normal and tumour tissues were collected and analyzed for MSI degree according to molecular markers BAT25, BAT26, BAT40, APC-D5S346, D2S123, and D17S250. Eight patients (12.1%) fulfilled the Amsterdam II guidelines, and 15 (22.7%) met the Bethesda guidelines. BAT25 was the most sensitive marker (86.7%), while BAT26 was the least sensitive (66.7%). The specificity of both markers was 100%, but all of the markers must be used since the contribution of each marker to the sensitivity and specificity of the test is complementary. Proximal tumours were significantly predominant among RER+ patients.


CONCLUSIONS
Patients with a family history of colorectal cancer with the tumour in the proximal colon must be screened to replication error status as early as possible in order to avoid the progression of the disease.
Department of Coloproctology, Santa Casa de Belo Horizonte, MG, Brazil. sinara.monica@uol.com.br
Sinara M O
SM
Leite
Karina B
KB
Gomes
Victor C
VC
Pardini
Alessandro C S
AC
Ferreira
Vanessa C
VC
Oliveira
Geraldo M G
GM
Cruz
D000328:Adult; D000368:Aged; D001938:Brazil; D015179:Colorectal Neoplasms / Q000235:genetics*; D005260:Female; D005819:Genetic Markers; D006801:Humans; D008297:Male; D053842:Microsatellite Instability; D008875:Middle Aged
D005819:Genetic Markers