HUBUNGAN STATUS INSTABILITAS MIKROSATELIT DAN EKSPRESI P53 DENGAN ETIOPATOLOGI ADENOKARSINOMA KOLOREKTAL PADA ORANG INDONESIA DI KELOMPOK USIA KURANG DARI 40 TAHUN

Abstract

Epidemiologically, the percentage of colorectal adenocarcinoma (CRC) in the age group ≤40 years old in Indonesia is higher than in the West European, North American and other developed Asian countries with different clinico-pathological features. In the afromentioned countries, the carcinogenesis pathway of this group is hereditary which show high microsatellite instability (MSI), whereas the age group >40 years old is sporadic of which show chromosomal instability (CIN) with the mutation of p53 gene. To elucidate the carcinogenesis pathway with its molecular characteristics of this group among Indonesians, a cross sectional study was conducted by performing the immunohistochemical detection of MLH1 and MSH2 expression (MSI status), and mutated p53 gene expression (CIN) in the CRC group ≤40 years old and >40 years old at Dr. Hasan Sadikin Hospital, Bandung, from May 2008 until November 2009. Thirty nine CRC patients, consisting of 22 patients of  ≤40 years old and 17patients >40 years old, were eligible for this study. The CRC patients of ≤40 years old showed 4 MSI high,  1 MSI lowand 17 MSS (microsatellite stable), associated with 10 p53 positive and 12 p53 negative status. In the CRC group of >40 years old, there was no MSI high, but 4 MSI low and 13 MSS were found, associated with 11 p53positive and 6 p53negative status. There was no significant difference with regards to the association between MSI status and p53 expression in both groups (p MSI=0.95, p p53=0.23).