Mammographic Density and Estrogen Receptor α Gene Polymorphism in Javanese Women
Abstract: Estrogen plays
important roles in breast cancer as it binds its receptor in breast tissue. The
most studied variants in estrogen receptor α encoded by ESR1 gene are the ESR1
PvuII and XbaI polymorphisms, which were associated with lower sensitivity to
estrogen. We determined the proportion of ESR1 XbaI and PvuII polymorphisms in
Javanese woman in Yogyakarta, Indonesia and analyzed the correlation between
genetic variations with mammogram density. ESR1 XbaI and PvuII polymorphisms of
50 cases and 58 controls were identified using PCR-RFLP. Breast density was
assessed based on digitizer mammograms. Quantitative analysis was performed
using an interactive program based on cumulus of two thresholds. Mean of
density and frequencies of SNPs were compared between cases and controls to
identify the association between SNPs and cancer susceptibility. Mammographic
density was significantly higher in cases (52%) than controls (0.41%) (p <
0.05). Women with one or two copies of the PvuII T allele and XbaI A allele had
higher mammographic density compared with women with C and G alleles,
respectively. The proportion between PP and TT genotype was not statistically
significant (p > 0.05), while the proportion between AA and GG was
significantly different (p < 0.05). Haplotype 2 (CG/PX) was associated with
lower sensitivity to estrogen and reflects a decrease of mammographic density.
These findings were consistent with other studies that showed that ESR1
polymorphisms may affect breast cancer risk through differences in breast
density.
Keywords: Breast cancer, DNA
polymorphism, ESR1 PvuII, ESR1 XbaI, Mammogram Digitizer
Author: Lina Choridah
Journal Code: jpkedokterangg170292
