Women with specific DNA characteristics in certain areas of the genome may live longer if they take aspirin before they are diagnosed with breast cancer, according to a study at the University of North Carolina at Chapel Hill.
It is often unclear why some patients benefit from a particular therapy while others do not. In some cases, gene sequences play a role, but in other cases, chemical modifications to DNA may be important. The latter are termed epigenetic changes, and they include a process called DNA methylation.
The researchers examined DNA methylation in breast tumor tissues—including at DNA sites that control the expression of 13 breast cancer-related genes—and also in cells circulating in patients’ blood. The study, published in Cancer, is the first to examine the effect of DNA methylation on the association between aspirin use and mortality in women with breast cancer.
Of 1,266 women who were diagnosed with breast cancer between 1996 and 1997, 476 died from any cause and 202 died specifically from breast cancer by the end of 2014. In women who used aspirin, the risk of dying from breast cancer was lower among those whose DNA was not methylated in the region controlling expression of the breast cancer-related BRCA1 gene. Other methylation patterns related to aspirin use and mortality were also observed.
The authors suggest that future research should consider a more comprehensive DNA methylation profile in order to better characterize women who are at risk.
Source: MedicalXpress, August 12, 2019