Chemical changes in DNA found in blood and breast cancer tumors may modify aspirin’s role in mortality risk.
Previous studies have shown that some women who use aspirin and are later diagnosed with breast cancer may live longer, which may be related to the drug’s anti-inflammatory effects on the body. However, a portion of aspirin users with breast cancer appeared to have a higher risk of death. According to a new study from researchers at the University of North Carolina Gillings School of Global Public Health, the reason for this reverse effect could be explained by DNA methylation of genes in breast cancer tumors or peripheral blood.
Methylation is a chemical modification wherein a methyl group acts like light switches along the DNA molecule, turning some genetic activity on and some off. Chemical shifts in areas of DNA that are responsible for cell death, damage and repair – such as occurs in methylation – are known contributors to the development of cancer over time. Identifying the areas where these epigenetic changes take place show promise in predicting certain risks or effective methods of treatment.
A new study, published today in the American Cancer Society’s interdisciplinary journal CANCER, is the first to examine the effect of DNA methylation in breast tumor tissues and cells circulating in the patients’ peripheral blood on the association between aspirin use and mortality in women with breast cancer. All-cause death after breast cancer was elevated by 67 percent among women who had used aspirin at least once a week for six weeks pre-diagnosis and had a methylated tumor promotor of breast cancer gene 1, known as BRCA1.
The results suggest real differences in breast cancer mortality risk in patient groups with different methylation profiles.Friday Letter Submission, Publish on August 16