Genetic factors may determine impacts of aspirin use on breast cancer patients’ survival
New research has observed that, depending on the degree of methylation of certain patients’ genes, aspirin use prior to breast cancer diagnosis may differentially prolong or lessen patients’ survival.
There is conflicting literature concerning the beneficial impacts of aspirin use prior to breast cancer diagnosis on patients’ survival. New research, conducted at University of North Carolina’s Gillings School of Global Public Health (NC, USA) suggests that the underlying methylation status of patients’ tumor and/or peripheral blood genes may determine whether pre-diagnosis aspirin use boosts their survival or not.
Changes in DNA methylation status – referred to as epigenetic alterations – directly impact on the transcriptional activity of genes. If such alterations occur within loci of genes that affect cells’ survival, death or replication, these may be predictive of cancer development.
The novel study, published in Cancer, has assessed the association between patients’ aspirin use prior to breast cancer diagnosis and their survival rates, specifically considering the methylation status of patients’ tumor and/or peripheral blood cells genes.
Tengteng Wang, first study author from the department of epidemiology at Gillings School, explained: “Chronic inflammation is a key player in the development of multiple cancer types, including breast cancer. Aspirin is a major non-steroidal anti-inflammatory drug…Given this, substantial evidence from laboratory and population studies suggests that taking aspirin may reduce the risk of developing breast cancer.”
In the study, researchers analyzed data from the Long Island Breast Cancer Study Project – a federally-mandated, population-based study assessing the effects of environmental exposures on women’s breast cancer risk – on 1266 women with breast cancer who were followed-up with until their death.
Pre-diagnosis aspirin use was defined by patient-reported use.
Amongst women who took aspirin at least once a week for 6 weeks prior to their breast cancer diagnosis, and who had methylated promoter regions of their BRCA1 genes, all-cause mortality was 67% greater compared with women who did not take pre-diagnosis aspirin.
By contrast, amongst patients with unmethylated BRCA1 tumor promoters and/or progesterone receptor genes, who took pre-diagnosis aspirin, breast cancer-related mortality was at least 22% lower compared with patients who did not take such aspirin.
The results of the study suggest that differences in gene methylation status contribute towards the differential impacts of aspirin use on patients’ survival. However, as the authors stress, there is no clear indication as to whether pre-diagnosis aspirin administration is definitively beneficial or not, with respect to breast cancer patients’ survival.
Wang concluded: “Future research designed to replicate our findings should include a larger sample size to allow examination of patterns of aspirin use, and an enlarged panel of genes to explore the role of genetic predisposition in driving overall genetic instability on survival after breast cancer diagnosis.”
Wang T, McCullough LE, White AJ et al. Prediagnosis aspirin use, DNA methylation, and mortality after breast cancer: A population‐based study. Cancer. doi: 10.1002/cncr.32364 (Epub ahead of print) (2019);