Two new studies shed more light on whether of aspirin can help treat breast cancer patients. Both studies were authored by researchers at the University of Pennsylvania. The first study found no improvement in clinical outcomes or survival among breast cancer patients. This was the largest study of aspirin use and breast cancer outcomes yet, with 1,000 patients analyzed by the study authors. All subjects were diagnosed with breast cancers including receptor positive, HER2-positive and triple negative cancers.

No association was found between aspirin usage and survival. Conversely, in a five year follow up researchers found that low-dose aspirin use was significantly associated with worse survival, compared to patients who didn’t take aspirin before their diagnosis.

This finding comes in the midst of recent studies revealing evidence to support aspirin’s benefit in oncology, reducing the risk of colorectal cancer. “Many of them [past studies] were preliminary, preclinical, and didn’t support a clear mortality benefit,” said Julia C. Tchou, MD, PhD, associate professor at Perelman School of Medicine, and the study’s lead author. “Our data did not support the notion that this century-old pill has protective qualities and down-the-road benefits for breast cancer patients. However, larger patient cohort studies are needed to confirm our results.”

The second study sought to find any association between aspirin and breast density, a widely accepted risk factor for breast cancer. Researchers examined the medical records of 26,000 women who underwent routine screening mammography, and had doctor visit within the previous year that included a recorded list of medication use. The results found a significant correlation between less dense breasts and aspirin usage. The researchers also found a lower chance of having extremely dense breasts with increased aspirin dose.

“Our findings highlight the potential value for a randomized controlled trial of aspirin as an agent in early detection of breast cancer, particularly for women with naturally dense tissues who may be at an increased risk for certain cancers,” said Despina Kontos, PhD, an assistant professor of Radiology, and co-author on the study.

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