Could aspirin treat breast cancer?

Researchers from Dana-Farber Cancer Institute and Brigham and Women’s Hospital (BWH) have received a $10 million Breakthrough Award from the Department of Defense’s Office of the Congressionally Directed Medical Research Program to test whether aspirin helps women with breast cancer avoid recurrence and live longer. This is the first ever randomized trial in the United States testing aspirin in the disease, which impacts more than 3 million American women who are living with a breast cancer diagnosis.

The Aspirin for Breast Cancer (ABC) Trial will recruit 3,000 women with Stages II and III breast cancer through The Alliance for Clinical Trials in Oncology (Alliance) which is a national clinical trials network sponsored by the National Cancer Institute (NCI). Half of the women participating in the trial will be randomly assigned to receive aspirin and half to receive a placebo pill.

Previous observational research, where scientists observe peoples’ behavior, and correlate that behavior with their health, has found that breast cancer survivors who were regular aspirin users had a 50 percent lower risk of breast cancer recurrence and death compared to those who did not use aspirin. This, along with other promising preclinical research, has led to intense interest among physicians and survivors to explore the therapeutic benefits of aspirin.

“Although chemo- and hormonal therapies have helped women with breast cancer live longer, they are expensive and have many side effects,” said Wendy Chen, MD, MPH, a senior physician at the Susan F. Smith Center for Women’s Cancers at Dana-Farber and co-investigator. “Women whose tumors are not sensitive to hormones have limited treatment options. The results of this trial, if positive, could have a huge impact on the disease, as we have estimated that that aspirin may save 10,000 lives a year in the U.S. and 75,000 lives in low-income countries.”

If proven effective, adding aspirin to current chemo- and hormonal therapy may enhance survival. Outside the US, aspirin’s low cost ($6/year) would make it a major aid in developing nations unable to access expensive therapies.

“The epidemiological and preclinical evidence linking aspirin with a positive effect on breast cancer recurrence is very strong, but we need a prospective trial like this one to definitively determine the role of aspirin in the disease,” said Michelle Holmes, MD, DrPH, who is an associate professor of Medicine and Epidemiology in the Channing Division of Network Medicine at BWH and one of the Partnering PIs of the trial.

In the U.S., the pharmaceutical industry plays a significant role in sponsoring cancer treatment, but there has been little industry incentive to fund a large-scale trial using aspirin, which is generic and widely available over-the-counter. However, the Department of Defense Breakthrough Award is a unique mechanism that supports studies like the ABC Trial which would be unlikely to receive funding through traditional sources.

“This trial will be the first of its kind in United States,” said Eric Winer, MD, Director of Breast Oncology Program, Professor of Medicine, and Thompson Chair of Breast Cancer Research at Dana-Farber Cancer Institute. “The potential benefits of aspirin in preventing breast recurrence are significant and we look forward to determining if aspirin could augment current therapies. This is a treatment that needs to be evaluated further,” emphasized Dr. Winer, who is also a Partnering PI of the grant.

The investigators plan to combine results with a large-scale international trial that is also exploring the role of aspirin in cancer and will allow researchers to analyze whether aspirin’s benefit is specific to certain subtypes of breast cancer. Researchers note that although aspirin has some known risks, most notably bleeding, it has been widely and safely used in many trials and in clinical practice to prevent other diseases, such as heart disease and colon cancer.

The Breakthrough Award, which is a unique mechanism for the support of studies which are not a good fit for traditional funding mechanisms, requires involvement of Patient Advocates at all levels of the research review and performance since they play an important role in education around breast cancer prevention and treatment, and often have personal experience with the disease.

“Access to effective and affordable treatment for breast cancer is an issue of global concern. The availability and relative low toxicity of aspirin and its potential to significantly extend survival (and potentially reduce deaths) could affect the lives of millions of patients and their families," said Carol Matyka, an ABC Trial Patient Advocate.