Heart disease linked to elevated risk for advanced breast cancer
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Key takeaways:
- Women with cardiovascular disease may have a higher risk for advanced breast cancer diagnosis.
- Researchers observed the association for hormone receptor-positive disease.
Women diagnosed with advanced breast cancer appeared more likely than those with earlier-stage breast cancer to have pre-existing cardiovascular disease, according to results of a retrospective study.
The association persisted among women with locally advanced or metastatic breast cancer, as well as for those with hormone receptor-positive disease.
“Cardiovascular optimization is going to potentially impact cardiovascular disease and cancer outcomes,” Kevin T. Nead, MD, MPhil, assistant professor of epidemiology and radiation oncology at The University of Texas MD Anderson Cancer Center, told Healio.
Background and methods
Cardiovascular disease and cancer cause the most deaths in the U.S.
“For a long time, we attributed that to shared risk factors,” Nead said. “If you don’t live a healthy lifestyle, some of those risk factors like smoking contribute to cardiovascular disease and cancer. In the last 5 years or so, there’s been more data coming out — mostly in mouse studies — showing a direct link between cardiovascular disease and cancer. In particular, they are showing that cardiovascular events like heart attacks essentially suppress the immune system. In mice, the immune system doesn’t do its job to stop cancers before they develop or help prevent them from spreading or progressing. You get more cancer, cancers that are faster growing and cancers that are more likely to spread in mice.”
Nead and colleagues used SEER-Medicare linked databases to evaluate the association between cardiovascular disease and cancer among 19,292 women (median age, 73 years; 86.5% white). All women had screening mammograms within 2 years of breast cancer diagnosis.
Researchers established two matched cohorts with 9,646 people in each. The first cohort consisted of women diagnosed with early-stage breast cancer and the other included women diagnosed with locally advanced or metastatic disease.
Prevalence of cardiovascular disease at time of breast cancer diagnosis served as the primary endpoint.
Results
About half (49.1%) of the individuals in the matched cohorts had cardiovascular disease. Of those, 91.5% of cases had been found in the 2 years before breast cancer diagnosis.
Women diagnosed with metastatic breast cancer had higher odds of pre-existing cardiovascular disease than those diagnosed with early-stage disease (OR = 1.1; 95% CI, 1.03-1.17).
Women diagnosed with locally advanced disease also had a higher likelihood of cardiovascular disease than those with early-stage disease (OR = 1.09; 95% CI, 1.02-1.17).
“Ten percent is not a huge absolute change but, in cancer and cardiovascular disease, we’re talking about potentially a lot of people,” Nead said.
Researchers observed the association for hormone receptor-positive breast cancer (OR = 1.11; 95% CI, 1.03-1.19) but not for hormone receptor-negative disease.
Approximately 70% of all breast cancer cases are hormone receptor-positive/HER2-negative, according to an MD Anderson Cancer Center press release. The 5-year survival rate for metastatic hormone receptor-positive/HER2-negative disease is 34%.
“Where the effect seemed to come from in our study is the hormone receptor-positive/HER2 negative subtype, which is typically the slowest growing breast cancer subtype,” Nead said. “I think that makes sense. I don’t think that the contribution of cardiovascular disease is so strong that if somebody develops a very aggressive, triple-negative breast cancer that there’s going to be a lot of space for cardiovascular disease to have an impact.
“But hormone receptor-positive/HER2 negative cancer [tends] to be slow growing. They might not get detected for quite a while,” he added. “They might stay small for a long time. It gives a larger window where that cancer might have developed prior to being formally diagnosed, where somebody could have a cardiovascular event or some other kind of cardiovascular health outcome that might have the chance to drive that immunosuppressive state and impact that breast cancer.”
Researchers acknowledged study limitations, including its observational nature and the inability to determine causality.
‘Reinforce’ the findings
Prospective studies are needed to further investigate this potential link, Need said, though he emphasized they would be difficult to conduct.
“The exposure is a cardiovascular event or severe cardiovascular disease. You can’t really randomize people to that,” Nead said. “The best study design you’re going to come up with is more of a prospective population that was probably run for some other reason. Researchers would identify the individuals who had an event and those who didn't, and then look forward in time to see if there's a difference in cancer incidence and severity at the time of diagnosis.”
Nead and colleagues also are testing the hypothesis on prostate cancer, another slow-developing malignancy.
“If we see this effect in low-risk prostate cancers but we don’t see it in a more aggressive type of cancer like pancreatic cancer, that would help reinforce this hypothesis,” Nead said.
“Cancer prevention and early detection is really where we can make the biggest positive impact on patients,” he added. “If we can prevent people from getting cancer, if we can detect them early while they’re curable, patients are in a much better position than having an advanced cancer with a fancy new medication.”
References:
- Angelov I, et al. JAMA Netw Open. 2025;doi:10.1001/jamanetworkopen.2024.52890.
- MD Anderson Cancer Center. Patients with heart disease may be at increased risk for advanced breast cancer (press release). Available at: https://www.mdanderson.org/newsroom/-patients-with-heart-disease-may-be-at-increased-risk-for-advanc.h00-159703068.html. Published Jan. 2, 2025. Accessed Jan. 8, 2025.
For more information:
Kevin T. Nead, MD, MPhil, can be reached at ktnead@mdanderson.org.
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