Statins may protect the heart from chemo for breast cancer

Women who received statins were less likely than those who did not to have ED* visits or hospitalizations for heart failure (HHF) following chemotherapy with anthracyclines for early breast cancer (EBC) — suggesting that statins may protect the heart against damage induced by chemotherapy, at least among older women.

“Two types of cancer medications, anthracyclines and trastuzumab, are effective treatments for many women with breast cancer, however, the risk of heart muscle damage has limited their use, particularly in women who are at higher risk for heart problems because of their age or other medical issues,” said lead author Dr Husam Abdel-Qadir from the Women’s College Hospital and the Peter Munk Cardiac Centre in Toronto, Canada.

“These medications are essential to kill breast cancer cells, however, these processes can also damage the cells of the heart muscle, leading to weakening of the heart,” he added.

The retrospective cohort study involved women aged ≥66 years who received either anthracyclines or trastuzumab for newly diagnosed EBC, using data from administrative health databases. Women who were taking statins were propensity-score matched in a 1:1 ratio to those not exposed to statins, based on demographic, medical, and social factor. Eligible participants were without a history of HF. [J Am Heart Assoc 2021;doi:10.1161/JAHA.119.018393]

Among the 666 pairs of women treated with anthracyclines (median age 69 years), the 5-year cumulative incidence of ED visits or HHF were more than halved in those who took statins vs those who did not (1.2 percent vs 2.9 percent) — translating to a significant risk reduction by 55 percent (hazard ratio [HR], 0.45; p=0.01).

Similar findings were also seen in the cohort of women treated with trastuzumab (n=390 pairs; median age 71). Women who took statins saw a 54 percent reduced risk of ED visits or HHF than those who did not (2.7 percent vs 3.7 percent), although the difference did not reach statistical significance (HR, 0.46; p=0.07).

“Our findings support the idea that statins may be a potential intervention for preventing HF in patients receiving chemotherapy with anthracyclines and potentially trastuzumab,” noted Abdel-Qadir. “For women with breast cancer who meet established indications for taking a statin, they should ideally continue taking it throughout their chemotherapy treatment.”

“Women who do not have an indication for a statin should ask their healthcare team if they can join a clinical trial studying the benefits of statins in protecting against heart muscle damage during chemotherapy,” he advised. “Otherwise, they should focus on measures to optimize their cardiovascular health before, during and after chemotherapy.”

While the mechanisms underlying the protective benefit of statins against cardiotoxicity remain unknown, researchers believed that statins may mediate this through antioxidative and anti-inflammatory actions. 

“If statins protect against cardiotoxicity, the underlying mechanisms [of action of statins] are not limited to prevention of acute myocardial infarction by lowering cholesterol levels,” the researchers pointed out.

Due to the observational nature of the study, the researchers cautioned against drawing any causal relationship between statin use and lower HF risk. Although the analyses have been adjusted for various potential confounders, there might be unmeasured confounding factors. Also, the study population was older women, and thus, the findings may not apply to younger women.

“This study does not conclusively prove statins are protective,” said Abdel-Qadir. “However, this study builds on the body of evidence suggesting that they may have benefits … supporting the need for randomized controlled trials on this topic.”

*ED: Emergency department