Could statins protect against heart harms induced by certain breast cancer treatments?

Written by Ilana Landau, Editor

New population-based research suggests that amongst older women with early-stage breast cancer receiving anthracycline or trastuzumab (Herceptin®) therapies, statins may be effective at protecting against treatment-included heart failure.

An estimated 25% of women with breast cancer will receive chemotherapy with anthracycline or a targeted therapy such as trastuzumab (Herceptin®). Though potentially lifesaving, these therapies can be associated with severe treatment-induced cardiac complications, including heart failure. New research, led by David Bobrowski (University of Toronto; ON, Canada), suggests that amongst women with breast cancer receiving anthracycline or trastuzumab therapies, statins may be effective at protecting against such treatment-included heart failure.

Studies have demonstrated that attenuated heart function resulting from breast cancer treatment initiation can occur within months of treatment start. In clinical trials, drugs such as angiotensin antagonists and beta blockers — which are commonly used to manage cardiac conditions — have displayed only modest cardioprotective effects in individuals with breast cancer, and may induce side effects that are especially debilitating for this patient population in combination with cancer treatment side effects.

Bobrowski explained: “To date, there has been limited evidence supporting the safety and effectiveness of large-scale use of cardioprotective medications for patients with early stage breast cancer. Our results suggest that taking statins is associated with a significantly lower risk of developing heart failure requiring hospital-based care among women with early stage breast cancer who received one of these cancer therapies.”

In this population-based study, investigators analyzed medical record data of close to 4000 women — without histories of heart failure — over the age of 66 years old with early-stage breast cancer; 2545 women had received anthracycline and 1345 had received trastuzumab therapy. Approximately 37% and 42% of anthracycline- and trastuzumab-treated women were prescribed statins whilst receiving their breast cancer treatment, though it was not possible to validate their adherence to the statin treatment regimen.

Researchers generated 1122 pairs of phenotypically similar women who had received the same breast cancer treatment; in each pair, one woman had also been prescribed a statin and the other had not. Compared with women who were not receiving statins, women who were prescribed statins has significantly lower risks of presenting, and being admitted to, hospitals with heart failure.

This study was unique as, unlike the majority of previous field research, the study investigators did not assess decline in left ventricle function of study participants — a commonly used indicator of heart failure. Instead, Bobrowski et al. evaluated clinically overt heart failure.

“Declines in left ventricle function can be predictive of heart failure, but overt heart failure gives a more clear-cut outcome that carries more relevance to cancer patients and their physicians,” explained Bobrowski.

Though this study builds on previous research, and represents the largest evaluation of the cardioprotective effect of statins for this patient population, the study authors stress the importance of further, prospective research: “If these associations are confirmed in a prospective trial, this will represent an important step forward to optimize cancer outcomes by decreasing the trade-off of long-term cardiac disease or related deaths,” concluded Bobrowski.