But it looks like lowering cholesterol is the key.
Taking statins significantly reduces breast cancer mortality, according to new research.
A Finnish retrospective population-based cohort study, published in JAMA Network Open, has revealed women using statins after being diagnosed with breast cancer have a 15% reduction in the risk of dying from breast cancer.
Researchers followed over 13,000 females with breast cancer for a median of 4.5 years after diagnosis to explore potential associations between serum cholesterol, statin use and breast cancer mortality.
Patients whose cholesterol level dropped after starting statins had a 51% reduction in the risk of dying from breast cancer. Statin use was not significantly associated with reduced breast cancer mortality in patients whose cholesterol remained unchanged.
Breast cancer is a leading cause of death worldwide among women.
Previous research suggests statins may improve breast cancer survival by reducing serum lipoprotein levels and/or inducing cell death by inhibiting HMG-CoA reductase activity.
Conversely, serum cholesterol, a precursor for oestrogen, may contribute to breast cancer risk. If, and how, statin use and cholesterol levels (independently or together) affect breast cancer outcomes has so far been unclear.
“The interplay between cardiovascular risk factors and cancer is a very important area of inquiry,” said Professor Bogda Koczwara, a medical oncologist at the Flinders Centre for Innovation in Cancer in South Australia.
“We need to start designing studies that answer the questions of whether mechanisms can potentially be targeted to benefit both cardiovascular risk factors and cancer. Wouldn’t it be exciting if we could get two for the price of one?”
Professor Koczwara felt it was a well-performed study but would have liked the researchers to include additional factors such as obesity and the use of lifestyle interventions in their analyses.
The researchers felt the changes in cholesterol after being prescribed statins could explain the association.
“The primary cholesterol metabolite activates the oestrogen receptors, subsequently increasing breast cancer cellular proliferation and tumour growth,” they wrote.
“Cholesterol is also a precursor for [the] biosynthesis of oestrogen, which in high levels is considered to be a mammary gland carcinogen.”
Professor Koczwara agreed with the potential mechanisms underlying the association between statin use and breast cancer-related mortality, but emphasised statins were not the only way to manage their cholesterol levels and cardiovascular health.
“There are significant trade-offs with putting people on statins. I think there is compelling enough evidence that if you had a diagnosis of cancer, you need to manage your weight, you need to exercise and have a healthy diet.
“This is not the study that says ‘you should put all patients with cancer on statins’,” she told TMR.