Vitamin D may fight aggressive breast cancer

By blocking a metabolic pathway that allows tumor cells to grow unchecked, vitamin D may play a role in providing a safe and cost-effective strategy to fight certain types of breast cancer with the poorest prognosis, new research from Spain suggests.

The in vitro study investigated molecular pathways that contribute to the growth of human breast tumor cells of the triple-negative type, a treatment-resistant form of cancer, which often proves fatal, that tends to strike younger women (1). The research identified a novel pathway that not only allows tumor cells to grow un-checked, but also explains the reduced sensitivity of these types of tumors to current therapeutic strategies. Vitamin D was found to play a role in turning off this pathway, providing the potential for a new therapy.

The researchers commented that in the future, women with triple-negative breast cancer may benefit from a treatment that includes vitamin D and some protease inhibitors. Although chemotherapy is the most effective treatment for triple-negative breast cancer, it has profound side-effects. In a further step, vitamin D therapy will have to be studied in clinical trials for its efficacy.

1. Grotsky D. A. et al. BRCA1 loss activates cathepsin L-mediated degradation of 53BP1 in breast cancer cells. The Journal of Cell Biology. 2013; 200(2):187–202.