Osteoprosis drug may be effective for aggressive breast cancer

CANCER DIGEST – May 5, 2018 – A common drug used to treat osteoporosis may be key to halting the most aggressive form of breast cancer, researchers say.

The drug zoledronic acid (Zometa®) is used to treat high blood calcium levels (hypercalcemia) that may occur with cancer. It is used in combination with chemotherapy for cancers of the breast and lung that have spread to bones.

In the new study by researchers at the Zhejiang University School of Medicine in Hangzhou, China found that zoledronic acid was effective in suppressing an enzyme that is produced in high levels by the aggressive subtype of breast cancer called basal-like breast cancer. The enzyme UGT8 stimulates the first step in making sulfatide, which fuels growth and metastasis in this type of tumor.

Basal-like breast cancer is very difficult to treat because it is what is referred to as triple negative. Most breast cancer treatments work by targeting tumors that are positive for estrogen receptors, progesterone receptors or a pair of hormone epidermal growth factors. Basal-like breast cancer is negative for all three and so treatments that target those factors are ineffective.

The researchers found that zoledronic acid blocked production of UGT8, which in turn caused the levels of sulfated to plunge, and halted tumor growth in mice. The study was published in the Journal of Experimental Medicine.

While much more study will be needed to confirm these findings, because zoledronic acid is already approved, it is likely a study in humans will be approved soon.