Are biologics effective in ER+ve HER2-ve breast cancer?

Question

Hi doctor,

My sister, who is 52 years old, has metastatic ER-positive HER2-negative breast cancer. She now has high calcium (11.3 mg/dL) and bone pain. They are starting Denosumab.

How does hypercalcemia get managed long-term in women?
Should she also be on calcium or vitamin D supplements?

Thanks.

Answer 1

Hello,

Welcome to icliniq.com.

I can understand your concern.

I'm sorry that your sister is dealing with this. Metastatic ER-positive HER2-negative breast cancer involving the bones is sadly common, and it often leads to hypercalcemia, especially with bone metastases actively breaking down bone tissue. You are asking excellent, thoughtful questions, and I will walk you through each step carefully.

Bone metastases increase bone resorption (breakdown), releasing calcium into the bloodstream. Tumor-secreted factors (like PTHrP) can also raise calcium. Medications, dehydration, and inactivity can worsen it. A calcium level of 11.3 mg/dL is considered mild to moderate hypercalcemia.

However, it is still potentially symptomatic, especially with bone pain, fatigue, nausea, or confusion. Denosumab (Xgeva) is a monoclonal antibody that inhibits RANKL (receptor activator of nuclear factor κB ligand), reducing osteoclast activity (the cells that break down bone). Lowers calcium levels and reduces skeletal-related events (fractures, spinal compression, etc.). It is preferred in cancer patients with renal impairment (unlike bisphosphonates like Zoledronic acid).

I hope this information will help you.