Advanced Oncology Certified Nurse Practitioner (AOCNP) Certification Practice Test

What effect do metastatic bone lesions have on calcium levels?

1. They decrease calcium levels.

2. They stabilize calcium levels.

3. They lead to hypercalcemia.

4. They have no effect on calcium levels.

The correct answer is: They lead to hypercalcemia.

Metastatic bone lesions often lead to hypercalcemia due to their ability to disrupt the normal balance of calcium metabolism in the body. When cancer cells metastasize to the bones, they can stimulate osteoclast activity, which are the cells responsible for bone resorption. This process results in the release of calcium stored in the bones into the bloodstream, thereby increasing serum calcium levels, a condition known as hypercalcemia. In conditions where bone is actively being resorbed, such as in cases of metastatic disease, there is a significant increase in the levels of circulating calcium. The presence of tumor cells in the bone can produce factors that directly stimulate osteoclasts or can cause osteolytic lesions where the bone is literally being broken down. This leads to a clinical scenario where patients may experience symptoms associated with hypercalcemia, such as fatigue, weakness, confusion, and nausea. In contrast, the other choices do not align with the pathophysiology of metastatic bone disease. While certain situations may involve different mechanisms, the overall impact of metastases to bone is predominantly an increase in calcium levels in the body.