Cancer is typically named for the primary site where it started in your body, such as breast or prostate cancer. It’s possible for cancer cells to break away from the primary tumor and travel to other areas of your body via your bloodstream or lymph vessels in a process known as metastasis.
While it’s possible for cancer cells to travel to virtually any tissue in your body, bones are a common landing place, especially in the case of breast, prostate, lung, thyroid and kidney cancers.
To be clear, bone metastasis is not the same as primary bone cancer (cancer that starts in your bones), the latter of which is much less common. There are two primary types of cells in your bones:
- Osteoblasts, cells that form new bone
- Osteoclasts, cells that dissolve old bone
These cells work each day to remodel (or break down and rebuild) your bones, but cancer cells can interfere with this important process. In addition, these cells produce factors that stimulate further cancer growth. Three primary bone complications may occur as a result of bone metastasis:
1. Bone pain
Bone pain resulting from metastatic cancer is a significant challenge for patients. It is often treated with opioid pain relievers or palliative radiation therapy for more localized areas of metastasis.
2. Bone loss or fracture
Bone loss may occur due to the direct effects of cancer cells or as a result of cancer treatments. Bisphosphonate medications that are commonly used to treat osteoporosis are often used to help strengthen the bones and prevent fractures in these cases.
Another option is denosumab, a drug that is injected under your skin. It’s approved to increase bone mass in people at high risk for fracture.
Hypercalcemia is an increased level of calcium in your bloodstream. The vast majority of your body’s calcium (99 percent) is stored in your bones while only the remaining 1 percent travels through your bloodstream to be used for a variety of purposes such as nerve function, blood clotting, muscle contraction and more.
When your body needs more calcium, it’s released into your bloodstream during bone remodeling. But in the case of bone metastasis, the cancer can disrupt the normal remodeling process, leading to an excess release of calcium into your bloodstream.
Hypercalcemia is treated by addressing the underlying cancer and, if that’s not possible, by increasing hydration, which helps decrease blood calcium levels. Diuretic medications may also be used because they’re known to decrease calcium levels. If left untreated, hypercalcemia can be life threatening.
In many cases, bone complications of cancer can be managed effectively to reduce your symptoms and even potentially improve bone density. If you or a loved one is affected, be sure to talk with your health care provider about what types of treatment options may be best for you.