Bones are made of salt deposits and a living, organic material. The salt deposits mainly contain calcium and phosphorus, with just a small amount of magnesium, sodium and potassium carbonate. Both the salt deposits and the organic material give bone its strength, but cancer treatments can be detrimental to bone health.
Normal Bone Health
The bones are constantly reforming. Bone cells called osteoclasts have the responsibility of breaking down all of the old bone in the body, while the osteoblast bone cells lay down new bone. A person normally has the highest density of bone when he is in his mid 20s, and starts to lose approximately 0.3 percent to 0.5 percent every year around 10 years later, according to Lawrence Raisz, M.D., director of the University of Connecticut Center for Osteoporosis in "The Merck Manual for Healthcare Professionals." Cancer treatments can affect bone health.
Cancer Treatments and Bone Health
Some cancer treatments, specifically the chemotherapeutic medications, can lower the levels of calcium, a mineral that plays a vital role in bone health. Low levels of calcium can lead to osteoporosis and fractures of the bones. Glucocorticoids are synthetic steroid hormones, and their long-term use can also result in osteoporosis and bone fractures, writes Robert Lindsay, M.D., Ph.D., chief of Internal Medicine at Helen Hayes Hospital in "Harrison's Principles of Internal Medicine." Radiation therapy is another cancer treatment that can negatively affect the health of the bones.
Metastasis to the Bones
Metastasis is the medical term that describes the spread of bacteria or disease from one area in the body to another area. Cancers of the breast, lung, thyroid, kidneys and prostate can all spread to the bone, explains Shreyaskumar Patel, M.D., deputy chairman at the University of Texas in "Harrison's Principles of Internal Medicine." In fact, approximately 80 percent of all metastases to the bone originate from cancers in the breast, lung and prostate. Most of the time, they spread through the bloodstream and affect the vertebrae, pelvis and hips.
Prevention of Bone Loss in Cancer
To help lower the bone loss that can occur during the treatment for cancer, the MD Anderson Cancer Center at the University of Texas recommends that people exercise by jumping rope, climbing the stairs or walking, because the weight associated with these type of exercises will build muscles and promote the production of osteoblasts. They recommend people consume enough vitamin D and calcium, take precautions to avoid falls and do not become underweight.
Medical Prevention of Bone Loss in Cancer
People having treatments for cancer should get a bone density scan before starting cancer treatment, during the treatment and after, suggests the MD Anderson Cancer Center. The bone density scan is called the DEXA scan, short for dual-energy x-ray absorptiometry, and it measures the density of the bones and can predict the possibility that someone may develop a fracture. There are also medications, called bisphosphonates, which will slow the loss of bone and may even stimulate the growth of new bone.
References
- "Harrison's Principles of Internal Medicine"; Anthony Fauci, M.D., Dennis Kasper, M.D., Dan Longo, M.D. et al.; 2008
- "MD Anderson Manual of Medical Oncology"; Hagop Kantarjian, M.D., Robert Wolff, M.D., Charles Koller, M.D.; 2006
- The Merck Manual for Healthcare Professionals: Osteoporosis
