Assessing the Risk
What you should know about bone density during cancer treatment.
Genes. Exercise. Medication. A combination of factors probably saved Stan Rosenfeld’s bones during prostate cancer treatment. Receiving his diagnosis at age 59 and learning that the cancer may have spread, he secured “a second, third and fourth medical opinion” and then opted for hormone therapy to reduce testosterone levels right away. Surgery, radiation and more hormone therapy followed.
Because loss of bone density and increased fracture risk are possible side effects of reduced testosterone, Rosenfeld was given a scan with low-dose radiation, or DEXA (dual energy X-ray absorptiometry), to establish his baseline bone density. He also took medication to build bone mass.
The baseline result was fine, he says. At the end of 14 months of hormone therapy, he had another DEXA scan that again showed healthy bones.
A DEXA scan, usually of the femoral neck or spine, takes up to 30 minutes. A patient’s bone density is compared against young, healthy adults, and the result is expressed as a T-score.
A T-score of 0 means that an individual’s bone mineral density (BMD) is equal to the norm for a young adult. Any BMD score between +1 and −1 is considered normal or healthy. A T-score between −1 and −2.5 indicates low bone mass, called osteopenia, but not low enough for an osteoporosis diagnosis. Healthier habits are generally encouraged for all patients, such as a calcium-rich diet or mineral supplements, weight-bearing exercises, limited alcohol and no smoking. A T-score of −2.5 or lower indicates osteoporosis and high risk of fracture. Medication may be prescribed for this group.
The World Health Organization developed a Fracture Risk Assessment Tool, or FRAX, based on data collected from populations worldwide. Using the T-score (although this is not required) and other measures, as well as answers to questions about clinical risk factors related to age, family history and lifestyle, the FRAX model calculates a patient’s risk for a hip fracture or other major skeletal incident, such as a break to the spine, hip, forearm or shoulder.
