Why do bone complications occur so often in men with prostate cancer?
They occur for a number of reasons. Principally they are the result of the disease itself; the vast majority of prostate cancers spread to bone. They can also be the result of treatment itself. The treatment of prostate cancer commonly involves the use of androgen deprivation therapy, which reduces the male hormone involved in the growth of prostate cancer. This is principally achieved through medical or surgical castration, which can reduce bone mass quite considerably. This reduction in bone mass can lead to osteoporosis, which is another potential bone complication of prostate cancer.
What are the main risks of these complications in the bone?
The main risks are pain and disability. If bones are weakened, they are more prone to fracture. The location of the metastases can determine fracture risk. If there's a metastasis in a weight-bearing bone such as the femur, for example, this bone might be more prone to fracture than others.
Additionally, if the cancer is in the spine and it presses on the spinal cord, this can result in spinal cord compression, which can result in significant disability, such as paralysis. So these are important complications.
What are the goals of therapy for bone involvement?
The goal is to prevent bone complications if possible, and treat them when they occur. I think the physician in charge of a patient with prostate cancer first has to be sensitive to the possibility of these complications, and aware of the early signs of such complications.
For example, pain is a common warning sign of an impending complication in bone. If pain is coming from a weight-bearing bone, it could be a sign that fracture is imminent. If it's back pain, it could be a sign that spinal cord compression is imminent. And this would require specific diagnostic tests such as X-rays or bone scans or MRIs, to define this risk and intervene accordingly.
