Prostate Cancer's Aftermath
A highly successful treatment for the disease brings a serious side effect: weakened bones. A new therapy, however, can help.
About 15 years ago, Matthew Smith, a prostate cancer researcher at MGH, drew attention to the dark side of a highly successful treatment for advanced prostate cancer. Androgen deprivation therapy depletes the testosterone that fuels prostate cancer cell growth. But the loss of the hormone weakens bone, putting men on ADT at greater risk of osteoporosis and bone fractures.
Smith is finding that alleviating the problem of bone fractures may also alleviate the related problem that prostate cancer tends to metastasize to the bone, which is what makes the cancer deadly. Bone constantly remodels itself, with cells called osteoblasts constructing new bone, and their counterparts, osteoclasts, absorbing old bone tissue. This ongoing reconstruction project makes the bone fertile soil for prostate cancer cells, which use the same growth signals that orchestrate the coming and going of bone cells. But drugs that limit osteoclast activity keep bones strong and, Smith’s research is showing, can both treat and prevent bone metastasis. In part because of trials led by Smith, the FDA has approved such a drug, denosumab, to treat bone metastasis and help prevent fractures in prostate cancer patients.