Osteoporosis Drugs Counteract Bone Metastasis
“The discovery and development of the bisphosphonates … is a paradigm of a successful journey from ‘bench to bedside’.”i
Bisphosphonates are a class of drugs most commonly used to strengthen thinning bones (low bone mass) in older people. During aging, the normal balance of healthy bone maintenance (re-absorbing old bone and building new bone) may become disrupted. When too much old bone is being re-absorbed, not enough new bone is being built, or both, many tiny holes form that make bone less dense and more prone to break. Bisphosphonates such as Fosomax, Boniva, Actinel etc. help keep bones strong by helping prevent too much reabsorption of old bone.
Bone mets also disrupt normal bone activity
Prostate, breast and lung cancers that start to spread (metastasize) from their primary tumor have a preference for colonizing bone, where they wreak havoc. The tumor cells are drawn to bone and marrow because of high blood flow which carries oxygen and nutrients to fuel tumor cells, and because the bone’s growth factors that control the reabsorption/building balance are hijacked by the tumor cells to direct their own growth. In the process, the new bone tumors severely interrupt normal bone balance by taking one of two extreme directions. Either
a) They form osteolytic tumors in which the bone rapidly becomes porous and fragile, or
b) They form osteoblastic tumors in which too much new bone is formed, causing thickened inflexible bone that is painful and brittle.
Both types of bone mets eventually lead to nerve pain that can become excruciating if not managed.
Bisphosphonates – a good treatment for bone mets
While bisphosphonates have been in use for age-related osteoporosis for roughly 40 years, they were not vigorously studied for bone mets until the 1990s onward. Now they are a treatment of choice for bone pain, and the earlier therapy with bisphosphonates begins, the more effective it is at suppressing tumor activity in the bone, minimizing or even preventing pain, and keeping bones strong. Although these drugs cannot cure bone metastasis,
In fact, some researchers theorize that bisphosphonates may be able to prevent bone mets, and research efforts are ongoing in hopes of developing bisphosphonate-based deterrence. Meanwhile, chemotherapies and bisphosphonates used in combination are generally highly effective in controlling tumor activity as well as alleviating bone pain.
When medication loses effectiveness
Since bisphosphonates are not curative, bone mets may eventually progress to a point where drug management is no longer effective for easing pain. However, a noninvasive outpatient treatment that involves no surgery or radiation is highly effective for this purpose. It is called MR-guided Focused Ultrasound (MRgFUS). Using real-time magnetic resonance imaging (MRI) guidance, sound waves are harnessed to focus on the tumor. Where the rays converge, they generate intense heat to destroy the local tumor and deaden the nerves that send pain signals to the brain. Although it does not cure the cancer, most patients find it highly effective for pain relief.
For more information, or to find out if you or a loved one is a candidate for MRgFUS for bone mets, contact the Sperling Medical Group.
- Bone mets