Osteoporosis in Men with Cancer
Osteoporosis is a disease in which bones become porous and weak. As they lose strength,
they are more likely to break. Bones in the spine, hip, wrist, pelvis, and upper arm
are particularly at risk of fracture in people with osteoporosis.
Osteopenia is a condition in which less bone has been lost than in osteoporosis. But
people with osteopenia are more likely to develop osteoporosis if something is not
done to stop the loss of bone.
The disease usually progresses without symptoms until it is diagnosed after a fracture.
How does osteoporosis develop?
Bone is made up of calcium and other minerals, which make bone hard. Bone density,
or more specifically, bone mineral density, refers to the mineral content of the bones.
It is related to how hard and strong they are. Low bone density is seen in osteoporosis.
Bone is a type of tissue. Like other tissues in the body, bone constantly repairs
and renews itself. In bone, this process is called remodeling. Two kinds of cells
carry out remodeling:
Osteoclasts. Cells that break down, or resorb, bone and release calcium into the blood.
Osteoblasts. Cells that draw calcium from the blood and create new bone.
A balance between the bone-building osteoblasts and bone-dissolving osteoclasts keeps
In young people, bones lengthen and increase in density. After about the age of 35,
however, bones start to lose density and strength. Most cases of osteoporosis result
from the speeding up of bone loss that can occur for a number of reasons:
Decrease in the levels of hormones (estrogen and testosterone) in the body
Lack of physical activity
Lack of calcium and vitamin D
Excessive alcohol use
Osteoporosis is more common in women than in men. This is because during menopause,
a woman's ovaries greatly slow their production of estrogen, a hormone that keeps
the bone-dissolving activity of the osteoclasts in check. After menopause the osteoblasts
continue to build bone, but they cannot keep up with the speed at which the osteoclasts
break it down. If no measures are taken to prevent or slow bone loss, osteoporosis
Bone loss in men generally begins later and advances more slowly than it does in women.
Men tend to have larger and stronger bones than women do and they do not go through
the abrupt hormonal changes that occur with menopause. But as they age men do lose
bone density, in part because of a natural decrease in testosterone. By age 65 or
70 men and women lose bone mass at similar rates. Calcium absorption, which is needed
to keep bones healthy, also decreases in men and women.
How does cancer treatment affect bone loss?
Various cancer treatments can increase the risk of osteoporosis for both men and women.
Some chemotherapy drugs used in the treatment of breast cancer and various hormonal
therapies for breast and prostate cancer can cause a loss of bone density. There are
a number of strategies to prevent and treat osteoporosis. Discuss these options with
your healthcare provider.
What causes osteoporosis in men with prostate cancer?
It is well known that testosterone and other male hormones, called androgens, can
stimulate the growth of prostate cancer. For this reason, a common treatment approach
for prostate cancer is to lower the level of testosterone in the body. This approach
has been successful in treating men with advanced prostate cancer (disease that has
spread throughout the body). Some doctors may also use it when the disease is diagnosed
early, before it has spread beyond the prostate.
While low testosterone levels can slow prostate cancer growth, they can also lead
to loss of bone density in men. In particular, hormonal therapies that deprive the
body of androgens--called androgen-deprivation therapy--increase the risk of osteoporosis.
Androgen-deprivation therapies include:
Orchiectomy. A surgical procedure to remove the testicles, the main source of testosterone.
Luteinizing hormone-releasing hormone (LHRH) analogs, or agonists. Drugs, such as
leuprolide and goserelin, that lower testosterone levels in the body.
Another class of hormonal drugs used to treat prostate cancer is the antiandrogen
agents. This class includes the drug bicalutamide.
Can osteoporosis in men with prostate cancer be prevented or treated?
Not all men develop osteoporosis as a result of androgen-deprivation therapy. But
because this hormonal treatment can increase the risk of this disease, these men should
consider having routine bone mineral density screenings. A type of X-ray called the
bone mineral density test is a safe and noninvasive way to diagnose osteoporosis,
detect low bone density, monitor the effectiveness of treatments, and predict the
risk for future fractures.
Once bone is lost, it cannot be completely replaced using current therapies. Although
it cannot be cured, osteoporosis can be slowed down. A number of approaches are available
for preventing and treating osteoporosis in men.
Lifestyle approaches for preventing bone loss in men include:
Calcium and vitamin D. Calcium comes from the food we eat. Dairy products, such as milk, yogurt, and cheese,
and nondairy foods, such as salmon, spinach, and tofu, are good sources. Vitamin D
comes from diet and the sun. For men older than 50, the recommended daily intake of
calcium is 1000 to 1200 mg, and of vitamin D, 600 to 800 international units (IU).
Exercise. Regular physical activity, especially weight-bearing exercises, such as jogging, dancing,
stair-climbing, and arm exercises can help prevent bone loss.
Limit alcohol intake
Medical approaches for preventing and treating bone loss in men include:
Bisphosphonates. Bisphosphonates are drugs that prevent the breakdown of bone. There are different
types of bisphosphonates, some that are taken orally (by mouth), others that are given
intravenously (in a vein). Two bisphosphonates--pamidronate (Aredia) and zoledronate
(Zometa), which are given as intravenous injections--can be used to treat prostate
cancer that has spread to the bones. They may also help prevent osteoporosis in men
during androgen-deprivation therapy for prostate cancer. Risedronate and alendronate
are approved by the FDA for preventing and treating osteoporosis in men and women.
Both drugs are available as oral tablets.
RANKL (receptor activator of nuclear factor kappa-B ligand) inhibitors. These drugs act in a very similar way to bisphosphonates. Prolia (denosumab) is FDA
approved for the treatment of osteoporosis. It is also approved for the prevention
of bone loss caused by hormonal therapy given for the treatment of cancer, if used
in combination with calcium and vitamin D supplement.