Greater Boston Urology Blog

Prostate Cancer and Bone Health: What You Need to Know

Written by GBU | Feb 10, 2017 3:32:26 PM

NOTE: What follows is informational only. Consult your personal physician regarding your specific case.

Below is a Q&A with Dr. Michael Geffin, the Director of the Advanced Prostate Cancer Clinic at Greater Boston Urology. We pulled this Q&A from Dr. Geffin's presentation at the 19th Annual Prostate Cancer Symposium in 2016. Click here to watch his complete presentation.

In the Q&A, Dr. Geffin addresses prostate cancer and bone health. Many men don't understand or realize the importance of having healthy bones, especially in the setting of prostate cancer.

Reminder: prostate cancer is the most common non-skin cancer amongst American men. It's the second leading cause of cancer death in men in this country. One in seven men will be diagnosed with prostate cancer in their lifetime. Ten to 20% of the men who present with prostate cancer will have locally advanced disease, which means it's no longer contained to their prostate. It's outside the prostate.

When prostate cancer spreads distant, it generally spreads to the bones, which is why we need to address bone health before, during, and at the end of treatment.

Without further ado, here is Dr. Geffin.

What specific bone health issues do we need to address?

We should talk about osteoporosis, but, first, let's provide a brief overview of bones. Bones are made up of two parts: the edge part (or the lamellar bone, which is like a shell) and the inner part, which is what we call the spongy bone. With osteoporosis, both areas become thinner, more brittle, and more likely to cause pain and/or fractures. Note: osteoporosis happens to women and men.

Many of the prostate cancer treatments for men—what we call androgen-deprivation therapies or ADTs—further enhance rapid osteoporosis.

Also, keep this in mind: if prostate cancer goes to the bones, those bones are going to be more brittle and more likely to fracture as well. Men who have metastatic prostate cancer to the bones could also have bone pain.

So bone health matters because we want to avoid osteoporosis and all the associated problems. In a metastatic disease, avoiding fractures will increase quality of life as well as improve survival.

When it comes to bone health, monitoring is essential. Avoid doing things that are bad for bones. Do more things that are better for bones. In addition, bone mineral density tests look at how dense your bones are. If your bones are not dense, they're brittle, osteoporotic. It's good to know this information.

How does bone density testing work?

We order a DEXA scan. The DEXA scan gives what's called a T-score. It looks at three areas of the body: the lumbar spine, the femoral neck, and the total hip. If the T-score is lower than 2.5, that's defined as osteoporosis. If it's between -2.5 and -1, that's osteopenia. Osteopenia just means thinning of the bones. It's just a different definition.

We closely watch men on androgen deprivation therapy (think Lupron, Eligard), because, again, those medications are going to cause osteoporosis to happen more rapidly.

Now, there needs to be a baseline DEXA scan done at initiation of therapy. There are some recommendations in the Canadian literature about checking this every 12 months if the DEXA scan is normal at baseline, and every 6 months if the initial DEXA scan shows osteopenia at baseline. Again, we need to monitor it.

Are there any other tools available?

The World Health Organization has what's called a Fracture Risk Assessment tool or FRAX. Essentially, it looks at the probability of hip or other fractures. It's country dependent. Men in Canada, men in the United States, men in Europe—they're going to have different parameters, but in general, it's going to look at the factors of sex, age, body mass index, prior fractures.

For example, if your parents have had a hip fracture, you're at risk. If you were on steroids for any reason, that causes further osteoporosis. Rheumatoid arthritis. Smoking history, alcohol intake, and then the femoral neck bone mineral density status as well.

Can anything improve bone health?

Yes. Let's discuss exercise and supplements, specifically calcium and vitamin D.

1. Exercise. As men get older, their strength lessens; they become weaker. They're going to lose bone muscle mass. They might experience gait issues as well. It's just the aging process in the male. The androgen deprivation therapy accelerates this process. We need to counter that. How do we counter that? An active lifestyle.

Repetitive weight-bearing exercises can increase your bone mineral density—it's something you can do while going on daily walks. If you walk with five-pound weights in each hand, you're going to improve the musculature and you're going to improve your bone density better than just walking without weights.

Exercising does a number of things. You're going to improve your quality of life and you're going to have less fatigue as well. You're going to improve your lean muscle mass, muscle strength, balance, and physical function overall. Regular exercise not only improves bone health, but also your general health.

2. Supplements. If you're on Lupron or Eligard, you need to be on calcium and vitamin D. Calcium and vitamin D are extremely important to bone health.

Many men don't understand what vitamin D does. Essentially, vitamin D allows the gut to absorb the calcium and put it into the bone. If you're eating calcium-rich foods and you're not taking vitamin D, the calcium is going to go through your gut and out the backside. It's not going to be absorbed into the blood and placed into the bones. You need to have both calcium and vitamin D as the building blocks.

Recommendations are vitamin D 800 International Units a day, maximum of 2000. There are going to be times where one does need more than 2000 International Units a day, but those are uncommon.

The calcium is recommended at 1200 mg of elemental calcium. Calcium carbonate is the general calcium that we see in our supplements.

If you are on omeprazole (e.g. Prilosec, Zegerid), you need to be on calcium citrate. Calcium carbonate will not be absorbed by your stomach and your bowels in the setting of a low acidity, which is what omeprazole does. So you'll need to take calcium citrate if you're on omeprazole. Otherwise, you'll take calcium carbonate.

Are there any medications that can help?

Yes. But before we get to that, a little background: remember, your bones are alive. They're alive now. They're being remodeled constantly. There's a constant balance between two types of general cells: osteoclasts and osteoblasts.

Osteoclasts break down the bone. Osteoblasts make the bone. Over life, you have a good balance of both. They're breaking down and building all the time. The pharmacologics will then use that balance to improve the ability to build the bone or decrease the breakdown of the bone.

The first medication, which we don't use much with prostate cancer anymore, is the bisphosphonates. It inhibits the osteoclasts, the breaking down cell. We deliver it via IV infusion that the patient would get every three months over the course of a year. It's indicated by the FDA for prevention of skeletal-related events in men with castrate-resistant prostate cancer and bone metastases. It's for a very select group of men, meaning men who are on Lupron, Eligard, but your PSA is still rising, and you have metastases. Otherwise, it's really not indicated by the FDA, and its efficacy is limited.

The more commonly used medication is denosumab. It's an antibody. Here are the brand names: Prolia® and XGEVA®. Which version a patient receives depends on the indication—i.e. if you're on androgen deprivation therapy, then you would take Prolia, which we deliver via a subcutaneous injection once every six months. If you have metastatic disease, then you would go on XGEVA (you would receive a monthly injection).

Like any medications, these drugs have side effects. The complications we worry about are low calcium and some other bone issues. Bottom line: if you're on these drugs, your doctor needs to closely monitor you. In addition, you need to take your calcium and vitamin D supplements.

One final word of caution: Be aware of osteonecrosis of the jaw. Good dentition is critical! The jaw tends to be an area where these medicines tend to cause complications, and the bone will actually die. Men will lose teeth, and then people can actually have fractures in their femurs as well.

Are there any other medications that men should consider?

In men who have prostate cancer and there's metastases to the bone, we have a newer medicine called Radium-221, brand name Xofigo®.

This drug decreases bone pain, and it increases survival in men with prostate cancer and metastases to the bones. This is a very useful drug, one we hope to—and should—use more.

Conclusion

In summary, bone health is important. In the setting of aging and prostate cancer, if you take care of your bones, your quality of life is going to improve and your overall survival will likely improve.

Your actions make a difference. You can't be sedentary. You need to be active, and you need to use weights. Get your doctor to work with you. They have the tools to help you at different stages of the prostate cancer, whether it's osteoporosis, androgen deprivation therapy, or bone metastases.

Would you like to make an appointment with Dr. Geffin or one of our other urologists? Schedule an appointment now.