Bone problems and osteoporosis in prostate cancer

Hormone therapy for prostate cancer can lower the levels of sex hormones (testosterone) in the blood. This can cause different side effects including problems with your bones.

Prostate cancer usually needs testosterone to grow. Hormone therapy aims to:

• stop the testicles from making testosterone
• stop testosterone from reaching cancer cells

Examples of hormone treatments include:

• drug treatments such as goserelin (Zoladex), leuprorelin (Prostap) and decapeptyl (Triptorelin)
• surgery to remove your testicles (orchidectomy)

Bone loss is a common side effect of hormone therapy. But how much bone loss you might have varies from person to person. And not all hormone treatments cause bone loss. 

Your nurse or doctor will tell you if they think you might be at risk of bone loss. Especially, if you are at high risk of having problems with your spine.

Bone loss (osteoporosis) and ageing

Getting older can also cause your bones to get thinner and weaker. Thinner bones are more at risk of breaking (fracturing). This bone thinning is called osteoporosis.

Tests for bone loss

Your doctor will assess if you are at high risk of bone loss. Getting older and having cancer treatment can increase the risk of bone loss. You'll have a bone density scan (also called a DEXA or DXA scan) if you are at high risk. 

Reducing the risk of bone loss

There are different things you can do to reduce your risk of bone loss. These include:

• making sure your diet has enough calcium and vitamin D
• avoiding caffeine and alcohol 
• exercising regularly 
• taking medicines called bisphosphonates 

Calcium and vitamin D 

Adults should generally have 700mg of calcium a day. People with osteoporosis should aim for 1000mg a day.

Dairy products such as milk, cheese and yoghurt contain calcium. Some foods have added calcium. Check food labels to see how much calcium they contain. Milk substitutes such as soya or rice milk usually do not contain as much calcium as dairy products.

You can also get calcium from:

• green vegetables (cabbage, broccoli and okra)
• soya products including tofu
• tinned fish with bones like sardines, salmon and pilchards
• nuts and dried fruit
• fortified breakfast cereals 
• bread and foods made from flour 
• tap water 

Calcium supplements are available. Dietitians recommend that you do not have more than 1500mg of calcium. This total calcium could come from your diet or a combination of diet and supplements. Too much calcium can cause tummy (abdominal) pain and diarrhoea.

Your body needs vitamin D to absorb calcium. Sunlight helps the body to make vitamin D. A daily short walk in natural sunlight makes enough vitamin D for most people. Vitamin D is also found in margarine, oily fish and egg yolks. Public Health England recommends that in winter and autumn, people in the UK should consider taking a daily supplement of vitamin D containing 10 micrograms. This is because it is difficult for people to get enough vitamin D through their diet.

Your doctor or nurse can refer you to a dietitian to check that your diet has enough calcium and vitamin D to keep your bones healthy. 

Alcohol and caffeine 

Drinking alcohol increases the risk of bone loss (osteoporosis). National guidelines recommend that you don't drink more than 14 units of alcohol per week. Caffeine can cause calcium to be lost in the urine.

Exercise

Exercise is important for bone health but it needs to be weight bearing exercise. This means that you are supporting your own weight with your legs and arms. This can strengthen muscles, improve posture, and could help with pain.

Many of us don’t do enough regular exercise. Bringing exercise into your daily life is the best way to make sure you get enough. Walking is good. Household activities are helpful, such as cleaning, gardening, shopping or even going up and down stairs. Or you could join an exercise group or class. It doesn’t have to be very energetic.

Gentle controlled exercise such as Tai Chi can be good. Although swimming doesn’t help, exercise classes in the swimming pool (aqua-aerobics) can. Walking and exercising in the pool is quite hard work because of the resistance of the water.

Don’t jog or take exercise that involves jumping if you already have osteoporosis. It puts too much strain on your bones. Take advice from your doctor or specialist nurse before starting any new type of exercise.

Medicines to help bone loss

Bones naturally break down and repair themselves. Hormone therapy can make bones break down faster than they are repairing themselves. This makes them weaker.

You might have bisphosphonates if you have cancer that has spread to other parts of your body. This is metastatic or advanced prostate cancer. Bisphosphonates can help with: 

• bone pain 
• prevent bone thinning 

You might also have bisphosphonates if you have osteoporosis and are having hormone therapy. 

Bisphosphonates move calcium cells from your blood stream into your bone. This helps to keep the bone strong. As you need to keep some calcium in your blood stream, your doctor may give you calcium tablets.

Bisphosphonates include:

• alendronate tablets
• risedronate tablets
• zoledronic Acid (Zometa) - this is a drip that you have into your bloodstream

Denosumab is a different type of drug. It works by stopping the activity of bone cells called osteoclasts. Denosumab can increase bone density to help strengthen the bone. It can be used instead of bisphosphonates to help to reduce fractures in people whose cancer has spread.

Coping with prostate cancer

It can be difficult coping with prostate cancer and its treatment. There is support available.