On the helpline, we often get enquiries from people (particularly women), who are concerned about weakening of their bones following treatment for cancer. We can't see or feel our bones getting thinner and many people are unaware of any problems until they break a bone. Oncologists acknowledge that this can sometimes be a neglected subject.
So what can cause it?
Some cancer treatments including those such as:
can affect the level of hormones in the body. Oestrogen helps to maintain bone calcium levels and bone density and without it bones can become weakened. Also, prostate cancer drugs that affect either the production of the male hormone testosterone, or the way it works in the body, can also impact on bone health. Bone loss also increases as we get older (osteoporosis), and this in itself can lead to an increased risk of fracture. Often aches and pains can be caused by osteoarthritis and they are not always, as many people fear, a sign of secondary bone cancer.
What can you do to reduce your risk?
Fortunately, there are things we can do to influence and reduce our risk of future fractures. Below is a list of lifestyle changes you may want to consider:
Reduce/stop smoking - current smokers are more likely to break bones as smoking can reduce calcium levels.
Don't drink too much alchohol - This can disrupt the calcium balance within the body. If you drink alcohol, try not to go over the maximum daily intake which is three to four units for men and two to three units for women. One unit counts as a single, 25ml measure of spirit, 125ml (small glass) of wine, or half a pint of standard strength lager, cider or beer.
Diet- ensure you get enough Calcium and Vitamin D. A well-balanced diet will normally give you all the calcium and vitamin D you need . However, if you're already identified as having osteoporosis, calcium and vitamin D supplements may be recommended by your consultant.
What can your doctor do?
Your consultant may use a risk assessment questionnaire to identify whether your age, family history, lifestyle and treatment put you at increased risk of fracture in the future. This questionnaire has been devised by the World Health Organisation (Fracture Risk Assessment Tool - FRAX), and you may want to look at the type of questions you might be asked here.
If you are identified as being at high risk of breaking a bone in the future, your doctor might recommend you have a special scan which measures bone density called a dual energy x-ray absorptiometry (DEXA) scan. This is a simple and painless procedure and gives a baseline from which to monitor your bone health. The result of this scan is known as a 'T' score. This measures the difference between the amount of calcium in your skeletal bones compared with a twenty-six-year-old of the same size and BMI. It is represented as a minus figure.
'T' score:
However, even if your 'T' score shows you have osteoporosis, this doesn't necessarily mean that you're at risk of breaking a bone in the short term. Other factors (such as lifestyle factors mentioned above) will be taken into account together with your T score to determine your future risk.
If you're identified as being at high risk of a fracture in the future, you might be started on a bisphosphonate to help protect your bones against some of the effects of cancer induced bone loss. Sometimes the risk of fracture is very obviously high, especially when bones have broken easily after the age of 75. In these situations, drug treatments may be prescribed without a scan.
In summary
As you can see, your risk of future bone loss and fracture is dependent on many factors. What's important is that your individual, future risk is assessed at the outset. For many people, lifestyle adjustment and monitoring is often all that is required initially. Regular monitoring will help to identify any changes from your baseline assessment and appropriate treatment can be started if required at a later date. It's recommended that monitoring be carried out every 1-2 years (depending on risk), for those at risk of cancer treatment induced bone loss.
I hope this helps to demystify why some people are started on bisphosphonates rather quickly and others are not. In short, it depends on your own individual situation and risk.
