You've just moved house and want to register with a new GP. You drop in to reception and the receptionist gives you a form to fill in, and a questionnaire asking about any health problems, medicines you take etc. At your registration health check the nurse checks you weight, height and blood pressure. So far, so familiar. But just imagine if she then asked you to open wide - a mouth swab of your saliva would give your doctor your whole genetic print-out, predicting what diseases you were most likely to get and when, and which medicines you were most likely to be cured by.
Sound like science fiction? Well, maybe - but the future might be nearer than you think. Personalised medicine - using information about your individual make-up (for instance your genes) to tailor treatment just to you is happening up and down the country already. Some of the results are nothing short of remarkable.
Blood pressure treatment - already tailored to you
You may not know it, but if you're taking medicine to keep high blood pressure controlled your doctor may already be 'personalising' your treatment. He didn't need a fancy test - just your birth certificate. Younger people with high blood pressure (under 55) often respond best to medicines called ACE inhibitors or ARBs (all these tablets have names ending in '-pril' or '-sartan', such as losartan. For over-55s, the best bet for first blood pressure treatment is water tablets or calcium- channel blocking tablets like amlodipine. People of Afro-Caribbean origin don't tend to respond as well to ACE inhibitors or ARBs as first-line treatment, so they will usually also get amlodipine as first- line treatment.
Personalising cancer treatment
We all know breast cancer is different from lung cancer, so they won't necessarily respond to the same treatments. But did you know even one cancer, like lung cancer, comes in several types? Doctors have known for years about different cell types that grow out of control, causing a given kind of cancer. Now they're discovering more and more 'tissue types' within a cell type. This is helping them to understand why one patient will respond to particular cancer treatment while another, with the same cancer, won't. That's great news because it helps doctors target treatment, giving it to the people most likely to benefit and avoiding chemotherapy that won't help but almost always causes side effects.
Giving breast cancer a personal service
Perhaps the best known advances in personalised medicine came with breast cancer. Last year, Angelina Jolie's courageous decision to speak publicly about her mastectomies highlighted the risks associated with carrying the BRCA gene. Women with a strong family history of breast and/or ovarian cancer can now be tested for this gene, to help make decisions about whether they should consider similar surgery or take preventive hormone treatment. Oestrogen 'receptors' on breast cancer cells tell us whether a cancer will respond to hormone therapy - about 75% of breast cancers in postmenopausal women do. Herceptin can produce dramatic results but only in patients whose cancer has a 'HER-2' receptor.
Next stop lung cancer
Lung cancer has a bit of a bad reputation, because survival rates are less good than for most other cancers. But that's changing, thanks to personalised medicine. First scientists discovered one gene mutation, now another protein called ALK1 has been discovered. That's led to the recent 'fast-tracked' approval of a drug called Xalkori®, which has more than doubled survival time in the right patients. These medicines only work for a small proportion of patients with lung cancer so far, but these discoveries should mean more patients get the tissue typing of cancers they need for this sort of targeted treatment. There will undoubtedly be more to come.
This inherited condition affects the lungs and digestive system by clogging them with thick, sticky mucus. Treatments have been improving slowly for years, but gene typing has meant major advances. Last year saw a new medicine, Kalydeco®, made available to offer potentially dramatic improvements to symptoms and life expectancy for patients with the 'Celtic gene' type of cystic fibrosis.
Asthma - breathing more easily?
Also in the headlines recently is the finding of a new gene in asthma, which might explain why some sufferers don't respond well to standard inhalers. In a few years, patients might be routinely tested to see if a tablet called montelukast might work better for them. This medicine works well for some kinds of asthma which are made worse by allergy (such as hay fever or contact with dogs and cats).
With thanks to 'My Weekly' magazine where this article was originally published.