When Karen Gault's treatment for bowel cancer began to fail last year, there was one snag with Avastin, the last-ditch drug that her doctor recommended. The NHS would not pay for it - and officials warned that if she bore the cost of the medicine herself, she would have to take over the funding of her entire treatment.

Avastin is prescribed in many countries. But Ms Gault - who herself long worked for the NHS, with its pledge since its creation 60 years ago of free healthcare for all - was suddenly faced with bills of more than £7,000 a month, including £2,000 for the drug itself.