A cancer specialist has warned that tough choices may need to be made over which treatments should be paid for from limited public funds.

Professor John Smyth from the University of Edinburgh points out that while enormous progress has been made in cancer treatments, the health service does not have a limitless budget.

He said that means that decisions will need to be made about which types of screenings, therapies and drugs are made available.

The professor was speaking before he raised the issue at an event at the Edinburgh International Science Festival on Monday night.

As part of that he will call for a wider debate on how best to distribute the available resources, saying that others from outside the medical profession - such as lawyers and ethical experts - should have a voice in this.

The talk - titled The future of cancer treatment: Can we afford it? - will also raise the question of whether funding should be spend on treating one illness rather than another.

Mr Smyth said: "Advances in medical science are taking place as the health service comes under increased pressure. We have an ageing population, with fewer people contributing to the National Insurance budget, and this is exacerbated by a financial recession.

"Medical research is not going to slow down in the years to come, and so we must determine a way to fairly distribute available resources to patients."