More than 15,000 patients are dying in Britain every year as a result of cancer treatments rather than the disease itself, warns Lord Saatchi Tory peer's wife Josephine Hart died from a form of ovarian cancer in 2011 He is campaigning for law changes to let doctors carry out alternative treatments without fear of litigation More than 15,000 people in Britain die every year as a result of cancer treatments rather than the disease itself, Lord Saatchi has said. The Tory peer said he had been given the estimate from someone in the medical profession. The advertising mogul has been campaigning for law changes to enable more innovation in treatment since his wife, novelist Josephine Hart, died from a form of ovarian cancer in 2011. Campaign: Lord Saatchi (right) with his wife Josephine Hart who died in 2011 from cancer Lord Saatchi said: 'The point is we don't know if it is 1 per cent of patients or 100 per cent of patients who die as a result of the treatment. What we do know is that the cancer drugs do such damage to the immune system that the patient is helpless to resist fatal infections like E.coli or MRSA or septicaemia. He said the Office for National Statistics under World Health Organisation guidelines only recorded 'the single underlying cause of death'. Lord Howe said statistics were collected for when cancer was the cause of death but not when treatment of cancer was the cause of death 'In other words it doesn't record what is known as the sequence of causation, sometimes known as the sequence of conditions that led to the actual death,' he said. At question time in the House of Lords, he asked health minister Earl Howe: 'As this is supposed to be the era of big data, will you review the limitations of cancer mortality statistics in order to assist scientists and doctors to have the information to move forward innovation towards a cure for cancer?' Lord Howe said statistics were collected for when cancer was the cause of death but not when treatment of cancer was the cause of death. He agreed it was 'important to have more information about the effect of cancer treatments on mortality' but added that "new data collections" were under way to provide more detail. He said new figures would provide better information about deaths following the delivery of chemotherapy while others statistics would give information about death after surgical treatment. But he warned: 'It can be very hard to identify the precise cause or sequence of progression of factors resulting in death, particularly for those with end-stage cancer or who are particularly frail and are experiencing physical deterioration. So this can never I think be a precise science.