Cancer patients' chances of survival could be put at risk by growing delays in the NHS carrying out tests that can diagnose the disease, experts have warned. The number of patients in England waiting longer than the recommended six weeks for investigations such as MRI and CT scans has doubled in a year. In April, the figure reached 16,981 - or 2.2% of all the patients waiting for such tests. Macmillan Cancer Support called the delays ‘worrying’ and said each hospital has a responsibility to meet the targets. But, it added, ‘this Government and the next one also need to take responsibility’. The charity's chief executive Ciaran Devane said: ‘It is extremely worrying that the proportion of people who face delays in receiving vital tests which can diagnose cancer has doubled since this time last year. Only two weeks ago we heard that more people are waiting longer to start treatment and now more people are waiting longer just to get diagnosed.’