CANCER waiting times provide a revealing snapshot of the state of the National Health Service.

Because, in many cases, cure depends on early diagnosis and prompt treatment, guarantees about the length of waiting times were brought in to avoid delay.

Under Scottish Government targets, patients urgently referred to hospital with suspected cancer should be seen within 62 days and treatment should start for all those who require it within 31 days of the decision to give them therapy. As The Herald reveals today, however, hundreds of cancer patients in Scotland have to wait much longer because of a shortage of operating theatre time, equipment or staff.

In the last two-and-a-half years, waiting time guarantees have been broken more than 1000 times because the NHS could not cope with the demand. And that situation is growing worse.

From a Freedom of Information inquiry, our Health Correspondent Helen Puttick has established that last year 440 breaches of the waiting time targets were due to lack of theatre space or equipment failure and 90 the result of staff shortages. This was a 41% increase on the figures for 2010, a worrying development. The trend is confirmed by the figures for the first six months of this year. These show 290 breaches of targets, again due to lack of theatres, equipment or staff.

Given the toxic combination of a continuing rise in the incidence of cancer and increasing pressure on health board budgets, the bleak prognosis is that more cancer patients will have to wait longer for treatment.

While imposing waiting time targets has the beneficial effect of focusing attention on avoiding delay, it can also have the unintended consequence of causing staff to change the criteria to meet the targets. The SNP Government set up a ticking clock system to monitor how long it took for each patient referred to hospital to be treated. This was a welcome attempt to bring transparency to waiting times information. But documents leaked to The Herald in October revealed staff were allowed to adjust waiting list results to filter out delays caused by the failure of diagnostic tests or change to a different treatment.

The Scottish Government says that the proportion of patients breaching the targets has remained relatively stable at around 5% since 2012. As the total number of patients rises, however, so does the number of those who do not receive treatment within the target time.

Targets have been effective in reducing waiting times for cancer treatment but patients and their families will be worried by the revelation they are not being met due to lack of resources and staff shortages.

An additional £30 million for the Detect Cancer Early Programme will help only if theatres, staff and equipment are available when required. Until the squeeze on health budgets can be eased, some waiting time targets will continue to be missed and patients will suffer.