Urgent checks as 4,500 may have wrongly been given cancer all-clear by blundering doctor

It has emerged that a senior pathologist made mistakes when examining up to 4,500 tissue samples.

Samples that should have given reason for concern were labelled as "all clear" by Dr Roger Williams, a former trust executive.

Three patients have already been traced and are being treated for cancer. Another 12 are being contacted by the hospital.

But experts have warned that pathologists carry out thousands of tissue tests each year and dozens of patients given the allclear-could have the disease.

Dr Williams, 64, a respected consultant, had made serious errors while carrying out tests for the disease.

During a review of results, medical staff found that three patients who should have been told their samples were clinically suspicious and, in some cases, actually indicative of cancer, were actually given the all-clear.

An inquiry has been launched at the Wrexham Maelor Hospital, in North Wales, to establish how many may be affected.

Up to 4,500 cancer tests will be checked again.

Trust bosses did not reveal what type of cancers were being tissuetested or the condition of the three patients being treated.

But one colleague of Dr Williams was astonished by his errors.

He said the pathologist was "one of the most thorough and competent I have ever met".

When the Daily Mail approached him at his £700,000 home in Llangollen, North Wales, last night, Dr Williams said: "I have had a very bad day. My career is ended. I have harmed patients."

Tissue samples given a clinically suspicious or positive result are routinely double checked at the hospital.

But in May, the NHS Trust started checking results designated as not clinically suspicious.

This is how the errors came to light on September 5.

Hospital bosses said the investigation involves the testing of tissue samples between April 2006 and September last year by Dr Williams, a consultant of 25 years experience.

He was working as a locum at the hospital following his retirement from the post of trust medical director three years ago.

He stepped down after the errors were discovered.

Mary Burrows, chief executive of the North East Wales NHS Trust, said: "Our first rule was to make things clinically safe, then we contacted the three patients concerned, then went to the Royal College of Pathologists to ask how big the problem was and arranged for a 10 per cent sample review which is being carried out by the Countess of Chester Hospital."

The Trust said patients with concerns should note that the tests in question relate solely to tissue samples and not, for example, to blood tests, cervical smear tests, urine tests, swabs or X-rays.

Last night MPs and patient groups called for a full investigation to establish how Dr Williams was able to make such errors.

Roger Goss, of Patient Concern, said: "The patients must be distraught with worry over this dreadful announcement.

"The fact that it appears tissue samples were taken from patients suggests they had symptoms of cancer and this wasn't a simple screening procedure.

"This could be a very serious thing indeed.

"This graphically highlights the case for an evaluation of every doctor's fitness to practise every five years."

Ian Lucas, MP for Wrexham, said: "For those who had the tests it's a very worrying time indeed and I feel for them.

"We do need to have a full investigation to find out what went wrong."

North East Wales NHS Trust said: "While we recognise that this statement may cause worry and distress we would like to reassure patients who may be concerned that we are using all possible resources to investigate every case and to contact affected patients on an individual basis as quickly as possible."

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