Audit shows weaknesses in cervical cancer screening

An audit of cervical cancer screening in Leicestershire has shown that 1 in 3 women who go for screening may be given an incorrect result.

The audit, carried out last year by an internal team of experienced clinicians who wanted to improve standards, studied 403 women who had developed cervical cancer between 1993 and last year. Of those, 79 had not been for regular smears. In 122 of the remaining 324 cases, an error had occurred in the way the screeners had reported the slide results.

In 44 of the 122 cases there had been no adverse consequences as the cancer was diagnosed soon afterwards. But the other 78 experienced a worsening of their condition before it was diagnosed, and 14 died.

In an executive summary to the report, the authors said: “The audit concluded that, while the findings are clearly a matter for concern, the cervical cancer screening programme is not failing.

“Currently there are about 20 deaths each year from cervical cancer in Leicestershire, compared with around 30 each year in the late 1980s. If all the slides had been “correctly” reported, a further two deaths each year might have been avoided and eight-nine women each year might have been spared radical treatment.”

The Leicestershire cervical screening service serves a population of 970000, of whom 230000 are women in the age range of 20-64 years. About 75000 cervical smears from about 60000 women are examined each year.

Dr Sheila Adam, health services director at the Department of Health, alerted all doctors in England to the fact that the results of the audit were going to be announced and warned them that patients might contact them with concerns about their own screening results.

She emphasised that the programme had achieved its quality standards throughout the period. “However, as would be expected given that the cervical smear is predictive of disease rather than a definitive diagnostic test, the audit has revealed a number of reporting discrepancies, including false negatives and under-reporting.

“On rereading by a consultant pathologist, some of the false negatives had relatively obvious abnormalities, but most were of a type which remains difficult to recognise. No individual screener was implicated.”

Dr Adam added that in future, whenever a woman was diagnosed with either invasive cervical cancer or an interval breast cancer, her consultant would explain that her screening history would be reviewed and would offer to discuss with her the outcome of that clinical audit.

A statement from Leicestershire health authority said that all of the 122 women, or their next of kin, were being contacted by letter, and were being offered early appointments with a consultant to discuss the clinical details and would be offered counselling and support.

“We have also made improvements to the local screening service as a result of the audit. A protocol has been introduced locally which ensures that the screening history and smear slides are reviewed again as and when a woman is diagnosed with cervical cancer.” (See p 1188.)