Any mistakes in diagnosing cancer at the hospital were "within the expected range" of error, according to the Royal College of Pathologists.

However, these "acceptable mistakes" involved 1.6 per cent of cases, and included two cases in which breasts were unneccessarily removed from women.

The Kent and Canterbury's laboratory, which has now closed, was dogged by scandal after it was discovered that mistakes by cervical screeners missed cancers in hundreds of women.

A report into the events blamed staff shortages, poor morale, insufficient training and the failure of doctors to respond to warning signs about bad quality work at the laboratory.

However, the Royal College, which was brought in to look at the laboratory's work involving other cancers, did not find a similar situation.

Misdiagnosis and oversights

It did find seven cases in which misdiagnosis by laboratory experts worsened the clinical outcome for the patients.

And in 35 other cases it found "oversights" which could have affected the way that people were treated.

The Kent and Canterbury Hospital has now closed its laboratory

However, experts say that it is impossible for any cancer diagnosis service to report with 100 per cent accuracy, and that a small number of mistakes are inevitable.

All of these cases are now under review by the Kent of Canterbury, and one expert has been ordered to undergo retraining, with his work the subject of more scrutiny by trust bosses.

The college report said: "On the basis of comparison with available published data the error rate was within the expected range, and thus there is no indication to carry out a further external retrospective review."

Eight women died

The failures in the cervical screening programme at Kent and Canterbury are believed to have led to the deaths of eight women, and forced 30 to undergo hysterectomies which might have been avoided by earlier diagnosis.

More than 90,000 slides of cervical smear cells were retested.

Three women have already won a court cases claiming that their cancers should have been spotted. The hospital has settled other cases out of court.

The laboratory service at Kent and Canterbury has now been moved to the nearby William Harvey Hospital in Ashford.

The trust's chief executive, David Astley, said he was "very sorry" about the cases in which breasts were unneccessarily removed, and was taking steps to inform the patients concerned.

He said: "People can be confident about using health services in East Kent. We have a centralised laboratory where doctors are able to work in a larger team."

In an appeal against a decision to award damages to women with rare forms of cervical cancers, the health authority stressed that the public should not expect cervical screening to find 100 per cent of cancers.