Cervical Screening Wales has written to 369 women to advise them of an issue identified by the screening programme.
The programme, run by Public Health Wales, has become aware that a small percentage of smear test samples were sent for screening in vials (sample pots) that were out of date.
Smear tests are carried out at GP practices, sexual health clinics and hospital clinics.The cervical sample is put into a vial containing preservative fluid, and returned to the Cervical Screening Wales laboratory for screening.
It has been found that, for a very small percentage of samples, vials past the manufacturer’s expiry date were accidentally used.
Some affected samples were screened before the issue was identified, and Cervical Screening Wales has been working to review test results and to contact affected women to offer advice.
The issue affects fewer than two per cent of women who received cervical screening in Wales between July and October 2018.
Dr Sharon Hillier, Director of Screening for Public Health Wales, said:
“We apologise sincerely to all women who will receive a letter from us related to this issue.
“I can reassure women that there is no evidence that any harm has been caused by this issue. We have looked carefully at all of the results issued already and where possible have rescreened samples.
“Anyone who has not received a letter from us has not been identified as affected by the issue, and does not need to be concerned or to contact us.
“We continue to work with our health board partners to investigate how this issue arose and ensure appropriate procedures are in place.”
The incident took place at a time when Cervical Screening Wales was rolling out HPV screening – testing for the virus that causes nearly all cases of cervical cancer.
Just under half of the affected women were screened for HPV and will be advised that they should arrange a repeat smear test, as their sample cannot be rescreened.
The remaining samples, those which were initially examined for abnormal cells, have been rescreened.Of the affected women, the majority will be advised that their result is unchanged and they do not need to take further action.
A very small number – fewer than three per cent of those whose samples were rescreened – will be advised that they should have a repeat smear test.
Women in Wales aged between 25 and 49 are invited for a smear test every three years, and women aged 50 to 64 are invited every five years.
The test involves a small sample of cells from the cervix, at the top of the vagina, being taken with a small soft brush.At the laboratory, samples are first tested for the presence of high-risk types of the HPV virus that causes most cases of cervical cancer.
Cervical Screening Wales invited 210,800 women for screening in 2017/18.
Symptoms of cervical cancer can include unusual discharge from the vagina, bleeding between periods, and bleeding or pain during or after sex.
Women of any age who experience these symptoms should contact their GP, regardless of when they had their last cervical screening.