Processing of cervical screening tests recommences in Dublin

In 2018, Dr Gabriel Scally, author of the Scoping Inquiry into the CervicalCheck Screening Programme, identified concerns about the reliance on the US in processing Irish samples amid public fears about how CervicalCheck was structured at that time.

By last year, however, his final report found significant changes and the “introduction of a properly structured quality assurance process” across screening in Ireland and the US.

The NCSL, based in the Coombe Maternity Hospital, is one of those changes. Opened in December 2022, it was welcomed by patient advocacy group 221+, which has called for processing to be returned to Ireland.

There was shock when it paused work in March after the HSE said the documentation required for the Irish National Accreditation Board was not complete. This additional work took until mid-October to complete.

The NCSL aims to process 10% of Irish samples, although the HSE expects it to do more as staff numbers increase.

“There will always be a need for a second laboratory in a quality-assured national population screening programme,” a spokeswoman said, explaining that the NCSL was never intended to do all processing.

CervicalCheck now has a single US partner, Quest Diagnostics.

In his final report, Dr Scally said that the screening service could work with fewer laboratories abroad than was previously the case because of the switch to HPV screening.

As these tests are processed differently from the old smear tests, he said this change has “dramatically reduced the number of cytology slides requiring examination”.

He said: “This HPV test is automated and has a very low false negative rate”, and this initial screening test is the only test most women will need.

“A key benefit of the switch is HPV screening tests increase detection of potential risks for women as this virus causes almost all cervical cancers,” he wrote in his final report.

According to CervicalCheck: “For every 1,000 women screened, there will be 20 who have abnormal cells.

“HPV screening detects 18 of these 20 and fails to detect two out of 20. The old ‘smear’ test would have detected 15 of these 20 and failed to detect five out of 20.”

CervicalCheck explained that this is why women have repeat screening, which should pick up on missed cases.

CervicalCheck has seen an expected 40% increase in referrals for colposcopy and said in a statement to the Irish Examiner that “the majority of women” referred for further treatment do not need to have abnormal precancerous cells removed.

It is hoped that improved screening combined with the HPV vaccine can move Ireland towards eliminating cervical cancer.

#Read My Lips

In memory of Vicky Phelan, seven high-profile Irish women get behind a special cervical screening initiative. Their call to action is 'Read my lips... choose screening - book a cervical screening test today.' 

Screening process - step by step 

The screening journey starts with invitations to women and people with a cervix aged between 25 and 65. They are usually screened in a GP practice or women’s health clinic.

HPV cervical screening tests are quick but can be uncomfortable. A nurse inserts a speculum into the woman’s vagina and uses a specialised brush to remove a sample of cells from the cervix.

On arrival in a laboratory, this sample is given a unique number. It is then put into an analyser machine, which tests it for high-risk human papillomavirus (hrHPV). These are the forms of HPV which can lead to cervical cancer.

If high-risk forms of HPV are not found, the result is sent back to the GP and CervicalCheck, which informs the woman.

However, if HPV in its high-risk form is identified, laboratory staff make a cytology slide containing some cells from the original sample. This is examined by at least two medical scientists.

If they don’t see abnormal cells, the cytology result is reported as normal and sent back to the GP and CervicalCheck. In this case, the woman will need to be screened again in one year.

If that follow-on smear is also positive for HPV but no abnormal cells are found, she will be referred for a colposcopy.

If any abnormal cells are seen, or there is a difference of opinion between the scientists, the cytology slide is sent to a cytopathologist.

The cytopathologist examines the cells to decide if they are most likely normal or more likely to be abnormal. If hrHPV is found and abnormal cells are seen, the woman is referred for a colposcopy.

This is where a specialist doctor or nurse examines the woman’s cervix using a camera with a microscope attached and can take a biopsy if necessary to be reviewed by a histopathologist.

A colposcopy happens in an outpatient clinic in one of 15 approved clinics, including St Finbarr’s Hospital in Cork and University Hospital Kerry. The results of these biopsies will clarify the diagnosis and will be discussed with the woman.

• See CervicalCheck.ie