Testing standards specified by the HSE for its cervical cancer services are lower than those used in the US, according to a pathologist working with the company at the centre of the screening scandal.
Texas-based Clinical Pathology Laboratories Ltd (CPL) settled a High Court action with Limerick mother-of-two Vicky Phelan for €2.5 million.
It emerged from a 2014 audit that Ms Phelan had received erroneous results for a smear test she underwent in 2011, but she was not told until last September. She is now terminally ill.
Dr Thomas Wheeler, chair of pathology and immunology at the Baylor College of Medicine in Houston who also partners with CPL Laboratories, said the best way to test for cervical cancer in women over 30 is to conduct a test for the HPV virus in addition to a smear test.
However, the HSE only required the companies it contracted to carry out its screening services to conduct the regular smear test.
“Co-testing – the process of testing for HPV as well as cervical cancer – is by far the best way of screening for cervical cancer, as the HPV virus is one of the major causes of cervical cancer,” Dr Wheeler said. “As a result it is not surprising that all potential cervical cancers are not detected when a pap smear only is undertaken.”
Every year
He also noted that, even in the past in the United States when a pap [[smear] test was undertaken on its own, women were tested every year rather than every three years. Under the HSE screening programme, women are only tested every three years.
CPL Laboratories has defended its role in the cervical screening scandal, noting that it was only contracted to test the smear tests.
In a statement, the company said it is “internationally recognised that no screening is 100 per cent effective at identifying all patients who may have a particular disease.” It said it began screening for HPV in 2002.
It has also emerged that CPL Laboratories performed the screening of Irish samples through the manual examination of individual slides, rather than the computer-based imaging system it mostly uses.
The company said the results of cervical cancer screens at its lab – and the other labs contracted by the HSE to perform the testing – are “well above the accepted accuracy rate for the type of screening” and have been “continuously monitored and repeatedly endorsed by Irish health authorities as well as US laboratory accrediting agencies.”
The statement added: "What has happened to Mrs Phelan and her family from Ireland is tragic, and we deeply regret her situation. Our earnest hope is that her treatment program will result in an improved prognosis and quality of life."
Co-testing system
A spokeswoman for the HSE noted that CervicalCheck is currently moving to the co-testing system, noting "across Europe where there are national screening programmes, the most effective and recommended strategy involves HPV testing following by triage (cytology)".
The HSE also noted there is a preference in the US for this approach, though it highlighted the absence of an organised population-based cervical screening progamme like Ireland’s national screening programme.
The US operates a screening programme for low-income women, though only a small percentage of women avail of it. About 300,000 women were screened through the system in 2016. There is no requirement for a HPV test as part of this programme.
However, the vast majority of American women are screened for cervical cancer through their doctor or health insurance programmes where the co-testing approach is recommended best practice.
According to the US National Cancer Institute, "for women age 30 and older, pap and HPV co-testing is less likely to miss an abnormality than pap testing alone".
