Big Read: Why the WHO is reviewing Ireland’s cancer screening and what’s at stake

Delivering a state apology to women affected by the CervicalCheck controversy in 2019, then taoiseach Leo Varadkar outlined the “litany of failures” that had led to a collapse of confidence in the cancer screening system. Those failures related to the non-disclosure by the HSE of a review of cancer patients’ screening tests which showed missed signs of cancer or pre-cancer on earlier slides, despite those slides having been given the all-clear at the time.

Buried in Varadkar’s speech, however, was a briefly made but crucial point. “We know that cervical screening programmes cannot detect all cancers,” he said, before noting that not all missed cancers could be considered negligent.

Such clarity was arguably absent from the controversy that arose in 2018. Sections of the debate at the time involved misinformation about the effectiveness and safety of Ireland’s screening programmes, leading to immeasurable distress for women, especially for patients and their families.

While legal teams will still argue that negligence was a central factor in CervicalCheck missing cancers, repeated reports have found that Ireland’s cancer screening programmes were operating to the same standards and producing the same outcomes as well-run programmes in other developed countries. In other words: Ireland’s cervical screening programme did not miss cancers because it was dysfunctional, it missed cancers because all screening programmes inevitably do.

At their core, screening programmes are crude population-wide risk reduction exercises, not focused diagnostic tools that guarantee detection of disease. As a result, it is a statistical certainty that many cancers or pre-cancers are missed, but that apparent harm is outweighed by all the detected and treated cancers that would also have been missed were screening not in place. The risk for anyone participating in a screening programme is that you may fall into the category of people whose cancers are definitely going to be missed.

Ireland now finds itself at the centre of a global debate about what to do when cancers are inevitably missed by screening, and the options are not straightforward.

As revealed in last week’s Business Post, the International Agency for Research on Cancer (IARC), a World Health Organisation (WHO) body, is working with the HSE to conduct a review of the country’s cancer screening programmes, amid concerns that unique public trust and litigation issues here arising from the CervicalCheck controversy pose a threat to screening globally.

IARC’s concerns relate chiefly to the volume of litigation in Ireland relating to screening programmes, mostly contained to CervicalCheck. With 360 claims lodged against the CervicalCheck programme, Ireland is now a global outlier both in the amount of litigation of screening underway, and in the newly-rooted public perception that all missed cancers in screening equate to negligence.

“We are concerned that the controversies surrounding the cancer audits in the CervicalCheck programme in Ireland not only could potentially derail the well-organised cervical, breast and colorectal cancer screening programmes in the country, but also may have a ripple effect across Europe,” Partha Basu, deputy head of early detection, prevention and infections at IARC, told the Business Post.

“Many of the tests included in the screening continuum are subjective and they have limitations that are inherent in the test technology. The litigations that we are discussing in the context of cancer audit outcomes need to be revisited with more scientific rigour. Women undergoing regular cervical screening may still get cancers due to several reasons that are unlikely to be of wilful negligence in nature.”

Fiona Murphy, the chief executive of the National Screening Service, said the fallout from the 2018 controversy had been extremely damaging to the reputation of Ireland’s screening programmes, and that there had been a failure to communicate adequately that screening was not a diagnostic tool.

“The rest of the screening world looked on in horror in 2018, because Ireland’s cervical screening programme was just as good as any other international programme. It had the same rate of detection. It had the same rate of discordance (changed results) on review and so on,” Murphy said.

Despite the apparent high standards of Ireland’s screening service, the nature and volume of litigation here now threatens existing and future screening programmes to the extent that the international public health community is getting nervous. Difficult decisions now loom around the country’s screening policy.

Inexact process

In 1951 the United States Commission of Chronic Illness gave one of the earliest definitions of screening as: “the presumptive identification of unrecognised disease” by the use of tests that could be “applied rapidly”.

“Screening tests sort out apparently well persons who probably have a disease from those who probably do not. A screening test is not intended to be diagnostic,” the Commission noted.

Ireland’s first cancer screening programme, BreastCheck, was introduced on a pilot basis by Micheál Martin when he was minister for health in 2000, and was expanded nationwide from 2003 onwards. It is estimated now that breast screening in Ireland prevents 120 deaths from breast cancer every year.

Eight years after BreastCheck was first trialled, CervicalCheck was introduced in 2008, followed by BowelScreen in 2012. All three continue to operate alongside Ireland’s other non-cancer screening programmes.

All screening programmes are designed and conducted differently depending on the nature of disease being screened for. Up until 2020, cervical screening in Ireland involved the taking of a cervical smear and the examination of slides of those smear cells in a laboratory to try to detect early changes to the cervix; a process known as cytology.

It is an inherently inexact process, balancing the affordability, non-invasiveness and time limitations required for a viable mass screening programme, with the best possible accuracy under those conditions. Those with clear slides are not contacted again until their next screen, while those whose slides aren’t deemed clear are sent on for further and more precise investigations.

“Consistently, in cervical cytology you would expect about five out of 20 of the women who end up developing cancer to not be detected by the screening programme,” said Susan O’Reilly, who headed up the expert reference group which reported on CervicalCheck interval cancers (cancers that develop in between screens) in 2020.

“It was not stated clearly enough by the HSE at the time that this was not a foolproof programme. There is no all-clear in screening. A clear screen simply means we haven’t found anything today, not that there is nothing there.”

As part of a standardised approach to improving the quality of the CervicalCheck programme in 2014, a review was initiated of the slides of women who had participated in the first years of the programme and subsequently developed cancer. The purpose was never to uncover whether or not cancers had been missed, as that was a certainty, but rather to gather data on exactly how many had been missed, and to use that data to further improve screening and to create a data bank which could be used for international comparison.

Under national HSE patient safety guidelines, it ordinarily would not have been required to disclose the findings of this audit to patients, as an open disclosure policy only related to “unintended or unanticipated” adverse clinical incidents or harms. Missed cancers in a screening programme did not meet that definition, due to the certainty of their occurrence.

In fact, internationally, most screening programmes examined by the expert reference group on interval cancers have a policy of not disclosing the results of their audits to patients, as they are regarded as educational exercises to improve service quality and staff performance, not a process to uncover wrongdoing. Some of those regions even have legislative protection from disclosure.

Following the 2014 audit of the CervicalCheck programme, however, the HSE decided to create a customised policy to inform “as appropriate” the more than 200 women whose earlier screens showed “discordance” – where a review of their previously cleared slides resulted in a change of opinion on whether abnormal cells might have been present.

When it emerged that the HSE had not fully made the promised disclosures, and that most women affected by the change to their initial screen result had not been informed, the story quickly escalated.

The lack of understanding of screening by the political system was demonstrated early on when Simon Harris, then minister for health, offered repeat smears to women, which suggested there was something inherently wrong with Ireland’s screening programme, and clogged up a system that was already trying to offer smears to its target population for that year.

Varadkar similarly promised early on that no woman affected by the controversy would have to go to court, suggesting that all cases of missed cancer were conclusively negligent, something he later admitted was wrong as he hadn’t appreciated that negligence would be disputed by those involved in screening.

The resignations of Gráinne Flannelly, clinical director of CervicalCheck, and Tony O’Brien, chief executive of the HSE, somewhat calmed the public disquiet, while the government set up a scoping inquiry into the entire affair, headed up by Gabriel Scally, a respected public health physician.

That report eventually made numerous recommendations to improve screening in Ireland which are still being implemented today. But it did not identify evidence to suggest that the foreign labs involved in analysing samples had been operating to a lower standard than what would have been expected.

Scally is now preparing his final review of the implementation of his recommendations. Reflecting on the entire episode, he told the Business Post that all screening has a negative aspect to it, which was not well communicated by the HSE in 2018.

“Getting the balance right between earlier treatment for conditions and the negatives of over-treatment and invasive investigations is difficult,” Scally told the Business Post. “They also get things wrong. Screening often involves human judgment. The boundaries of where that judgment lies can be difficult and once you introduce a human aspect you always run the risk of error.”

The problem, of course, is defining whether that human error, uncovered upon review of slides, qualifies as negligence. “It is extraordinarily difficult to establish what negligence is in these circumstances,” Scally said.

When it comes to establishing negligence, it is important to note that discordance, or change of screening result upon a review of slides, is a very common occurrence in cervical screening. That is because the conditions for screening are inherently imprecise and time-limited, requiring imperfect human judgment, while the conditions for review are often different and biased by the knowledge that cancers have developed, leading to greater level of revised judgments.

“You aren’t comparing like with like,” Scally said. “The judgment being passed is on a vastly different set of information, expertise and time.”

An external report by the Royal College of Obstetricians and Gynaecologists (RCOG) compared data from England with that of Ireland between 2008 and 2018, and found the rate of revised results during audits of cervical screening was pretty much equal at around 25-30 per cent.

Addressing the inevitability of missed cancers and revised results while ensuring screening programmes can continue to operate requires a look at three major areas: how audits are conducted, how the legal system protects programmes and patients, and how the harms and benefits of screening can be better communicated to those who participate.

Three technical working groups have now been established by IARC to look specifically at these areas, using Ireland as a foundational case study. The groups consist of a total of 20 international experts, and Ireland has an outsized representation of two members on each panel.

They will first produce a global report on best practice guidance for screening, drawing on lessons learned from the Irish experience. Subsequently, IARC will engage with a separate committee of Irish health stakeholders to create customised advice for the Irish government on how it can successfully continue and expand its screening programmes.

The question of how to conduct audits of screening programmes is a central one for IARC, as it believes a properly-constructed audit system may avoid the need for litigation in the first place.

Making her recommendations in the 2020 Expert Reference Group report on Interval Cancers in CervicalCheck, O’Reilly noted that only three countries in the world took the approach of disclosing the results of audits to patients, those being England, Wales and Norway. All others that were examined either didn’t disclose the revised results of the audits, or didn’t conduct audits at all.

O’Reilly and the expert group made three major recommendations around audit and disclosure.

The first is that any woman who develops cancer who has previously participated in the screening programme should be allowed to request a full review of her screening history. This recommendation is about to be implemented by CervicalCheck imminently.

“There needs to be education for the patient and emotional support when this happens,” O’Reilly said. “In general, based on English data, about 40-50 per cent of women will want to be told if a review of their samples turns up a different result, while the other half would prefer not to know.”

Another recommendation was to establish a new standard for assessing and improving the quality of programmes. This would emulate what has been done in breast screening, by using the rate of interval cancers as the key indicator of programme quality, rather than the type of audits that gave rise to so much pain and confusion in 2018.

The problem with this is that there is no agreed standard internationally for what constitutes an interval cancer in cervical screening, but that is another issue IARC is working on.

The other recommendation is to continue to do programme-wide audits for internal use, such as the controversial CervicalCheck audit, but with strict conditions around disclosure and legal protection.

“The proviso is either that those slides must be anonymised, which is technologically very difficult, or there has to be legislative protection for the programme in place,” O’Reilly said.

That would mean audits like those that gave rise to the 2018 controversy would require anonymity or legislative protection from mandatory disclosure, a proposal that could cause some controversy once it reaches the political system.

Without such protections, O’Reilly said these programme-wide audits would continue to give rise to the type of controversies that have led Ireland to become a global outlier in the number of legal cases being taken against screening here.

Ireland as an outlier

Mary Donnelly, professor of law at University College Cork, is a member of the IARC legal working group and a renowned expert in medical law. She is conducting a research project to compare the volume of litigation of screening programmes in Ireland with other countries. Although she does not yet have the complete data, she told the Business Post that it was obvious Ireland was now an outlier in the volume of litigation happening against screening programmes.

“The message we are getting back very clear is that the kind of situation we have in Ireland is not happening anywhere else that we can identify,” Donnelly said.

An attempt to set up a tribunal to deal with CervicalCheck cases has broadly failed, with only 20 cases having made claims since it was set up, while 360 cases have been lodged with the courts over CervicalCheck alone, 87 of which have concluded. Many of those cases, however, are not going to judgment, and are being settled outside court.

“We really only have had two full cases in the courts: Morrissey vs the HSE which was successful, and then Freeney vs the HSE which was dismissed. So we are not actually seeing many or almost any cases in the courts due to settlements. That is a relevant feature because the legal arguments aren’t necessarily getting ventilated before the courts.”

One legal source suggested that the cases were settling because the cost of defence was too high, while the outcome was too uncertain due to the large scope for human error in screening.

In the case of the late Ruth Morrissey, a judgment was made and upheld on appeal that the missed abnormalities on her screens had amounted to negligence, because lab technicians had to have “absolute confidence” that the sample was clear. The judgment caused disquiet in the screening community, as it appeared to create an impossible standard for screening.

But according to Cian O’Carroll, solicitor for Morrissey and many other women affected by the CervicalCheck programme, there is a big difference between standard errors in screening and negligence.

“The Supreme Court ruled in the Morrissey case that there is a standard of approach that is adopted by the screening community when deciding whether a false negative is acceptable or not. An acceptable false negative does not result in legal liability, because there is no breach of duty. So if a screener is looking at a slide and they have a doubt as to whether it is normal, they cannot class it as normal. That is the standard,” he told the Business Post.

“The legal costs and all of the damages are coming from insurance companies for international labs who screwed up and caused women to lose their health or their life. The idea that this is being pinned on some kind of compensation culture is disgusting, actually.”

In the case of Siobhan Freeney vs the HSE, the only other case to go to judgment, there was a thorough ventilation of the issues around interval cancer in breast screening, and the BreastCheck service was found not to be negligent.

“It is possible that negligence can happen,” Donnelly said. “The problem is that people inevitably develop interval cancers and many now believe there must have been negligence in their situation and therefore they pursue a legal action.

“We are rather restricted in what we actually can do about that. Even if we thought for public health reasons that we should restrict the right to sue screening programmes, constitutionally we couldn’t.”

According to Scally, the mechanisms to resolve clinical error are seriously deficient in Ireland.

“All too often, it ends up in litigation, which is extremely traumatic for those who have to go through this process. The system is not set up to help people. It is set up to deliver a legal judgment based on evidence provided in a legal forum. That rarely produces a satisfactory outcome,” he said.

“I am an advocate of no-fault compensation approach to that. It should be possible to set up a system whereby somebody who thinks they have been damaged by a screening service can get the information they want, and ask for some compensation if that is appropriate in a way that doesn’t involve huge legal expense and the trauma of court appearances.”

Cost of compensation

The reasons litigation of screening programmes for interval cancers pose a risk to screening are threefold.

First, the cost of compensation, estimated to be in the tens to hundreds of millions a year, outstrips the cost of running the programme in the first place.

Second, asking technicians, radiologists or external labs to work for an Irish programme where errors are a certainty, but legal protection from those errors cannot be guaranteed, is likely to make screening an undesirable employment opportunity for skilled workers.

Finally, litigation eats away at confidence in screening programmes, and coverage of the targeted populations may fall below the level needed to make them effective.

But according to James O’Mahony, a health economist at Trinity College Dublin and a member of the National Screening Advisory Committee, the real threat is to future screening programmes that haven’t been introduced yet.

“When we do a cost effectiveness on lung screening, for example, they are probably going to have to consider the cost of litigation in it, and it would be a real shame if that means that we don’t adopt it,” O’Mahony told the Business Post, adding that sensible changes to existing programmes, such as dramatically reducing the frequency of cervical screens in HPV vaccinated populations, would also likely be politically unpalatable.

“It is chilling that such a thing could happen,” he said.

The recent introduction of HPV screening into CervicalCheck is viewed as a far more accurate and conclusive test, and an example of world leading improvement in screening. But other policy decisions and developments outside of expanding or refining screening programme also lie ahead, and they pose their own problems.

A new National Cervical Screening Laboratory is due to open this autumn, but will take many years to fully staff. The idea is that the national lab will in time take on all the screening work that was outsourced to private labs overseas. But, in doing so, it will also take on the legal liability, while the quality of the service provided is likely to be the exact same as what is offered by contracted labs.

The chief issue of concern for O’Reilly of the expert reference group on CervicalCheck is the idea of mandatory disclosure of programme-wide audit results. This is something being considered as part of the new Patient Safety Bill currently making its way through the Dáil, and it isn’t yet clear whether statistically certain errors within screening programme will be included as notifiable events for mandatory disclosure.

“If we are to have mandatory disclosure for something that is not considered an adverse event, it would do untold damage to all screening programmes, not just CervicalCheck,” she said. “If we have automatic disclosures relating to the programmatic review of interval cancers, that could be so harmful that it could destroy the screening programme.”