Thursday 22 August 2019

Ciara Kelly: 'Our cervical screening is not perfect, but women will die if we throw it away'

Problems in the smear test system must not obscure the vital role screening plays in saving lives, writes Dr Ciara Kelly

CONTROVERSY: Vicky Phelan’s case sparked outrage. Picture: Damien Eagers
CONTROVERSY: Vicky Phelan’s case sparked outrage. Picture: Damien Eagers

Ciara Kelly

Cervical screening was back in the news last week with the report that 80,000 women are currently waiting for smear test results - some for as long as 33 weeks - as a result of the backlog of repeat smears done on women in the fall-out from the CervicalCheck controversy. Dr Grainne Flannelly, former director of CervicalCheck who resigned in the wake of Vicky Phelan's case, said she warned officials that thousands of recheck smears would create exactly this problem and Minister for Health Simon Harris is once again in the firing line about why he offered these repeat smears in the first place.

And I despair. Because in a nutshell what's happening now is opposition politicians are crying foul about repeat smear tests being rolled out to women - when those self-same politicians clamoured for those very repeat smear tests to be rolled out. They want to know why no one listened to Grainne Flannelly - a very fine physician - when the truth is no one wanted to hear from her in their rush to condemn her and CervicalCheck.

Even last week I saw a former senator tweeting that women should know that the same labs are being used for CervicalCheck as were being used previously - as if that was a bad thing. That person clearly hadn't read The Scally Report or they would know that the labs in question were found to meet the international standards for labs providing cervical cytology. They are perhaps also unaware that when CervicalCheck was launched we didn't have the lab capacity needed to do the testing ourselves. And that prior to CervicalCheck - even though we were doing less smear testing - results here routinely took six months in our Irish labs. But it made me realise that people still don't really understand what happened with CervicalCheck.

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And it's important that they do. Because what I'm now hearing is doctors are no longer signing up for colposcopy certification. They don't want to be involved with CervicalCheck. They feel they're being scapegoated and vilified.

I've also heard the labs are unhappy. Our court system is now describing misread or false negative smears as negligence. That isn't happening elsewhere. Because if approximately a quarter of abnormal test results are misread (false negative) - then ascribing negligence to all of them with subsequent million-euro compensation will simply render our screening service financially unviable. And if CervicalCheck fails because doctors and labs don't want to be involved, and because financially we can't afford it, make no mistake, it will be women who are the losers.

So let us recap on what actually happened here. Cervical screening is done by sampling cells from the cervix in asymptomatic women and examining them to look for pre-cancerous abnormalities that might predict future development of cervical cancer. I've chosen those words carefully because it's a test designed to pick up small changes in well women. It's not designed to pick up cervical cancer. Even though on occasion it may do so.

The difference between negative and positive (normal and abnormal) results are subtle enough. Cytologists try to differentiate between shades of purple and numbers of cells - hence the high rate of "false negatives" (smears that are read as normal but actually some abnormalities are present). But studies show that false negatives - while not being entirely normal - tend not to look the same as truly positive, obviously abnormal samples. Still with me?

Basically, screening is a leaky sieve that not all abnormal - particularly subtly abnormal - samples gets picked up by. And why can't it be better? Because it can't. That's the limitation of screening - here, there and everywhere else in the world. HPV testing will increase its accuracy when it's rolled out but there'll still be false negatives. That is one of the reasons we do repeat smears - to double-check previous results.

When a woman is diagnosed with cervical cancer, her old smear tests are reviewed to see if they were read correctly. This is done for quality control to make sure the rate of false negatives in the lab is within the acceptable (albeit high) range. That's called audit and systems that do this (including ours) are considered to be of a higher standard to those that don't. Most countries never disclose audit results to patients as it's done to check the system - not as part of a patient's clinical care. And also, if you knew your old smear was a false negative it'd probably bring you nothing but heartache.

The UK, however, does disclose audit results - if patients request it. But it explains in advance that false negatives are inherent in screening and there may well be a false negative result in a woman with cancers past. Half of all women offered audit results there, when that is explained, refuse them.

Where we went wrong was: we audited - good. But we never decided how to handle disclosure of audit results - bad. That's what The Scally Report found - not that our labs were faulty or that women's diagnoses were withheld, but that those running the system never explained audit to Irish patients.

So when Irish women started to find out often inadvertently - which is truly terrible - that they'd had previously misread smears, they had no context for this. No understanding that that is a very common issue in screening. And no understanding of why this information hadn't been given to them.

The difficulty we have now is that CervicalCheck is under pressure. Doctors and labs don't want to work in it. And our courts are treating misread smears as requiring compensation. The court of public opinion is also deeply sceptical of the screening programme - when the truth is that it picks up as many cancers as every other cervical screening programme in the world and has reduced the incidence of cervical cancer here by 7pc a year since its inception. It has saved thousands of lives. But sadly not every life - and that's what screening does.

If it collapses, more women will get cervical cancer. And don't forget what a horrible cancer that is. It destroys women's sex lives, leaves them in terrible pain and kills one-third of them within five years. The HPV vaccine and screening are all we have to try and prevent it. The failures in CervicalCheck were all to do with disclosure and governance. They were not to do with screening itself. I can see a situation where our system either stops auditing (which would lower standards) to avoid litigation. Or where the HSE decides it simply can't afford - because of litigation - to continue it.

The 'what if' of false negative is a personal tragedy for a woman with cancer but a greater tragedy for all women is the loss of life caused by no screening service at all. Screening is imperfect but it's the best tool we have in the fight against cancer. Throwing away the good because it's not the perfect, is short-sighted and dangerous.

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