Cervical Check

Irish women aged over 25 years are expected to have three to five yearly screening using a modification of the 1920's Pap smear method, to detect precancerous changes at the neck of the womb.

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A relatively infrequent cancer it is the 8th most common among Irish women and accounts for just under  3% of female cancer deaths.[Nat Cancer Registry Report  2015]

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Nevertheless nearly  300 cases are diagnosed each year and there are some 90 deaths annually.

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Also, cervical cancer  deaths tend to occur at a younger age, which adds to the importance of

doing something, if we can.  Well, can we? 

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Sadly, the answer is not as clear cut as we might wish. While not the worst screening programme, the current method of cervical cancer screening was rolled out without there being adequate trials to prove its effectiveness. Research does appear to show a consistent benefit to populations that have screening even though the quality of many studies is low. [Peirson et al. Systematic Reviews 2013, 2:35 ]

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Also, it does seem apparent that deaths from cervical cancer are in decline and it has become accepted that organised national screening programmes like our own, are preventing as many as 70% of deaths from invasive cancer.

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So what's not to like? Well, firstly, cervical cancer  deaths are in decline anyway, regardless of the screening programme. The graph on this page shows annual death rates over the last 60 years or so.

While information from the UK have shown an acceleration in the rate of decline of mortality since  screening started it is noteworthy that the trend was well established before the introduction of the national screening programme.

 

This would have to make you suspect that screening, at least to some extent, is getting the credit for a reduction in deaths that is due to something else-perhaps better human immunity, something in our lifestyle and certainly nothing that causes the major downsides of screening.

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This is the second caveat: Cervical screening is not without unintended consequences. For every 100 women screened as many as  three may have a false positive test and require colposcopy or have necessary surgery. For  every  100 women with precancerous  changes  30 will have  falsely  negative  smear reports.

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Extra testing is very risky because women and their doctors naturally tend towards  a sort of ' If in doubt, cut it out' policy, even for the sort of low risk changes that may not be precancerous at all.  Expert proponents of screening aim that no more than 15% of all operations arising out of screening for cervical cancer should be unnecessary. Given the risk of such unnecessary surgery including bleeding, hysterectomy, reduced fertility and miscarriage, not to mention the substantial emotional stress of a false diagnosis, even as few as 1 in 7 operations being unnecessary may be a risk you want to think about.

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This is to say nothing of the feeling of a broken promise when the screening tests miss a cancer as has become all too apparent in Ireland in 2018. 

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On a more positive note the Irish screening programme is adapting it's message to women in the light of new information. By adding testing for the HPV virus, the number of women with minor abnormalities on their smear test who need re-testing or colposcopy is being reduced.

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As I said, not the worst screening programme around, but still far from being  a no-brainer.

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