The more Pap tests, the worse

The reason why this website is called Cancer Screening reflects the issue that intrigues me the most in the cervical cancer debate. As I said before, in many countries, including Portugal where I come from, screening for cervical cancer usually starts as early as women become sexually active. In England it doesn’t start until the age of 25.

Different factors should be considered when judging the quality of a screening programme, regardless the type of cancer it applies to. Budget, culture and private health services are just some of them, which partly explains why there isn’t a common cancer screening programme, for example, on a European level.

Portuguese GP
Dr Armando Brito de Sá

I spoke to one expert who is particularly concerned about such discrepancies. Dr. Armando Brito de Sá is Professor of General Practice and Family Medicine at the Medical School of Lisbon University.

He agrees with the screening programme adopted by the NHS. Both the age to start screening and the frequency (every three to five years) are recommended for the Portuguese primary care services, following the British model.

Some important bodies, such as the U.S Preventive Studies Task Force (USPSTF), still recommend screening once a woman becomes sexually active. But the Portuguese expert highlights the position taken two years ago by the American College of Obstetricians and Gynecologists (ACOG):

Screening before age 21 should be avoided because women less than 21 years old are at very low risk of cancer. Screening these women may lead to unnecessary and harmful evaluation and treatment.

According to Dr. Brito de Sá, “this is a surprising statement given that it comes from an organisation of specialists [and not of a wider range of health professionals], which is very good news”. In his opinion, such organisations tend to be more aggressive.

ACOG also states cytology should be made every two years – a frequency that “prevents cervical cancer just as well, has decreased costs, and avoids unnecessary interventions that could be harmful.”

There is no scientific evidence that supports doing a Papanicolaou test every year, the GP adds.

The more medical exams, the healthier: a wrong message

One of my questions was that although the Portuguese health service takes the NHS as an example, both systems can never be totally similar since the private sector plays an important role in the country.

According to Portuguese database Pordata, 1,485 gynaecologists/obstetricians and 5,160 GPs were active in the country in 2009.

"Pap" test

Dr. Armando Brito de Sá points out that, although most people are consumers of the national health service (SNS in Portuguese), there is an overuse of medical exams in the private sector – not only in Portugal but worldwide. “This happens because of this general and wrong idea that the more exams we do, the better health we have.”

In line with this, I know many people who ask their private gynaecologist to be screened every year – sometimes even twice a year. So I asked Dr. Brito de Sá whether patients understand that paying for an exam could be more harmful than attending a national programme that recommends less frequent smear tests.

“Patients are not idiots,” he answers. “When you tell them the facts, they understand and are capable of making their own decision”.

Overscreening is a direct breach of “Primum non nocere”, an ethic principle taught in medical schools which means “First, do no harm”

And the facts are clear in his words: “The problem caused by early, frequent screening is not only the very small number of lives it would save but mainly the thousands of young women that are unnecessarily overwhelmed with additional exams whenever they have an abnormal test.”


Making medical students aware of different evidence-based policies

While lecturing the future generation of doctors, one role of Dr. Armando Brito e Sá is to make them understand that governments do not always follow the latest, best scientific advice.

He points out the dangers of overprevention and overmedication – an idea that was highlighted in 2001 when the American Family Physician journal published these Screening Guidelines.

Numerous medical organizations have developed cancer screening guidelines. Faced with the broad, and sometimes conflicting, range of recommendations for cancer screening, family physicians must determine the most reasonable and up-to-date method of screening.

Finally, the Portuguese expert shows conviction in saying that government’s policies are just partly determined by scientific evidence. The implementation of the HPV vaccines in different national programmes was “inevitably political, because of the excessively heavy disease-awareness produced in the media by the vaccine manufacturers.”


4 thoughts on “The more Pap tests, the worse

  1. Anne J.

    I don’t get it… There’s nothing on your article that supports the title in the first place…

    Why is it that “The more Pap tests, the worse”? At most, Pap tests are useless when done in excess (until the day)… But they are harmless, contrary to what your title suggests…

    And I understand overmedication… But overprevention!?

  2. Armando Brito de Sá

    Anne, I know it sounds counterintuitive. One of the problems with PAP smears is that they regularly lead to the identification of minor changes that, most often, have no clinical significance and tend to clear spontaneously. This is a sensitive subject: it involves some of the woman’s most intimate aspects, both physical and psychological. Knowing you have a “minor alteration” in your PAP will leave you anxious and eager to get rid of that “minor alteration” ASAP. This may lead to uncomfortable and, sometimes, painful treatment of something that might just go away spontaneously, rendering that treatment useless in the first place. So, too many PAP smears can, indeed, be harmful.

    Now, you may ask: “What if that minor alteration turns into a cancer and, if a PAP is not performed, the cancer disseminates?” Well, that is where the three-year interval between smears comes from. The natural history of cervical cancer is pretty well known: the time interval between the first cellular changes in the cervical lining and the crossing of a membrane beneath that lining (the crossing of that lining defines a cervical cancer invasive status) is between five and ten years. This means that a PAP smear every three years gives ample safety margin for identification and treatment of any potential cancer developing in the cervix. One can reasonably assume, and barring the odd exception that always exists, that if we could perform a PAP smear to every woman 25-65 old we might eliminate cervical cancer as a cause of death.

    This reasoning applies equally to almost all forms of prevention, making overprevention a health problem in itself. A concept has emerged in the nineties: quaternary prevention. This is “protecting the patient from unnecessary medical interventions” – and these are often preventive interventions, either in excess or poorly justified. There’s a lot of work to be done here.

  3. Elizabeth (Aust)

    Nice to read some correct information for a change – women around the world seem to get nothing but puff and spin. Australia over-screens and includes young women, so our referral rate after false positives is very high – of course, it’s hidden, few women know about it…that’s the cruel thing, most of these women “assume” they had or were treated for cervical cancer or for a lesion that would have become cancer. The burden placed on the healthy population of women who’d never have an issue with this cancer is unethical and very unfair – and that’s more than 99% of women.
    I got to the facts early – as a low risk woman, I have always declined pap tests.
    The situation is so bad that our doctors are even paid undisclosed target payments for pap tests – so much for informed consent! 77% of women are referred at some stage to possibly help fewer than 0.45% of women – that’s shocking over-detection and causes potentially harmful over-treatment.
    Sadly, women’s cancer screening is not evidence based – it’s emotive, irrational and very political…I’d also say it risks our health. There are also so many vested interests in cancer screening – all praising testing and getting rich on the over-treatment. In the States, excess cervical biopsies generate one billion dollars every year.
    Coercion is the norm in the States and Canada where women are routinely denied the Pill, HRT, other meds and even all medical care if they decline testing.
    IMO, the risks of cervical screening far exceed the benefits…thankfully, more women are getting to the truth and making informed decisions to adopt a schedule that provides some protection from over-detection (the Finnish program – 5 yearly from age 30, 5 to 7 tests in total) or not to screen at all.
    Fortunately the UK has some great advocates for informed consent in women’s cancer screening and their articles and research have been very helpful – sadly, few Australian women have seen it…but Prof Michael Baum, Angela Raffle, Hazel Thornton and others are the people I admire, brave enough to speak out, tell women the truth, warn us of the risks and respect our right to choose rather than treating us like sheep.
    A double standard applies – men are treated respectfully and informed consent matters…women are given misleading information and basically ordered into testing – it’s time to change an abusive system.

  4. niki

    I think what hasn’t been mentioned is how RARE the cancer is in the developed world even before testing began. I have heard anecdotal stories of doctors seeing maybe one genuine case of cervical cancer in 40 years of practice. Once I found out that cervical cancer occured at the rate of 15 per 100,000 before they introduced screening in Australia and how innacurate pap smears are I confidently gave pap screening away. I have never felt happier. I don’t think about the disease anymore.

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