Cancer screening? No thanks, says GP

The Glasgow-based GP, who is also an author and makes regular media appearances, has provoked controversy by arguing that women are not being properly informed about the pros and cons of smear tests, and are being "herded like sheep" into screening.

Instead of information about the risks of false positive test results and overtreatment, she says women are being fobbed off with "platitudes". And she criticised adverts which lack information – one suggested that smear tests should be put on a "to do" list by women along with booking a haircut and buying cinema tickets.

But doctors and charities have warned such remarks could deter women from coming forward for screening, with latest statistics showing just over seven out of 10 eligible women in Scotland have taken up the invite of a test.

McCartney is keen to point out she is not against screening programmes, but what she terms "unthinking screening". She also said that her arguments on the issue only apply to the testing of healthy women and not patients displaying potential symptoms of disease.

Explaining her decision, she said: "We know from research if you take 1000 women and screen them for 35 years, you can prevent one death from cervical cancer."

However, she said that to get that reduction, around 150 women would also get "an abnormal result" which could be false positive or require repeated smear tests. Another 50 women would require treatment for cells deemed abnormal but which might not develop into cancer.

She said: "I have made a decision based on my perception of the evidence, my own personal risk factors for cervical cancer and I have decided that as an autonomous woman, I would rather not risk overtreatment."

McCartney – who also addressed over-treatment in her recent book The Patient Paradox: Why Sexed-Up Medicine Is Bad For Your Health – has also questioned anxiety being mentioned as a "minor" side-effect of screening when some women become "ill with worry" if they are told their smear test is abnormal.

She argued that the pressure for women to attend smear tests means they may delay going to see a doctor for any kind of symptoms if they have missed a screening appointment, as they are concerned about being "given a row".

Women are also not being fully informed about research which has linked a common treatment to remove abnormal cells in the cervix, known as loop excision, with a higher risk of having a baby born before full term.

She said: "Women have a much higher chance of a false positive test than of having their life prolonged by it [screening]. Yet we are coy about the harms and the problems of screening. Why?"

However, consultant gynaecologist oncologist Pierre Martin-Hirsch, deputy editor-in-chief of medical journal BJOG: An International Journal Of Obstetrics And Gynaecology, raised concerns that McCartney's comments could deter women from being screened.

He said the accuracy of the cervical screening programme in the UK had been improved in recent years, reducing the number of false positive and false negative results. He also said new research has found the risk of pre-term delivery due to treatment of the cervix is not as great as previously thought.

Robert Music, director of cervical cancer charity Jo's Trust, said: "Research has shown that a high number of women diagnosed with cervical cancer delayed or ignored their cervical screening invitation - it's a real concern that misinformation, fear and myth contribute to persuading women that screening isn't necessary."

Jessica Harris, health information manager at Cancer Research UK, said: "On balance, the benefits of preventing cervical cancers considerably outweigh the harms of some unnecessary treatment."

A Scottish Government spokeswoman said: "Cervical screening has proven to be an effective method of reducing the incidence and mortality of cervical cancer. It saves around 5000 lives in the UK every year and prevents eight out of 10 cervical cancers from developing."