Название: What Doctors Don’t Tell You
Автор: Lynne McTaggart
Издательство: HarperCollins
Жанр: Медицина
isbn: 9780007374168
isbn:
Under National Health Service regulations, there is now more intense pressure on women to take the test with greater frequency as the fee per test becomes part of a doctor’s bread-and-butter work. Doctors in Britain get bonus pay only if more than 50 per cent of the women on their lists receive the tests, and triple the bonus pay if 80 per cent take it. But who would quarrel with the benefits of a simple, painless, risk-free test that promises to eradicate a common killer of women?
Nobody, if it actually worked. The problem is there is no convincing evidence anywhere to suggest that it does. Professor James McCormick of the Department of Public Health at Dublin’s Trinity College, an expert on mass screening tests, who studied much of the available medical literature on the subject, once declared: ‘There is no clear evidence that this screening is beneficial, and it may well be doing more harm than good.’8 By harm he means that many thousands of women are being subjected to risky treatments that could affect fertility for a condition they do not have or which could revert to normal.
First of all, it’s hard not to think, once you examine the figures, that medicine has backed the wrong horse. Cervical cancer is not the massive killer it’s often made out to be. Although some 2,000 women die from cervical cancer every year in the UK, that represents less than one-sixth of the number of women who contract breast cancer. In The Health Scandal, author Dr Vernon Coleman says that cervical cancer doesn’t even make the top 10 causes of death among women, falling behind breast, lung, colon, stomach, ovarian, even pancreatic cancers.9 And only 1.6 of every 1,000 women with abnormal smears go on to develop cancer.10
The smear test has also never been proven to save lives in any country where it has been introduced. In fact, every study shows that it is making virtually no impact. The only area in Canada where screening has been universally adopted is British Columbia; nevertheless, the death rate of cervical cancer there matches the death rate for the rest of the country.11 Mortality rates from cervical cancer may have fallen in British Columbia, but they also fell in other parts of Canada without organized screening programmes.12
In the UK, the death rate from cervical cancer fell before the test was introduced and has stubbornly remained at the 2,000 figure (although several years ago, the government announced that the annual figure has dipped to 1,700). There is also no evidence to support the common contention that things would be worse but for the test. Dr McCormick and his colleague, the late Petr Skrabanek, say that the blind enthusiasm for cervical screening ‘has produced a climate in which it has been impossible to mount controlled trials’.13 Twenty years ago, Dr Herbert Green, a New Zealand doctor who had the temerity to dispute many dearly held assumptions about cervical cancer, was even found guilty of disgraceful misconduct for conducting a trial to see whether cancer is inevitable after an abnormal screening test.14
In the UK and the US, mass screening programmes like the National Cervical Screening programme have been launched without a consistent nationwide policy about when or whom to screen or how to follow up abnormalities.
Several years ago, an official study confirmed that cervical screening isn’t doing any good, since death rates from cervical cancer haven’t varied in two decades, despite virtually universal screening. These findings are based on monitoring nearly a quarter of a million women in Bristol over 20 years. In 1992, the death rate was similar to that of 1975, when continuous screening was introduced.15
If screening has managed to put a slight dent in the death rate nationally (and there is no hard evidence that screening is behind the rate’s dipping from 2,000 to 1,700), it comes at an unacceptable cost, says Dr McCormick. Many thousands of women are given false-positives and unnecessarily treated and possibly even left infertile or with terrible side-effects. During every area-wide screening in the Bristol area, 15,000 women were told they were at risk of cancer, and more than 5,500 investigated and treated for mild abnormalities which never would have progressed to cancer.
Between 1988 and 1993, nearly 226,000 women were screened, and abnormalities were supposedly found in more than 15,000 – or about one out of every 15 women. This figure is absurdly high compared with the actual rate of cervical cancer, which kills one woman in 10,000. The Bristol level of false-positives (where a ‘discovery’ of cancer turns out to be false) demonstrates to what extent cervical screening is simply causing unnecessary worry in healthy women.16
Over the years, the smear test’s reputation has been stained by a number of catastrophic errors. At Kent and Canterbury Hospital, for instance, more than 90,000 smears taken between 1990 and 1995 had to be rechecked, after eight women died following mistakes in reporting results. The problem, according to Britain’s National Institute for Clinical Excellence (NICE), is that the test is still appallingly inaccurate.
NICE estimates that up to 13 per cent of smear tests are false-positives and 20 per cent are false-negatives, where women with possible problems will have a test result come back as normal. In other words, out of 1,000 women screened, two women who could have cancer will be given the all clear. Other research has estimated a false negative rate of up to 60 per cent.17
In the US, the Centers for Disease Control and Prevention recently warned against annual Pap smear testing because of the high rate of false-positives, particularly for low-grade abnormalities, which result in potentially damaging treatment for symptoms which might have gone away if left alone.18 Even if screening were better set up in the UK and the US, the problem lies with the very medical foundation on which the test is based. Mounting evidence suggests that the smear campaign may be based on a faulty assumption: that abnormal, or ‘precancerous’, cells on the cervix lead to cancer. This assumption has been inferred from two facts: 1) that cervical cancer progresses slowly and, 2) if caught early enough, can be cured.
There are four categories of abnormal lesions, or ‘cervical interstitial neoplasia’: CIN I, II, III, and cancer. What we don’t know is whether the early lesions – those in the CIN I and II categories – will go on to develop cancer, or even what to do about them. In one study examining the accuracy of cytology (cell) screening, some 10 per cent of women screened had cervical abnormalities, ‘most of which’, notes Professor McCormick, ‘would not progress to cancer’.19
Medicine also doesn’t really understand the usual progression of this kind of cancer, a fact they have tacitly begun to admit. Some cervical cancers appear to regress if left alone, while others progress so rapidly that the three-to-five year gap recommended by most screening programmes would fail to pick them up in time. On this fragile foundation, women with an abnormal smear are frightened and stigmatized by the term ‘precancerous’ when no one knows whether it is appropriate or not.
This very situation happened to Anna. After her smear test came up positive, the 25-year-old spent months worrying that she had cancer. She also felt deeply embarrassed by the test results, as though it were a public comment on her sex life, since cervical cancer is known to occur among women who are highly promiscuous. In the end, she discovered that she had suffered all her distress for nothing. Follow-up tests some months later proved the first test was wrong.
One СКАЧАТЬ