PEOPLE WITH undiagnosed cancer fall into three groups. Some have clinical features that meet the criteria of the referral guidelines produced by the Department of Health. They are eligible for an appointment with a specialist within two weeks. The second group contains people who have symptoms which are caused by their cancer, but who do not yet meet the criteria. They do not particularly stand out from a larger group of patients with symptoms of indeterminate cause. Their GP may or may not choose to refer as a routine appointment. They may have to wait to have their cancer diagnosed. The third group contains those people who have no symptoms of their cancer. This group is the target audience for this book.
More specifically, the target is people who are considering purchasing cancer-screening tests in a private sector healthcare system, particularly the United States. Dr Welch works for the United States Veterans Administration (VA). As such he is perhaps the closest thing in the USA to an NHS doctor, because the VA provides healthcare free of charge to those who have served in the US Armed Forces. Publicly-funded healthcare such as that provided by the VA costs Uncle Sam more per capita than HM Treasury spends
on the NHS.
Welch’s perspective allows him to stand aside from the commercial hurly burly of American medicine. He describes attitudes very fairly in a chapter entitled “Understand the culture of medicine” in the second part of the book, which is about becoming a “better educated consumer”. The style of the book is typical American writing intended for the lay public in that it attains simplicity through verbosity.
This succeeds in presenting clearly the arithmetic behind cancer tests and screening. The crucial message is that only a tiny minority of people benefit from screening, because very few of those screened actually had cancer, and because only a minority of people with cancer that is present – whether detected or not – at the time of the screening exercise actually avoids death from it. He describes in detail the ambiguities that exist in screening. Ambiguous results require further investigation and not all the detected cancers would go on to be a serious threat to the patient’s health. He takes this approach a little too far when he discusses a patient who had an abnormality on the kidney found incidentally when tests were being done for something else. This was very likely to be a cancer and the opinion of the urologist was that the kidney needed to be removed, but the patient did not want this. Welch positively advocates the patient’s decision as being the right one when I feel he should have presented it as a legitimate gamble, an exercise of free choice.
When Welch discusses the five-year survival statistics he explains the problem of lead-time bias – take, for example, a patient whose cancer presents without screening and kills her after four and half years. An identical patient has a screening test which brings the diagnosis forward by one year. If she dies five and a half years after the screening, she has become a five-year survivor, but her death has not been delayed. So the screening benefits the statistics but not the patient. He amplifies this point to the extent that one might conclude that no cancer treatment has any impact on survival whatsoever. More balance is required.
Welch’s criticisms of the randomized trials that have led to the offer of services such as screening for breast cancer are very valid. He spends little time discussing screening for cervical cancer which, in my view, is extraordinarily successful but the evidence is indirect. We know that cervical cancer is a sexually transmitted disease. pH7 has previously discussed the rise in the incidence of sexually transmitted infections. The fact that this country has not seen a sharp rise in the incidence and mortality from cervical cancer that the Third World has, must reflect the efficacy of the screening process. This is due to the fact that an early phase of this disease and a simple means for identifying and treating it exist. This gives cervical screening a great advantage over screening for other cancers.
In the UK, the main concern is in what services should be provided by the NHS. American individuals may be willing to pay whatever they can afford for something which might just benefit them but most likely will not. The NHS has to consider devoting some of its strictly limited budget to purchasing large numbers of tests plus paying for the knock-on effects of further tests to evaluate the ambiguities. There is not only a financial cost, but also an opportunity cost in that the pathologists and the radiologists that are required to do this work are in short supply. It is this lack of resources that leads to there being two groups of patients with symptoms due to cancer. The Cancer Referral Guidelines are essentially a rationing procedure in that they place as least as much emphasis on the gatekeeping role of the GP to protect the diagnostic services against excessive workload as they do their role in diagnosing cancer. Whilst the attainment of an early diagnosis of cancer by screening is of dubious value, late diagnosis misses opportunities for successful treatment of the patient. In those healthcare systems where the diagnostic services have adequate resources, there is no need for a distinction based on referral guidance; all patients in whom the doctor wishes to exclude cancer can expect to be investigated very promptly resulting in a more timely diagnoses.
The message from this book for the NHS, therefore, is this: do not fritter away health resources on screening programmes that have little benefit. Rather, invest in the services for the diagnosis and treatment of patients who present with symptoms, especially ambiguous symptoms, which are in fact due to early, curable cancer. Screening is healthcare activity that belongs at the luxury end of the service and that therefore legitimately belongs in the private sector.
