The Rise and Fall of Modern Medicine (51 page)

Finally, it must be presumed that forms of biological agents as yet undreamed of hold the key to the understanding of some diseases, or as Hamlet tells Horatio: ‘There are more things in heaven and earth, than are dreamt of in your philosophy.' The biological world, it cannot be stressed enough, is full of mysteries. We have encountered many along the way. Why do bacteria produce antibiotics? Why are plants medicinal factories? We do not, and probably cannot, answer these questions because, as Einstein once famously observed, nature is ‘damned weird'. And perhaps somewhere in this damned weirdness will be found the as yet unanswered explanations for the causes of disease. Two examples must suffice. Every living organism from amoeba to man shares the one common feature that the DNA of their genes makes the messenger RNA that codes for the construction of the proteins that make up their cells. Or at least
that was the dogma until the discovery in 1970 of the one solitary exception to this rule, a retrovirus that takes RNA and turns it back into DNA. The discovery of this utterly unique biological organism proved to be enormously significant on two counts. The enzyme produced by the retrovirus – reverse transcriptase – was the crucial step that allowed the New Geneticists to identify the genes for haemoglobin and insulin. Then, in 1984, Robert Gallo of the National Cancer Institute discovered that one species of retrovirus – human immunodeficiency virus (HIV) – was responsible for the most lethal new infection to have emerged in the Western world over the last 100 years, AIDS, which again, utterly uniquely, wreaked its havoc by destroying the immune system of those infected.
¹⁴

Again, the notion that a non-living organism, a protein, could cause a transmissible disease would until recently have been inconceivable – until, that is, Stanley Prusiner discovered a special type of protein, the prion. Prions, it subsequently emerged, could be transmitted from the brains of sheep to those of cattle to cause mad cow disease, and then to the brains of humans to cause the variant of the lethal dementing illness Creuzfeldt-Jakob disease. Prions are, in the words of Chief Medical Officer McCoy of the starship
Enterprise
, ‘life, but not as we know it'. Prusiner duly received the Nobel Prize for medicine in 1997 ‘for his pioneering discovery of an entirely new genre of disease-causing agent'.
¹⁵

There is no precedent in the whole of biology for either retroviruses or prions, but that does not prevent them from having an enormous influence on human disease. Perhaps it is in such mysterious niches of the natural world that the last great intellectual problem facing medicine – the causes of disease – will be found. Or perhaps they never will be.

PART IV

T
he pattern of the Rise and Fall identified in the Introduction is clear enough. For thirty years from the mid-1940s onwards, the combination of clinical science, fortuitous drug discovery and innovative technology – together with the human virtues of imagination, perseverance and hard work – impelled medicine forward. By the late 1970s, these dynamic forces had become exhausted, creating the intellectual vacuum that was filled by the two radical but ultimately unsuccessful approaches of The Social Theory and The New Genetics. Further, as promised in the Introduction, this pattern of a Rise and Fall helps to explain the paradox that, despite medicine's staggering success, doctors are increasingly discontented and the public is increasingly neurotic about its health. It would be reasonable to infer that doctors' discontents may be related to the fact that medicine is not quite as exciting as in the past, while increasing public neuroticism may be related to the anxiety-mongering of the proponents of The Social Theory. It is necessary, however, to dig a bit deeper than this.

First we must satisfy ourselves – for the last time – that the pattern of a Rise and Fall is indeed correct. There can be no doubting the concentration of major discoveries prior to 1975, while other evidence for the decline in innovation around this time, such as the Dearth of New Drugs and the demise of
The Medical Annual
, the ‘bulletin' of the therapeutic revolution, is clear enough.

This interpretation of events is admittedly difficult to accept, primarily because the belief in the limitless possibilities of medical progress is so pervasive, but it is a common historical observation that such things do happen. Every field of human knowledge has its Golden Age, which is followed by a decline in creativity and new ideas.
¹
Geology's ‘finest hour' was the mid-nineteenth century, with the startling discovery that the world was billions of years old. Then it was the turn of natural history, with the Darwinian theory of evolution. The glory days of theoretical physics were between the wars, grappling with quantum physics and Einstein's Theory of Relativity. The 1960s were the heyday of space exploration, and so on. Medicine's Golden Age lasted longer than most and had a greater impact, but there is no reason why it should be an exception to this rule, for just as the nineteenth-century European explorers eventually found there was no more left of Africa to explore so, once hearts are being transplanted and childhood cancer cured, the potential for further progress in these areas is clearly constrained. Medicine, like any field of endeavour, is bounded by its concerns – the treatment of disease – so success necessarily places a limit on further progress. Indeed, according to the ‘Law of Acceleration' proposed by the American historian Henry Adams, it is precisely at the moment that a scientific discipline is at its most apparently successful, as medicine was in the 1960s and early 1970s, that it will be approaching its apotheosis.

But there are also specific reasons why medicine should conform to this pattern of a Rise and Fall. First, it is limited to doing what is ‘do-able', and by the 1970s much of what was ‘do-able' had been done. The main burden of disease had been squeezed towards the extremes of life. Infant mortality was heading towards its irreducible minimum, while the vast majority of the population was now living out its natural lifespan to become vulnerable to diseases strongly determined by ageing. Second, these age-determined diseases, which are far and away the dominant preoccupation of Western medicine, are of two sorts. Some, like arthritis of the hips and furred-up arteries, can be markedly improved with drugs and operations, while others, like cancer and the circulatory disorders, can be palliated though not postponed indefinitely. Thirdly, and very importantly, the rate of medical innovation was bound to decline because so many of its important discoveries had depended on luck. The bountifulness of nature in providing the extremely potent but entirely unanticipated antibiotics and cortisone is unlikely to be repeated, while sooner or later research chemists will find they are scraping the bottom of the barrel of chemical compounds that can be synthesised and screened for their therapeutic potential. And finally, medical research is, in Peter Medawar's memorable phrase, ‘the art of the soluble'. As of this moment, it is not at all clear whether or how the last challenge left – the discovery of the causes of diseases like multiple sclerosis and leukaemia – is indeed ‘soluble'.

Now this contention that science has ‘reached its limits' has been expressed many times in the past, only to be repeatedly disproved. Famously Lord Kelvin, at the close of the nineteenth century, insisted that the future of the physical sciences was to be looked for in ‘the sixth place of decimals' (that is, futile refinements of the then present state of knowledge). Within a
few years Einstein had put forward his Theory of Relativity and the certainties of Lord Kelvin's classical physics were eclipsed. Perhaps predictions about medicine ‘having reached its limits' will be similarly overthrown in the coming years. Perhaps, but the brick wall blocking further medical progress is solidly built, being no less than four layers thick. The readily do-able has been done, the chronic diseases of ageing have been ameliorated, the bottom of the barrel of lucky drug discoveries has been scraped and the causes of the common diseases of mid-life remain a mystery.

The epochs of the Rise and Fall of medicine do not just follow each other chronologically, but are dynamically related. The Fall from the late 1970s onwards is best understood as a set of false strategies by which the express train of medical advance, fuelled by the successes of the Rise, sought to variously hammer away at, pole-vault over, circumvent or undermine this four-layered brick wall impeding further progress.

The essence of ‘hammering away' is to do the same things but at greater intensity. We encountered this in Technology's Failings, with the excessive use of new investigative techniques for straightforward medical problems: an endoscopy for everyone with a stomach ache, a CT scan for everyone with a headache, and complex studies of urine flow for every male with symptoms of an enlarged prostate. The potential for expanding the use of these diagnostic techniques is virtually limitless, especially if the age group being investigated is pushed upwards to include those in their eighties and nineties. There was also considerable scope for hammering away in the pursuit of marginal treatment benefits, as in the massive overuse of chemotherapy in the palliation of age-determined cancers or futile attempts to prolong life, as illustrated by the description of General Franco's final illness. A quarter of all health expenditure
in the United States, it will be recalled, is now spent on patients during the last six months of their lives.

The pharmaceutical industry has also had no alternative, in the absence of new and lucky drug discoveries, other than to keep hammering away. This takes several forms, of which the most obvious is the ‘better mousetrap' – new and more costly variants of drugs already available. These may well be ‘better' in the sense of being easier to take and having fewer side-effects, but they are no more effective therapeutically. Alternatively, when there is no effective remedy for a disease the drug companies have adopted the ‘useless mousetrap' strategy on the grounds that patients and relatives want to be doing ‘something'. Thus new drugs for Alzheimer's and multiple sclerosis are increasingly widely prescribed even though their efficacy is scarcely detectable.

The second response to the brick wall was to try and pole-vault over the lack of effective treatments with complex and expensive strategies. The saga of foetal monitoring introduced in the 1970s in the hope of preventing cerebral palsy belongs in this category, as do the national screening programmes for the early detection of cancers of the breast and cervix. Screening certainly can work. There is no simpler and more effective medical intervention than screening every newborn baby to detect those at risk of mental deficiency from an underactive thyroid. A spot of blood obtained from a heel prick can be automatically processed at virtually zero cost to establish the diagnosis, while treatment – thyroxine replacement – is 100 per cent effective. By contrast, the principle behind screening for cancer may be the same – the detection of disease at an early enough stage for it to be curable – but that is all. Cancer screening is logistically very complex to organise, the techniques of diagnosis – cervical smears and mammography – require
considerable skill, while the distinction between the normal and the pathological is uncertain. Finally, even though cancer screening involves the dedicated skills of nurses, radiologists, pathologists, gynaecologists and surgeons, the impact is marginal, because the most aggressive cancers that need to be caught early arise so rapidly.
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The third option, circumventing the brick wall, sought to bypass the dearth of new treatments by preventing disease in the first place. This was The Social Theory. Its approach, if not examined over-critically, certainly appeared plausible enough and indeed was widely perceived as representing a further stage in the evolution of medicine, where prevention was a more sophisticated response to the problem of illnesses such as cancer and heart disease than an attempt to ‘cure' them with relatively ineffective medical therapies. Enormous sums of money have been expended on ‘health promotion' to achieve these ends. Its drawback is that it does not work. The Social Theory fulfilled another important function by expanding the influence of medicine beyond the traditional confines of the consultation between doctor and patient to reach out to the healthy too. It provided apparently authoritative advice to the public on how they should lead their lives, instructing them in what they should and should not eat, while alerting them to previously unsuspected hazards in their everyday lives.

Finally, The New Genetics sought to undermine the wall by illuminating the workings of the human organism at its most fundamental level with the promise that at some indefinable point in the future the wall would come tumbling down, leaving a long straight road to health and happiness for all.

The perverse consequence of all these unsuccessful attempts to hammer, pole-vault, circumvent and undermine the brick wall is that medicine has sustained, even enhanced, its dominant
position within Western society. Medicine has never been so powerful, and yet its success is seriously compromised by another ‘rule of four', the four-fold paradox noted in the Introduction.

The causes of these four paradoxes are diverse and complex. Nonetheless, as was suggested in the Introduction, an historical perspective suggests they can also be seen as the multi-faceted side of the singular phenomenon of medicine's Rise and Fall.