Last month, in his Times column, Matt Ridley explained why — until we discover a treatment for aging itself — rising cancer rates are a weird form of good news:
If we could prevent or cure all cancer, what would we die of? The new year has begun with a war of words over whether cancer is mostly bad luck, as suggested by a new study from Johns Hopkins School of Medicine, and over whether it’s a good way to die, compared with the alternatives, as suggested by Dr Richard Smith, a former editor of the BMJ.
It is certainly bad luck to be British and get cancer, relatively speaking. As The Sunday Times reported yesterday, survival rates after cancer diagnosis are lower here than in most developed and some developing countries, reflecting the National Health Service’s chronic problems with rationing treatment by delay. In Japan, survival rates for lung and liver cancer are three times higher than here.
Cancer is now the leading cause of death in Britain even though it is ever more survivable, with roughly half of people who contract it living long enough to die of something else. But what else? Often another cancer.
In the western world we’ve conquered most of the causes of premature death that used to kill our ancestors. War, smallpox, homicide, measles, scurvy, pneumonia, gangrene, tuberculosis, stroke, typhoid, heart disease and cholera are all much rarer, strike much later in life or are more survivable than they were fifty or a hundred years ago.
The mortality rate in men from coronary heart disease, for instance, has fallen by an amazing 80 per cent since 1968 — for all age groups. Mortality rates from stroke in both sexes have halved in 20 years. Cancer’s growing dominance of the mortality tables is not because it’s getting worse but because we are avoiding other causes of death and living longer.
It is worth remembering that some scientists and anti-pesticide campaigners in the 1960s were convinced that by now lifespans would be much shorter because of cancer caused by pesticides and other chemicals in the environment.
In the 1950s Wilhelm Hueper — a director of the US National Cancer Institute and mentor to Rachel Carson, the environmentalist author of Silent Spring — was so concerned that pesticides were causing cancer that he thought the theory that lung cancer was caused by smoking was a plot by the chemical industry to divert attention from its own culpability: “Cigarette smoking is not a major factor in the causation of lung cancer,” he insisted.
In fact it turns out that pollution causes very little cancer and cigarettes cause a lot. But aside from smoking, most cancers are indeed bad luck. The Johns Hopkins researchers found that tissues that replicate their stem cells most run the highest risk of cancer: basal skin cells do ten trillion cell divisions in a lifetime and have a million times more cancer risk than pelvic bone cells which do about a million cell divisions. Random DNA copying mistakes during cell division are “the major contributors to cancer overall, often more important than either hereditary or external environmental factors”, say the US researchers.
To sum it up, until or unless medical research finds a way to stop the bodily effects of aging, cancer becomes the most likely way for all of us to die. Cancer is a generic rather than a specific term — it’s what we use to describe the inevitable breakdown of the cellular division process that happens millions or even trillions of times over our lifetime. As Ridley puts it, “even if everybody lived in the healthiest possible way, we would still get a lot of cancer.” I’m not a scientist and I don’t even play one on TV, but I suspect that the solution to cancers of all kinds are to boost our immune systems to more quickly identify aberrant cells in our bodies before they start reproducing beyond the capability of the immune system to handle. The short- to medium-term solution to cancer may be to make us all a little bit cyborg…