Jane McCredie: From cannonballs to cancer

SCIENCE fiction writers often try to imagine the brave new future worlds that will be created by medical advances — the ultimate conquering of disease perhaps, or a nightmare society in which genetic engineering turns us into something less than human.

But speculative time travel is a risky business when it comes to medicine. Take this 1912 editorial from the New England Journal of Medicine, for example:

“Perhaps in 1993, when all the preventable diseases have been eradicated, when the nature and cure of cancer have been discovered, and when eugenics has superseded evolution in the elimination of the unfit, our successors will look back at these pages with an even greater measure of superiority.”

In an article celebrating the journal’s 200th anniversary this year, authors from Harvard Medical School discuss what the topics covered over those two centuries have to tell us about the changing face of medicine.

Their conclusions? Well, for one thing, cannonball injuries are a lot less common than they were 200 years ago. Apparently, back in 1812, you could be blinded or killed by a cannonball whizzing by, even if it didn’t actually touch you.

Papers from the journal’s inaugural year covered topics that remain familiar today — angina, diabetes, cancer, epilepsy — although reports of spontaneous combustion, especially of “brandy-drinking men and women”, also received serious, if somewhat sceptical, attention.

Of course, the causes of disease remained largely obscure in 1812, something that had begun to change a century later when many of the infections filling the journal’s pages had been reclassified in line with their microbial origins.

It was in this somewhat more scientific age that the Medical Journal of Australia joined the growing ranks of international journals, with a stated aim “to record the progress of scientific medicine, and to assist in rendering the practice of medicine in all its branches of the greatest benefit to the people of Australia”.

Original papers in that first issue of the MJA from July 1914 covered cardiac irregularities, surgery of the subphrenic space and a case of bilateral duplication of ureters. Shorter articles looked at venereal disease, alcoholism, mental illness and medical education — still familiar themes today.

One thing that has changed dramatically over the last century is the way we die and the things that kill us.

A graph in the New England Journal compares mortality in 1900 and 2010 and strikingly illustrates the shift in our relationship with infectious disease: at the outset of the 20th century, pneumonia/influenza was the biggest killer of Americans, followed by tuberculosis and gastrointestinal infections.

Medical advances and improved hygiene and sanitation have since pushed those diseases way down in the leagues table, here as much as in the US. Not that we’re in a position to be complacent about infectious disease, mind you, especially given the reckless squandering of precious antibiotics.

But the leading players now are chronic disease and cancer. Both heart disease at number 1 and cancer at number 2 account for more American deaths in absolute terms than they did in 1900.

The picture is similar here, where the Australia’s Health 2012 report ranked coronary heart disease as the major killer in both sexes. In women, stroke came second, followed by dementia. In men, it was lung cancer, followed by stroke.

Without letting our increasingly sedentary and indulgent lifestyles off the hook, the rise of cardiovascular disease and cancer is partly a result of increased longevity and substantial reductions in other causes of mortality.

If you get rid of the cannonballs, something else will rise up to take their place.

We probably have as much chance of accurately predicting the changes that will occur in medicine over the next 200 years — or even the next 100 — as an early 19th-century medical man would have had of predicting genetic testing, magnetic resonance imaging, or the emergence of HIV and AIDS.

But if there’s one thing the New England Journal’s brief survey makes clear, it’s that disease is as much a social and political concept as it is a scientific one: “the line between the normal and the pathological requires value judgments”, these authors write.

Although 23rd-century medicine will no doubt encompass things we cannot even imagine now, it will also at some level be built on not just scientific advances of today but also those value judgements.

The topics researched, the symptoms defined as disease, the decisions made about how, when and who to treat will all help to set the parameters for that unknowable future.

We won’t live to see it but we will help to create it. Just as those early 19th-century attempts at establishing a scientific process fed into today’s evidence-based medicine (studies of spontaneous combustion notwithstanding).

Jane McCredie is a Sydney-based science and medicine writer.

Posted 16 July 2012