Wednesday, October 21, 2009

Cancer Funding in Canada

Today's Globe has this interesting piece on how small the portion of cancer research spent on childhood illness is. A sample:

One dollar in every $30 invested in cancer research goes specifically to research on childhood and adolescent cancers, according to a new report.

In 2007, $13.2-million of the $402.4-million that was invested in cancer research in Canada was aimed at understanding the causes and improving the cancer of younger patients, the study from the Canadian Cancer Research Alliance shows

Now the fact that only 3% of cancer research focuses on childhood illnesses will surprise, and no doubt trouble, many people.

Let me first address the sensibility that spending only 3% of cancer funding on childhood and adolescent cancers is unfair. What most people don't realise is the fact that cancer is predominately a disease of aging. Like other chronic diseases (heart disease, AD, etc.), most people who die of cancer are over the age of 65. So if one wants to spend money on things that will help save more young lives then one should support tackling more prevalent risks. Look here, for example, to see what kills more young people than cancer. For every young person ages 14-24 that dies of cancer, 6 die in accidents, and 3 die from suicide.

Furthermore, the death rates for the young in Canada are very low, especially compared to the morbidity and mortality rates of the aged. This is not to suggest that we shouldn't do more to reduce early life morbidity and mortality (we should), but that any response should be proportionate to the risk. A 20 year-old smoker has a much lower risk of cancer and death than a 75 year-old active, non-smoker. Why? Because aging is the major risk factor for disease and death in Canada.

So while the intuition that it is unfair to spend so much on cancer research for the aged rather than the young misses the mark, there is a legitimate complaint to make here. Once we make explicit the point that cancer research aims, primarily, at benefiting people in late life, how much bang for the buck will it actually yield? Would we be better served investing more money in aging research rather than cancer research?

Imagine, as fantastical as it is, there was no cancer in Canada. That all 200+ types of cancer were eliminated overnight, just like that. How much longer could Canadians expect to live? 10 years? 20 years? 40 years? The answer will no doubt surprise you. If there were no cancer to kill us the *average* life expectancy would rise by about 3 years.

Why is the number so low? Because removing cancer as a cause of death will simply delay, by only a few years for most people, one of the other chronic diseases of aging. So a 75 year-old who doesn't die of cancer will probably suffer a stroke or heart attack a few years later. See this paper in Science for an overview of the estimates of the upper limits of human longevity.

Aging limits average life expectancy to around 85 years. To add real quality of life in late life we need to tackle the major cause of chronic diseases--- aging itself.

So the real problem with the current approach is that by aggressively going after each specific disease of aging, rather than the aging process itself, we pursue a sub-optimal approach to health extension. One that requires much more funding and yields smaller health dividends. Retarding aging would help delay, simultaneously, most these afflictions, thus freeing up more money to spend on improving the lives of young Canadians.

Thus everyone, young and old alike, would benefit from a more inclusive approach to medicine. To get there we need doctors and medical researchers (and politicians and the general public!) to adopt a Darwinian-based approach to health and disease.

The funding numbers for cancer research reveal that cancer research is really striving to help the aged. But the problem is it focuses only on the proximate cause, rather than the ultimate cause, of mortality. If you really want to improve the health prospects of people in late life we should search for ways to modulate the biological clocks we have inherited from our Darwinian past.