Cancer Won’t Be the Last of Our Problems

For the last few decades at least, the phrase “a cure for cancer” has, in many ways, stood for more than just ending this terrible side-effect of being a multicelled organism.

In some respects, “cure for cancer” is code for humans gaining final and ultimate control over our own biology. In the sense of us defeating the last great killer.

We beat the beasts. We beat the elements. We beat the bacteria and the viruses. To a large extent, we’ve even beaten those loaded genetic dice that lead to terrible congenital conditions.

And in the years ahead, if the latest research and tests go well, we’ll have beaten our own cells’ propensity to occasionally go nuts and replicate out of control.

Unfortunately, this list of achievements makes something really clear. Every time we “win” against something that kills us, something newer and even harder adds itself to the top of the list.

It’s hard to imagine, but for people living anything more than about 100 years ago, cancer was barely a thing.

Sure, people died of it. But you had to survive bacterial and viral infection first. And war, of course. Malnutrition. And all the other things that contributed to the vastly lower life expectancy of the past.

And if you did manage to live to 83 in, say, 1876 and then died of cancer, you were still celebrated as someone who lived a notably long life. Dying of cancer at 83 was an achievement, not a tragedy.

Each time we defeat a whole class of killer - micro-organisms being the classic example - we extend our life expectancy, and allow harder and more insidious diseases a chance to become “the biggest killer” in turn.

In the mid- to late-20th-century we became so good at medicine that people started being able to die of “lifestyle diseases”. For thousands of years, death from complications due to obesity used to be something that could only kill a king. Half of the really bad drugs only exist because medical research invented them. Type II Diabetes? How many people living in 18th century rural Europe could even find the calories necessary to develop such a condition?

The curing of cancer - or rather, the understanding and management of the wide range of conditions that cause cell replication to go haywire - is already well underway. Many cancers are already downgraded to something you live with, rather than die from. Survival rates for childhood cancers are incredible, from almost-certain-death in 1900 to almost-certainrecovery in 2000.

So what gets us next? Curing cancer in the young will be a good thing, just as eradicating smallpox and creating reliable defences (many not even medical) against most other diseases has been key to creating the world we take for granted.

But if reducing all forms of cancer to a health condition no more serious than a bad infection doubles our life-expectancy again - as antibiotics, sewerage, and nutrition did over the last 200 years - we’re going to have to face a fact that’s been staring us down for a while now.

At 80 years old, your “lifetime risk” of developing Alzheimer’s is 14%. At 85 years old it’s 19.3%. At 90, it’s 30.8%. And if you live to 95, there’s a 50% chance you have some form of Alzheimer’s. That’s a flip of a coin.

The cause and pathology of Alzheimer’s and dementia isn’t yet fully understood, but given how much harder “curing cancer” has been compared to, say, developing antibiotics... the next war against disease isn’t going to be straightforward, or short.

But we’ll still win.