Believe it or not, even your ever-lovin’ box of colored blinking lights can malfunction, and it happened to me over the weekend. Actually, sometime around New Years, I caught some sort of crud, and have been battling it since. There’s nothing like hacking up a lung and not being able to sleep well for days to put one in a perfect mood to be particularly Insolent. And so it would have been, until my part of the country managed to be buried in snow all day and night Sunday, necessitating multiple rounds of going out to use the snow blower in spite of my condition and having to get up super early to do it again so that I could get to work. As a result, I’m beat.
That doesn’t stop me from taking interest in an article published in the New York Times over the weekend entitled Why Everyone Seems to Have Cancer. Basically, it’s a neat take on the annual government Report to the Nation on the Status of Cancer, which was released shortly before the holidays last year. George Johnson, the article’s author, notes that, every year, after the report is issued, there almost inevitably arises a cry that we’re “losing the war on cancer.” That claim is a topic I’ve written about on quite a few occasions, most notoriously when I took an overly nihilistic view on cancer progress that somehow found its way into Skeptical Inquirer and irritated the crap out of me, recently having pointed out that cancer is complex and curing various cancers will be hard. Johnson then points out something I’ve pointed out before:
Half a century ago, the story goes, a person was far more likely to die from heart disease. Now cancer is on the verge of overtaking it as the No. 1 cause of death.
Troubling as this sounds, the comparison is unfair. Cancer is, by far, the harder problem — a condition deeply ingrained in the nature of evolution and multicellular life. Given that obstacle, cancer researchers are fighting and even winning smaller battles: reducing the death toll from childhood cancers and preventing — and sometimes curing — cancers that strike people in their prime. But when it comes to diseases of the elderly, there can be no decisive victory. This is, in the end, a zero-sum game.
As I like to say, life is a sexually transmitted fatal disease. Nobody gets out of here alive. Success against one major killer disease (like heart disease) just means that all those people who would have died of heart disease must die of something else eventually. Of course, we’d all prefer that “something else” to be old age, whatever death from old age is, but it doesn’t have to be. So, as fewer people die of heart disease and other vascular diseases (like stroke), truly a triumph of science-based medicine, more must die of other diseases of old age, the most prominent of which is cancer. Even so, mortality from cancer has been decreasing steadily. Looking at the graph Johnson cites, you’ll notice that deaths from Alzheimer’s disease have skyrocketed since 1980, and deaths from Parkinson’s disease have also increased, although not nearly by as much.
In a way, Johnson argues, this “standoff,” as he calls it, is evidence of our success. Since 1990, heart disease mortality has declined by 44%, while cancer mortality has declined only by 20%, a fact that—I can’t resist pointing out—is contrary to the claims of all the cancer quacks that more people than ever are dying of cancer. Yes, maybe in sheer numbers that is true, but as a percentage of the population every year (i.e., deaths per 100,000 population) it is not. In any case, cancer is a disease of old age, and more and more of us are living long enough to be at risk for it. In many ways, though, as I’ve described before, heart disease is simpler. The cells that proliferate in blood vessels to cause blockages are genetically normal cells. The processes by which they proliferate, although complex, are nonetheless much simpler than the processes that result in the dozens, even hundreds, of different kinds of cancers, and the cells in these cancers are most definitely not genetically normal. They are about as far from it as possible as cells can get from “genetically normal.” Moreover, the consequences of vascular disease that result in the most common form of heart disease, which is due to decreased blood flow to the heart, can often be corrected, at least temporarily, by mechanical interventions, such as angioplasty or coronary artery bypass. Other forms of heart disease can also often be corrected with devices, such as artificial valves.
This is likely why cancer will always be with us and will be the hardest to combat:
Over the eons, cells have developed complex mechanisms that identify and correct many of the glitches. But the process is not perfect, nor can it ever be. Mutations are the engine of evolution. Without them we never would have evolved. The trade-off is that every so often a certain combination will give an individual cell too much power. It begins to evolve independently of the rest of the body. Like a new species thriving in an ecosystem, it grows into a cancerous tumor. For that there can be no easy fix.
As people age their cells amass more potentially cancerous mutations. Given a long enough life, cancer will eventually kill you — unless you die first of something else. That would be true even in a world free from carcinogens and equipped with the most powerful medical technology.
That’s why, when it comes to cancer, the biggest bang for the buck is prevention, but, contrary to what is often claimed by quacks and cranks, it is not, nor will it ever be, possible to completely eliminate cancer through alterations in diet, lifestyle, or environment. It’s too much part of how our cells function, a consequence of evolution. In fact, I tend to look at cancer as evolution run amok in the body, but at the cellular level, rather than at the level of the organism. In fact, the organism suffers because of the cancer cell’s drive to reproduce and expand. it’s also the powerful force that makes cancer so hard to treat, because chemotherapy itself is a selective pressure selecting for ever more resistant cells. None of this is to say that large decreases in various cancers can’t be achieved through prevention. Eliminating tobacco use alone would cause enormous declines in one of the most lethal cancers, lung cancer. Obesity is also associated with certain cancers, and infectious agents, like H. pylori and HPV, are associated with others.
If I really wanted to get complicated, I could point out that not all cancers necessarily kill. For example, autopsy series demonstrate that 75% of men over 80 have identifiable foci of cancer in their prostates; yet nowhere near 75% of men who die over age 80 die of prostate cancer. The implication is obvious; the vast majority of prostate cancer is a disease that most elderly men die with, not of. Yet this very fact suggests that in at least one way Johnson is right. If men lived to be 150 or 200, rather than just 80, 90, or, occasionally, 100, there would be more time for those foci to continue to develop, and likely nearly every man would develop prostate cancer that actually threatens his life.
Life is indeed a sexually transmitted fatal disease. All science-based medicine can do is to try to prolong it as much as biology will allow, eliminate diseases that shorten it or cause suffering, and palliate diseases that can’t be cured.