NPR has a great blog on their website called “Shots” about current events in health care. Last week Scott Hensley, the main blogger there, posted about a recent article on treatment of prostate cancer from the Archives of Internal Medicine.
If you look at the article, you may notice a very small subheading above the article’s title. It reads “Less is More.”
The thrust of the article and the subsequent blog post is that men diagnosed with prostate cancer that have PSA values of less than 4.0 nanograms per milliliter of blood (“ng/mL”, the standard measurement) usually opt for treatment of their cancer, even though their cancer may not necessarily harm them.
What’s that, you say? How can cancer not harm someone?
This is an extremely vexing issue in the world of medicine, so it bears exploring.
Most importantly, it’s important to understand that “Cancer” is not one disease. This is perhaps the most commonly repeated media misconception, as when talking heads go to commercial break and say, “Coming up next: Scientists at Yada Yada U. claim that they have the cure for cancer. Is it true? Stay tuned to find out.”
Cancer is a process, in which the genetically-programmed regulation of normal cells goes haywire and leads to unfettered replication. It can occur in many different cell types, in almost any of your body’s organs. As such, there are numerous cellular and molecular targets of potential medicines, so a claim that one thing can cure [all] cancer is ludicrous on its face.
It so happens that on the spectrum of cancers, prostate cancer is the most commonly occurring one in men. That said, its fatality rate, the rate at which death is caused by the cancer, is very low.
Well, the five-year survival of diagnosed prostate cancer is one hundred percent. That means if you’re diagnosed with prostate cancer today, you’re essentially guaranteed to be around in five years. The ten-year survival is 91%. Not perfect, but not bad. I’d take those odds. [By the way, this is data I pulled from the American Cancer Society website.]
Contrast that to cancer of the pancreas. A much less common occurring cancer, but much more fatal: The five-year survival is 5.6%. [Source: National Cancer Institute.]
So what’s the point of all this?
I was taught an aphorism in medical school: “Most men die with prostate cancer, not because of it.” At autopsy, old men frequently had cancer in their prostates–but died from other, unrelated causes.
The point becomes think twice; think even four times about treating low grade prostate cancer. The treatments are invasive. The surgery usually leaves men with incontinence (leakage of urine) and impotence (inability to achieve erections). The problem is that the non-surgical option, radiation, causes the same harms at comparable rates.
Men are offered this bargain, and based on the article mentioned at the outset, it seems that they choose treatment over non-treatment (“watchful waiting”). For most of us, just hearing the word cancer is enough to make us terrified and want some kind of treatment, no matter how invasive. We’re a culture of doing something.
If you go over to the Shots blog linked at the top, you can read the comments below the post. Many are along the lines of “I’m grateful to have been diagnosed and treated early; my incontinence is mostly gone, or an inconvenience that I can live with, so this is article is a disservice to men everywhere, etc.”
I have no qualms with men having a choice about whether they want treatment or not. But those commenters suffer from what we call “treatment bias.” They want to justify their decision to undergo treatment, which is fine; I’m merely saying that treatment of ‘garden variety’ prostate cancer is neither mandatory, nor in every man’s best interest.
I will agree, however, that there exists an aggressive subtype of prostate cancer that metastasizes early and does have the power to harm and ultimately kill (cf. Zappa, Frank.)
And that’s what we need to figure out. Who (and how often) has this aggressive subtype that warrants more urgent treatment? Riches and prizes will certainly flow to those who solve this one.
But for the majority of men diagnosed with prostate cancer, watchful waiting (i.e. doing no harm) is a viable, underutilized option. This vexing issue is one of many examples of a Pandora’s box that our technologies (e.g. the PSA test) burden us with.