25 Overdiagnosis?

In my last post I left you hanging with suspense! Well, in this post I have a couple of issues to raise that should quell any after effects of inordinate suspense left behind from reading my last post. One is about overdiagnosis, which I promised to raise again, and the other is about cancer itself and what would happen if it didn’t exist.

So, in her book Natural Causes, Barbara Ehrenreich addresses what she calls overdiagnosis. This is a situation wherein currently powerful imaging techniques can, for example, ‘see’ many more, and smaller, lumps in a person’s neck than was previously possible. The question is then put to the patient: “We’ve found a lump in your neck. What would you like us to do?” Patient, very concerned: “Is it cancer?” Doctor: “We don’t know, but we can always remove it.” Patient: “Well, let’s not take any chances. Let’s get rid of it.” Ehrenreich claims that in seventy to eighty percent of these cases in the US the surgery was unnecessary.

I have my own example of overdiagnosis. I had a parotid gland removed from the left side of my face years ago. There was evidence that it was enlarged, but nothing to say it was malignant. I had a choice to make and opted to have it removed. It was unnecessary surgery. Because of it I was left with insensitivity on the left side of my face and a scar leading from my ear down the side of my neck. It’s a crapshoot. How many people do you think would turn down the surgery?

Recently, Dr. Brian Goldman of the CBC’s program White Coat, Black Art, wrote in his blog about overdiagnosis. He writes that overdiagnosis “means identifying problems that weren’t causing symptoms and were never going to cause the patient harm.” The source for most of his information is a study led by Prof. Paul Glasziou, director of the Institute for Evidence-Based Healthcare at Bond University in Australia. It used data collected over a thirty year period by the Australian Institute of Health and Welfare. The results are quite astounding. Goldman writes:

The researchers found that, in men, 42 per cent of prostate cancers, 42 per cent of kidney cancers and 58 per cent of melanomas were overdiagnosed. In women, 22 per cent of breast cancers, 58 per cent of kidney cancers and 54 per cent of melanomas were overdiagnosed.

Overdiagnosis can arise from overly prescribed testing including screening tests like mammography. Increasingly sensitive imaging equipment can detect smaller and smaller lesions and tumours, benign or malignant. It’s often difficult to tell whether a tumour is benign or malignant. In the case of kidney cancers, invasive biopsies are not often carried out for fear of spreading cancer cells to adjacent lymph glands. So, surgery is a crapshoot. Do we operate or not? The default position is surgery because few people would be willing to take the risk of leaving a possibly benign tumour in their bodies.

To take this even further, Goldman’s blog post argues that even “incidental abnormalities” or cancers that would never have caused symptoms or led to full-blown rapid onset pathological mitosis are being surgically extirpated. We probably all have asymptomatic cancer cells in our bodies that may never result in any health threat because of them.

In the September 11, 2017 issue of The New Yorker Siddhartha Mukherjee is back at it with a thoroughly provocative article entitled: Cancer’s Invasion Equation: We can detect tumors earlier than ever before. Can we predict whether they’re going to be dangerous?

Good question. The gist of Mukherjee’s argument in this article is that two things are required for a full-blown cancer to make itself known which he metaphorically refers to as the seed and the soil. This metaphor he borrowed from a 19th Century English doctor interested in cancer research, Stephen Paget. His idea was that a cancer cell (the seed) would grow only if the local bodily ecosystem (the soil) was conducive to that growth. It could happen that the cancer cell falls on barren ‘soil’ and does not grow and divide. On top of that, on close examination cancer cells could be found that would never produce any symptoms. Some cancer researchers were now becoming human ecologists. Some even began to ask why people don’t get cancer and not just why they do when they do.

In my case, I may have carried the myeloma ‘oncogene’ for a long time but my ‘soil’ wasn’t yet ready to receive it. It may be that it was just a matter of time in my case, age being a big factor, but there may have been others that contributed too to creating the right conditions for my myeloma to go from dormant (smoldering) to active. Now, there’s no turning back for me. The seed has been planted and the hemoglobin garden in my bones is turning into an oncological garden.

There’s a final note towards the latter part of Mukherjee’s book The Emperor of all Maladies that makes me realize how little we know about cancer at this stage and about the process of dying and what that entails. Mukherjee writes:

“Taken to its logical extreme, the cancer cell’s capacity to consistently imitate, corrupt, and pervert normal physiology thus raises the ominous question of what “normalcy” is. “Cancer,” Carla said, “is my new normal,” and quite possibly cancer is our normalcy as well, that we are inherently destined to slouch towards a malignant end. Indeed, as the fraction of those affected by cancer creeps inexorably in some nations from one in four to one in three to one in two, cancer will, indeed, be the new normal—an inevitability. The question then will not be if we will encounter this immortal illness in our lives, but when.” (from “The Emperor of All Maladies: A Biography of Cancer” by Siddhartha Mukherjee)

So, how exactly does the body shut down as it’s dying? Cancer may very well be one (a very important one) of the mechanisms that is ‘natural’ in its role in having us die. Maybe cancer is not the pathological evil that it’s made out to be. What would happen if cancer did not exist? How would we die then? What does it mean to die of natural causes? How can we figure that out? Stay tuned. I think science and medicine have a lot to learn about us yet.