Overdiagnosis can become a bigger problem than some cancers

Over the past 30 years, we have heard that early cancer detection saves lives. But is this true? Does it save lives? Or instead, does it lead to an overtreatment of potentially harmless “cancer” cells that don’t really behave like cancer?

In March 2012, researchers from the National Cancer Institute (NCI) convened to look at the evidence. And they just published their stunning conclusions in a recent issue of the Journal of the American Medical Association.

The NCI researchers found cancer overdiagnosis and overtreatment is indeed a major problem in modern medicine. And it’s only getting worse. Especially when it comes to prostate cancer and breast cancer.

In fact, the researchers suggested we redefine some types of “cancer” altogether. They suggested reserving the term “cancer” for “describing lesions with a reasonable likelihood of lethal progression if left untreated.”

So–ideally–how do we go about diagnosing cancer?

After the physical exam, the next step happens in the lab. Pathologists look under the microscope at a biopsy and determine whether individual cells look like cancer. If they do look malignant, they assign the cells a “grade.”

Clinicians also determine whether the cancer has metastasized, or grown outside of its original site. Did it invade adjacent tissues? Did the cancer cells travel up the lymphatic system to lymph nodes? And did they “invade” the blood circulation and travel elsewhere to “seed” into other parts of the body?

Ultimately, by looking at how the cancer grows and how fast it spreads, clinicians come up with a prognosis, or an estimate of how long the patient will go on to live.

Regardless of how a cell might “look” under the microscope, we must always consider the clinical prognosis. This helps us understand a disease’s overall mortality risk.

So, if it takes longer for a “cancer” to grow than the average human lifespan, it’s not really a problem. Or if it grows, but does not invade or metastasize to other parts of the body, it can’t kill you…as long as you remove it eventually.

Unfortunately, in far too many cases, clinicians don’t fully consider the clinical prognosis. They look at the pathology results and go straight to a treatment plan. This “rush to judgment” is not always the most judicious approach, especially when it comes to prostate cancer and breast cancer.

In fact, the new JAMA report mainly focused on the overdiagnosis of these two types of cancer. Interestingly, however, it made no mention of skin cancer.

A little while back, I wrote about the misconceptions concerning the dangers of skin cancer. And it may teach us something about how to diagnose and treat other types of cancer as well.

You see, more than 90 percent of skin “cancers” are low grade. Most forms of skin cancer arise from the upper layers of skin (squamous) or the bottom layer of skin (basal). And we can easily detect most growths in these layers. As you recall, you only have about seven layers of skin, so these cancer cells all form close to the surface, away from vital organs. So, they are easy to see. And relatively easy to remove as well.

They very rarely cause any problems, unless you completely ignore them. In fact, under the microscope, individual skin cancer cells often look so benign that we assigned them a pathology grade of “one-half.” (A grade of “one” is the minimum for judging true malignancy)

About 9 percent of skin cancers, however, arise from the pigment-producing cells of the skin called melanocytes. And these malignant melanomas are dangerous. They can and do turn deadly.

Clinicians need to get better at assessing other types of cancers, as we already do with skin cancer. Is it deadly? Or isn’t it? This will help patients avoid unnecessary treatments.

Overdiagnosing cancer may very well be the most dangerous, unspoken epidemic in modern medicine. Particularly since it can lead to faulty approaches in medical research, as well as in clinical practice. This dilemma is an important topic that warrants much more space than I have available here. So I’ll cover it in more detail in a future issue of my Insiders’ Cures newsletter.

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1.    “Overdiagnosis and Overtreatment in Cancer: An Opportunity for Improvement,” JAMA 2013;310(8):797-798