A little healthy skepticism goes a long way

I consistently encourage you to exercise some healthy skepticism about mainstream medicine’s “party lines.” Especially when it comes to the benefits of cancer-screening tests. In the past, I’ve been considered a heretic–or worse–for this perspective.

But now, cancer-screening skepticism has actually hit the mainstream.

In fact, in August an essay by Cary Gross, M.D., from Yale University appeared in the JAMA Internal Medicine. And it finally raises many of the very same concerns I’ve been writing about for years.

Dr. Gross says cancer screening was relentlessly promoted as another miraculous medical “wonder” in the “war on the cancer.” But after a half-century, we now know the data doesn’t add up. More cancer screenings don’t necessarily translate into more saved lives. And many “experts” are now wondering whether screening helps or hurts. And they’re rethinking what the public health agenda really should be.

Dr. Gross thinks the U.S. may be at a “tipping point” with cancer screening–with the “credibility” of the entire enterprise at risk.

I believe we need to look at each screening test individually. Some tests have much more value than others.

For example, the one and only cancer screening program that works as well as advertised is the Pap Smear test for cervical cancer. The Pap smear test helped bring down cervical cancer death rates by 60 percent from the 1950s to the 1990s. And this success led to the widespread promotion of other cancer screening methods, such as breast cancer mammography (since 1963) and colonoscopy for colorectal cancer (since 1969).

Of course, a major Canadian study recently called into question the benefits of mammography in younger women.

I also frequently warn about the dangers and misuse of colonoscopy as a screening tool.

First of all, oncologists and researchers link colon and rectal cancer together as “colo-rectal.” And they say colonoscopy screening will detect them both.

But the fact is, colon cancer and rectal cancer are different, distinct diseases. With some potentially different, distinct causes. Plus, you don’t need a colonoscopy to detect rectal cancer. It is fully detectable the “old fashioned” way–by a digital rectal exam. (You can detect prostate cancer this way as well.) Even better, this screening method has no additional cost or danger to the patient, and requires no “prep.” But it seems doctors no longer want to get their hands dirty, so to speak.

The American Cancer Society (ACS) clings to data that says we have witnessed a 43 percent reduction in deaths from colorectal cancer over the past few decades of screening. However, there was a drop in the incidence of colorectal cancer by 30 percent. So–let’s make one thing clear…30 percent of the ACS’s 43 percent drop did not die from colorectal cancer because they never had it in the first place!

And what about the remaining 13 percent reduction?

The ACS claims the 13 percent net reduction in colorectal cancer deaths is due to screening (early detection), such as colonoscopies.

I have two major problems with that assumption.

First, it’s an assumption. The evidence does not point to colonoscopy specifically, versus other types of screenings. So–they can’t say that it was colonoscopy that brought down the rates.

Second, there is every possibility that the reduction had something to do with improvements in colorectal cancer treatments, as well as primary prevention. Let’s hope in all of this somewhere that there has been at least a little improvement in treatments to help account for the better survival.

Don’t get me wrong: I seriously doubt we have mainstream colon cancer treatments to thank for all this improvement. But we can’t rule it out without the hard data. And something is preventing more colorectal cancers in the first place. But the truth is, we just don’t know exactly what.

We do know it takes 15 years for a pre-cancerous growth (polyp) to become malignant cancer (assuming that it ever becomes malignant at all). So the ACS admits that the use of colonoscopy has negligible benefit in the elderly. Ironically, Medicare recommends and reimburses for colonoscopy once you hit 65.

Doctors are also performing too many repeat colonoscopies on people who have already had pre-cancerous growths removed. Many of these people have no greater risk of dying from colon cancer than the general public. In fact, according to a brand-new study, people who have had a single, low-risk polyp removed actually have a much lower risk of colon cancer compared to both the general public and patients who have multiple polyps.

Meanwhile, another government agency found that more than half of all people 65 years and older who had life expectancy less than nine years where nonetheless given colon, breast, cervical and/or prostate cancer screenings.

The National Committee for Quality Assurance–a quasi-government agency in D.C.–recently proposed that, as of next year, screening for colon cancer in people over 85 and screening for prostate cancer in men over 70 should be considered inappropriate.

I say why wait until next year?

In 2009, Otis Brawley, M.D., Chief Medical Officer of the ACS said, “for years, cancer screening has been oversold.”

It caused a firestorm at the time. But in the few years since, the data is coming in fast and furious to substantiate his statement. Like other government health efforts, the cancer-screening program became the subject of mindless promotion instead of thoughtful public health education.

Of course, don’t ask the public health bureaucrats to quit mindlessly promoting these cancer-screening programs anytime soon. Not when they’ve made careers out of them.


  1. “Cancer Screening in Older Persons: : A New Age of Wonder,” JAMA Internal Medicine published online 8/28/2014
  1. “Cancer Screening Rates in Individuals With Different Life Expectancies,” JAMA Internal Medicine published online 8/18/2014