Patients and physicians should screen for cancer, but cautiously

To screen or not to screen? That is not the question.

The question is not whether to screen, it is why, what, where, when, how, and how much, how often, and at what cost for what benefit.

Patients and physicians must and do screen. The issue is cautious appropriateness. Self-screening by patients is easy, free, and fundamentally harmless. Look at your skin for potential melanomas, be alert to warning symptoms of a stroke, learn the early signs of alcohol dependence, observe your urine for gross blood.

These are observations that have almost no downsides and could trigger life saving interventions. But when the American Medical Marketing Machine (AMMM) starts screening campaigns, watch out. Both the well intended zeal of the advocacy groups and the ambitious avarice of the suppliers and providers can wreak real havoc, especially when they combine forces.

Is the benefit to individuals or the public going to be worth the harm to individuals and the costs to whomsoever pays the bills? Case in point: lung cancer.

The number one cancer killer in America. A really big deal. Caught late; usually kills; caught early; also often kills. How could even earlier change that equation? What are the downsides to screening for it?

Five investigators at the National Cancer Institute in 2010 reported in the Annals of Internal Medicine the results of a randomized, controlled clinical trial using low dose computed tomography (CT) versus chest x-ray on more than 3,000 current or past 30 pack-year smokers ages 55 to 74 with no history of lung cancer.

The cumulative risk outcome of a false-positive after one annual screen with CT was 21% and after two, 33%; false positive rates after chest x-ray were 9% and 15% at one and two years.

Not trivial results, and they often triggered an unnecessary and potentially hazardous invasive procedure, not to mention the hazard of the radiation itself.

Good things can happen after screening. But so can bad. A false positive means you found something that was not there; a false negative means something was there and you did not find it; a misidentification means you found something that was there but you called it the wrong thing.

Those are all bad. It is a little like in football; you throw a forward pass; three things can happen, but two of them are bad.

So, sure, screen; but remember Hippocrates. First, do no harm.

George Lundberg is a MedPage Today Editor-at-Large and former editor of the Journal of the American Medical Association.

Originally published in MedPage Today. Visit for more lung cancer news.

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  • steven shie

    George, I’m actually feeling more confused after reading your post. I understand that there are always risks involved in any medical procedures but You didn’t give a specific solution of what we can do strategically to balance the benefits and risks.

  • thedocsquawk

    Good read George. I noted that the percentage of people who got lung cancer diagnosis was 1.9% in the CT arm while it was 0.45% in the CXR arm. So we gain 1.45% if we use CT over CXR. It would be interesting to see if this difference vanishes if CXR is done over several years. Even CXR over ten years annually would still likely be less radiation than a LDCT. Also interesting was the CXR didn’t include a lateral view.

  • Richard Leff

    You left out one very important part of the risk/benefit equation–the benefit. Many studies of /CT screening of high risk patients for early lung cancer have been conducted and have failed to show any significant increase in cure rates. There is no benefit. Disease is detected earlier so the survival (time from diagnosis to death) is longer but the natural history of the disease is unchanged. Maybe you could rewrite the editorial about breast cancer. At least there is a modest increase in cure rate with mammographic screening.

    • Linda R

      Richard, I’d beg to differ that there is “no benefit” … to the person who lives longer before dying, that additional life may be a significant benefit.

      • gzuckier

        What he’s trying to suggest is that even if the patient is not living longer and the date of death is “hypothetically” the same, still if we now discover the cancer 5 years before his death, we say he survived 5 years; if we would have discovered the cancer only a year before his death, then he only survived 1 year. So earlier discovery may lead to “longer survival” statistically, but with no benefit at all to the actual patient.

  • J.T. Wenting

    the more you screen people, the more become hypochondriacs.
    After all, there must be something wrong else the doctor wouldn’t want you tested…

    All those “prescan” services offering “preventative health scans” always find things to refer to their contracted “specialists” to cure. That’s the way they make the real money.

  • Paul Dorio

    Steven brings up a great point: this stuff is quite complex.

    The main issue is whether screening catches cancers early enough, in enough people to make it cost effective, and so that lives are lengthened or saved as a result.

    Otherwise, we are just spinning our wheels.

    The verdict is not in on the answer to that question, unfortunately. So we are left to debate whether breast, lung, colon screening is useful. The odds must be weighed. And people of all walks must chime in, not just current Administrations or doctors or advocacy groups.

    My opinion? Screening must be performed extremely judiciously and there should be sovereign immunity for doing so. For example: mammography has been shown to save lives (notwithstanding, again, some recent reports that have injected controversy into the discussion). But mammography also has been shown to miss two-thirds of cancers that can be seen to be on the films in retrospect but were too tiny or similar to background breast tissue to be picked up. Should the doctor get sued for missing such a cancer? Or should the system be taken for what it is – a best attempt at catching the cancers in as many people as possible to hopefully save as many people as possible from an early death?

    Imperfect though screening may be, it will continue to be the best we have at finding cancers early.

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