False Positives and Real Dollars: Why $88 won’t effectively screen for lung cancer

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Let me be clear.  I think lung cancer screening is a good thing.  The National Lung Cancer Screening Trial (NLST) had air-tight design and was impeccably performed.  Those who have paid attention know that the NLST demonstrated a 20% relative reduction in mortality from low-dose CT screening (as opposed to chest x-ray).  Plus, the all-cause rate of death in the low-dose CT group was 6.7% lower than the radiography cohort.

But the details reveal concerns – those with financial and geographic-specific implications that have, until now, mostly escaped public debate.  The fanfare that accompanied the glorious NLST quest has supplied perverse financial incentives for entrepreneurial types – and has put patients in places such as the Ohio River Valley at potentially increased risk from exploitation of our interminable fear of cancer.  It has also given providers in these regions the unenviable and perhaps impossible task of balancing costs, patient expectations, and disease prevalence.

The Histo-belt

I took this picture while driving along a rural southern Indiana highway during a recent trip to visit family.  Southern Indiana (and neighboring northern Kentucky) are known for blue-collar shipping industries, steamboats, and high school basketball.  They also rest squarely in what is colloquially known as the “Histo-belt.”  Histoplasma capsulatum is a fungus endemic to the Ohio and Mississippi River Valleys.  It is everywhere.  You get it by breathing.  Prior studies suggest that >80% of those living in these regions have contracted the fungus.  The majority of people with histo don’t get sick.  But – they get lung nodules.  Lots of them.  The nodules are benign but often indistinguishable on imaging from “early” lung cancer. 

The entrepreneurial owners of the pictured urgent care center likely know this.  They also know that Medicare and other carriers have limited coverage (reasonably so) to patients between the ages of 55 and 74 with at least a 30 pack year history of smoking.  If patients have quit smoking, they must have quit within 15 years to be eligible for coverage.  At first glance, it may seem like offering cheap, $88 screening for Americans ineligible for lung cancer screening coverage, or those eligible citizens too busy to get a physician order for a screening exam, is a good deed.  But, $88 is just the tip of the iceberg.  Additional screening exams and subsequent procedures/biopsies will all incur additional costs.

Our collective fear of malignancy, the unfortunately high frequency of lung cancer, and the promise of low dose CT screening for this disease will drive people outside of the NLST’s strict inclusion criteria into these low-cost, high-volume CT-scanning conveyor belts to “catch the cancer early.”

And what will they find in the Ohio River Valley?

Lots and lots of lung nodules.

Now What?

Joe, a 45 year old in Jeffersonville, Indiana has a 4 millimeter non-calcified nodule detected on a chest CT from CTs-R-US.  The CT was interpreted at a teleradiology outpost and naturally the interpretation says that “While likely representing infectious or granulomatous disease, malignancy cannot be entirely excluded.”  Of course Joe has a long smoking history, so further follow-up is recommended to ensure that the nodule doesn’t grow.  At only $88 for each subsequent scan (less than the price of a ticket to an NFL game), the price is reasonable.  The exam is quick and easy, requiring no IV placement or contrast administration.  Take a breath in, hold your breath – and presto — a screening exam that is quicker than a car wash.  When Joe turns 55, insurance coverage can kick in to help cover costs of additional screening tests.

You get the picture.

Furthermore, the markedly increased propensity of patients in this region to have pulmonary nodules is likely to lead to an increased number of image-guided and open surgical biopsies (when the image-guided biopsy provides insufficient tissue for analysis).  More invasive procedures will naturally lead to more cost-inducing complications (such as pneumothorax and pulmonary hemorrhage) and, in some instances, death.

The Universal Applicability (or lack thereof) of Data

The NLST impressively accrued over 53,000 patients from 33 centers.  But, less than 12% of those patients were screened in the Ohio and Mississippi River Valleys.  Will low-dose CT screening reduce mortality by 20% in Owensboro, Kentucky.  In the NLST, 0.06% of positive screening tests (that did not result in the diagnosis of lung cancer) were associated with major complications.  Will this low complication rate be maintained in a region that will undoubtedly experience a higher false-positive rate?  Will CT lung cancer screening in Louisville cost $116,300 per QALY gained for current smokers and $2.3M per QALY gained for former smokers – as suggested by cost effectiveness analyses of the NLST?  Will implementation of low dose CT lung cancer screening really only cost $3 per month per Medicare beneficiary in Memphis?


And in the meantime, the public praise for screening combined with the fear of cancer will provide platforms for entrepreneurs to unconscionably prey upon the anxiety of human beings.

There is no doubt that lung cancer screening with low dose CT is effective.  The data prove it.  But, the promise of this screening technology must be coupled with population-specific reality.  Moving forward, health policy experts may want to reflect upon the notion that medical trials and sweeping Medicare coverage policies may not be symmetrically applicable across all geographies for all diseases — and that they may expose patients to unintended exploitation.  Socioeconomic factors aside, lung nodules in Cincinnati and Seattle are not the same.  But the fear of cancer is.

These are all important conversations to have.  And don’t forget, I think CT lung cancer screening is a good thing.

The author is a radiologist at Emory University.


NLST Research Team.  The National Lung Screening Trial: Overview and study design.  Radiology 2010;258(1):243-253.

NLST Research Team.  Reduced lung-cancer mortality with low-dose computed tomography screening.  N Engl J Med 2011;365(5):395-409.

Mahadevia PJ, Fleischer LA, Frick KD, et al.  Lung cancer screening with helical computed tomography in older adult smokers: A decision and cost-effective analysis.  JAMA 2003;289(3):313-322.

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11 replies »

  1. Thanks for this. Tight reasoning. Good article. Would you want to do anything that reduced your TOTAL rate of death by 6.7%? Well, if you have smoked one pack a day for 30 years and you are now 55-74 years of age, you can do this. But it is going to cost you or someone on average a lot of dough. Are you worth this? And you can’t have smoked less than yearsXpack=30. And you can not be less than 55 or older than 74. Only if you fit, will it work. And you should not be living in a place that has an enrichment of background nodules like histo or cocci or TB.

  2. If you have seen the movie “War Games,” Joshua concludes that nuclear warfare is “a strange game” in which “the only winning move is not to play.”

    The same rings true for some, not all medical screening tests.

  3. Amazing isn’t it that for a political movement that prizes itself on nuance, its singular health policy has been demeaned to a dichotomy, and a dull one as well.

  4. Sorry to hear about your cancer.

    “As a 38 year old never-smoker living with metastatic lung cancer, I would happily take a boatload of false positives if it means they could have caught my cancer when it was still curable.”

    You would not have taken the boatload of false positives. You would have been a true positive.

    Others would have taken the boat load of false positives. And one of the false positives would have died from a biopsy of a nodule which was never going to be cancer.

    This is a vexing problem. To pick up one lung cancer several people are messed up to varying degrees.

    Sure, you save a life. But is it fair to those who are subjected to unnecessary biopsies?

  5. “Yes, that’s an important number to quote during shared decision making”

    Haven’t you heard? HHS is switching everything to P4P. Shared decision making is passé; now it’s all black and white, no gray areas.

  6. Tori — no doubt a step in the right direction. I certainly don’t mean to suggest we stop screening or try finding better ways to do so.

    And you’re right, screening via other methods may be more effective in the future.

    We’re still learning how to use imaging as a screening tool. With so many diseases “looking” like each other on imaging tests (and accompanied by asymptomatic clinical histories) — current technologies (while a step in the right direction) — leave a lot to be desired.

  7. Couldn’t agree more. There are substantial costs associated with finding things that aren’t cancer. And the risks are significant, as well.

    I appreciate you taking the time to read and leave thoughtful comments.

  8. As a 38 year old never-smoker living with metastatic lung cancer, I would happily take a boatload of false positives if it means they could have caught my cancer when it was still curable. These screenings are not perfect, but they are a step in the right direction. Now, let’s develop a blood or breath test that can catch lung cancer in us young, never-smokers who have no risk factors. Please don’t give up on us.

  9. “A third point is that 2/1000 had a major complication from screening.”

    Yes, that’s an important number to quote during shared decision making.

    The piece highlights the end result of screening becoming a commodity – a race to the bottom. I fear the advocates of screening have already started the journey to the bottom by suggesting that the elibility criteria be expanded beyond NLST.

    A line has to be drawn somewhere. Once you break the line, you’ve broken the logic for having a line. Then what’s to say we shouldn’t screen 35 year old non smokers?

    Unfettered logic is the abode of unlimited idiocy.

  10. Three additional considerations.

    For Joe, the 45 year old in Indiana with a smoking history, the first scan is screening and costs $88. If, as you postulate, it finds a 4 mm non-calcified nodule and follow-up scans are recommended, these follow up scans are no longer $88 screening scans. They are full price diagnostic scans to evaluate a nodule. The $88 initial scan might be called a loss leader.

    A second point is that you cite only the 20% relative risk reduction in mortality, not the absolute risk reduction of 3 out of 1000 scanned over ~ 7 years. The lung cancer death went from 21/1000 to 18/1000 and the total deaths went from 75/1000 to 70/1000.

    A third point is that 2/1000 had a major complication from screening.


  11. Filtering out false positives will be an important part of advancing lower-cost diagnostics for cancer, but I would argue these should be advanced. The potential goes way beyond cheaper CT / PET scans to bioinformatic methods that can be used with smart phones. Final diagnosis should still be made by a qualified physician.