In about 60 seconds, this broadcast ably summarizes a complex study that explores the value of computed tomography (CT) screening for detecting lung cancer in high-risk individuals and prolonging survival in those diagnosed with early stage disease. Although lung cancer is a lethal and aggressive disease, cancer detected early responds remarkably well to treatment. So, what’s to debate about a screen that appears to boost 10-year survival rates to 92%? As Charles Gibson and Dr. Tim Johnson point out, plenty. The broadcast focuses on the major finding of the study—the estimated survival rate among stage I lung cancer patients who quickly underwent surgical resection—and the most important limitations in the New England Journal of Medicine study that reported the findings. In addition to accurately quantifying the apparent benefits of CT screening, the story notes that the true meaning of this finding is unknown because there is no comparison group of people who did not get scans; it is possible that screened patients do not actually live longer than unscreened patients do, but simply appear to live longer because they receive a diagnosis earlier. The story also cautions that the CT screen is capable of identifying benign “spots” of no medical consequence, which may require biopsies. It suggests that there are potential harms associated with such overdiagnosis and invasive diagnostic testing. The broadcast’s brief format naturally has limitations of its own. It does not make explicit all of the potential harms of screening, nor their frequency or seriousness (e.g., CT radiation exposure; fear and anxiety after a positive CT scan; partial lung collapse, bleeding, infection, pain, and discomfort after the subsequent biopsy). As the National Cancer Institute notes, CT scans “can trigger unnecessary invasive testing or even chest surgery that may potentially lead to decreased pulmonary function or death.” (See http://www.cancer.gov/cancertopics/factsheet/lung-spiral-CTscan.) It omits mention of the availability and cost of CT screening, important considerations for the elderly who may be susceptible to the marketing of these services and who will likely shoulder the costs of uncovered tests on their own. The broadcast also omits mention of another limitation of the study—that the authors followed the patients in their cohort for an average of only 40 months, not 10 years, and estimated 10-year survival using historical data from earlier studies by others. And the story relies on a single source (Johnson) to summarize all of the study’s pros and cons.
Arguably the most egregious defect in this potentially useful broadcast is the contradictory message it sends. After capably answering the question, “So why caution flags?” Johnson undercuts his own answer when he declares he “would probably get a scan” if he were at high risk for lung cancer. The "caution" message was likely lost on viewers as soon as he said this.
The broadcast does not mention costs associated with lung CT scans. The authors of the New England Journal of Medicine study cite four studies published since 2000 that estimate the cost at less than $200 each. The National Cancer Institute says each scan costs $300 to $1000.
The story accurately quantifies the apparent benefits of CT screening, noting that the estimated 10-year survival rate was a very high 92% among screened high-risk patients with early-stage cancer who underwent surgical resection. It notes that without a comparison group of people who did not get scans, the true meaning of this finding is unknown.
The potential harms of screening include radiation exposure, the fear and anxiety caused by false positive CT scans that turn out to identify benign or meaningless “spots,” and complications associated with the inevitable biopsies that follow positive scans. The broadcast points out that CT scans identify tumors of no medical consequence, and mentions biopsies. However, it does not talk about radiation exposure, not does it discuss the frequency or seriousness of any potential harms.
The broadcast states the study’s essential findings and devotes most of its time to cautioning viewers against over-interpreting them. It clearly explains the study’s key limitation–that it is an observational study lacking a comparison group, and is thus unable to definitively state “if there’s a real survival difference between people getting scanned and not,” according to ABC’s Dr. Tim Johnson. But Johnson tilts the evidence on its head when he declares he “would probably get a scan” if he were at high risk for lung cancer.
The broadcast appropriately hints at the seriousness of lung cancer, but still contributes to disease-mongering. On the one hand, ABC's Dr. Tim Johnson nicely summarizes the problems with the New England Journal of Medicine study, downplaying the scientific evidence to support CT screening. But he twice undermines this by saying that if he were an individual at high risk, "I would be very tempted” to get a scan. This sentiment plays to viewers’ fears.
The broadcast relies on a single source, ABC’s in-house physician, Dr. Tim Johnson. Johnson in turn cites unnamed “experts,” saying they are not yet willing to issue screening recommendations based on this study. The story provides no details on potential conflicts of interest.
The story suggests that one alternative to CT screening is to not screen. There are no proven effective alternatives for early diagnosis in high-risk patients.
The broadcast does not mention the availability of lung CT scans. Some 60% of hospitals in the U.S. own spiral CT machines, and some are promoting scans to smokers.
The story states that a new study provides "the strongest evidence yet that screening smokers for lung cancer early with CT scans might detect lung cancers earlier." So it is clear this is not a new area of investigation.
There was no obvious use of text from a press release.