It is still a difficult concept for many people to grasp: how can there be harms from screening for cancer?
Maybe the study published this week in JAMA Internal Medicine, “Overdiagnosis in Low-Dose Computed Tomography Screening for Lung Cancer,” will make some of the potential harms a little more clear.
The analysis shows that nearly 20% of all lung cancers found by CT screening seemed to be harmless (indolent is the term the researchers used). The researchers wrote:
“These patients may undergo an invasive diagnostic procedure, have surgical resection, be given a diagnosis of lung cancer, and require multiple sequential follow-up studies when some tumors are potentially clinically insignificant. These cases of overdiagnosis are treated as any other lung cancer because it is generally not possible to distinguish indolent lesions from more aggressive tumors.”
“Putting the word ‘harmless’ next to cancer is such a foreign concept to people,” said Dr. Michael LeFevre, co-chairman of the U.S. Preventive Services Task Force.
In testimonials, patients often say lung cancer screening via CT scans cured them, but the study suggests that in many cases, “we cured them of a disease we didn’t need to find in the first place,” LeFevre said.”
WebMD quoted Dr. Otis Brawley of the American Cancer Society:
Brawley said the clinical trial had successfully detected two types of lung cancers — the 80 percent that could not be cured and the 20 percent that could be successfully treated.
“Now we’re realizing there’s a third kind of cancer — the kind that doesn’t need to be cured but can be cured,” Brawley said. “We cure some people who don’t need to be cured, but the study clearly shows by treating everyone we cure people who need to be cured.”
Meantime, the Chicago Tribune carried a story promoting a hospital’s free lung cancer screening on the same day that most other news media were reporting on the troubling findings from the study. The Tribune story made no mention of the new study. Sigh.
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