Catching up on some important reading.
Before this week ends and before the piece is forgotten, I wanted to draw attention to Dr. Peter Bach’s column in Slate, “CT Scam: Don’t believe the hype about lung-cancer screenings.” He hits on evidence, on harms, on costs, and on marketing that has already exploded all over the country after the National Lung Screening Trial results were announced. Excerpts (although I urge you to read the whole piece at the link above):
“Cancer screening is fundamentally inefficient: Hundreds, and sometimes thousands, of people must be screened to help just one or two. Each person who undergoes the test may suffer consequences from it, even though most will never get any counterbalancing benefit. This is why the recent study–called the National Lung Screening Trial–focused on a narrow, “high-risk” subgroup of the adult population who ranged from 55 to 74 years old and had smoked at least a pack a day for 30 years. If they had quit, it was within the past 15 years.
These are strict criteria, and they ensured that the patients had a meaningful chance of developing lung cancer during the course of the decade long study–and thus an opportunity to benefit from being screened. But people who are younger or have smoked less than the test subjects are at much lower risk for the disease (although no one is entirely safe from it).
If you have a lower risk of lung cancer, there’s less of a chance that screening will help you, as you can’t prevent something that wasn’t going to happen. But that doesn’t mean there’s less of a chance you’ll be harmed by the procedure. Taking a CT scan of the chest can uncover something that looks abnormal but ends up being nothing. Along the way there are more scans, biopsies and, sometimes, unnecessary surgeries. In the NCI study one in four people had these false positives. A prior study from the University of Pittsburgh pegged the rate at around two out of five, and in that study one in 100 subjects had parts of their lung removed for no good reason.
Some day CT screening will save lives–hopefully a lot of them. It will harm some people, too. We can stay ahead in this tradeoff if we are circumspect about whom we screen, and if we don’t believe every radio ad we hear.”