As much as we like to trust in science, nothing is perfect—not even medicine. And the tools used to diagnosis illness every day can, and do, make mistakes.
In a study including more than 1,000 patients screened for prostate, lung, colorectal, and ovarian cancers, 43% of people were given at least one false positive. Other studies suggest the stress caused by a false cancer diagnosis can last for years.
But stress and worry aren’t the only problems false positives on cancer screenings cause. They’re also expensive.