in South Korea the incidence of thyroid cancer soared with the introduction of widespread ultrasound screening. But deaths did not increase. It was estimated that 90 percent of the cancers that were discovered and treated in women did not need to be found.

 

Why Some Doctors Say There Are Cancers That Shouldn’t Be Treated

Statistics show a clear spike in eight cancers in younger people, but that has brought a debate over whether many cases ever needed to be found.

By Gina Kolata

Dec. 8, 2025