Finding and treating very slow-growing cancers through aggressive screening doesn’t help people live longer overall — it just finds cancers that wouldn’t have hurt them anyway.

Doctors tested if yearly blood tests and ultrasounds could save more lives from ovarian cancer, but even though they found more early cancers, the number of deaths didn’t go down — meaning finding these slow-growing tumors didn’t help people live longer.

This study found that nearly 1 in 5 lung cancers found by CT scans are harmless and would never hurt the person — but they still get treated, causing stress and side effects. Since these fake threats don’t save lives, the screening doesn’t really lower death rates overall.

South Korea started screening lots of healthy people for thyroid cancer with ultrasounds, and found way more tiny cancers — but people didn’t start dying less. That means they were finding cancers that never would’ve hurt anyone, proving that screening too much doesn’t save lives.

Korea started screening for thyroid cancer a lot, and found way more cases — but people didn’t start dying less. That means many of those 'cancers' were harmless and didn’t need to be found or treated.

This study shows that many breast cancers found by screening would never hurt you, so finding them doesn’t save lives — it just causes unnecessary stress and treatment. That means more screening doesn’t necessarily mean fewer deaths.