[michael1999]

It could also mean there are other negative forces balancing out the positive forces. Negative outcomes for broad screening include.

- Early testing means more visits to the hospitals/clinics. Those are famously dangerous places to get sick.

- False positives mean unneeded treatment. That can shorten your life.

- Finding things earlier also means earlier treatment. That can kill you. Every trip to a hospital means a non-zero risk of catching MRSA and other nasties.

- Some things would be handled by the immune system anyway. The treatment might provide no benefit over an ignorant outcome.

I also find it easy to believe that among all the oncologists and hospitals, some of them might be at best neutral, or even net-negative in mortality and morbidity. This is about the whole population, not just leading units at famous hospitals. There are doctors out there with the ethics of a bent mechanic.