[mbreese]

(Screening detected) Found during a routine/annual colonoscopy/mammogram/etc...

vs

(Symptomatic detected) Hey, what is this lump here? Why am I so tired? etc...

[nonbel]

I see, it should have been written "screening-detected" to be as clear as possible.

Yes, the latter is more likely to be comparable over time but it will still have issues with changes in how likely someone is to report it to their doctor, etc.