[jhayward]

No, because you'll be telling 1 out of 20 healthy people they tested positive for cancer. Or, if it's 95% selectivity per test, which it probably is, 13 out of 20 healthy people will test positive.

[BiteCode_dev]

You won't, of course. Just like with aids, a positive would be then double checked with a safer test.

EDIT: nevermind, I got educated by _Microft.