> It was retrospective-only, i.e. a case series on women who were known to have breast cancer, so there were zero false negatives and zero true negatives, because all patients in the study truly had cancer.

Well yes, that's the denominator for determining selectivity, which is what the headline claim is about.

Also, they need to set up their next paper:

> However, the retrospective, cancer-only design limits generalizability, highlighting the need for prospective multicenter screening trials for validation.