Biopsies are small but still invasive. There’s risk of infection or reactions to anesthesia in any surgery. If 100 million women get this test, a 5% false positive rate will mean 5 million unnecessary interventions. Not to mention the stress of being told you have cancer.

5 million unnecessary interventions means a small percentage of those people (thousands) will die or be harmed by the treatment. That’s the harm that it causes.