A new study finds about a quarter of people with early stages of breast cancer get expensive tests they don't need.
Advanced imaging - like CAT scans, PET scans, or bone scans - are usually not recommended for people with ductal carcinoma in situ, stage one or stage two breast cancer.
Tara Breslin is a cancer surgeon at the University of Michigan.
She says it's not clear who is asking for the extra scans, but it could be both doctors and patients.
"It may be that clinicians feel that it would be reassuring," she says. "But patients may also feel that a negative test would be reassuring and help them feel better about their treatment."
But, those extra tests can be the opposite of reassuring.
False positives can lead to more tests and more anxiety.
Unnecessary testing also increases aggregate health care costs.
