What the radiologists are not required to tell you, and almost never do, is that a breast ultrasound exam may actually be harmful. This test has a vastly higher rate of “false alarms” than a mammogram. False-positive readings lead to many biopsy recommendations, in exchange for relatively few additional cancers found. For the great majority of women who have a worrisome finding on screening breast ultrasound, the additional tests, biopsies and follow up tests turn out to show completely benign conditions. These women and their loved ones experience tremendous fear and anxiety during this ordeal, with lots of tense waiting for results.
The addition of breast ultrasound to mammographic screening for breast cancer remains controversial among medical societies. Clearly, a lower specificity for cancer means that there will be a higher rate of false-positive readings. That may seem a small price to pay for the peace of mind of knowing that you don’t have breast cancer, and if that is beneficial for you, then, by all means, have an ultrasound. But not every woman sees this issue the same way. You have a right to say, “No,” and leave without an ultrasound, if you don’t want the additional test.