False Positives

False positives are a risk of any screening test. For mam-mography, Elmore et al.43 estimated that after 10 annual screening mammograms, nearly 24% of women had had a false-positive result at least once, with a cumulative risk of a false-positive mammogram of 49.1%. Of women who did not have breast cancer, 18.6% underwent biopsy after 10 mammograms.43 Short-interval follow-up of specific lesions, such as nonpalpable circumscribed masses and focal asymmetries has been validated,44-46 with risk of malignancy less than 2% among appropriately classified lesions. Importantly, the prognosis is not adversely affected by short-interval follow-up in this setting.

Biopsy of benign lesions seen only sonographically, and induced short-interval follow-up, are risks of screening ultrasound. Across the five series where specifics are detailed,27-30,32 after 38,602 screening sonograms, 1,137 (2.9%) resulted in biopsy and 134 (11.8%) biopsies showed malignancy. In the four series with details,27,29,30,32 short-interval follow-up was recommended in another 6.6% of women. Criteria for classifying a lesion seen only sonographically as probably benign have been proposed47,48 but require broader validation. Follow-up is generally performed only for nonpal-pable lesions, although one recent study suggests the combination of benign-appearing features on both mammography and sonography may allow follow-up of even palpable lesions49; further validation of such an approach is required. It should be noted that in all but one series30 only a single prevalence screen was performed: these rates of false positives are likely higher than would be seen on annual incidence screens.

With MRI, from 2% to 17% of women screened were recommended for biopsy based on MRI, and 24% to 89% of MRI-prompted biopsies proved malignant (see Table 28.2). Short-interval follow-up was recommended in 5% to 24% of women on the first screening round where specified38,39,50-52 and decreased to 3% to 7% when results of subsequent screening rounds were detailed.39,52 With MRI, the criteria for follow-up and risk of malignancy in lesions followed have not been widely studied. Liberman et al.51 report 7% of lesions seen only on MRI that were followed proved malignant, and another 3% of patients developed cancer elsewhere in their breasts during short-interval follow-up. It is encouraging that, in the series of Kriege et al.,38 275 of 4,169 (6.6%) of examinations were recommended for short-interval follow-up, with only 3 of 275 (1.1%) of those proving malignant. MRI-guided core and vacuum-assisted biopsy are becoming more widely available53,54 but require availability of scanner time and personnel. A facility that offers breast MRI should observe standardized technique and interpretive criteria55 and offer MRI-guided biopsy.

Herbal Remedy Secret Uncovered

Herbal Remedy Secret Uncovered

Discover How To Use Herbal Medicine Effectively To Heal Away Disease amp illnesses That Most Of The Herbalist Do Not Want You To Know About. If You Have Never Know What Is All About Herbal Medicines amp The Correct Way Of Using Herbs To Build A Healthier Life, Then This Guide Is About To Reveal All Just That.

Get My Free Ebook


Post a comment