Study Advocates Breast Ultrasound Screening as an Adjunct to Mammography

With improved instrumentation and scanning techniques, breastultrasound screening is earning a prominent role in the detectionof breast cancer in women with dense breasts when no lump is feltand no abnormalities are detected on the mammogram.

Results of a study by Barbara Weinstein, md, of Pittsburgh, Pennsylvania,and colleagues, led to the recommendation that complete bilateralbreast ultrasound be done in women with dense breasts whenevera cancer is suspected. This recommendation applies particularlyto cases in which breast-conservation surgery (lumpectomy) isbeing contemplated. The finding of an additional cancer site mayindicate that more extensive surgery is necessary. The serendipitousfinding in this study of nine breast cancers in women who hadno suspicious mammographic finding suggests that the role of ultrasoundin the detection of breast cancer in women with dense breastsneeds to be investigated further.

According to Dr. Weinstein, "While it may not prove to becost effective to screen all women with mammographically densebreasts by sonography, our study suggests that it should be consideredas an adjunct to mammography for women with dense breasts whohave a strong family history or personal history of breast cancer."

The authors' findings support breast ultrasound's value. In 20women, breast cancer was found by sonography only. That is, nolump was felt in the area where the cancer was discovered, andno abnormal changes were present on the mammogram in this location.The women ranged in age from 34 to 83 years, with a median ageof 52. The occult cancers ranged in size from 5 to 24 mm, witha median size of 9 mm. Of interest was the fact that 10 of the20 women were at high risk for breast cancer: They had a motheror sister with breast cancer, or a personal history of breastcancer.

Nine of the cancers were discovered when a suspicious abnormalityat a different location in the same breast was being evaluated.In two other instances, a second breast cancer was found in theopposite breast. Seven cancers were detected as an incidentalfinding in the same breast while unrelated benign abnormalitieswere being scanned. Two of the malignancies were detected in breastsscanned because of the marked degree of breast density found onthe mammogram.

Expanded Use of Ultrasound

Although many imaging specialists advocate "targeted"breast ultrasound examinations (scanning only the area of breastthat is in question), the authors of the study routinely surveyedthe entire breast when the mammogram was limited by marked breastdensity. If there were any suspicious findings, both breasts werecarefully scrutinized. All suspicious abnormalities were thenfurther evaluated by means of fine-needle aspiration biopsy, corebiopsy, and/or surgical excision. To date, the major indicationsfor breast ultrasound include evaluation of suspected mammographicabnormalities, evaluation of palpable breast masses, and evaluationof symptomatic women who are under age 30, pregnant, or lactating.It is hoped that this study will expand the use of ultrasound,especially in cases in which the mammogram is limited by markedbreast density.

Dr. Weinstein reported the study's findings on March 18 at theAmerican Institute of Ultrasound in Medicine's 40th Annual Conventionin New York.