Mammography and physical examination are both used to detect the possibility of breast cancer. A woman receiving an abnormal mammogram or physical examination needs further confirmation to determine whether cancer is present. Currently, confirmation is recommended through a tissue biopsy, either by surgical excision or needle sampling.
Only about one in five women currently getting a biopsy for an abnormal mammogram or breast examination has breast cancer. The need for confirmation of the mammogram means some 80% of women with an abnormal mammogram must undergo the biopsy procedure, even though they ultimately prove not to have cancer. Accurate noninvasive tests could reduce the number of women needing to undergo a biopsy.
However, the Agency for Healthcare Research and Quality’s (AHRQ) Effectiveness of Noninvasive Diagnostic Tests for Breast Abnormalities report indicates that four common tests – magnetic resonance imaging, ultrasonography, positron emission tomography scanning, and scintimammography – would miss about 4% to 9% of cancer cases among women testing negative who have average risk for the disease, with potentially more missed cancers among women at higher risk.
The AHRQ’s review is somewhat worrying, but, according to the American College of Radiology (ACR), the report presents a “simplistic, misleading, and inaccurate” assessment of the role of various breast imaging modalities, and reflects a lack of understanding of the steps involved in detecting and diagnosing breast cancer using imaging procedures.
According to the ACR, the study, whose list of authors includes no radiologists, fails to recognize that there is a difference between an inconclusive screening mammogram and a mammogram, which, after a thorough workup, is assessed as showing a suspicious finding.
The college says that it is well known among breast imagers that additional imaging studies should not be used to obviate the need for biopsy of a suspicious mammographic finding.
“Women should not be mislead by this report into thinking that additional imaging evaluation after an inconclusive screening mammogram is unnecessary or inaccurate, and should not prematurely demand biopsy of findings before they are thoroughly evaluated,” said Dr Carol Lee, chair of the ACR’s Breast Imaging Commission.