The American Geriatrics Society recommends annual or at least biennial mammography for women up to age 75 years, and after that age, every 2 to 3 years if the woman has a life expectancy of more than 4 years (36). The reasons for liberalization of the screening interval recommendations for older women include improved biology profile, slower growth rate, and lower risk for recurrence (37–41). The natural history of the disease in older women must be balanced against life expectancy as a function of overall health (42). For high-risk women, consideration can be given to earlier initiation of screening (5 to 10 years earlier than the age of the index case) and shorter intervals between screening, and the use of additional imaging modalities such as breast ultrasonography and magnetic resonance imaging (MRI) with dedicated breast coils. No screening test is perfect, and false-negative imaging studies or benign clinical examinations may lead the patient to an erroneous sense of well-being only to be confronted later with a subsequent cancer. Likewise, a false-positive result can lead to significant anxiety and unnecessary biopsy.
A mammographic abnormality includes a mass (solid versus cystic), microcalcifications (benign, indeterminate, suspicious), asymmetric density, architectural distortion, and appearance of a new density. There are eight morphologic categories of mammographic abnormalities (43,44): 1.
2.
Number of calcifications 3.
Description of calcifications 4.
5.
Shape of mass 6.
Density of mass 7.
8.
Mammographic abnormalities should be visible on two views, usually craniocaudal (CC) and mediolateral oblique (MLO). The lesion should triangulate to the same location on those two views. Calcifications can be macrocalcifications, which are coarse and usually represent benign degenerative breast conditions. Calcifications associated with breast cancer are clustered pleomorphic microcalcifications; typically five to eight or more calcifications are aggregated in one part of the breast (45). These calcifications may be associated with a mammographic mass density. A mass density may appear without evidence of calcifications. It can represent a cyst, benign tumor, or a malignancy. A malignant density usually has irregular or ill-defined borders and may lead to architectural distortion, which may be subtle and difficult to detect in a dense breast. Other mammographic findings suggesting breast cancer are architectural distortion, asymmetric density, skin thickening or retraction, or nipple retraction. Examples of mammographic abnormalities can be found in several electronic sources (46).
The American College of Radiology recommended the Breast Imaging Reporting and Data System (BI-RADS) as a standardized scheme for describing mammographic lesions (47). In the BI-RADS system, there are six categories for mammographic findings (other than incomplete) (43,44).
0.
Incomplete, needs further imaging 1.
2.
3.
Probably benign, short-interval follow-up recommended 4.
5.
Highly suggestive of malignancy and appropriate action should be undertaken 6.
Known malignancy (a category that is often used for follow-up of a lesion that is undergoing neoadjuvant treatment)
The patient should be referred for tissue diagnosis if the report identifies a lesion as a category 4 or 5 (47). A category 0 indicates incomplete evaluation, and further diagnostic studies are required. Category 3 connotes a finding that is most likely benign; a short-interval follow-up is recommended, and breast examination by an expert should be considered.
Correlation of Findings