Lesion and patient characteristics associated with malignancy after a probably benign finding on community practice mammography.

OBJECTIVE

The purpose of this study was to identify patient and lesion characteristics associated with a diagnosis of breast malignancy within 3 years of having a probably benign finding (BI-RADS category 3) on a mammogram obtained in a community radiology practice.

MATERIALS AND

METHODS

The subjects were women 30 years old and older without breast implants or previous breast cancer who received notice of a probably benign finding on a bilateral screening mammogram between January 1, 1996, and June 30, 1999, in a community-based practice. From 82,898 mammograms, we identified 129 breast lesions designated probably benign that progressed to malignancy within 3 years of an index examination (cases) and matched them to 129 lesions designated probably benign that did not progress to malignancy within 3 years (controls). A breast imaging specialist blinded to case-control status interpreted all examinations and recorded detailed lesion descriptors according to the BI-RADS lexicon.

RESULTS

Case lesions were more likely in patients who were older, postmenopausal, or had a strong family history of breast cancer or previous biopsy. The lesions were more likely masses with obscured, indistinct, or spiculated margins compared with control lesions (84.6% vs 66%, p = 0.03). Case lesions were more likely calcifications (29.5% vs 17.8%, p = 0.03). No cases were encountered among calcifications considered typically benign in the BI-RADS lexicon (vascular or coarse), and no controls were encountered among calcifications considered suspicious or highly suggestive of malignancy in the BI-RADS lexicon (amorphous, pleomorphic, branching, and fine linear) (p < 0.0001).

CONCLUSION

In community practice, patient and lesion mammographic characteristics can be predictive of the likelihood of a subsequent cancer diagnosis of mammographic lesions designated as probably benign. Careful evaluation of mass margins and of the morphologic features of calcifications can help distinguish a malignant lesion from a probably benign finding.