Digital mammography increases high-risk breast lesion detection

Transitioning from film-screen mammography (FSM) to digital mammography (DM) lead to a threefold increase in the detection rate of high-risk breast lesions, according to a study published in the November issue of the American Journal of Roentgenology.

High-risk breast lesions, like atypical ductal hyperplasia (ADH) or lobular neoplasia (LN), greaten a patient’s risk of developing breast cancer. Calcifications present as mammographic manifestation of ADH and LN. The progression of these lesions, however, is not fully understood and the clinical significance of their diagnoses has not been established. DM’s improved contrast over FSM has led to better detection rates of breast cancer that manifests as calcifications.

“Implementation of screening mammography has contributed to decreased breast cancer mortality,” wrote Colleen H. Neal, MD, of the University of Michigan, and colleagues. “Through the detection of preclinical disease, screening mammography has also fostered detection and characterization of premalignant breast lesions.”

As facilities have begun transitioning from FSM to DM, Neal and colleagues designed a study to determine if the shift was associated with an increase in the detection of high-risk breast lesions.

The researchers identified 142 cases of atypia or LN diagnosed in women with mammographic calcifications between January 2004 and August 2010. Eighty-two of the cases were ADH, 17 were atypical lobular hyperplasia, 25 were lobular carcinoma in situ (LCIS), 12 were atypia and LCIS, and six were other atypia.

In 2004, the institution primarily used FSM, but by 2010 only DM was performed. The pathology was interpreted by breast pathologists and the annual detection rate was calculated by dividing the number of high-risk lesions by mammography volume.

Of the 142 cases evaluated in the study, 52 were detected using FSM and 90 were identified using DM. The detection rate with DM was 1.24/1,000 mammographic studies, while the rate with FSM was 0.37/1,000 mammographic studies.

The detection rate ranged from 0.21 to 0.64 per 1,000 mammographic studies for FSM and 0.32 to 1.49 per 1,000 mammographic studies for DM. The median size of the calcifications was 8 mm on DM and 7 mm on FSM. Clustered amorphous and indistinct calcifications were the most common on both FSM and DM.

“These results suggest that the improved detection rate of DM for calcifications and breast cancer is translated into the detection of high-risk lesions,” wrote the study’s authors.” Improved detection of high-risk lesions may allow enhanced screening, risk reduction treatment, and possibly prevention of breast cancer in some women. However, because the progression of these lesions is not known, increased detection could result in oversurveillance and treatment.”