Retrospective Review of a Mobile Mammography Screening Program in an Underserved Population within a Large Metropolitan Area

Rationale and Objectives: Mobile mammography units provide preventive health care to patients facing barriers to annual screening. This study reviews the outcomes of a mobile mammography service during a recent 5-year period. Materials and Methods: This retrospective study analyzed the examinations by mobile mammography during a 5-year period (9327 examinations). The patients recalled, biopsies performed, and cancers detected were tallied. The race, age, breast cancer size, lymph node involvement, and metastases were recorded. The positive predictive value (PPV) and cancer detection rate metrics were calculated as outlined by the American College of Radiology Breast Imaging Reporting and Data System Atlas. Results: The program identified cancer in 14 cases (cancer detection rate = 1.5 per 1000 examinations [95% confidence interval [CI], 0.9–2.5]) with 11 being invasive. The majority of these cancers were small and of low stage. Lymph node status was determined in 11 of the 14 cases (1 as N1mi, 5 as N0, 4 as N1,1 as N2a). Abnormalities led to 1686 examinations recalled (Recall Rate = 17.8%; PPV 1 = 0.8% [95% CI, 0.5%–1.4%]). One hundred and one were recommended for biopsy (PPV 2 = 13.9% [95% CI, 8.4%–21.9%]), and 98 pursued biopsy (PPV 3 = 14.3% [95% CI, 8.7%–22.6%]). Patient age ranged from 41 to 67 years with an average of 50.6 years. Conclusion: The program detected many cancers in an asymptomatic population facing barriers to breast cancer screening. These findings are underscored by the cancers detected at an early stage with a favorable prognosis and support the need for the development of similar programs.