Downstream Breast Imaging Following Screening Mammography in Medicare Patients with Advanced Cancer: A Population-Based Study.

Abstract

Screening tests are generally not recommended in patients with advanced cancer and limited life expectancy. Nonetheless, screening mammography still occurs and may lead to follow-up testing. We assessed the frequency of downstream breast imaging following screening mammography in patients with advanced colorectal or lung cancer. Population-based study. The study included continuously enrolled female fee-for-service Medicare beneficiaries ≥65years of age with advanced colorectal (stage IV) or lung (stage IIIB-IV) cancer reported to a Surveillance, Epidemiology, and End Results (SEER) registry between 2000 and 2011. We assessed the utilization of diagnostic mammography, breast ultrasound, and breast MRI following screening mammography. Logistic regression models were used to explore independent predictors of utilization of downstream tests while controlling for cancer type and patient sociodemographic and regional characteristics. Among 34,127 women with advanced cancer (23% colorectal; 77% lung cancer; mean age at diagnosis 75years), 9% (n=3159) underwent a total of 5750 screening mammograms. Of these, 11% (n=639) resulted in at least one subsequent diagnostic breast imaging examination within 9months. Diagnostic mammography was most common (9%; n=532), followed by ultrasound (6%; n=334) and MRI (0.2%; n=14). Diagnostic mammography rates were higher in whites than African Americans (OR, 1.6; p<0.05). Higher ultrasound utilization was associated with more favorable economic status (OR, 1.8; p<0.05). Among women with advanced colorectal and lung cancer, 9% continued screening mammography, and 11% of these screening studies led to at least one additional downstream test, resulting in costs with little likelihood of meaningful benefit.