RESUMO
PURPOSE: Advanced imaging is commonly used for staging of early-stage breast cancer, despite recommendations against this practice. The objective of this study was to evaluate and compare use of imaging for staging of breast cancer in two integrated health care systems, Kaiser Permanente (KP) and Intermountain Healthcare (IH). We also sought to distinguish whether imaging was routine or used for diagnostic purposes. METHODS: We identified patients with stages 0 to IIB breast cancer diagnosed between 2010 and 2012. Using KP and IH electronic health records, we identified use of computed tomography, positron emission tomography, or bone scintigraphy 30 days before diagnosis to 30 days postsurgery. We performed chart abstraction on a random sample of patients who received a presurgical imaging test to identify indication. RESULTS: For the sample of 10,010 patients, mean age at diagnosis was 60 years (range, 22 to 99 years); with 21% stage 0, 47% stage I, and 32% stage II. Overall, 15% of patients (n = 1,480) received at least one imaging test during the staging window, 15% at KP and 14% at IH (P = .5). Eight percent of patients received imaging before surgery, and 7% postsurgery. We found significant intraregional variation in imaging use. Chart abstraction (n = 129, 16% of patients who received presurgical imaging) revealed that 48% of presurgical imaging was diagnostic. CONCLUSION: Use of imaging for staging of low-risk breast cancer was similar in both systems, and slightly lower than has been reported in the literature. Approximately half of imaging tests were ordered in response to a sign or symptom.