Variation in use of advanced imaging at the time of breast cancer diagnosis in a statewide registry.

Abstract

287 Background: Advanced imaging for diagnosis of metastatic disease at the time of diagnosis of stage 0-II breast cancer is not recommended according to national guidelines. The purpose of this study was to examine the variation in ordering of CT chest, abdomen, and pelvis, PET, and bone scans across the state of Michigan, and to investigate clinical and non-clinical factors associated with test ordering. Methods: We prospectively collected data from all patients diagnosed with stage 0-II breast cancer from 2008-2014 in 25 health systems in the Michigan Breast Oncology Quality Initiative (MiBOQI), a Blue Cross Blue Shield of Michigan/Blue Care Network-sponsored quality initiative. Demographic, imaging, and pathologic data were abstracted from the medical record. The primary endpoint was the percentage of patients with at least one advanced imaging test performed within 90 days after diagnosis of breast cancer. Analyses were performed using the chi-squared test of association. Results: Of the 27,011 patients, 4799 (17.8%) had at least one staging exam performed within 90 days of diagnosis. Imaging tests were primarily performed post-operatively. The average percentage of patients who had at least one staging exam performed varied by stage and by site (Table). The rate of testing decreased over time for stage 0-IIA cancers but not for stage IIB. On multivariate analysis, younger age, black race, hormone receptor negativity, HER2 positivity, and higher grade were associated with increased likelihood of undergoing imaging. Conclusions: There is considerable variability in ordering of staging scans at the time of diagnosis of early stage breast cancer across Michigan. Factors underlying use of imaging in stage IIB disease should be examined in order to develop interventions for rate reduction. [Table: see text]