Patterns in breast cancer staging imaging: Are we choosing wisely?

Abstract

51 Background: The American Society of Clinical Oncology’s Choosing Wisely guidelines recommend no staging imaging in early stage breast cancer (ESBC) patients with low risk of metastasis, as it is potentially harmful and provides no survival benefit. This study evaluates local adherence to this recommendation and identifies factors contributing to unnecessary staging imaging. Methods: This retrospective cohort study included patients with AJCC stage 0-II BC diagnosed from 2013-2015 at a single-site, academic medical center. Data was abstracted from chart review. Imaging included computed tomography, positron emission tomography, or bone scans. Imaging for documented symptoms was considered appropriate. Abstracted patient data included demographics, medical oncologist, and clinical characteristics. To evaluate factors influencing inappropriate screening imaging, risk ratios (RR) and corresponding 95% confidence intervals (CI) were estimated using generalized linear models with a log link and Poisson distribution with robust variance estimates. Results: Of the 872 ESBC patients, 262 (30%) underwent staging imaging. Median diagnosis age of patients receiving imaging was 55 (IQR 48-63) compared to 60 (IQR 52-68) for patients with no or appropriate imaging. Risk of inappropriate screening imaging was increased for patients who were younger (RR 0.98, 95% CI 0.97-0.98), had triple negative disease vs any hormone receptor positive (RR 2.98, 95% CI 2.25-3.95), had higher stage BC (I vs. 0, RR 3.58, 95% CI 2.05-6.25; II vs. 0, RR 10.86, 95% CI 6.43-18.33), and did not have Medicare insurance (RR 1.52, 95% CI 1.22-1.89). Rates of imaging did not vary by race (non-white vs. white: RR 0.98, 95% CI 0.78-1.23). For medical oncologists with at least 15 patients, prevalence of inappropriate imaging varied from 26-68%. Conclusions: A substantial proportion of ESBC patients received unnecessary and potentially harmful staging imaging inconsistent with guidelines. Staging imaging was associated with patient demographic and clinical characteristics related to increased recurrence risk, suggesting a need for further physician education about the low-risk nature of this ESBC population to ensure high value oncologic care.