Patterns of utilization of imaging studies and serum tumor markers among patients with de novo metastatic breast cancer

Abstract

Background: When monitoring patients with metastatic breast cancer (mBC), the optimal strategies for imaging and utilization of tumor markers (TM) are uncertain. Patients and Methods: We used a retrospective cohort of 302 patients with de novo mBC treated from 2000 to 2012 at Dana-Farber Cancer Institute to describe the type and timing of imaging and TM testing during the first line of treatment (baseline, first, and subsequent testing). Results: At baseline, all patients had staging scans, with increasing use of PET/PET-CT (17.5% from 2000-2002; 40.3% from 2009-2012). PET/PET-CT was used by itself in only 12.5% of cases. Overall, 30.1% of patients, of whom 80.2% had no neurologic symptoms, underwent central nervous system (CNS) screening; 78.2% of patients had baseline TM testing. Over the course of treatment, 23.5% of patients had TM retested once a month or more. Time-to-first reimaging varied by disease site (hazard ratios for shorter time-to-first reimaging [95% CI] vs bone: brain, 4.27 [1.46-12.50]; liver, 2.19 [1.39-3.46]; lung, 2.75 [1.66-4.57]), but was not associated with tumor subtype or baseline TM testing, regardless of test results. First reimaging was prompted by an elevation in TM in only 1.4% of cases. There was weak correlation between frequency of imaging and TM tests (r=0.33; R2=0.11; P