Overuse of Chest CT in Patients With Stage I and II Breast Cancer: An Opportunity to Increase Guidelines Compliance at an NCCN Member Institution.

Background: The NCCN Clinical Practice Guidelines in Oncology (NCCN Guidelines) recommend that patients with clinical stage I/II breast cancer undergo advanced imaging for staging only when symptomatic. Regardless, many asymptomatic patients undergo chest CT. The goal of this study was to assess the use and results of chest CT in these patients at an NCCN Member Institution. Methods: Patients with breast cancer diagnosed between 1998 and 2012 were identified in a prospectively maintained database. All patients with clinical stage I/II disease who did not receive neoadjuvant chemotherapy were included. Data collected included demographics, tumor size, node status, chest CT within 6 months of diagnosis, imaging findings, need for additional workup, and identification of metastatic disease. Appropriate statistical tests were used for analysis. Results: From 1998 to 2012, 3,321 patients were diagnosed with early-stage breast cancer. Of these, 2,062 (62.1%) had clinical stage I breast cancer at diagnosis and 1,259 (37.9%) had stage II; 227 patients (11%) with stage I and 456 (36.2%) with stage II breast cancer received staging chest CT. Of patients undergoing CT, 184 (26.9%) were found to have pulmonary nodules, which measured ≤5 mm for 128 patients (69.6%), 5 to 10 mm for 46 patients (25.0%), 11 to 20 mm for 6 patients (3.2%), and ≥20 mm for 4 patients (2.2%). Patients undergoing chest CT for staging subsequently underwent a mean of 2.34 (range, 0-16) additional CTs in follow-up. Of all patients undergoing chest CT for staging, only 9 (1.3%) were ultimately diagnosed with pulmonary metastases at an average of 25 months (range, 0-97) after initial staging chest CT. Conclusions: A significant percentage of patients with stage I/II breast cancer underwent unnecessary chest CT as part of their initial workup. Nearly one-third of these patients were found to have pulmonary nodules, but only 1.3% were ever diagnosed with pulmonary metastases. Adherence to NCCN Guidelines will reduce the excessive use of CT chest imaging.