Supplementary Material for: Staging of Primary Breast Cancer Is not Indicated in Asymptomatic Patients with Early Tumor Stages

<b><i>Background: </i></b>The routinely practiced staging for distant metastasis in patients with primary breast cancer has been increasingly questioned. <b><i>Patients and Methods: </i></b>Data from 742 patients with breast cancer who had completed staging (chest x-ray, liver ultrasound, and bone scan) were retrospectively analyzed. Present findings were transferred to a dataset of a voluntarily monitored benchmarking project by the West German Breast Center that included patient data of 179 breast cancer centers. <b><i>Results: </i></b>Routine staging examinations revealed in 1.2% (n = 9) distant metastasis and in 38.8% (n = 288) suspicious results. In total, 15 patients (2%) had distant metastases confirmed by additional diagnostics. The existence of distant metastases correlated with tumor size, nodal state, and lymphatic vessel spread. Tumor size and nodal state were independent predictors for disseminated disease. The risk of exhibiting distant metastases was 0.77% for patients with tumor stage pT1 pN1. Based on these findings, in 159,310 patients 41,728 chest x-rays, 43,950 liver ultrasounds, and 39,037 bone scans could have been avoided. <b><i>Conclusion: </i></b>Asymptomatic patients with tumor stages ≤ pT1 pN1 do not benefit from staging of primary breast cancer. Suspending staging examinations for these patients could reduce cost without restricting oncologic safety.