Abstract P4-01-05: Utility of Preoperative Routine MRI and PET/CT in Breast Cancer Staging vs. Surgical Staging

Abstract

Abstract Background: Staging of breast cancer is one of the most important factors in determining treatment options. The aim of this study is to assess the utility of routine magnetic resonance imaging (MRI) and positron emission tomography and computed tomography (PET/CT) in preoperative breast cancer staging. Patients and methods: We examined 616 consecutive patients, who were newly-diagnosed with operable primary breast cancer less than 3 cm, at our institution between 2009 and 2011. They all underwent MRI and PET/CT to assign the clinical stage by TNM classification. Tumor size was measured by contrast MRI examinations and node status and metastases were evaluated on PET/CT. We examined their clinical and pathological T and N status retrospectively to assess the utility and concordance rate of preoperative imaging studies. Patients with tumors more than 3 cm were excluded from this study, since preoperative systemic therapy is the standard therapeutic strategy for those patients. Results: The concordance rate of T status was 79.9% in clinical T1 patients (366/458) and 55.6% in clinical T2 patients (88/158). The concordance rate of N status was 83.8% in clinical N0 patients (495/591) and 60.0% in clinical N1 patients (15/25). As a result, the concordance rate of clinical stage was 66.5% in clinical stage I patients (296/445) and 55.0% in clinical stage II patients (94/171). In addition, 43 patients were diagnosed as contrary breast cancer by MRI (7.5%) and 31 contrary breast cancer (5.4%) and 12 other malignant disease (1.9%) were found by PET/CT. Conclusions: MRI and PET/CT are valuable tools to provide information on tumor size, lymph node involvement, distant metastases and other occult primary disease. Preoperative routine MRI and PET/CT studies have a substantial impact on patients with operable primary breast cancer. Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P4-01-05.