Abstract P1-01-24: Which combinations are helpful to predict axillary lymph node metastasis in T1 breast cancer with ultrasonography and contrast-enhanced MRI and contrast-enhanced 18F-FDG PET-CT?

Abstract

Backgrounds: Axillary lymph node(ALN) status has been important factor of treatment and prognosis for patients with breast cancer. Even though the better ultrasonographic instruments have been developed, it is still difficult to predict axillary lymh node metastasis (ALNM) with only ultrasonography(US) in T1 breast cancers which most of newly diagnosed breast cancers are recently since T1 breast cancers have low rate and less tumor burden of ALNM. This study evaluated the accuracy of prediction of ALNM in T1 breast cancer with US, contrast-enhanced MRI (cMRI) and contrast-enhanced 18F-FDG PET/CT (cPET/CT) and found out adequate combinations of these modalities. Method: Retrospectively, we reviewed 351 breast cancer patients with tumors(T1) ≤2cm in size between January 2008 and December 2011 who were preoperatively examined with US, cMRI, and cPET/CT and underwent pathologic evaluation of axillary lymph nodes acquired by sentinel lymph node biopsy or axillary dissection. Results: 94(26.8%) patients of 351 had ALNM. The sensitivity, specificity, positive predictive value(PPV), negative predictive value (NPV), and accuracy of ALNM with US were 0.457, 0.887, 0.597, 0.817, 0.772, respectively. cMRI had similar results with US. The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy of ALNM with cPET/CT were 0.447, 0.942, 0.737, 0.823, 0.809, respectively. The sensitivity if any one or more modalities were suspicious was 0.563. The specificity if all modalities were suspicious was 0.992. The PPV if cMRI and cPET/CT were suspicious was highest than if other combinations were suspicious. Conclusion: US, cMRI, and cPET/CT are helpful in prediction of ALNM of T1 breast cancers. However, there are no definite modality and combination of modalites to predict ALNM of T1 breast cancers. Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P1-01-24.