Predictive value of primary tumor parameters using 18 F-FDG PET/CT for occult lymph node metastasis in breast cancer with clinically negative axillary lymph node.

OBJECTIVE: This study aimed to demonstrate the clinical significance of total lesion glycolysis (TLG) of primary breast cancer using 18 F-FDG PET/CT to predict axillary lymph node (ALN) metastasis in invasive ductal breast cancer (IDC) with a clinically negative axillary lymph node (cN-ALN).

METHODS: 135 patients, newly diagnosed with IDC with C N-ALN between July 2016 and October 2017, were retrospectively enrolled. We estimated primary tumor PET/CT parameters including the maximum standard uptake value (SUVmax ), metabolic tumor volume (MTV), and TLG, as well as clinicopathologic findings. All patients received breast surgery followed by pathologic axillary lymph node examination.

RESULTS: Of the 135 patients, 31 (23.0%) were diagnosed with pathologically proven metastatic ALN. In univariate analysis, SUVmax , MTV, and TLG of the primary breast tumor were correlated with metastatic ALN along with tumor size, lymphovascular invasion, CD34, and D2-40. On multivariate analysis, TLG (> 5.74, p = 0.009) had independent significance for predicting ALN metastasis in IDC with cN-ALN.

CONCLUSION: We demonstrated that TLG of primary tumors can be useful in predicting pathologic ALN metastasis in IDC patients with cN-ALN.