Predictors determining the status of axilla in breast cancer: Where is PET/CT on that?

Purpose: 18 F-FDG PET/CT has an acceptable specificity but a low sensitivity on the prediction of axillary lymph node (ALN) metastasis in breast cancer. We analyzed the factors that could possibly affect this prediction. Methods: The records of 270 patients with T1-2 invasive breast cancer who underwent surgery, 116 of whom had been evaluated by preoperative 18 F-FDG PET/CT were reviewed. Prediction of ALN status by PET/CT according to tumor stage, estrogen receptor (ER), progesterone receptor (PgR) and HER2 status, histology, age and sentinel node properties was assessed. Results: ALN metastasis was present in 62 of 131 T1 (43.7%) and 106 of 142 T2 tumors (74.6%), 20 of 46 (43.5%) ER(-) and 146 of 222 (65.8%) ER(+) tumors, 38 of 71 (53.5%) PgR(-) and 127 of 200 (63.5%) PgR(+) tumors. On multivariate analysis only the tumor size (>2 cm) independently correlated with ALN metastasis (Odds ratio/OR=3.1). None of the other parameters had statistical significance in terms of ALN prediction on FDG-PET/CT. Conclusion: Though T2 tumors showed increased tendency to metastasize to the axilla, prediction of ALN metastasis in preoperative FDG-PET/CT was not associated with any of the predictive factors.