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

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.

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.

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.

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.