18F-fluoro-2-deoxy-glucose positron emission tomography/computed tomography evaluation to predict postoperative outcomes for patient with luminal-type breast cancer.

e22207 Background: 18F-fluoro-2-deoxy-glucose positron emission tomography/computed tomography (18F-FDG PET/CT) has been reported as an useful tool for evaluating prognosis of cancer. Maximum standardized uptake value (maxSUV) and ER status were reported to be predictive factors for relapse-free survival (RFS) on breast cancer patients. In this study, 18F-FDG PET/CT was evaluated for predicting postoperative outcomes on hormonal receptor-positive breast cancer patients retrospectively. Methods: Three hundred forty four breast cancer patients with clinical Stage I-III who underwent preoperative 18F-FDG PET/CT were enrolled between January 2006 and December 2011 in two institutes. These patients were classified into 5 subtypes, Luminal A: Estrogen receptor (ER)(+) or Progesterone receptor (PR)(+), human epidermal growth factor receptor type 2 (HER2) (-), and nuclear grade (NG)1-2, Luminal B: ER(+) or PR(+), HER2(-), and NG3, Luminal HER2: ER(+) or PR(+), and HER2(+), HER2: ER(-), PR(-), and HER2(+), Triple negative: ER(-) , PR(-), and HER2(-) according to the subtype classification by hormonal receptors status, HER2 expression and nuclear grade. Patients diagnosed as luminal types were 262 in total (Luminal A 166; Luminal B 96 patients) and evaluated in this study. Statistical analyses were performed using Student t test, Cox regression model and log-rank test. Results: Patients were divided in two groups according to cut-off maxSUV on receiver operating characteristic (ROC) analysis (≤4.0 group vs >4.0 group, AUC=0.830). Significant correlations were shown between maxSUV and clinical T-factor, nuclear grade, vascular invasion and presence or absence of recurrence (p<0.0001, p<0.0001, p=0.0181, and p=0.0056, respectively). In uni- and multivariate analyses using Cox model for recurrence, only maxSUV was shown to be significant (p=0.021 and p=0.043, respectively). RFS curves showed the maxSUV≤4.0 group had significantly better prognosis compared to that of the maxSUV >4.0 group (p=0.003). Conclusions: Using 18F-FDG PET/CT is concluded to be useful for predicting prognosis on luminal types breast cancer patients.