Abstract P6-07-26: Prognostic significance of the maximal value of the baseline standardized uptake value on fluorine 18 fluorodeoxyglucose positron emission tomography/computed tomography for predicting pathologic malignancy of operable breast cancer with neoadjuvant chemotherapy

Abstract

Abstract PURPOSE: [18F]-fluorodeoxyglucose (FDG) positron emission tomography (PET)/computed tomography (CT) is potentially useful in predicting pathological complete response (pCR), disease free survival (DFS) and overall survival (OS) of breast cancer patients with neoadjuvant chemotherapy. MATERIALS AND METHODS: 77 breast cancer patients (mean age ± SD: 52.6 ± 11.2 years) with clinical Stage I∼III between January 2006 and December 2011, were prospectively evaluated (median follow up period:26.5 months). Neoadjuvant chemotherapy of an anthracycline-based regimen and taxane was performed, and patients underwent a whole-body FDG PET/CT before and after chemotherapy. The maximal value of the baseline standardized uptake values (SUVmax) were assessed for predicting pCR, DFS and OS. For the evaluation of relationship between SUVmax values and prognosticators such as hormone receptors, human epidermal growth factor receptor 2 (HER2), nuclear grade, lymph node metastasis and tumor size, statistical analyses were performed using Student t test and log-rank test, and p values of less than 0.05 were considered to indicate statistically significant differences. RESULTS: Clinical Stage included were I (n = 2, 2.6%), II (n = 62, 80.5%) and III (n = 12, 15.6%). Tumors with estrogen receptor positive were 52 (67.5%) and negative were 24 (31.2%). Therapeutic response by neoadjuvant chemotherapy was obtained in 15 patients (19.5%) with pCR and 60 (77.9%) without pCR. Patients were divided into two groups according to cut-off SUVmax established on the basis of receiver operating characteristic (ROC) analysis (<6.0 vs. ≥6.0, AUC=0.721). When related to the biologic parameters, estrogen receptor (OR:3.75, 95%Cl:1.36–10.35, p = 0.02), but not progesterone receptor (OR:2.31, 95%Cl:0.89–6.00, p = 0.08) nor HER2 status (OR:1.51, 95%Cl:0.47–4.85, p = 0.70) were found strong relation to SUVmax values. There was a significant difference in OS between two groups (p = 0.05), but, pCR (OR:1.07, 95%Cl:0.34–3.40, p = 0.86) and DFS (p = 0.07) did not show strong relationship with SUVmax values. CONCLUSION: SUVmax on FDG PET/CT before neoadjuvant chemotherapy have a predictive value for high-grade malignancy and prognosis in clinical Stage I∼III breast cancer. Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P6-07-26.