369P - Whole-Body Metabolic Tumor Volume on F-18 Fdg Pet/Ct As a Prognostic Factor in Breast Cancer Patients with Distant Metastasis

Abstract

ABSTRACT Aim: This study was performed to evaluate the prognostic relevance of PET parameters measured by F-18 FDG PET/CT in invasive ductal breast cancer (IDC) patients with distant metastasis at initial diagnosis. Methods: Forty female IDC patients with distant metastasis at initial diagnosis that underwent pretreatment F-18 FDG PET/CT were enrolled. Clinicopathologic parameters [age, TNM stage, location of metastatic lesion, estrogen receptor (ER) status, progesterone receptor (PR) status, human epidermal growth factor receptor2 (HER2) status] and metabolic PET parameters [SUVmax of the primary tumor (pSUVmax), SUVmax of axillary lymph node (nSUVmax), SUVmax of whole malignant lesions (wSUVmax), whole-body metabolic tumor volume (WBMTV), and whole-body total lesion glycolysis (WBTLG)] were analyzed with respect to the prediction of overall survival (OS). Univariate and multivariate analyses were performed to assess the prognostic significances of parameters using Kaplan-Meier and Cox proportional hazards models. Results: Twenty of the 40 patients (50 %) died during follow-up (mean, 34.7 months; range, 0.8–71.4 months). Non-survivors had a significantly higher mean WBMTV than survivors (444.7 ± 695.0 cm3, vs. 88.0 ± 95.4 cm3, p = 0.0287). Receiver-operating-characteristic analysis showed that a WBMTV of 167.8 cm3 (sensitivity, 50.0 %; specificity, 90.0 %; area under the curve, 0.670) was an optimal cutoff for predicting OS. T stage, location of metastatic lesion, ER status, PR status, wSUVmax, WBMTV, and WBTLG were found to be prognostic factors of OS by univariate analysis, but age, N stage, pSUVmax, nSUVmax, and HER2 status were not. Multivariate analysis revealed only WBMTV independently predicted OS (HR, 4.70; 95 % CI, 1.33–16.56; p = 0.0165). Conclusions: WBMTV on pretreatment F-18 FDG PET/CT was found to be an independent prognostic factor of OS in invasive ductal breast cancer patients with distant metastasis at initial diagnosis. Disclosure: All authors have declared no conflicts of interest.