Abstract
1319
Objectives Total lesion glycolysis (TLG) is a derived parameter combining volumetric and metabolic information of tumors with increased uptake on 18F-FDG PET/CT. The aim of this study was to investigate whether pretreatment TLG of primary tumor provides additional prognostic value in stage III or IV breast cancer (BC) patients beyond standard clinico-pathological factors.
Methods Pretreatment PET/CT scans from 240 consecutive patients with newly diagnosed stage III or IV BC were retrospectively analyzed. Maximum standardized uptake value (SUVmax), metabolic tumor volume (MTV), and TLG of primary tumor and clinico-pathologic factors were compared. Univariate and multivariate analyses were performed to identify factors associated with progression-free survival (PFS) and BC-specific overall survival (OS).
Results TLG with a threshold of 30% (TLG30%) outperformed SUVmax and volume-based metabolic parameters for predicting disease progression and death. Mean TLG30% of primary tumors for stage III and IV patients were 405.14 g and 753.44 g, respectively. Optimal cutoff value of TLG30% was 158 g. PFS rates at 5 years for stage III patients with TLG30% ≤158 g versus TLG30% >158 g were 82.2% and 65.7%, respectively. PFS rates for stage IV patients with TLG30% ≤158 g versus TLG30% >158 g were 40.0% and 8.8%, respectively. OS rates at 5 years for them were 86.4%, 68.0%, 57.4% and 14.1%, respectively. Patients with stage III BC and TLG30% >158 g had similar OS rates as those with stage IV and TLG30% ≤158 g (P = 0.359), especially for the first 3 years. Patient survival with stage IV disease and a primary tumor TLG30% greater than 158 g remained worst.
Conclusions This is the first and largest series of patients reported to show that TLG30% from pretreatment PET/CT images can effectively stratify both stage III and IV BC patients, may lead to better management of these high-mortality-risk patients.