Prognostic value of [18F]-FDG PET/CT in patients with meta-static breast cancer treated with cyclin-dependent inhibitors

Objective The addition of cyclin-dependent kinase 4/6 inhibitors (CDK4/6i) to endocrine therapy impressively improved the outcome patients with hormone receptor-positive metastatic breast cancer. Despite their great efficacy, not all respond treatment and many them develop acquired resistance. aim this retrospective study was assess role [18F]-FDG PET/CT in predicting PFS OS cancer treated CDK4/6i. Methods 114 who performed an scan before (PET1) 2-6 months (PET2) after starting were retrospectively enrolled. Metabolic response evaluated by EORTC, PERCIST Deauville Score correlated OS. Results In did progress at PET2 (n = 90), rates significantly different between classes EORTC PERCIST. Conversely, showing a score ≤3 had longer (median 42 vs 21.0 months; p 0.008). A higher total metabolic tumor volume PET1 (TMTV1) also associated shorter 18 0.0026). TMTV1 only independent prognostic factors for multivariate analysis combination stratified population four definite relapse risk. above parameters affect which influenced progressive disease (3-years survival rate 29.8 84.9%; p<0.0001). Conclusion TMTV significant Their determination could help physicians select may need closer follow up.