The Maximum Standardized Uptake Value For F-18Fluorodeoxyglucose Correlates With Molecular Subtype And Survival Of Metastatic Breast Cancer

Purpose:Tumor glucose metabolism correlates with tumor biology and clinical outcome of breast cancer patients. This prospective cohort study was to explore correlations of18F-FDG uptake, a surrogate for glucose metabolism, with molecular subtypes of breast cancers in women with stage IV disease. We also explored the correlations between molecular subtypes of primary tumor in luminal breast cancer and SUVmax of recurrence disease, and different recurrence patterns between luminal A and B subtypes.Methods and Materials:Two hundred and forty four patients diagnosed as advanced breast cancer were enrolled in the study. PET/CT was performed and the Maximum Standardized Uptake Value (SUVmax) of each lesion was documented as baseline, so was clinical information. Diagnosis of malignant nature of a lesion was confirmed by pathology or further follow-up. At the study start, patients with progressive disease were assigned new drug therapy as per institutional guidelines. In the second section we used the same methods and enrolled191patients with luminal breast cancer who had complete records from the diagnosis of breast cancer to disease recurrence (for RFS and OS,), and from the disease recurrence to progression of the recurrent disease, or patient death (for PFS and OS2).Results:244patients met the study criteria and all were analyzed. Independent factors for influencing SUVmax value included different number of metastatic sites (p<0.001) and presence of visceral metastases (p<0.001). A higher SUVmax was significantly associated with poorer median PFS (6.9vs.8.1months, p=0.040) and OS (13.8vs.16.9months, p=0.003). Cox Regression analysis showed that SUVmax value, previous treatments, subsequent treatments and treatment efficacy were four independent prognostic factors for PFS, while age, menopausal status, disease free interval,4subtypes, previous treatments, number of metastatic sites, SUVmax value and subsequent treatment efficacy were independent prognostic factors for OS. In the second section, when we chose SUVmax=7.0as the cut-off value, PFS was significantly different between higher and lower SUVmax groups (p=0.004). The RFS and OS1were different between luminal A and B subtypes(p<0.001, p=0.034, respectively). No significant difference in PFS (p=0.713) and OS2(p=0.498) was present between the subtypes.Conclusions:18F-FDG uptake has no correlation with molecular subtypes in women with advanced breast cancer. Baseline SUVmax is an independent prognostic factor for survival of patients with advanced breast cancer. Based on the information of molecular subtypes in primary breast cancer, we can predict the RFS but not the PFS or OS. The SUVmax of the recurrent disease can predict the PFS in patients with luminal breast cancer. The luminal A and B subtypes had different recurrence peaks, with luminal A subtype occurring late.