18F] Fluorodeoxyglucose positron emission (FDG-PET) in breast cancer: Clinical utility in neoadjuvant and metastatic setting.

Abstract

e12584 Background: FDG-PET in clinical practice is based on the detection of a relapse and the initial staging but its role as a predictive factor or its correlation with biological parameters is very controversial. Methods: We analyzed the SUV of FDG-PET in a cohort with 36 patients in neoadjuvant setting and 112 with metastatic disease. Results: The median of SUV in neoadjuvant was 8,95 (range 2,8-30) with higher SUV in triple negative (11,7 range 2,8-18,8) than HER2 positive (8,75 range 4-30) and luminal patients (7,9 range 4,4-16). We don´t find a correlation between the SUV with either histological and clinical variables but there was a slightly correlation with residual tumor (p:0,068) and initial node involvement (p:0,069). In the 112 metastatic cohort the median SUV was 7,95 (range 2-28) with higher SUV in triple negative (10,1 range 3,4-19) than HER2 positive (9,7 range 4-28) and luminal patients (7,6 range 2.21). We found only a correlation between the SUV and progesterone receptor value (OR 0,875 p:0,005) but not in estrogen receptor, Ki67 index and HER2 status. In the survival analysis we don´t find a correlation between the SUV value and the disease free and overall survival included the analysis for different phenotypes. Conclusions: The SUV of the FDG-PET is very variable in all phenotypes of breast cancer being higher in the triple negative phenotype and lower in the luminal. The SUV value is very similar in neoadjuvant and metastatic setting. We only correlated the SUV value with the progesterone receptor in the metastatic cohort. We don´t find a prognostic value of the initial value of SUV in the two cohorts.