Correlation between Imaging Markers Derived from PET/MRI and Invasive Acquired Biomarkers in Newly Diagnosed Breast Cancer.

Purpose: Evaluate the diagnostic potential of [F]FDG-PET/MRI data compared with invasive acquired biomarkers in newly diagnosed early breast cancer (BC).

Methods: Altogether 169 women with newly diagnosed BC were included. All underwent a breast- and whole-body [F]FDG-PET/MRI for initial staging. A tumor-adapted volume of interest was placed in the primaries and defined bone regions on each standard uptake value (SUV)/apparent diffusion coefficient (ADC) dataset. Immunohistochemical markers, molecular subtype, tumor grading, and disseminated tumor cells (DTCs) of each patient were assessed after ultrasound-guided biopsy of the primaries and bone marrow (BM) aspiration. Correlation analysis and group comparisons were assessed.

Results: A significant inverse correlation of estrogen-receptor (ER) expression and progesterone-receptor (PR) expression towards SUV was found (ER: = 0.27, 0.01; PR: = 0.19, 0.05). HER2-receptor expression showed no significant correlation towards SUV and ADC values. A significant positive correlation between Ki67 and SUVmax and SUV ( = 0.42 0.01; = 0.19 0.05) was shown. Tumor grading significantly correlated with SUV and SUV (ρ = 0.36 and ρ = 0.39, both 's < 0.01). There were no group differences between SUV/ADC values of DTC-positive/-negative patients.

Conclusions: [F]FDG-PET/MRI may give a first impression of BC-receptor status and BC-tumor biology during initial staging by measuring glucose metabolism but cannot distinguish between DTC-positive/-negative patients and replace biopsy.