PET/MRI of hypoxia and vascular function in ER-positive breast cancer: correlations with immunohistochemistry

• Published in: European radiology 2023-09, Vol.33 (9), p.6168-6178
• Main Authors: Carmona-Bozo, Julia C., Manavaki, Roido, Miller, Jodi L., Brodie, Cara, Caracò, Corradina, Woitek, Ramona, Baxter, Gabrielle C., Graves, Martin J., Fryer, Tim D., Provenzano, Elena, Gilbert, Fiona J.
• Format: Article
• Language: English
• Subjects: Abnormalities; Biopsy; Breast; Breast cancer; Breast carcinoma; Breast Neoplasms - pathology; Carbonic anhydrase; Carbonic anhydrases; Density; Diagnostic Radiology; Diameters; ErbB-2 protein; Estrogen receptors; Female; Fluorine isotopes; Humans; Hypoxia; Hypoxia-Inducible Factor 1, alpha Subunit; Hypoxia-inducible factor 1a; Imaging; Immunohistochemistry; Internal Medicine; Interventional Radiology; Magnetic Resonance Imaging; Medical imaging; Medicine; Medicine & Public Health; Microvasculature; Neuroradiology; Parameters; Pharmacokinetics; Positron emission; Positron emission tomography; Radiology; Regression analysis; Tumors; Ultrasound
• ISSN: 1432-1084; 0938-7994; 1432-1084
• DOI: 10.1007/s00330-023-09572-6

Objectives To explore the relationship between indices of hypoxia and vascular function from 18 F-fluoromisonidazole ([ 18 F]-FMISO)-PET/MRI with immunohistochemical markers of hypoxia and vascularity in oestrogen receptor–positive (ER +) breast cancer. Methods Women aged  > 18 years with biopsy-confirmed, treatment-naïve primary ER + breast cancer underwent [ 18 F]-FMISO-PET/MRI prior to surgery. Parameters of vascular function were derived from DCE-MRI using the extended Tofts model, whilst hypoxia was assessed using the [ 18 F]-FMISO influx rate constant, K i . Histological tumour sections were stained with CD31, hypoxia-inducible factor (HIF)-1α, and carbonic anhydrase IX (CAIX). The number of tumour microvessels, median vessel diameter, and microvessel density (MVD) were obtained from CD31 immunohistochemistry. HIF-1α and CAIX expression were assessed using histoscores obtained by multiplying the percentage of positive cells stained by the staining intensity. Regression analysis was used to study associations between imaging and immunohistochemistry variables. Results Of the lesions examined, 14/22 (64%) were ductal cancers, grade 2 or 3 (19/22; 86%), with 17/22 (77%) HER2-negative. [ 18 F]-FMISO K i associated negatively with vessel diameter ( p  = 0.03), MVD ( p  = 0.02), and CAIX expression ( p  = 0.002), whilst no significant relationships were found between DCE-MRI pharmacokinetic parameters and immunohistochemical variables. HIF-1α did not significantly associate with any PET/MR imaging indices. Conclusion Hypoxia measured by [ 18 F]-FMISO-PET was associated with increased CAIX expression, low MVD, and smaller vessel diameters in ER + breast cancer, further corroborating the link between inadequate vascularity and hypoxia in ER + breast cancer. Key Points • Hypoxia, measured by [ 18 F]-FMISO-PET, was associated with low microvessel density and small vessel diameters, corroborating the link between inadequate vascularity and hypoxia in ER + breast cancer. • Increased CAIX expression was associated with higher levels of hypoxia measured by [ 18 F]-FMISO-PET. • Morphologic and functional abnormalities of the tumour microvasculature are the major determinants of hypoxia in cancers and support the previously reported perfusion-driven character of hypoxia in breast carcinomas.