Patterns of alphavbeta3 expression in primary and metastatic human breast cancer as shown by 18F-Galacto-RGD PET.
The integrin alpha(v)beta(3) is a key player in angiogenesis and metastasis. Our aim was to study the uptake patterns of the alpha(v)beta(3)-selective PET tracer (18)F-galacto-RGD in invasive ductal breast cancer.


METHODS
Sixteen patients with primary (n = 12) or metastasized breast cancer (n = 4) were examined with (18)F-galacto-RGD PET. Standardized uptake values (SUVs) were derived by region-of-interest analysis, and immunohistochemistry of alpha(v)beta(3) expression was performed (n = 5).


RESULTS
(18)F-Galacto-RGD PET identified all invasive carcinomas, with SUVs from 1.4 to 8.7 (mean +/- SD, 3.6 +/- 1.8; tumor-to-blood and tumor-to-muscle ratios, 2.7 +/- 1.6 and 6.2 +/- 2.2, respectively). Lymph-node metastases were detected in 3 of 8 patients (mean SUV, 3.3 +/- 0.8). SUVs in distant metastases were heterogeneous (2.9 +/- 1.4). Immunohistochemistry confirmed alpha(v)beta(3) expression predominantly on microvessels (5/5) and, to a lesser extent, on tumor cells (3/5).


CONCLUSIONS
Our results suggest generally elevated and highly variable alpha(v)beta(3) expression in human breast cancer lesions. Consequently, further imaging studies with (18)F-galacto-RGD PET in breast cancer patients for assessment of angiogenesis or planning of alpha(v)beta(3)-targeted therapies are promising.
Beer
Ambros J
AJ
Department of Nuclear Medicine, Klinikum rechts der Isar, Technische Universität München, Munich, Germany. beer@roe.med.tum.de
Niemeyer
Markus
M
Carlsen
Janette
J
Sarbia
Mario
M
Nährig
Jörg
J
Watzlowik
Petra
P
Wester
Hans-Jürgen
HJ
Harbeck
Nadia
N
Schwaiger
Markus
M
D014408:Biomarkers, Tumor / Q000378:metabolism; D001943:Breast Neoplasms / Q000000981:diagnostic imaging* / Q000378:metabolism*; D044584:Carcinoma, Ductal / Q000000981:diagnostic imaging* / Q000378:metabolism*; D005260:Female; D005690:Galactose / Q000031:analogs & derivatives* / Q000493:pharmacokinetics; D006801:Humans; D039302:Integrin alphaVbeta3 / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D009363:Neoplasm Proteins / Q000378:metabolism; D010456:Peptides, Cyclic / Q000493:pharmacokinetics*; D049268:Positron-Emission Tomography / Q000379:methods; D019275:Radiopharmaceuticals / Q000493:pharmacokinetics; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014018:Tissue Distribution
D014408:Biomarkers, Tumor; D039302:Integrin alphaVbeta3; D009363:Neoplasm Proteins; D010456:Peptides, Cyclic; D019275:Radiopharmaceuticals; C423503:fluorogalacto-RGD; D005690:Galactose