Gastrin-releasing peptide receptor imaging in breast cancer using the receptor antagonist (68)Ga-RM2 and PET Journal Article


Authors: Stoykow, C.; Erbes, T.; Maecke, H. R.; Bulla, S.; Bartholomä, M.; Mayer, S.; Drendel, V.; Bronsert, P.; Werner, M.; Gitsch, G.; Weber, W. A.; Stickeler, E.; Meyer, P. T.
Article Title: Gastrin-releasing peptide receptor imaging in breast cancer using the receptor antagonist (68)Ga-RM2 and PET
Abstract: Introduction: The gastrin-releasing peptide receptor (GRPR) is overexpressed in breast cancer. The present study evaluates GRPR imaging as a novel imaging modality in breast cancer by employing positron emission tomography (PET) and the GRPR antagonist 68Ga-RM2. Methods: Fifteen female patients with biopsy confirmed primary breast carcinoma (3 bilateral tumors; median clinical stage IIB) underwent 68Ga-RM2-PET/CT for pretreatment staging. In vivo tumor uptake of 68Ga-RM2 was correlated with estrogen (ER) and progesterone (PR) receptor expression, HER2/neu status and MIB-1 proliferation index in breast core biopsy specimens. Results: 13/18 tumors demonstrated strongly increased 68Ga-RM2 uptake compared to normal breast tissue (defined as PET-positive). All PET-positive primary tumors were ER- and PR-positive (13/13) in contrast to only 1/5 PET-negative tumors. Mean SUVMAX of ER-positive tumors was 10.6±6.0 compared to 2.3±1.0 in ER-negative tumors (p=0.016). In a multivariate analysis including ER, PR, HER2/neu and MIB-1, only ER expression predicted 68Ga-RM2 uptake (model: r2=0.55, p=0.025). Normal breast tissue showed inter- and intraindividually variable, moderate GRPR binding (SUVMAX 2.3±1.0), while physiological uptake of other organs was considerably less except pancreas. Of note, 68Ga-RM2-PET/CT detected internal mammary lymph nodes with high 68Ga-RM2 uptake (n=8), a contralateral axillary lymph node metastasis (verified by biopsy) and bone metastases (n=1; not detected by bone scan and CT). Conclusion: Our study demonstrates that 68Ga-RM2-PET/CT is a promising imaging method in ER-positive breast cancer. In vivo GRPR binding assessed by 68Ga-RM2-PET/CT correlated with ER expression in primary tumors of untreated patients. © Ivyspring International Publisher.
Keywords: positron emission tomography; breast cancer; estrogen receptor; pet; er; bombesin; gastrin-releasing peptide receptor; grpr
Journal Title: Theranostics
Volume: 6
Issue: 10
ISSN: 1838-7640
Publisher: Ivyspring International Publisher  
Date Published: 2016-01-01
Start Page: 1641
End Page: 1650
Language: English
DOI: 10.7150/thno.14958
PROVIDER: scopus
PMCID: PMC4955063
PUBMED: 27446498
DOI/URL:
Notes: Article -- Export Date: 6 December 2016 -- Source: Scopus
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  1. Wolfgang Andreas Weber
    173 Weber