PSMA expression and PSMA PET/CT imaging in metastatic soft tissue sarcoma patients, results of a prospective study.
prospective_cohort · Level II
Where this comes from
- Record sourced from PubMed, PMID 40146266.
- Also identified by DOI 10.1007/s00259-025-07224-z and PMC identifier 12316757.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
Prostate-specific membrane antigen (PSMA) expression has been observed in a subset of soft tissue sarcomas, mainly in the neovascular endothelial cells. This feasibility study aimed to evaluate PSMA expression and PSMA PET/CT imaging in metastatic soft tissue sarcoma, providing important insights for potential future exploration of PSMA-targeted radioligand therapy. This prospective single-center study included adult patients with metastatic soft tissue sarcoma, with measurable disease (lesion diameter > 1 cm), available biopsy/resection material, ECOG/WHO performance status of 0-2 and either no prior systemic treatment, progressive disease during/after treatment, or stable disease/partial response with the last dose > 8 weeks prior. Immunohistochemical PSMA staining was performed on previously obtained biopsy or resection material. In case of high PSMA expression, a [<sup>18</sup>F]-JK-PSMA-7 PET/CT scan evaluated tracer uptake, with adequate uptake defined as SUV<sub>max</sub> > 8. Of 25 included patients, 11 (44%) had high PSMA expression: 4/11 leiomyosarcomas, 3/4 dedifferentiated liposarcomas, 2/5 undifferentiated pleomorphic sarcomas, 1/2 myxofibrosarcomas and 1/1 malignant peripheral nerve sheath tumour. Five of 11 patients agreed to a [<sup>18</sup>F]-JK-PSMA-7 PET/CT, of which 3 had lesions that showed adequate tracer uptake (SUV<sub>max</sub> 10.7-16.7). However, uptake across all metastatic lesions was highly heterogeneous (median SUV<sub>max</sub> = 3.8; range 0.5-16.7), indicating that these patients are unlikely to benefit sufficiently from PSMA-targeted therapy. The study was therefore terminated prematurely. PSMA expression and PSMA tracer uptake in metastatic soft tissue sarcoma were highly heterogeneous. A deeper understanding of PSMA biology and improved patient selection criteria are essential for future application of PSMA-targeted radioligand therapy in this disease. clinicaltrials.gov, NCT05522257. Registered 31-08-2022.
Medical subject headings
- Positron Emission Tomography Computed Tomography
- Sarcoma
- Glutamate Carboxypeptidase II
- Antigens, Surface
- Gene Expression Regulation, Neoplastic