The Effect of Androgen Deprivation Therapy on the Expression of Prostate Specific Membrane Antigen (PSMA) Evaluated With 18F-PSMA PET/CT in Treatment naïve Metastatic Prostate Cancer Patients
Overview
- Phase
- Not Applicable
- Intervention
- GnRH antagonist
- Conditions
- Prostate Cancer
- Sponsor
- Turku University Hospital
- Enrollment
- 35
- Locations
- 1
- Primary Endpoint
- PSMA-flare after ADT
- Last Updated
- 5 years ago
Overview
Brief Summary
Thirty-five men with newly diagnosed, metastatic prostate cancer are scanned with 18F-PSMA 1007 PET/CT at baseline, 3 weeks after the initiation of GnRH-antagonist, at one year and at the time of castration resistant prostate cancer (CRPC). The aim of the study is to classify metastatic lesions into those with PSMA-flare and those without and determine their potential to progress during the follow-up until CRPC.
Detailed Description
In metastatic prostate cancer androgen deprivation therapy (ADT) has been traditionally used as a first line approach. Based on histological studies, animal models and PSMA-PET imaging, it is known that administration of ADT increases prostate specific membrane antigen (PSMA) expression. Preliminary results of our previous prospective clinical trial (clinicaltrials.gov identifier: NCT03313726) with nine men demonstrated a heterogenous flare in PSMA expression 2-3 weeks after ADT, more evidently in bone metastases. Our hypothesis is that metastatic lesions having PSMA-flare respond differently to ADT and have different outcome than those without PSMA-flare. Therefore, the objective of the study is to demonstrate the PSMA-flare seen in bone lesions 3 weeks after ADT and then determine the potential predictive value of the phenomenon in the progression to castration resistant prostate cancer (CRPC). Thirty-five men with newly diagnosed, metastatic PC will undergo 18F-PSMA 1007 PET/CT before and 3 weeks after the initiation of sub-cutaneous injection of GnRH-antagonist (Degarelix, Firmagon®). A subgroup of 20 patients will receive an additional FDG PET/CT scan before ADT to investigate whether lesions with PSMA flare show a different metabolic behaviour on FDG PET. During the follow-up, 18F-PSMA 1007 PET/CT will be also performed once a year. Finally all patients will repeat 18F-PSMA 1007 PET/CT at the time of CRPC. In addition to imaging, PSA is measured, and blood drawn for androgen levels and biomarkers in three months interval.
Investigators
Eligibility Criteria
Inclusion Criteria
- •Age: 40 to 85 years old
- •Language spoken: Finnish
- •Diagnosis: Histologically confirmed adenocarcinoma of prostate
- •Adequate histological sampling consisting of at least 3 biopsy samples from each lobe
- •No previous surgical, radiation or endocrine treatment for prostate carcinoma
- •Clinical stage:T1c-T4NanyM1
- •Serum creatinine ≤ 1,5 x ULN
- •Mental status: Patients must be able to understand the meaning of the study
- •Informed consent: The patient must sign the appropriate Ethical Committee approved informed consent documents in the presence of the designated staff
Exclusion Criteria
- •Previous PC treatment
- •Uncontrolled serious infection
- •Prior usage of 5-ARI medication in past 12 months
Arms & Interventions
GnRH antagonist
Administration of GnRH antagonist (subcutaneous injection, 240 mg) after baseline 18F-PSMA 1007 PET/CT.Then 18F-PSMA 1007 PET/CT is repeated 3 weeks after ADT and at development of CRPC
Intervention: GnRH antagonist
Outcomes
Primary Outcomes
PSMA-flare after ADT
Time Frame: 2-3 weeks
Comparison of mean increase of SUVmax in 18F-PSMA 1007 PET between bone lesions and prostatic lesions after the initiation of ADT
Secondary Outcomes
- PSMA-flare in the follow-up until CRPC(2-3 years)