Inclusion Criteria:  Men >18 years of age. Mentally competent and understanding of benefits and potential burden of the study. Written and signed informed consent. Histological confirmed diagnosis of adenocarcinoma of the prostate. Indicated to start on hormonal therapy (any LHRH agonist or antagonist). Indicated to start on upfront therapy (i.e. docetaxel, abiraterone, apalutamide, or enzalutamide). Any initial PSA. Any Gleason score. Any T-stage. Any N-stage. Stage M1, with multiple / high volume metastasis:More than three (>3) metastatic lesions (any combination of either lymph node metastasis outside of pelvis, bone metastasis, or visceral metastasis), as seen on PSMA-PET/CT-imaging. As these patients are treated with palliative intent.  Exclusion Criteria:  Concomitant malignancy (except from BCC of the skin). History of prior diagnosed or treated PCa. Any unrelated illness (e.g. active infection, inflammation or laboratory abnormalities) that in the judgment of the investigator will significantly affect patient's clinical status and/or outcome of the study. Any known allergy for the upfront therapy. Any known allergy for LHRH agonist or antagonist.