Retrospective cohort study with clear associations between PSA dynamics, metastatic status and time to progression, but limited by single-country setting, lack of multivariate adjustment, and no comparison group receiving alternative therapy.
Single-centre prospective observational study over 9 weeks with small absolute number of events (n=7) reporting incidence rate; descriptive rather than comparative, and lacks control or mechanistic depth to support generalization.
Single-centre retrospective study of 141 patients with observational outcomes; no randomised comparator, no prospective design, and no hard clinical endpoints with effect sizes reported.