Natural history of untreated prostate cancer: a comprehensive review of long-term progression patterns and survival outcomes

Abstract

We systematically reviewed the long-term outcomes of untreated prostate cancer across different risk categories to inform treatment decisions and active surveillance protocols. This comprehensive analysis synthesizes long-term progression data across tumor staging and grading systems. We conducted a systematic literature search of PubMed, EMBASE, and Cochrane databases (1990–2025) for studies reporting ≥10-year outcomes in untreated or conservatively managed prostate cancer patients. Eligible studies included observational cohorts, population registries, and meta-analyses. Primary endpoints included prostate cancer-specific mortality, metastatic progression, and competing mortality. Fifteen major studies encompassing 43,127 patients (median follow-up 15–30 years) demonstrated heterogeneous progression patterns. Ten-year prostate cancer-specific survival ranged from >95% for Gleason 6 tumors to <60% for Gleason 8–10 disease. Grade Group 1 tumors showed <5% metastatic risk over 15–20 years, while Grade Groups 4–5 exhibited rapid progression with median disease-specific survival <5 years. Across all risk groups, disease progression accelerated markedly after 15 years. Men diagnosed after age 75 faced substantial competing mortality (~57–60% 10-year non-cancer mortality), regardless of tumor grade. Tumor grade is the strongest prognostic factor in the natural history of untreated prostate cancer. Low-grade disease often remains indolent for 15–20 years, whereas high-grade tumors frequently progress to lethal disease within a few years, warranting early intervention. These findings support contemporary active surveillance protocols for low-risk patients and inform evidence-based treatment decisions for higher-risk disease.