Metastatic Prostate Cancer Prognosis Calculator
This calculator estimates overall survival probability for men with metastatic castration-resistant prostate cancer (mCRPC), based on the 11-variable PREVAIL prognostic model validated in a phase III trial of enzalutamide. Enter the clinical values below to see the predicted 5-year survival rate, estimated median survival in months, risk tier (low, intermediate, or high), and a projected survival curve over 60 months. All inputs are optional, and the result updates as you type. This tool is for educational and informational purposes only and does not replace oncology consultation.
What this calculator estimates
This tool applies the PREVAIL prognostic model to estimate overall survival for men diagnosed with metastatic castration-resistant prostate cancer (mCRPC). The PREVAIL model was developed and validated from a phase III clinical trial of enzalutamide versus placebo in chemotherapy-naive mCRPC patients. It combines 11 independent prognostic variables, ranging from lab markers such as PSA, hemoglobin, albumin, LDH, and alkaline phosphatase, to disease characteristics such as bone and visceral metastatic burden, pain level, time to CRPC, and Gleason score. Each adverse factor contributes points to a total risk score that places patients into low (0-4), intermediate (5-7), or high (8-11) risk tiers, with corresponding 5-year overall survival estimates of approximately 42%, 24%, and 5% respectively in the enzalutamide arm.
Understanding the 11 prognostic variables
The PREVAIL model weighs the following factors. Laboratory values: PSA at or above 100 ng/mL, hemoglobin below 120 g/L (anemia), albumin below 35 g/L (hypoalbuminemia), LDH above the laboratory upper limit of normal, alkaline phosphatase above the laboratory upper limit of normal, and a neutrophil-to-lymphocyte ratio at or above 2.5. Disease factors: the presence of liver metastases (strongest single adverse predictor), extensive bone disease with 10 or more lesions on bone scan, significant pain (5 or above on a 0-10 scale), a short time from initial diagnosis to castration resistance (under 12 months indicating aggressive biology), and a Gleason score of 8-10 at the original biopsy. Prior chemotherapy adds one additional adverse point. The more of these factors are present, the worse the expected prognosis. The most impactful single factor is liver metastasis, followed by elevated LDH.
How overall survival is estimated
Once the total PREVAIL score is calculated, the corresponding 5-year overall survival probability is read from the validated risk group lookup table derived from the PREVAIL trial. From that 5-year probability, this calculator uses an exponential survival model to derive the estimated median survival in months and to plot a projected survival curve across the 60-month follow-up window. The exponential model assumes a constant hazard rate, which is a simplification: actual survival curves for mCRPC typically show steeper early decline followed by a longer tail for responders. The 1-year and 2-year survival estimates are computed from the same model. These are population-level averages; individual outcomes depend on treatment response, comorbidities, and evolving therapies.
Limitations and clinical context
The PREVAIL model was trained on patients treated with enzalutamide in a controlled trial setting and may not generalize equally to all populations, treatment sequences, or patients with significant comorbidities. Newer treatments, including abiraterone acetate, cabazitaxel, PARP inhibitors (for BRCA1/2 or homologous recombination repair mutations), and 177Lu-PSMA-617 radioligand therapy, have improved survival outcomes for subpopulations beyond what the original model predicted. Genomic profiling (e.g., somatic BRCA2, ATM mutations) is now standard of care and can identify patients likely to respond to targeted agents. This calculator does not adjust for genomic biomarkers, immunotherapy eligibility, or treatment sequence. Always interpret these estimates alongside your oncology team.
PREVAIL Risk Groups and 5-Year Overall Survival
| Risk Group | Score Range | 5-Year OS (%) | Median OS |
|---|---|---|---|
| Low | 0-4 | ~42% | ~55-75 months |
| Intermediate | 5-7 | ~24% | ~30-45 months |
| High | 8-11 | ~5% | ~10-18 months |
Based on Armstrong et al. (2020), European Urology. Survival estimates are from the enzalutamide arm of the PREVAIL phase III trial. Individual prognosis may differ.
Frequently asked questions
What does "castration-resistant" prostate cancer mean?
Castration-resistant prostate cancer (CRPC) means the cancer continues to grow despite medical or surgical castration that reduces testosterone to very low (castrate) levels. It is defined by rising PSA or radiographic progression while on androgen deprivation therapy. When it has also spread beyond the prostate or nearby lymph nodes, it is called metastatic CRPC (mCRPC), which is the advanced stage this calculator addresses.
Why is Gleason score important for prognosis?
The Gleason score reflects how abnormal the cancer cells look under a microscope, graded 2-10. Higher scores (8-10) indicate poorly differentiated, more aggressive cancer that is more likely to spread and resist treatment. In population data, men with Gleason 8-10 prostate cancer have roughly 20 times the prostate-cancer-specific mortality rate of men with Gleason 2-4 disease. Even at the mCRPC stage, the original Gleason grade continues to carry prognostic information about disease biology.
What is the 5-year survival rate for metastatic prostate cancer?
For metastatic (stage IV) prostate cancer as a group, the SEER database reports an approximately 31-37% 5-year relative survival rate. However, outcomes vary substantially by castration sensitivity, metastatic burden, and treatment received. Within mCRPC specifically, which is a more advanced subset, survival ranges from around 42% at 5 years for low-risk patients (few adverse factors, enzalutamide-treated in the PREVAIL trial) to approximately 5% for high-risk patients. Modern therapies introduced after the original PREVAIL trial may have shifted some of these estimates upward.
How does liver involvement affect prognosis differently from bone metastases?
Bone metastases are by far the most common site of spread in prostate cancer (around 85-90% of metastatic cases) and carry a variable prognosis depending on burden: fewer than 10 lesions is considerably better than widespread disease. Liver metastases occur in a smaller subset (around 10-15%) but indicate visceral progression with aggressive disease biology and are associated with much shorter median survival. In the PREVAIL model, liver metastasis carries greater adverse weight than extensive bone disease alone.
Can the PREVAIL score be used outside a clinical trial setting?
The PREVAIL model was developed from trial data where patients were either on enzalutamide or placebo, and the survival benefits modeled reflect that context. The model has been used in real-world prognostic assessment and as a benchmark in subsequent trials. It has not been externally validated in populations outside the original PREVAIL dataset to the same degree as some other nomograms, such as the Memorial Sloan Kettering Cancer Center mCRPC nomogram. It is best used as a supplementary tool alongside clinical judgment, not as a definitive prediction.
What treatment options exist for high-risk mCRPC?
High-risk mCRPC (score 8-11) typically has multiple adverse factors and requires aggressive, multidisciplinary management. Current options include novel hormonal agents (enzalutamide, abiraterone, apalutamide, darolutamide), taxane chemotherapy (docetaxel, cabazitaxel), radium-223 for bone-predominant disease, 177Lu-PSMA-617 radioligand therapy for PSMA-positive disease, and PARP inhibitors (olaparib, rucaparib) for tumors with homologous recombination repair gene mutations. Clinical trial participation is strongly encouraged in this setting because outcomes remain poor with standard approaches.
Sources
- Armstrong AJ et al. Five-year Survival Prediction and Safety Outcomes with Enzalutamide in Men with Chemotherapy-naive Metastatic Castration-resistant Prostate Cancer from the PREVAIL Trial. European Urology. 2020.
- Albertsen PC et al. Twenty-five year follow-up for prostate cancer among men managed conservatively: the natural history of untreated disease. Journal of Urology, 2005. (Gleason-specific mortality data)
- SEER Cancer Statistics Review 1975-2020, National Cancer Institute. Prostate Cancer Stage-specific Survival Tables.