“Natural course” of disease in patients with metastatic castrate-resistant prostate cancer: Survival and prognostic factors without life-prolonging treatment

Abstract

Objective: The aim of this study was to determine survival and prognostic factors in unselected patients with metastatic castrate-resistant prostate cancer (mCRPC), who never received life-prolonging treatment. Materials and methods: The study was a retrospective analysis of a consecutive sample of patients with mCRPC seen at the urological unit of a local hospital from 2000 to 2005, their mCRPC diagnosis based on rising prostate-specific antigen (PSA) during androgen depletion treatment (ADT). Results: Median overall survival was 12.3 months (range 0.2–108 months), the 3 year survival was 16.9% (95% confidence interval 0.11–0.24) and two patients were alive at the end of follow-up. Compared to a PSA nadir of greater than 11 μg/l during ADT, a PSA nadir of less than 1 μg/l significantly decreased the risk of death by 71%. A PSA doubling time less than 1.6 months during the early phase of mCRCP almost tripled the risk of death compared to a PSA doubling time longer than 3 months. Alkaline phosphatase serum levels and hemoglobin levels within the normal range indicated a favorable prognosis. Conclusions: The “natural course” of mCRPC varies without life-prolonging treatment along with PSA nadir during ADT, PSA doubling time, alkaline phosphatase and hemoglobin level at mCRPC diagnosis. 3-year survival or longer is observed in 16.9% of patients. In clinical intervention trials among mCRPC patients, all known prognostic factors should be taken into account during the randomization process and during survival analyses.