Purpose: To report treatment outcomes in a cohort of extreme-risk prostate cancer patients and identify a subgroup of patients with worse prognosis.
Materials and methods: Extreme-risk prostate cancer patients were defined as patients with at least one extreme-risk factor: stage cT3b-cT4, Gleason score 9-10 or PSA > 50 ng/ml; or patients with 2 or more high-risk factors: stage cT2c-cT3a, Gleason 8 and PSA > 20 ng/ml. Overall survival (OS), cause-specific survival (CSS), clinical-free survival (CFS), and biochemical non-evidence of disease (bNED) survival are the four outcomes of interest in a population of 1341 patients.
Results: With a median follow-up of 71.5 months, 5- and 10-year bNED survival, CFS, CSS and OS for the entire cohort were 77.1 % and 57.0, 89.2 and 78.9 %, 97.4 and 93.6 %, and 92.0 and 71.3 %, respectively. On multivariate analysis, PSA and clinical stage were associated with bNED survival. PSA and Gleason score predicted for CFS, whereas only Gleason score predicted for OS. When a simplified model was performed using the "number of risk factors" variable, this model provided the best distinction between patients with ≥2 extreme-risk factors and patients with 2 high-risk factors, showing a hazard ratio (HR) of 1.737 (p = 0.0003) for bNED survival, HR 1.743 (p = 0.0448) for OS and an HR of 3.963 (p = 0.0039) for the CSS endpoint.
Conclusions: Patients presenting at diagnosis with two extreme-risk criteria have almost fourfold higher risk for prostate cancer mortality. Such patients should be considered for more aggressive multimodal treatments.
Keywords: Androgen deprivation; Extreme risk; Multimodal treatment; Prostate cancer; Radiotherapy; Survival.