903 CHARLSON COMORBIDITY INDEX IS NOT AN INDEPENDENT PREDICTOR OF OVERALL SURVIVAL IN PATIENTS WITH INTERMEDIATE AND HIGH RISK PROSTATE CANCER TREATED WITH RADICAL PROSTATECTOMY

Abstract

INTRODUCTION AND OBJECTIVES: Radical prostatectomy (RP) represent the gold standard for the treatment of patients with prostate cancer (PCa) and a life expectancy of at least 10 years. However, life expectancy of untreated patients with intermediate and high risk PCa may be significantly lower as compared to low risk patients. We hypothesized that age and comorbidities may have a different impact on overall survival according to the pre-operative cancer characteristics. METHODS: The study included 2521 patients treated with RP at three tertiary care centres from 1998 to 2008. For the purpose of the study, comorbidities were coded according to the Charlson Index Score. Patients were stratified according to pre-operative cancer features in low (PSA 10 ng/ml, cT1, biopsy Gleason sum 6), high (cT3 or biopsy Gleason 8-10 or PSA 20 ng/ml) and intermediate risk (all the remaining patients). Kaplan-Meier and life table analyses addressed overall survival across all risk groups. Univariable and multivariable Cox regression models tested the association between Charlson comorbidity index and overall survival in the 3 risk groups, after adjusting for age at surgery. RESULTS: Of all patients, 481 (36.7%), 563 (42.9%) and 268 (20.4%) were categorized as low, intermediate and high risk, respectively. Mean age was 66.6 yrs (median 67.0, range 44–85 yrs). Mean follow-up was 68.5 months (median 61.7; range: 3–193 months). In the overall patient population, 5 and 10-years overall survival rates were 92 and 79%. A significantly higher overall survival was recorded for low risk patients as compared to intermediate and high risk patients at 5 (96 vs. 93 vs. 82; p 0.001) and 10-years (92 vs. 87 vs. 54%; p 0.001). At univariable analyses, age was significantly associated with overall survival in low (HR 1.16; p 0.002) and intermediated risk (HR 1.08; p 0.04) but not in high risk patients (p 0.1), while Charlson comorbidity index was a significant predictor only in low risk patients (HR 6.09; p 0.001). At multivariable Cox regression analyses, Charlson comorbidity index achieved independent status in low risk patients (HR 5.14; p 0.005) but not in intermediate and high risk (all p 0.1), after adjusting for age at surgery. CONCLUSIONS: In patients diagnosed with clinically localized PCa, age and comorbidities represent limiting factors for RP only in patients with low risk cancer characteristics. Conversely, patients with intermediate or high risk PCa may deserve an active treatment, independently from age or comorbidities.