Age-adjusted Charlson comorbidity index is a significant prognostic factor for long-term survival of patients with high-risk prostate cancer after radical prostatectomy: a Bayesian model averaging approach

Purpose: We investigated the long-term prognostic impact of age-adjusted Charlson comorbidity index (ACCI) on overall mortality (OM), cancer-specific mortality (CSM), and other-cause mortality (OCM) according to risk stratification in patients with prostate cancer who underwent radical prostatectomy. Methods: Data from 542 patients who underwent radical prostatectomy between 1992 and 2006 were analyzed. The impact of preoperative variables including age, prostate-specific antigen, biopsy Gleason sum, clinical stage, and ACCI on OM, CSM, and OCM were analyzed according to risk groups, with a median follow-up of 101 months. Results: Subjects were stratified into either the high-risk group (n = 241) or the non-high-risk group (n = 301). Cox proportional hazards model demonstrated that the ACCI was the only significant predictor for OM in all patients (hazard ratio, HR 1.41; 95 % confidence interval, CI 1.19–1.66), non-high-risk group (HR 1.45; 95 % CI 1.09–1.91), and high-risk group (HR 1.37; 95 % CI 1.11–1.69). In competing risk analysis, CSM was not associated with the ACCI in either risk group. However, the ACCI had a significant impact on OCM in both the non-high-risk (HR 1.55; 95 % CI 1.16–2.1) and high-risk groups (HR 1.60; 95 % CI 1.23–2.08). A Bayesian model averaging approach verified that the ACCI was the most powerful predictor for OM and OCM in the both high-risk and non-high-risk groups. Conclusions: A thorough assessment of comorbidities is mandatory in establishing prognoses, even when considering invasive treatment modalities in high-risk prostate cancer patients.