Prognosis of Prostate Cancer With Mucinous Components: A Propensity Score-Matched Study

Abstract

Purpose: Acinar adenocarcinoma with mucinous components is a rare histologic variant of prostate cancer (PC) that was previously reported to exhibit more aggressive behavior than typical PC. However, recent studies have suggested that PC with mucinous components may not be more aggressive and could even have a more favorable prognosis. Therefore, this study investigated the clinical outcomes of PC with mucinous components. Materials and Methods: We reviewed 7,983 patients with PC who underwent radical prostatectomy between 2006 and 2019. Propensity score matching and Kaplan-Meier analyses were performed to compare outcomes between patients with typical PC (group 1) and those with PC containing mucinous components (group 2). Matching variables included age, initial prostate-specific antigen level, clinical stage, and pathological Gleason score (GS). Biochemical recurrence-free survival (BCRFS) and cancer-specific survival (CSS) were analyzed using Cox regression analysis to identify survival predictors. Results: Sixty-one patients (0.76%) had PC with mucinous components. No significant differences were observed in matched variables between the 2 groups. Pathological stage, lymph node invasion (LNI), and positive surgical margin rates were also comparable. At a median follow-up of 53 (interquartile range, 24–80) months, biochemical recurrence occurred in 29 patients in group 1 and 24 in group 2 (p=0.361). Two patients in group 1 and 3 in group 2 died from PC (p>0.999). BCRFS and CSS did not differ significantly between the 2 groups (p=0.676 and p=0.458, respectively). High GS (≥8) (p=0.007) and pT3b stage (p=0.035) were independent risk factors for BCRFS, while LNI (p=0.001) predicted CSS. The presence of mucinous components was not a significant predictor of either BCRFS or CSS (p=0.127 and p=0.561, respectively). Conclusion: PC with mucinous components demonstrated clinical outcomes comparable to those of typical PC and was not an independent prognostic factor for survival. PC with mucinous components may not be as aggressive as previously believed.