Role of serum cholinesterase in patients treated with salvage radical prostatectomy

Background: Serum cholinesterase (ChE) a serine hydrolase that catalyses the hydrolysis of esters of choline, is involved in cellular proliferation and differentiation, therefore affecting carcinogenesis. The aim of this study was to understand the prognostic role of preoperative serum ChE in patients with radiation-recurrent prostate cancer (CaP) treated with salvage radical prostatectomy (SRP). Material and methods: This retrospective study included 214 patients with radiation-recurrent CaP treated with SRP from January 2007 to December 2015 at 5 academic centers. Patients were considered with abnormal/decreased ChE levels if <5 kU/l. Biochemical recurrence-free and metastases-free (MFS) survival analyses were performed. Results: Median serum ChE level was 6.9 (interquartile range) 6–7.7) kU/l. Serum ChE level (<5 kU/l) was decreased in 25 (11.7%) patients. Decreased serum ChE level was associated with lower body mass index (P = 0.006) and metastasis to lymph nodes (P = 0.004). In multivariable analysis, continuous ChE was an independent predictor of MFS (hazard ratio [HR] 0.48, confidence interval [CI] 0.33–0.71, P < 0.001), overall survival (HR 0.68, CI 0.48–0.96, P = 0.03) and cancer-specific survival (HR 0.41, CI 0.2–0.84, P = 0.01). Serum ChE improved the C-index (by 2.54%) to 87.8% for prediction of overall survival and (by 3%) to 92% for prediction of MFS. Conclusion: Preoperative serum ChE is associated with the development of metastasis in patients with radiation-recurrent CaP who underwent SRP. The biological underpinning of this association with the biological and clinical aggressiveness of CaP needs to be further elucidated.