Serum calcium is not predictive of aggressive prostate cancer after radical prostatectomy

Objectives: To investigate the effect of preoperative total serum calcium on disease progression after radical prostatectomy (RP). Elevated total serum calcium has been linked to death from prostate cancer in the National Health and Nutrition Examination Surveys I and II. However, these findings have not been studied in a large cohort of patients with prostate cancer. Methods: We identified 10 532 consecutive patients who had undergone RP from 1990 to 2004 for prostate cancer. Total serum calcium levels were available for 7648 (72.6%) of these patients within 90 days before RP. Postoperative survival was estimated using the Kaplan-Meier method and compared using the log-rank test. Cox proportional hazard regression models were used to analyze the ability of serum calcium to predict biochemical recurrence, systemic progression, and cancer-specific survival. Results: The median patient age at surgery was 64 years. The median total serum calcium level was 9.4 mg/dL (range 6.8-11.2). On univariate analysis, the total serum calcium level was not significantly associated with any clinical or pathologic variables, including tumor stage, preoperative prostate-specific antigen, Gleason score, tumor volume, surgical margins, or lymph node status. Furthermore, the serum calcium level was not significantly associated with biochemical failure, systemic progression, or prostate cancer death on univariate or multivariate analysis. Conclusions: The total serum calcium level was not predictive of cancer outcomes in patients who had undergone RP. Additional investigations of the preoperative disease predictors after RP for patients with nonmetastatic disease might be better directed toward other markers.