ABSTRACT
INTRODUCTION: Recently, new drugs have caused a paradigm shift in the treatment of metastatic hormone-sensitive prostate cancer (HSPC). Meanwhile, research has identified several prognostic factors of metastatic HSPC. OBJECTIVE: The present study focused on remission depth in metastatic HSPC and evaluated its association with remission depth. METHOD: We analyzed 427 patients diagnosed with metastatic HSPC with serum initial prostate-specific antigen (PSA) > 100 ng/ml. The nadir serum PSA value was used as a marker of remission depth for each duration to castration resistance by using receiver operating characteristic (ROC) curves. Cox proportional hazards regression was used to assess for any correlation of progression-free survival (PFS) and overall survival (OS) with the nadir PSA level. RESULTS: The cut-off value for the nadir PSA level per time to castration resistance (TTCR) at three, five, seven, and nine years was calculated. The nadir PSA value alone was able to predict prognosis because of its high sensitivity, high specificity, and high AUC in ROC analysis. The nadir PSA level can be an independent prognostic marker not only for TTCR but also for OS on multivariate analysis. CONCLUSION: We identified the cut-off value for nadir PSA per TTCR period in patients with metastatic HSPC. The nadir PSA value alone can predict prognosis; this demonstrates utility in routine clinical practice due to its simplicity and accuracy.
