Predictors of survival in prostate cancer patients with bone metastasis and extremely high prostate-specific antigen levels.

Purpose: Prostate-specific antigen (PSA) is a surrogate marker of disease progression; however, its predictive ability in the extreme ranges is unknown. We determined the predictors of survival in patients with bone metastatic prostate cancer (BMPCa) and with extremely high PSA levels.

Methods: Treatment-naïve patients (n = 248) diagnosed with BMPCa between December 2002 and June 2012 were retrospectively analyzed. Clinicopathological features at diagnosis, namely age, body mass index, serum alkaline phosphatase (ALP) and PSA levels, PSA nadir, time to PSA nadir and its maintenance period, PSA declining velocity, Gleason grade, clinical T stage, pain score, Eastern Cooperative Oncology Group performance score (ECOG PS), and the number of bone metastases were assessed. The patients were stratified according to PSA ranges of <20 ng/mL, 20-100 ng/mL, 100-1000 ng/mL, and 1000-10,000 ng/mL. Study endpoints were castration-resistant PCa (CRPC)-free survival and cancer-specific survival (CSS).

Results: Patients with higher PSA and ALP levels showed more bone lesions (P < 0.001). During the follow-up period (median, 39.9 months; interquartile range, 21.5-65.9 months), there were no differences between the groups in terms of the survival endpoints. High ALP levels, shorter time to PSA nadir, and pain were associated with an increased risk of progression to CRPC, and high ALP levels, ECOG PS ≥ 1, and higher PSA nadir independently predicted CSS.

Conclusions: PSA response to androgen deprivation therapy and serum ALP are reliable predictors of survival in patients with BMPCa presenting with extremely high PSA levels. These patients should not be deterred from active treatment based on baseline PSA values.