Objective: The aim of this study was to evaluate the prognostic significance of each of the following in the development and progression of hormonal refractory disease in patients with metastatic prostate cancer under hormonal palliative treatment: The initial serum level prostate specific antigen (PSA), the Gleason score (GS), the presence of bone metastases with or without visceral metastases, and the PSA decline.
Patients and methods: During the time period from January 2005 to December 2008, a total of 92 patients with newly diagnosed, histologically confirmed metastatic prostate cancer (MPC) were under palliative androgen deprivation therapy. The age range was 52 to 85 years with a mean age of 66.2±7.9 years. MPC was diagnosed histologically after transrectal ultrasonography guided biopsy. The Gleason score assessment was determined by low power microscopic examination. Metastases were confirmed by positive bone scintigraphy with 925 MBq 99mTc-MDP using a tomographic gamma camera, computerized axial tomography or magnetic resonance imagining. Measurements of PSA levels were conducted by the radioimmunoassay method. The influences of the following prognostic factors were evaluated: The initial serum level of prostate specific antigen (PSA), the Gleason score (GS), the presence of bone metastases with or without visceral metastases, and the PSA decline, on the time to disease progression.
Results: The time to progression was significantly delayed in patients with initial PSA level $50ng/ml (median: 32 months), Gleason Score $7 (median: 33 months), bone metastases only (median: 30 months) and PSA level normalization within 6 months (median: 30 months) compared to that of patients with initial PSA level >50ng/ml (median: 24 months), Gleason Score >7 (median: 24 months), bone, distant lymph nodes and/or visceral metastases (median: 24 months), PSA level decline (median: 18 months) (p-values were 0.002, <0.001, <0.001 and <0.001 respectively). The time to progression was not significantly delayed in patients with $6 sites bone metastases (median: 30 months) compared to that of patients with >6 sites bone metastases (median: 28 months) (p=0.122).
Conclusion: Our results showed that the initial PSA level, the Gleason score, the presence of bone, lymph nodes and visceral metastases, and the PSA level decline could predict increased risk of disease progression in patients with metastatic prostate cancer.
Key words: Prostatic specific antigen - Gleason score - Bone scan - Androgen deprivation therapy.