BERKELEY, CA (UroToday.com) - Androgen deprivation therapy (ADT) has been the standard of treatment for metastatic prostate cancer in the past decades.
However, despite the initial good response to ADT, most patients progress to develop castration-resistant prostate cancer and might require further hormonal manipulation or chemotherapy. It is important to identify those patients with prostate cancer of clinically more aggressive behavior so other forms of systemic treatment might be considered at earlier junctures.
While the previous literature was largely based on Caucasian data, whether there are any differences in the clinical or biological behaviors of prostate cancer between different ethnicities remained largely unknown. We conducted this study to provide Chinese-specific survival data and to investigate the prognostic role of prostate-specific antigen (PSA) nadir in metastatic prostate cancer in the Chinese population.
In our study, all Chinese prostate cancer patients who received primary ADT from year 2000 to 2009 were reviewed. Only patients with radiological or histological evidence of bone metastases were included, whereas patients who had prior radical prostatectomy or radiotherapy as the primary form of treatment were excluded. With this relatively homogeneous group of patients, we believed our study would be able to yield more accurate and reliable results, which would be more clinically applicable in the context of Chinese population.
A total of 419 patients were included in our study. PSA nadir appeared to be a good predictor for progression-free survival (PFS) (hazard ratio [HR] 1.86, 95% confidence interval [CI] 1.35-2.56, P < 0.001), cancer-specific survival (CSS) (HR 1.60, 95% CI 0.98-2.64, P=0.063) and overall survival (OS) (HR 1.77, 95% CI 1.20-2.41, P < 0.001) upon multivariate Cox regression analyses. In the PSA nadir groups of ≤ 1.0 and > 1.0ng/mL, the 1-year PFS rates were 64% and 40%, respectively; the 5-year CSS rates were 53% and 28%, respectively; and the 5-year OS rates were 45% and 19%, respectively.
To our knowledge, this is the largest Chinese series investigating the prognostic significance of PSA nadir in prostate cancer patients with bone metastases following primary ADT. Our study provided results that would be more applicable in managing prostate cancer in the Chinese population. We believe the utility of PSA nadir would be important in deciding the best treatment strategy, and the survival data would be useful in counseling Chinese prostate cancer patients with disease progression after primary ADT.
Jeremy Y.C. Teoh, MBBS, MRCSEda and Ming-Kwong Yiu, FRCSEd (Urol), FHKAM (Surgery)b as part of Beyond the Abstract on UroToday.com. This initiative offers a method of publishing for the professional urology community. Authors are given an opportunity to expand on the circumstances, limitations etc... of their research by referencing the published abstract.
aDivision of Urology, Department of Surgery, Prince of Wales Hospital, The Chinese University of Hong Kong