The Investigation of New Biological Markers for Prostate Cancer Diagnosis and Management in Chinese Population

Prostate cancer (PC) is highly prevalent worldwide and is currently the 3rd most commonly diagnosed prostate cancer in Hong Kong male population with more than 1600 new cases diagnosed per year. Even with widely used serum Prostate Specific Antigen (PSA) diagnostic testing, more than 50% men with newly diagnosed PC are deemed to have highrisk disease. 1 However, the current use of serum PSA as a diagnostic marker is unsatisfactory. Many patients has elevated serum PSA is actually due to other causes and also the level of serum PSA do not correlate with the staging and grading of prostate cancer. 2 Moreover, the current risk stratification system, based on PSA, clinical staging and Gleason score is of only limited value, as a significant proportion of patients with high-risk nonmetastatic PC have incurable disease due to locally advanced and/or occult metastasis, whilst others with indolent disease may never suffer morbidity or mortality from PC. Furthermore, high-risk (non-metastatic) prostate cancer (thus defined) exhibits a high degree of heterogeneity of response to current treatment protocols. Lastly, the characteristics of prostate cancer in our Chinese population might not be the same as those in Caucasian. 3,4 Several single biomarkers have been introduced in an attempt to address the clinical need for better prognostic tests in prostate cancer. For example, increased pre-operative PSA velocity (≥2ng/ml/per year) has been associated with increased risk of recurrence after prostatectomy5 and mortality6, as have increased serum levels of Kallikrein-2 and \[-2\]-pro PSA.7-10 Pre-operative levels of prostate cancer gene 3 (PCA3) have been found to be elevated in tumours \>0.5cc, 11 however these findings could not be confirmed in recent work.12 Therefore, in order to improve patient management and outcome, there is therefore an urgent need to improve our ability to identify newer markers and also validate some potential markers in our population.