Tumour markers in prostate cancer II: Diagnostic and prognostic cellular biomarkers

The main goal of prostate cancer tissue biomarkers is to improve diagnostic and prognostic accuracy. A particularly important question is whether the cancer needs immediate treatment or if treatment can be deferred. It is highly unlikely that a single biomarker that provides comprehensive prognostic information about a newly diagnosed prostate cancer will be forthcoming. Despite extensive research efforts, very few biomarkers of prostate cancer have been successfully implemented into clinical practice today. This can be partly explained by a lack of standardised methods for performance and interpretation of immunohistochemistry, but also by poor study design with insufficient biomaterial or inappropriate statistical analysis. Also appropriate cohorts to test prostate cancer biomarkers do not exist. It must be kept in mind that unsuccessful integration of new biomarkers in nomograms can also be explained by the good performance of the clinical and pathological base model with serum PSA as the only independent biomarker. A new biomarker must be powerful enough to improve this prediction model and not merely replace. Material and methods. In this report, we focus on diagnostic and prognostic cellular biomarkers in prostate cancer, recent advances and future aspects by reviewing currently available literature. Results. Similar to other malignancies, the proliferation marker Ki-67 seems to be a prognostic tissue biomarker and a strong candidate for integration in prediction models. Circulating tumour cells are promising markers of response to treatments in patients with metastatic disease. Conclusion. Important technical advances together with histological techniques of antibody or probes conjugated with different fluorophores will certainly improve standardisation and make immunohistochemical biomarker research more reliable and precise in the future. Cellular biomarker studies are also expected to change in the future towards a complexed individualised profiling of human tumours with integrative analysis using different technologies, genome-wide scanning and expression profiling.