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Prostate-specific antigen (PSA) is the recommended tumor marker for individual screening and follow-up of prostate cancer. This paper reviews main structural and physiological data about prostate specific antigen isoforms: total PSA, free PSA, [-2]proPSA (also named p2PSA). It describes the pre-, per- and post-analytical conditions for these different parameters. It presents the interpretation of results and derived calculated indices (free/total PSA ratio, Prostate Health Index or PHI) for the management of prostate cancer (initial diagnosis and follow-up).

The total PSA testing has been frequently criticized for its effectiveness in the early detection of prostate cancer. These widely resumed in and out of the medical community have led to a decrease in prescriptions. Recommendations against the use of PSA for screening have been issued in France and in most countries. In the US, the significant decline in total PSA use since 2004 has led to an increase in advanced cancer diagnosis, which has led the authorities to back down. The US preventive services task force (USPSTF) now recommends that men between the ages of 55 and 69 make an individual decision about prostate cancer screening with their clinician. The purpose of this work is to summarize the good practices for the use of the total and free PSA with the views of these last data.

To systematically review the evidence for the use of PSA and other biomarkers in the early detection of prostate cancer, we searched PubMed for clinical trials and studies assessing PSA and other biomarkers in the early detection of prostate cancer, published between 2000 and May 2013 that included >200 subjects. The level of evidence (LOE) for clinical utility was evaluated using the tumor marker utility grading system. A total of 84 publications, corresponding to 70 trials and studies were selected for inclusion in this review. We attributed a level of evidence (LoE) of IA to PSA for early PCa detection, but we do not recommend its use in mass screening. Emerging biomarkers were assessed in prospective case-control and cohort studies: PCA3 (n=3); kallikreins (n=3); [-2]proPSA (n=5); fusion oncogenes (n=2). These studies used biopsy results for prostate cancer to determine specificity and sensitivity, but they did not assess the effect on PCa mortality. The LoE attributed was III-C. PSA can be used for early prostate cancer detection but mass screening is not recommended. Studies on other biomarkers suggest that they could be used, individually or in combination, to improve the selection of patients with elevated PSA levels for biopsy, but RCTs assessing their impact on prostate cancer management and mortality are needed. A better use of available tests is possible for men at risk in order to maximize the risk-benefit ratio.

Application fields of RT-PCR (reverse transcription-polymerase chain reaction) in clinical diagnosis comprises the assessment of viral load for RNA viruses and the analysis of gene transcription products. RT-PCR is also helpful when large genes have to be sequenced. Developments of quantitative approaches using real-time PCR recently led to a major widening of RT-PCR applications in clinical diagnosis. However, RT reaction is delicate due to its lack of reproducibility and to RNA lability and frequent contamination by DNA. In some cases additional difficulties come from the need to obtain a specific amplification in the presence of homologous sequences which might be present in higher amounts than the sequence of interest. These caveats have to be taken into account, when designing the RT protocol, and when choosing PCR primers and internal and/or external references. This review is aimed at helping the experimental setup of a RT-PCR based assay according to the objectives., (Copyright John Libbey Eurotext 2003)

Recent advances in human, bacterial and viral genome projects and the development of quantitative real-time reverse transcription-polymerase chain reaction methods offer the possibility of analysing a large number of gene transcripts. These molecular developments represent an important advancein the field of genetics, cancer, virology, bacteriology and hematology. A limiting step remains the isolation of high quality mRNA purified from biological samples. This review describes the different methods used to isolate mRNA from biological samples and to verify RNA integrity and gives precise details about RNA storage conditions.