Methodology of a systematic review

CONTEXT

The objective of evidence-based medicine is to employ the best scientific information available to apply to clinical practice. Understanding and interpreting the scientific evidence involves understanding the available levels of evidence, where systematic reviews and meta-analyses of clinical trials are at the top of the levels-of-evidence pyramid.

ACQUISITION OF EVIDENCE

The review process should be well developed and planned to reduce biases and eliminate irrelevant and low-quality studies. The steps for implementing a systematic review include (i) correctly formulating the clinical question to answer (PICO), (ii) developing a protocol (inclusion and exclusion criteria), (iii) performing a detailed and broad literature search and (iv) screening the abstracts of the studies identified in the search and subsequently of the selected complete texts (PRISMA).

SYNTHESIS OF THE EVIDENCE

Once the studies have been selected, we need to (v) extract the necessary data into a form designed in the protocol to summarise the included studies, (vi) assess the biases of each study, identifying the quality of the available evidence, and (vii) develop tables and text that synthesise the evidence.

CONCLUSIONS

A systematic review involves a critical and reproducible summary of the results of the available publications on a particular topic or clinical question. To improve scientific writing, the methodology is shown in a structured manner to implement a systematic review.

PCA3 as a second-line biomarker in a prospective controlled randomized opportunistic prostate cancer screening programme

OBJECTIVES

PCA3 performance as a single second line biomarker is compared to the European Randomised Study of Screening for Prostate Cancer risk calculator model 3 (ERSPC RC-3) in an opportunistic screening in prostate cancer (PCa).

MATERIAL AND METHODS

5,199 men, aged 40-75y, underwent prostate-specific antigen (PSA) screening and digital rectal examination (DRE). Men with a normal DRE and PSA ≥3ng/ml had a PCA3 test done. All men with PCA3 ≥35 underwent an initial biopsy (IBx) -12 cores-. Men with PCA3 <35 were randomized 1:1 to either IBx or observation. We compared them to those obtained with ERSPC RC-3.

RESULTS

PCA3 test was performed on 838 men (16.1%). In PCA3(+) and PCA3(-) groups, global PCa detection rates were 40.9% and 14.7% with a median follow-up (FU) of 21.7 months (P<.001). In the PCA3(+) arm (n=301, 35.9%), PCa was identified in 115 men at IBx (38.2%). In the randomized arm, 256 underwent IBx and PCa was found in 46 (18.0%) (P<.001). The biopsy-sparing potential would have been 64.1% as opposed to 76.6% if we had used ERSPC RC-3. However, the estimated false negative cases for HGPCa would have been reduced by 37.1% (89 to 56 patients). Moreover, if we had applied PCA3-35 to avoid IBx, 14.7% PCa and 9.1% of clinical significant PCa patients would not have been diagnosed during this FU.

CONCLUSIONS

When PCA3-35 is used as a second-line biomarker when PSA ≥3ng/ml and DRE is normal, IBx could be avoided in 12.5% less than if ERSPC RC-3 is used and would reduce the false negative cases by 36.2%. At a FU of 21.7 months, this dual protocol would miss 9.1% of clinically significant PCa, so strict FU is mandatory with established biopsy criteria based on PSA and DRE in cases with PCA3 <35.

[Focal Laser Ablation and Photodynamic Vascular Therapy with soluble TOOKAD® in the treatment of low risk prostate cancer]

The increase of the diagnosis of low risk prostate cancer translates into a new clinical entity, for which active surveillance may not be always enough and conventional therapies are clearly overtreatment. Faced with the necessity of giving a therapeutic answer to these patients, and facilitated by the technological advances in the imaging field and new energy sources, the interest is centered in the clinical development of focal therapies as an alternative with minimal morbidity and oncologically safe. As a part of the review carried out in this monographic issue, this article focus on the features relative to the preclinical and clinical development of laser ablative therapy and the innovative photodynamic vascular therapy with soluble TOOKAD®. With this aim we performed an exhaustive bibliographic search, updated to February 2016, in the greater databases, including original articles and reviews in reference to the object of this review, without restrictions for year of publication. This article reviews the preclinical and clinical development of these innovative ablative techniques in the field of focal therapy for low risk prostate cancer.