IBBL (Integrated Biobank of Luxembourg) actively supports personalised medicine initiatives in Luxembourg. The biobank collaborated with national partners to assess the performance of the PCA3 assay for the diagnosis of prostate cancer and its implementation in the national healthcare system.
Prostate cancer (PCa) is the second most commonly occurring cancer in men and the fourth overall. About 1.3 million new cases were diagnosed globally in 2018, with Luxembourg reporting the 19th highest rate of occurrence. The early diagnosis of PCa currently relies on three main diagnostic tools, namely total serum prostate specific antigen (PSA), digital rectal examination (DRE) and biopsies. However, evidence suggests that PSA is not particularly reliable for PCa screening, since it is specific for prostate tissue inflammation but not necessarily for PCa, and is a poor indicator of tumour aggressiveness. More recently, Prostate Cancer Gene 3 (PCA3), a prostate-specific urine biomarker, has been shown to contribute to the identification of men with a high likelihood of developing PCa, with high levels of PCA3 being associated with the disease. However, given the elevated cost of the PCA3 test, there is the need for a thorough assessment of the ability of this assay to diagnose PCa when compared to cheaper PSA tests.
In this context, IBBL collaborated with Luxembourgish urologists and oncologists  , with national hospitals and clinical biomedical laboratories to evaluate the diagnostic performance of PSA versus urine PCA3 and provide the sensitivity and specificity of both assays. The highest diagnostic accuracy of a test is a value corresponding to the best trade-off between sensitivity and specificity. In order to determine such value, Dr. Monica Marchese, Biomarker Validation Scientist at IBBL, plotted receiver operating characteristic (ROC) curves for each test and identified the area under the curve (AUC), which defines the diagnostic performance of a test. She found the PCA3 test to have a better diagnostic accuracy than PSA in distinguishing patients with PCa from patients with other non-prostate cancer cases or from healthy individuals.
“Our results bear important repercussions for PCa patients. Through the PCA3 test, clinicians will be able to more accurately differentiate men requiring surgical or chemical treatment for aggressive cancer from those with non-life threatening conditions in a non-invasive way, thus sparing the latter from unnecessary biopsies, surgeries and related complications. This assay therefore guides clinicians in their choice of the most appropriate course of action for a specific individual, while giving patients a better sense of security”, explains Dr. Marchese. “Our work is in line with clinical findings in the US and in other European countries, which show the greater diagnostic performance of PCA3 compared to PSA”.
The study was carried out by a consortium of national partners including Centre Hospitalier de Luxembourg, Hôpitaux Robert Schuman, Centre Hospitalier du Nord and Centre Hospitalier Emile Mayrisch. The final report can be accessed here.
Additional specific guidelines on the diagnostic evaluation of prostate cancer from the European Association of Urology can be found here.
 Drs. Honoré Alzin, Guy Berchem, Leon Bropsom, Fernand Grunig, Alex Kohl, Antoine Lurquin, Robert Muller, Romain Poos, Christian Roller, Lamy Stanislas and Jean-Francois Wilmart.
 Sensitivity: true positive rate: ability of the test to correctly identify those with the disease.
 Specificity: true negative rate: ability of the test to correctly identify those without the disease.
 A plot of the average value of the sensitivity for a diagnostic test over all possible values of specificity, or vice versa.