To evaluate the diagnostic performance of the Conformité Européenne [CE]-certified microRNA-371a-3p (miR371a) assay in patients undergoing inguinal exploration for small testicular masses of unknown histology in a real-world setting.
Between March 2023 and March 2024, 60 patients underwent inguinal exploration for testicular masses of unknown histology. For miR371a analysis, peripheral venous blood was obtained and sent to the Department of Molecular Pathology within 30 min. The extracted miRNA was reverse-transcribed into complementary DNA (cDNA) with miRNA-specific stem-loop primers, followed by a pre-amplification step. Using quantitative polymerase chain reaction, the miR371a is quantified. The median crossing points of the triplicates was calculated and converted into a relative quantification value.
The evaluation of the miR371a assay showed a true-positive result in 25 patients with seminoma. Eight patients with seminoma had false-negative results. In the non-seminoma group, six of seven (86%) patients had a true positive result. The false-negative finding derived from a non-seminomatous germ cell tumour (NSGCT) with predominant teratoma. The test was true-negative in 16 patients with sarcoma, diffuse large B-cell lymphoma, Leydig cell tumour, and Sertoli cell tumour. False-positive results were obtained in four patients. The results yield a sensitivity of 77.5%, a specificity of 80% and a positive predictive value of 88.6% and negative predictive value of 64% for the miR371a test in our cohort. In the seminoma cohort, the sensitivity of the serum tumour markers was 12%. In the NSGCT cohort, the sensitivity was 66%.
In the absence of suitable markers, the miR371a assay shows promising results in the preoperative diagnosis of suspected localised small testicular tumour. Standardisation of pre-analytical handling and prospective multicentre validation are essential to define its optimal role in preoperative decision-making.
BJU international. 2026 Mar 13 [Epub ahead of print]
Felix Seelemeyer, David Pfister, Ruben Gößmann, Olivia Steenbock, Roberto Pappesch, Sabine Merkelbach-Bruse, Axel Heidenreich
Uniklinik Cologne, Department of Urology, Cologne, Germany., Uniklinik Cologne, Department of Pathology, Cologne, Germany.