Results from a recent study demonstrate the high sensitivity and specificity of the M371 test as a novel serum biomarker of germ cell tumors (GCTs) in seminoma and nonseminoma (J Clin Oncol. 2019 Mar 15. Epub ahead of print).

“Previous studies suggested that serum levels of microRNA (miR)-371a-3p (so-called M371 test) have a much higher sensitivity and specificity than the classic markers of testicular…GCTs…and are applicable toward both seminoma and nonseminoma,” explained Klaus-Peter Dieckmann, MD, Professor, Asklepios Klinik Altona, Department of Urology, Hodentumorzentrum, Hamburg, Germany, and colleagues, who sought to confirm the efficacy of this test as a novel biomarker for GCT.

In the prospective, multi-center study, Dr Dieckmann and colleagues used quantitative polymerase chain reaction to examine the serum levels of miRNA-371a-3p (miR levels) in 616 patients with testicular GCTs and 258 controls. Of the patients with GCTs, 359 had seminoma and 257 had nonseminoma; in addition, 371 had clinical stage I disease, 201 had systemic disease, and 46 had relapses.

A total of 424 patients had paired measurements conducted before and after orchiectomy; serial measurements were performed in 118 patients with systemic disease during the treatment period. In addition, the investigators compared miR levels with β-human chorionic gonadotropin, α-fetoprotein, and lactate dehydrogenase levels.

“For the primary diagnosis of GCT, the M371 test showed a sensitivity of 90.1%, a specificity of 94.0%, an area under the curve of 0.966 upon receiver operating characteristic analysis, and a positive predictive value of 97.2%,” Dr Dieckmann and colleagues reported.

Furthermore, α-Fetoprotein, β-human chorionic gonadotropin, and lactate dehydrogenase had sensitivities <50% in seminoma and slightly higher sensitivities in nonseminomas.

The investigators also observed a significant link between miR levels and clinical stage, primary tumor size, and response to therapy. Elevated miR levels in patients with disease relapse subsequently dropped and became normal upon remission.

Of note, teratoma was not shown to express miR-371a-3p.

“In conclusion, the current study strongly confirms previous data with regard to the usefulness of the M371 test as a new serum biomarker of GCT that is informative in both seminoma and nonseminoma,” Dr Dieckmann and colleagues concluded.

“Because of its high sensitivity and specificity, this test involves the potential of simplifying clinical pathways of the management of GCT, although further validation in an independent cohort is needed,” they added.—Hina Khaliq