Real-World Application of Pre-Orchiectomy miR-371a-3p Test in Testicular Germ Cell Tumor Management.

PURPOSE

Current serum tumor markers for testicular germ cell tumor are limited by low sensitivity. Growing evidence supports the use of circulating miR-371a-3p as a superior marker for malignant (viable) germ cell tumor management. We evaluated the real-world application of serum miR-371a-3p levels in detecting viable germ cell tumor among patients undergoing partial or radical orchiectomy.

MATERIALS AND METHODS

Serum samples were collected from 69 consecutive patients before orchiectomy. Performance characteristics of serum miR-371a-3p were compared with conventional serum tumor markers (⍺-fetoproteinβ-human chorionic gonadotropinlactate dehydrogenase) between patients with viable germ cell tumor and those without viable germ cell tumor on orchiectomy pathology. Relative miR-371a-3p levels were correlated with clinical course. The Kruskal-Wallis test and linear and ordinal regression models were used for analysis.

RESULTS

For detecting viable germ cell tumor, combined conventional serum tumor markers had a specificity of 100%, sensitivity of 58% and AUC of 0.79. The miR-371a-3p test showed a specificity of 100%, sensitivity of 93% and AUC of 0.978. Median relative expression of miR-371a-3p in viable germ cell tumor cases was more than 6,800-fold higher than in those lacking viable germ cell tumor. miR-371a-3p levels correlated with composite stage (p=0.006) and, among composite stage I cases, independently associated with embryonal carcinoma percentage (p=0.0012) and tumor diameter (p <0.0001). Six patients underwent orchiectomy after chemotherapy and were correctly predicted to have presence or absence of viable germ cell tumor by the miR-371a-3p test.

CONCLUSIONS

If validated, the miR-371a-3p test can be used in conjunction with conventional serum tumor markers to aid clinical decision making. A positive miR-371a-3p test in patients after preoperative chemotherapy or with solitary testes could potentially guide subsequent orchiectomy or observation.