Refining the serum miR-371a-3p test for viable germ cell tumor detection: Identification and definition of an indeterminate range.

425 Background: Existing conventional serum tumor markers (STMs) exhibit moderate performance for the detection of germ cell tumors (GCTs). Circulating miR-371a-3p has excellent in viable (non-teratoma) GCT pre-orchiectomy; however, its ability to detect occult disease is understudied. We refine assay and expand upon our previous experience this setting. Methods: compared raw (Cq) normalized (∆Cq, RQ) values from prior assays (n=93), validated interlaboratory concordance by aliquot swapping. Revised was determined a cohort 32 patients suspected retroperitoneal disease. Assay superiority comparing resulting receiver-operator characteristic (ROC) curves using Delong method. Pairwise t-tests were used test concordance. defined an indeterminate range as mean low Cq peak controls ± 2 SDs. Results: Performance comparable when thresholding based on vs. values. Calculated sensitivity specificity both greater than 0.9 all cases did not change appreciably across any metrics tested. Interlaboratory high, but reference genes miR-30b-5p cel-miR-39-3p discordant. identified 1 st time range; Introduction 28-35 with repeat run improved accuracy 0.84 0.92 group GCT. Conclusions: recommend that protocols are updated a) utilize threshold-based approaches values, b) continue include endogenous (e.g., miR-30b-5p) exogenous non-human spike-in cel-miR-39-3p) microRNA quality control, c) re-run sample result.