Analytical Validation and Performance Characteristics of Molecular Serum Biomarkers, miR-371a-3p and miR-372-3p, for Male Germ Cell Tumors, in a Clinical Laboratory Setting

Potential next generation markers of testicular germ cell tumors: miRNA-371a-3p

BACKGROUND

Testicular germ cell tumors (TGCTs) account for approximately 98% of all testicular cancers, predominantly affecting young to middle-aged men. Early diagnosis and treatment result in a cure rate of over 95%. However, conventional serum tumor markers (STMs) such as alpha-fetoprotein (AFP), β-human chorionic gonadotropin (β-hCG), and lactate dehydrogenase (LDH), which are recommended by NCCN and EAU guidelines, have limited sensitivity, often below 60%, which diminishes their clinical utility. Recently, miRNA-371a-3p, an embryonic stem cell-associated microRNA, has been identified as being specifically expressed in TGCTs. This microRNA can be reliably detected in peripheral blood and fulfills all seven Lange-Winfield criterias for tumor markers. Notably, miRNA-371a-3p has demonstrated superior diagnostic, therapeutic, and follow-up capabilities compared to conventional STMs in TGCTs. Its potential to replace conventional STMs in clinical practice is already recognized in several clinical guidelines.

METHODS

A PubMed search using subject headings and free-text terms related to MicroRNA-371a-3p in TGCT management was conducted. Relevant references were also tracked, and key studies were reviewed based on predefined exclusion criteria.

RESULTS

Out of 368 identified studies, 67 met inclusion criteria. These studies focused on MicroRNA-371a-3p's discovery, detection methods, diagnostic utility in TGCTs, and cost-effectiveness. First identified over a decade ago, microRNA-371a-3p is now established as a highly specific blood-based marker for TGCTs, valuable for diagnosis, monitoring, and follow-up, and more cost-effective than conventional STMs.

CONCLUSIONS

MicroRNA-371a-3p is a promising, highly sensitive marker for TGCTs, offering better performance and cost efficiency than conventional STMs, likely to become the next-generation diagnostic tool for TGCTs.

Review of microRNA detection workflows from liquid biopsy for disease diagnostics

MicroRNAs have emerged as effective biomarkers in disease diagnostics, particularly cancer, due to their role as regulatory sequences. More recently, microRNAs have been detected in liquid biopsies, which hold immense potential for early disease diagnostics. This review comprehensively analyses distinct liquid biopsy microRNA detection methods validated with clinical samples. Each step in the microRNA detection workflow, including sample collection, RNA isolation, processing, and detection of target microRNAs, has been thoroughly assessed. The review discusses the advantages and limitations of established and novel techniques in microRNA detection workflows, discussing their diagnostic capabilities and potential for future implementation at scale.

Expression of serum miR-135a in patients with allergic rhinitis and its relationship with Treg/Th17 balance

The dysregulation of microRNA (miRNA) expression contributes to the development of allergic rhinitis (AR). This study investigates serum miR-135a levels and their association with regulatory T cell (Treg) and T helper cell 17 (Th17) balance in AR patients. A total of 93 AR patients and 76 healthy controls were retrospectively recruited. Levels of serum miR-135a, peripheral blood Th17 and Treg cells, and Treg/Th17-related cytokines were measured. We assessed the diagnostic value of serum miR-135a for AR and its relationship with Treg/Th17 balance. AR patients showed significantly elevated immunoglobulin E (IgE), peripheral blood Th17 cells, and IL-17 and IL-6 levels, alongside reduced serum miR-135a, Treg cells, IL-10, TGF-β1, and Treg/Th17 ratios. A serum miR-135a of ≤0.536 demonstrated diagnostic potential for AR. Patients with higher serum miR-135a levels displayed increased Treg cell level and Treg/Th17 ratios, reduced Th17 cell, and lower total nasal symptom score (TNSS). Serum miR-135a levels in AR patients negatively correlated with TNSS, IL-17, IL-6, and Th17 cell percentages, and positively correlated with IL-10, TGF-β1, Treg cell percentages, and Treg/Th17 ratios. Collectively, decreased serum miR-135a levels in AR patients are associated with Treg/Th17 balance, supporting miR-135a as a potential biomarker for AR diagnosis.

Non-Invasive miRNA Profiling for Differential Diagnosis and Prognostic Stratification of Testicular Germ Cell Tumors

BACKGROUND/OBJECTIVES

Testicular germ cell tumors (TGCT) are common in young adult men and have high cure rates. Conventional serum tumor markers and imaging are not able to differentiate between histologic subtypes of the disease, which portend different prognoses and require distinct therapeutic strategies. Micro-RNAs (miRNAs) are small non-coding transcripts involved in the post-transcriptional regulation of gene expression, which have emerged as promising biomarkers in a variety of tumors. This study aimed to assess the potential of differentially expressed miRNAs in differential diagnosis and prognostication among TGCT patients with various histologic subtypes.

METHODS

Transcriptomic analysis of 134 patients from The Cancer Genome Atlas (TCGA)-TGCT database was conducted. miRNA differential expression analysis among seminomatous, embryonal carcinoma, mixed GCT, and teratoma was performed, followed by ROC curve analysis of the most significantly up- and downregulated miRNAs, respectively. Statistical associations of miRNA expression with AJCC stage were also investigated along with miRNA target network analysis and evaluation of miRNA detection in patients' fluids.

RESULTS

Upregulation of seven miRNAs (hsa-mir-135a-1, hsa-mir-135a-2, hsa-mir-200a, hsa-mir-200b, hsa-mir-203b, hsa-mir-375, hsa-mir-582) and downregulation of seven additional miRNAs (hsa-mir-105-1, hsa-mir-105-2, hsa-mir-4433a, hsa-mir-548x, hsa-mir-5708, hsa-mir-6715a, hsa-mir-767) were identified. miRNAs displayed a high sensitivity/specificity of 0.94/1.0 (AUC = 0.98) for the upregulated and 0.97/0.94 (AUC = 0.96) for the downregulated signature. Deregulated expression of these miRNAs was significantly associated with AJCC stage and distant organ metastasis (p < 0.001), overall supporting their prognostic strength. Both signatures were detectable in body fluids, particularly urine. miRNA target network analysis supported the functional role of these miRNAs in the regulation of cancer-related processes such as cell proliferation via deregulation of pivotal oncogenes.

CONCLUSIONS

These findings support the clinical value of two novel miRNA signatures in differential diagnosis and prognostic stratification of various histologic subtypes of TGCT, with potential treatment implications.

Perioperative Serum MicroRNA 371a-3p and 372-3p Levels in Patients with Clinically Localized Testicular Masses

Background

MicroRNAs (miRNAs) show promise as blood-based tumor markers for germ cell tumors (GCTs), with miRNA-371-3p being the most studied. The marginal benefit of including other candidate miRNAs to aid with the management of testicular GCTs remains unclear.

Objective

To assess the performance of our combined miRNA assay (371a-3p and 372-3p) in patients with clinically localized testicular masses.

Design setting and participants

This was a retrospective review of patients prospectively enrolled in an ongoing protocol collecting serum miR-371a-3p and miR-372-3p levels (together, Memorial Sloan Kettering Cancer Center [MSK] miRNA assay [MMA]) in patients with a suspected or diagnosed testicular GCT.

Outcome measurements and statistical analysis

The coprimary outcomes of interest were sensitivity and specificity of miR-371a-3p and 372-3p, individually and together, to detect nonteratomatous GCTs in the orchiectomy specimen. Secondary outcomes included additional assay diagnostic parameters, the relationship of patient and disease factors with variations in miRNA levels, and temporal patterns of miRNA normalization after orchiectomy.

Results and limitations

Sixty-two patients were included, 52 had a viable GCT at orchiectomy, and ten had no cancer or a non-GCT. Forty-six patients with a GCT had positive preorchiectomy MMA (sensitivity 88.5% [95% confidence interval {CI}: 79.8, 97.2]), and one patient had positive preorchiectomy MMA but no GCT (specificity 90.0% [95% CI: 71.4, 100]). The diagnostic performance of miR-371a-3-p and miR-372-3p was similar. The time for miRNA to decrease to undetectable levels varied, with some patients having positive levels up to 3 wk after orchiectomy.

Conclusions

The biomarkers miR-371a-3p and miR-372-3p demonstrated high sensitivity and specificity for localized testicular GCTs, but causes of variation in relative miRNA levels and time to normalization for individual patients remain unclear.

Patient summary

We studied the ability of the blood-based biomarkers miR-371a-3p and miR-372-3p to detect testicular cancer (germ cell tumors) in patients with small testicular masses. We found that together and individually these were sensitive and specific for testicular cancer.

Detection of Recurrence through microRNA-371a-3p Serum Levels in a Follow-up of Stage I Testicular Germ Cell Tumors in the DRKS-00019223 Study

PURPOSE

Surveillance of clinical stage I (CSI) testicular germ cell tumors (GCT) is hampered by low sensitivity and specificity of current biomarkers for detecting relapses. This study evaluated if serum levels of microRNA371a-3p (M371 test) can: (i) Accurately detect relapses, (ii) detect relapses earlier than conventional technology, and (iii) if elevated postoperative M371 levels may predict relapse.

EXPERIMENTAL DESIGN

In a multicentric setting, 258 patients with testicular CSI GCT were prospectively followed by surveillance for a median time of 18 months with serial measurements of serum M371 levels, in addition to standard diagnostic techniques. Diagnostic characteristics of M371 for detecting relapses were calculated using ROC curve analysis.

RESULTS

Thirty-nine patients recurred (15.1%), all with elevated M371 levels; eight without relapse had elevations, too. The test revealed the following characteristics: area under the ROC curve of 0.993, sensitivity 100%, specificity 96.3%, positive predictive value 83%, negative predictive value 100%. Earlier relapse detection with the test was found in 28%, with non-significant median time gain to diagnosis. Postoperative M371 levels did not predict future relapse.

CONCLUSIONS

The sensitivity and specificity of the M371 test for detecting relapses in CSI GCTs are much superior to those of conventional diagnostics. However, post-orchiectomy M371 levels are not predictive of relapse, and there is no significant earlier relapse detection with the test. In all, there is clear evidence for the utility of the M371 test for relapse detection suggesting it may soon be ready for implementation into routine follow-up schedules for patients with testicular GCT.

MicroRNA-371a-3p-The Novel Serum Biomarker in Testicular Germ Cell Tumors

INTRODUCTION

Testicular germ cell tumors (TGCTs) are a paradigm for the use of serum tumor markers in clinical management. However, conventional markers such as alpha-fetoprotein (AFP), beta-human chorionic gonadotropin (hCG), and lactate dehydrogenase (LDH) have quite limited sensitivities and specificities. Within the last decade, the microRNA-371a-3p (miR371) emerged as a possible new biomarker with promising features.

AREAS COVERED

This review covers the typical features as well as possible clinical applications of miR371 in TGCT patients, such as initial diagnosis, therapy monitoring, and follow-up. Additionally, technical issues are discussed.

EXPERT OPINION

With a sensitivity of around 90% and specificity >90%, miR371 clearly outperforms the classical serum tumor markers in TGCTs. The unique features of the test involve the potential of modifying recent standards of care in TGCT. In particular, miR371 is expected to aid clinical decision-making in scenarios such as discriminating small testicular TGCT masses from benign ones prior to surgery, assessing equivocal lymphadenopathies, and monitoring chemotherapy results. Likewise, it is expected to make follow-up easier by reducing the intensity of examinations and by sparing imaging procedures. Overall, the data presently available are promising, but further prospective studies are required before the test can be implemented in standard clinical care.

Testicular neoplasms: the interrelationships of serum levels of microRNA-371a-3p (M371) and classical tumor markers with histology, clinical staging, and age-a statistical analysis

PURPOSE

In testicular neoplasms, the interrelationship of elevations of the novel serum tumor marker microRNA-371a-3p (M371) and traditional markers with other clinical features is still incompletely understood. The present study evaluated marker expression rates in relation to various other clinical parameters.

METHODS

The following data were retrospectively registered from 641 consecutive patients with testicular neoplasms: histology, such as seminoma (n = 365), nonseminoma (n = 179), benign tumor (n = 79), other malignant tumor (n = 18); patients age (years); clinical stage (CS1, CS2a/b, CS2c, CS3); and preoperative elevation of beta HCG, AFP, LDH, M371 (yes/no). Descriptive statistical methods were employed with comparisons of various subgroups to disclose associations of marker expression rates with age, histology and CS, and of age with histology.

RESULTS

The histologic subgroups revealed significantly different expression rates of tumor markers. M371 performed best with expression rates of 82.69% and 93.58% in seminoma and in nonseminoma, respectively. In germ cell tumors, all markers had significantly higher expression rates in metastasized stages than in localized disease. All markers except LDH have significantly higher expression rates in younger than in older patients. Nonseminoma is most prevalent in the youngest age category, seminoma predominates in patients > 40 years, other malignancies were restricted to patients > 50 years.

CONCLUSION

The study documented significant associations of serum marker expression rates with histology, age and clinical staging, with highest rates in nonseminomas, young age and advanced clinical stages. M371 showed significantly higher expression rates than other markers suggesting its superior clinical usefulness.

Refining the serum miR-371a-3p test for viable germ cell tumor detection

Circulating miR-371a-3p has excellent performance in the detection of viable (non-teratoma) germ cell tumor (GCT) pre-orchiectomy; however, its ability to detect occult disease is understudied. To refine the serum miR-371a-3p assay in the minimal residual disease setting we compared performance of raw (Cq) and normalized (∆Cq, RQ) values from prior assays, and validated interlaboratory concordance by aliquot swapping. Revised assay performance was determined in a cohort of 32 patients suspected of occult retroperitoneal disease. Assay superiority was determined by comparing resulting receiver-operator characteristic (ROC) curves using the Delong method. Pairwise t-tests were used to test for interlaboratory concordance. Performance was comparable when thresholding based on raw Cq vs. normalized values. Interlaboratory concordance of miR-371a-3p was high, but reference genes miR-30b-5p and cel-miR-39-3p were discordant. Introduction of an indeterminate range of Cq 28-35 with a repeat run for any indeterminate improved assay accuracy from 0.84 to 0.92 in a group of patients suspected of occult GCT. We recommend that serum miR-371a-3p test protocols are updated to (a) utilize threshold-based approaches using raw Cq values, (b) continue to include an endogenous (e.g., miR-30b-5p) and exogenous non-human spike-in (e.g., cel-miR-39-3p) microRNA for quality control, and (c) to re-run any sample with an indeterminate result.

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

Circulating miR-371a-3p has excellent performance in the detection of viable (non-teratoma) GCT pre-orchiectomy; however, its ability to detect occult disease is understudied. To refine the serum miR-371a-3p assay in the minimal residual disease setting we compared performance of raw (Cq) and normalized (∆Cq, RQ) values from prior assays, and validated interlaboratory concordance by aliquot swapping. Revised assay performance was determined in a cohort of 32 patients suspected of occult retroperitoneal disease. Assay superiority was determined by comparing resulting receiver-operator characteristic (ROC) curves using the Delong method. Pairwise t-tests were used to test for interlaboratory concordance. Performance was comparable when thresholding based on raw Cq vs. normalized values. Interlaboratory concordance of miR-371a-3p was high, but reference genes miR-30b-5p and cel-miR-39-3p were discordant. Introduction of an indeterminate range of Cq 28-35 with a repeat run for any indeterminate improved assay accuracy from 0.84 to 0.92 in a group of patients suspected of occult GCT. We recommend that serum miR-371a-3p test protocols are updated to a) utilize threshold-based approaches using raw Cq values, b) continue to include an endogenous (e.g., miR-30b-5p) and exogenous non-human spike-in (e.g., cel-miR-39-3p) microRNA for quality control, and c) to re-run any sample with an indeterminate result.

The values of systemic immune-inflammation index and neutrophil-lymphocyte ratio in predicting testicular germ cell tumors: A retrospective clinical study

Purpose

To determine whether complete blood count (CBC) based inflammatory parameters can be used as markers predicting testicular germ cell tumors (TGCT).

Material and methods

Between 2013 to 2018 the data of 58 patients with testicular TGCT undergoing radical orchiectomy and 54 malignancy-free healthy men were retrospectively analyzed as tumor group and control group. Patient baseline characteristics including age, pathological stage and pre-surgery CBC based inflammatory parameters including neutrophil/lymphocyte ratio (NLR), platelet/lymphocyte ratio (PLR), lymphocyte/monocyte ratio (LMR), systemic immune-inflammation index (SII), lymphocyte ratio (LR), neutrophil ratio (NR), mean platelet volume (MPV) and red cell distribution width (RDW) were analyzed and compared between tumor group and control group. Receiver operating characteristic (ROC) curve were used analyzing data with significantly difference to assess the discriminative ability of the markers for TGCT, area under the curve (AUC), cut-off value, sensitivity and specificity were calculated. The binary logistic regression model was used to evaluate the association between significant inflammatory markers and risk of TGCT.

Results

Mean age of the tumor and control group was 41.1 ± 15.36 and 44.89 ± 9.2 years, respectively. Mean NLR, SII and RDW were significantly higher in tumor group compared with control group with P=0.005, P=0.001 and P=0.016, respectively; there were no significantly differences of age, PLR, LMR, LR, NR, MPV and RDW between groups. The ROC curve for NLR, SII and RDW was plotted in the diagnosis of TGCT and tumor progression, the cut-off value for NLR, SII and RDW were found as 3.38 (AUC: 0.704, sensitivity=51.4%, specificity=88.6%, P=0.003), 881.24 (AUC: 0.725, sensitivity=45.7%, specificity=91.4%, P=0.001) and 0.14 (AUC: 0.63, sensitivity=28.6%, specificity=97%, P=0.063), respectively. Patients were divided into two groups according to the threshold values, respectively. By using the multivariable logistic regression models, NLR ≥ 3.38 (OR, 5.86; 95% CI, 1.67-20.65, P=0.006) and SII ≥ 881.24 (OR, 4.89; 95% CI, 1.48-15.32, P=0.009) were independent risk factors predicting TGCT. Significantly statistical difference of pathological stage was also found between groups with respect to NLR cut-off values (P=0.034) and SII cut-off values (P=0.049). Combined the data together, NLR and SII both exhibited good differential diagnosis potential which could be used as markers predicting the TGCT.

Conclusion

As the CBC based inflammation parameters, both NLR and SII could be used as effective tumor markers predicting the TGCT, and higher NLR and SII are associated with higher pathological stage. In addition, SII is a more powerful tool among these two inflammatory markers.