Evaluation of a miRNA-371a-3p Assay for Predicting Final Histopathology in Patients Undergoing Primary Nerve-sparing Retroperitoneal Lymphadenectomy for Stage IIA/B Seminoma or Nonseminoma

Current Role of MicroRNAs in the Diagnosis and Clinical Management of Germ Cell Tumors

Germ cell tumors (GCTs) are a rare and heterogeneous group of neoplasms arising from primitive germ cells. MicroRNAs are small noncoding RNAs that have emerged as potential cancer biomarkers in the last decade. In particular, miR-371a-3p has shown good diagnostic performance for germ cell neoplasia in situ-derived testicular GCTs in several well-established cohorts and is expected to enter the clinical arena in the near future. GCTs universally exhibit high expression of miR-371-373 and miR-302/367 clusters and low expression of let-7 family miRNAs. Further studies are needed to assess the potential role of these miRNAs as biomarkers of ovarian and extragonadal GCTs.

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.

Biomarker microRNA-371a-3p - expression in malignancies other than germ-cell tumours

PURPOSE

microRNA-371a-3p (M371) is considered a highly sensitive and specific serum biomarker of testicular germ cell tumours (GCTs). However, little is known about the expression of M371 in nontesticular malignancies (NTMs), so far. As knowledge about the expression of the marker in other malignancies is a prerequisite for the clinical application of the test we aimed to explore the M371 expression in other cancers.

METHODS

M371 serum levels were measured in 137 patients with NTM of 12 different neoplastic entities using the IVDR-certified M371-Test for quantitative real-time PCR. Median M371 serum levels and percentages of M371 level elevations were calculated for the entire NTM group and for entity-specific subgroups. The results were compared with GCT patients (n = 20) and with tumour-free male controls (n = 20) using descriptive statistical methods.

RESULTS

Eight patients with NTMs had M371 serum level elevations, corresponding to a false-positive rate (FPR) of 5.84% (95% confidence intervals (CIs) 2.55-11.18%). Expression rates in GCTs and controls were 100% and zero, respectively. Thus, the specificity of the M371-Test for GCT is 94.90% (95% CI 90.21-97.77%) when all NTMs and tumour-free controls are considered. Remarkably, three out of 5 patients with multiple myeloma had elevated M371 levels.

CONCLUSION

The false-positive rate of the M371-Test in other malignancies than GCT is very low, and almost identical with that in healthy males, corresponding to a high specificity of 94.9% for detection of GCT. The surprising finding of M371 elevations in patients with multiple myeloma needs further investigation.

Long-term Clinical Outcomes of Patients With Negative Pathology (pN0) at Primary Retroperitoneal Lymph Node Dissection

BACKGROUND

Patients who undergo primary retroperitoneal lymph node dissection (pRPLND) for early-stage testicular cancer and have no cancer (pN0) found in the retroperitoneum are believed to have an excellent prognosis. However, some experience relapse, potentially due to limitations of current staging methods. We aim to describe long-term outcomes and relapse patterns among a contemporary cohort of patients found to be pN0 at pRPLND to identify opportunities for improved diagnostic approaches and optimal patient selection.

METHODS

We reviewed our prospectively maintained database for patients who underwent pRPLND for nonseminomatous germ cell tumors at our tertiary cancer center during the period from January 1, 2000, through September 30, 2023 (n = 628). We excluded 282 patients with node-positive pathology for a final analytic cohort of 346 patients. Our primary outcome was recurrence-free survival (RFS). Secondary outcomes included timing and location of recurrence.

RESULTS

Of 346 included patients with pN0 pathology, 23 experienced relapse with a 2-year RFS rate of 93% (95% confidence interval: 90, 96). Most recurrences (70%) occurred in the lungs and within 6 months of pRPLND. Serum tumor markers were positive in 43% of patients at the time of relapse. All patients who relapsed were treated with salvage chemotherapy; 6 patients required additional surgical procedures. There was no testis cancer-related deaths.

CONCLUSIONS

Two-year RFS for patients with pN0 pRPLND pathology is excellent. All recurrences were outside of the retroperitoneum, suggesting subclinical distant metastases at time of surgery and the benefits of a bilateral template dissection. Improved diagnostics may help better identify patients with disease within or outside of the retroperitoneum prior to pRPLND, helping guide treatment decisions.

[Primary retroperitoneal lymph node dissection in testicular germ cell cancer in clinical stage IIA/B-renaissance of an established treatment?]

BACKGROUND

The guideline-recommended treatment of choice for clinical stage IIA/B testicular germ cell tumors is chemotherapy with three cycles of PEB/four cycles of PE or, alternatively, radiation for seminomas. Despite their high curative efficacy, both options are associated with significant long-term toxicities. We evaluated the functional and oncological outcomes of primary retroperitoneal lymph node dissection (RPLND) as a therapeutic alternative.

PATIENTS AND METHODS

Between 2018 and 2022, 76 patients (n = 34 seminomas, n = 42 nonseminomas) underwent primary RPLND for marker-negative clinical stage IIA/B testicular germ cell cancer. All patients underwent nerve-sparing RPLND with a unilateral or bilateral template dissection and had a follow-up ≥ 3 months. None of the patients received adjuvant chemotherapy. In 24 patients, the serum concentration of miR371a-3p was evaluated preoperatively. Follow-up was performed according to EAU guidelines.

RESULTS

Median age and median follow-up were 30.1 (17-62) years and 29.3 (3-72) months, respectively. Mean operation time, blood loss, and duration of hospitalization were 131 (105-195) min, < 150 ml, and 4.5 (3-9) days, respectively. A Clavien-Dindo IIIa complication was experienced by 8 (10.9%) patients. Antegrade ejaculation was preserved in 90.8%. A mean number of 19 (7-68) lymph nodes were dissected. The mean number of positive lymph nodes was 1.1 (1-5), and the mean diameter of positive lymph nodes was 2.4 (0.8-4.6) cm. Eleven (14.5%) patients had stage pN0 (3/34 seminomas, 8/42 nonseminomas). In 24/27 patients (88.9%) miR371 was positive, and it was negative in 4/4 with pN0 and 3/3 (100%) with teratoma. An outfield relapse was experienced by 7 patients (9.2%), who then received salvage chemotherapy.

CONCLUSION

Primary RPLND for marker-negative clinical stage IIA/B germ cell tumors results in high cure rates without adjuvant chemotherapy and is associated with a low rate of complications if performed in experienced hands. Therefore, primary RPLND should be included in the management of these patients.

[Clinical stage IIA/B seminoma - to do or not to do: the role of retroperitoneal lymphadenectomy]

About 10% of patients with seminomatous testicuar germ cell tumors are diagnosed with clinical stage II/B. The current guideline recommended treatment options include systemic chemotherapy with 3 cycles PEB or radiation therapy with 30 Gy for CS IIA and 36 Gy for CS IIB. Despite a high cure rate of 90-94% and 82-90% for CS IIA and CS IIB, respectively, both options are associated with a high rate of treatment-associated long-term toxicities. A significantly increased risk for the development of secondary malignancies, cardiovascular and metabolic disease as well as an increased for treatment-associated mortality has been proven in various studies. Primary nerve sparing retroperitoneal lymph node dissection (nsRPLND) has been evaluated in 5 prospective and retrospective clinical studies and it has emerged as a valid treatment alternative. The relapse-rate after a median follow-up of 25-33 months is in the range of 11-30%, so that 70-90% of patients are cured without being subjected to chemotherapy and potential long-term toxicities. All relapsing patients have been cured with secondary salvage chemotherapy. The frequency of significant surgery-associated complications is low with 3-13%. Therapeutic success depends on the surgical experience of the various surgeons and the chosen template, so that this type of surgical interventions should only be performed in centres of excellence with dedicated surgeons. Preoperative evaluation of the new biomarker miR371 has been shown to predict the presence of metastatic disease with an accuracy of around 100% so that this marker might be used in daily routine prior to active treatment in CS IIA/B seminomas.

Retroperitoneal Lymph Node Dissection in Patients with Stage II Seminomatous Germ Cell Tumour

Treatment de-escalation strategies in patients with seminoma with retroperitoneal metastases are being investigated in ongoing clinical trials. Primary retroperitoneal lymph node dissection conducted by expert surgeons may avoid any cytotoxic treatment and related long-term side effects in ≥70% of patients with clinical stage IIA/B seminoma.