Human chorionic gonadotropin-positive seminoma patients: A registry compiled by the global germ cell tumor collaborative group (G3)

Pathogenesis and pathobiology of testicular germ cell tumours: a view from a developmental biological perspective with guidelines for pathological diagnostics

Testicular germ cell tumours (GCT) are divided into three different subtypes (types I-III) regarding to their developmental origin, histological differences and molecular features. Type I GCT develop from disturbed primordial germ cells and most commonly occur in children and young adolescents, which is why they are referred to as prepubertal GCT. Type II GCT develop from a non-invasive germ cell neoplasia in situ (GCNIS) and show an isochromosome 12p (i12p) or gain of 12p material as a common and characteristic molecular alteration. Type III GCT originate from distorted postpubertal germ cells (e.g. spermatogonia) in adult patients and have changes on chromosome 9 with amplification of the DMRT1 gene. Type I GCT encompass prepubertal-type teratomas and yolk-sac tumours (YST). Type II GCT include seminoma, embryonal carcinoma, choriocarcinoma, postpubertal-type teratoma and postpubertal-type YST. Types I and II GCT both show similar morphology, but are separated from each other by the detection of a GCNIS and an i12p in type II GCT. For type II GCT it is especially important to detect non-seminomatous elements, as these tumours have a worse biological behaviour and need a different treatment to seminomas. In contrast to types I and II GCT, type III tumours are equivalent to spermatocytic tumours and usually occur in elderly men, with few exceptions in young adults. The development of types I and II GCT seems to depend not upon driver mutations, but rather on changes in the epigenetic landscape. Furthermore, different pluripotency associated factors (e.g. OCT3/4, SOX2, SOX17) play a crucial role in GCT development and can be used as immunohistochemical markers allowing to distinguish the different subtypes from each other in morphologically challenging tissue specimens. Especially in metastatic sites, a morphological and immunohistochemical diagnostic algorithm is important to detect small subpopulations of each non-seminomatous GCT subtype, which are associated with a poorer prognosis and need a different treatment. Furthermore, primary extragonadal GCT of the retroperitoneum or mediastinum develop from misguided germ cells during embryonic development, and might be challenging to detect in small tissue biopsies due to their rarity at corresponding sites. This review article summarises the pathobiological and developmental aspects of the three different types of testicular GCT that can be helpful in the histopathological examination of tumour specimens by pathologists.

Molecular and histopathological characterization of seminoma patients with highly elevated human chorionic gonadotropin levels in the serum

Approximately 30% of seminoma (SEM) patients present with moderately elevated human chorionic gonadotropin (hCG) levels at first diagnosis. In case of high hCG serum levels, the presence of a non-SEM component, i.e. choriocarcinoma (CC), may be assumed. To characterize cases described as pure seminoma with high serum hCG levels, tissue samples and DNA were analyzed. Patient files from an international registry were screened for patients with SEM and extraordinarily high hCG serum levels. IHC and qRT-PCR analysis was performed for markers of SEM, embryonal carcinoma (EC) and CC/trophoblast cells. The cell lines TCam-2 (SEM), 2102EP, NCCIT, NT2/D1 (EC) and JAR, JEG3 and BeWo (CC) were included for comparison. Of 1031 SEM patients screened, 39 patients (3.7%) showed hCG serum levels > 1000 U/l. Of these, tumor material for IHC and RNA for qRT-PCR was available from n = 7 patients and n = 3 patients, respectively. Median pre-orchiectomy serum hCG level was 5356 U/l (range: 1224-40909 U/L). Histopathologically, all investigated samples were classified as SEM with syncytiotrophoblast sub-populations. SEM cells were SALL4+ / OCT3/4+ / D2-40+, while syncytiotrophoblast cells were hCG+ / GATA3+ / p63+ and SOX2-/CDX2-. qRT-PCR analysis detected trophoblast stem cell markers CDX2, EOMES and TFAP2C as well as the trophectoderm-specifier TEAD4, but not GATA3. Additionally, SOX17 and PRAME, but not SOX2, were detected, confirming the pure SEM-like gene expression signature of the analyzed samples. In conclusion, excessively increased hCG serum levels can appear in patients with pure SEM. To explain detectable hCG serum levels, it is important to diagnose the subtype of a SEM with syncytiotrophoblasts.

Serum β-hCG as a Biomarker in Pancreatic Neuroendocrine Tumors: Rethinking Single-Analyte Approach

Despite recent advances, neuroendocrine tumors (NETs) remain a challenging topic, due to their diversity and the lack of suitable biomarkers. Multianalyte assays and the shift to an omics-based approach improve on the conventional single-analyte strategy, albeit with their own drawbacks. We explored the potential of serum β-hCG as a biomarker for NETs and discussed its role in disease monitoring. We recruited 40 patients with non-functioning pancreatic NETs, all with liver metastases. Serum β-hCG concentrations were measured at 3-month intervals over 48 months. We performed a comparative and a repeated measures analysis of β-hCG depending on WHO grade (G1, G2), liver tumor burden (LTB; below 10%, 10-25%), and RECIST 1.1. (stable disease, progressive disease). Patients with progressive disease (p < 0.001), 10-25% LTB (p < 0.001) and WHO Grade 2 (p < 0.001) displayed higher β-hCG concentrations. Throughout the study, β-hCG concentrations consistently increased across the entire cohort. Delta β-hCG during the study period was greater in patients with 10-25% LTB (p < 0.001), progressive disease (p < 0.001), and G2 (p = 0.003). Serum β-hCG correlates with established indicators of malignancy and disease progression in metastatic NETs, supporting further studies as a monitoring and prognostic biomarker. Despite promising results from novel biomarkers, there is still a place for single-analyte assays in NETs.

[Fundamentals in the pathology of testicular germ cell tumours]

Testicular germ cell tumours (GCT) represent the most common malignant neoplasia in young male adults between the age of 15 and 44. Because of their different biological behaviour it is important to differentiate prepubertal GCTs from postpubertal GCTs. This distinction is made by presence or absence of a germ cell neoplasia in situ. Histopathological diagnostics can be challenging due to different tumour subtypes and their different growth patterns. Therefore, knowledge of morphologic variants and immunohistochemical markers is important.

The Subtype Identity of Testicular Cancer Cells Determines Their Immunostimulatory Activity in a Coculture Model

Testicular germ cell cancer (TGCC) is subdivided into several subtypes. While seminomatous germ cell tumors (SGCT) are characterized by an intensive infiltration of immune cells which constitute a pro-inflammatory tumor micromilieu (TME), immune cells in non-seminomatous germ cell tumors (NSGCT) are differently composed and less abundant. Previously, we have shown that the seminomatous cell line TCam-2 promotes T cell and monocyte activation in a coculture model, resulting in mutual interactions between both cell types. Here we set out to compare this feature of TCam-2 cells with the non-seminomatous cell line NTERA-2. Peripheral blood T cells or monocytes cocultured with NTERA-2 cells failed to secrete relevant amounts of pro-inflammatory cytokines, and significantly downregulated the expression of genes encoding activation markers and effector molecules. In contrast, immune cells cocultured with TCam-2 cells produced IL-2, IL-6 and TNFα, and strongly upregulated the expression of multiple pro-inflammatory genes. Furthermore, the expression of genes involved in proliferation, stemness and subtype specification remained unaltered in NTERA-2 cells during coculture with T cells or monocytes, indicating the absence of mutual interactions. Collectively, our findings uncover fundamental differences between SGCT and NSGCT in their capability to generate a pro-inflammatory TME, which possibly impacts the clinical features and prognosis of both TGCC subtypes.

Hodentumoren aus klinischer Sicht

Hintergrund

Keimzelltumoren des Hodens sind die häufigste maligne Tumorerkrankung bei Männern im Alter von 15–40 Jahren. Die Unterscheidung von Seminomen und Nichtseminomen hat prognostische Bedeutung und ist für Therapieplanung und Nachsorge essenziell. Durch interdisziplinäre, stadiengerechte Therapie haben Keimzelltumoren generell eine sehr gute Prognose. Eine Übertherapie sollte wegen möglicher Langzeitfolgen vermieden werden. Hierbei hilft die Risikobeurteilung anhand klinischer und pathologischer Faktoren.

Ziel der Arbeit

Darstellung der (histo-)pathologischen Charakteristika, die die uroonkologische Therapieplanung maßgeblich beeinflussen.

Material und Methoden

Nichtsystematischer Übersichtsartikel über die relevanten (histo-)pathologischen Befunde für die klinische Therapieplanung im interdisziplinären Kontext.

Ergebnisse

Zentrale Pathologiebefunde für Kliniker:Innen sind: (i) Identifikation eines Keimzelltumors, ggf. durch Nachweis eines Chromosom-12p-Zugewinns, (ii) Subtypenspezifizierung und (iii) Angabe von Risikofaktoren (insbesondere Invasion von Lymphgefäßen und/oder Rete testis und Tumorgröße). Molekularpathologische Untersuchungen i. S. von Mutationsanalysen sind angesichts einer sehr geringen Mutationslast und bislang fehlender prädiktiver Marker und zielgerichteter Therapieoptionen nicht Teil der Routinediagnostik.

Diskussion

Ein detaillierter, idealerweise synoptischer histopathologischer Befundbericht ist Grundlage der Planung und Durchführung einer leitlinienkonformen, risikoadaptierten Therapie und neben der bildgebenden Diagnostik und der Bestimmung der Serumtumormarker AFP und β‑HCG (letztere insbesondere bei Nichtseminomen) mitentscheidend, um die guten Heilungsaussichten zu wahren und eine Übertherapie zu vermeiden.

Improving outcomes in germ cell cancers using miRNA

Owing to advances in treatment paradigms across the last five decades, testicular cancer is now eminently curable. However, current serum tumour and imaging biomarkers lack adequate sensitivity, specificity, and predictive value. Subsequently, their utility in detecting active malignancy and informing treatment decisions is minimal in a large proportion of men with testicular cancer. Micro-ribonucleic acids (miRNA), pertinently miR-371a-3p, offer a new tool, which based on early data, appears to fill many of the gaps that existing biomarkers leave. This paper reviews the evolution of the technology, potential limitations, and discusses the clinical relevance of miRNA as it moves towards the clinic.

The prognostic significance of lactate dehydrogenase levels in seminoma patients with advanced disease: an analysis by the Global Germ Cell Tumor Collaborative Group (G3)

Purpose

The prognostic significance of lactate dehydrogenase (LDH) in patients with metastatic seminoma is not defined. We investigated the prognostic impact of LDH levels prior to first-line systemic treatment and other clinical characteristics in this subset of patients.

Methods

Files from two registry studies and one single-institution database were analyzed retrospectively. Uni- and multivariate analyses were conducted to identify patient characteristics associated with recurrence free survival (RFS), overall survival (OS), and complete response rate (CRR).

Results

The dataset included 351 metastatic seminoma patients with a median follow-up of 5.36 years. Five-year RFS, OS and CRR were 82%, 89% and 52%, respectively. Explorative analysis revealed a cut-off LDH level of < 2.5 upper limit of normal (ULN) (n = 228) vs. ≥ 2.5 ULN (n = 123) to be associated with a significant difference concerning OS associated with 5-years OS rates of 93% vs. 83% (p = 0.001) which was confirmed in multivariate analysis (HR 2.87; p = 0.004). Furthermore, the cut-off LDH < 2.5 ULN vs. ≥ 2.5 ULN correlated with RFS and CRR associated with a 5-years RFS rate and CRR of 76% vs. 86% (p = 0.012) and 32% vs. 59% (p  ≤  0.001), respectively.

Conclusions

LDH levels correlate with treatment response and survival in metastatic seminoma patients and should be considered for their prognostic stratification.

[Using preorchiectomy tumor marker serum concentrations for International Germ Cell Consensus Classification (IGCCCG) risk group assignment results in significant numbers of up- and downstaging]

Hintergrund

Das Klassifikationssystem zur Prognoseeinschätzung der International Germ Cell Cancer Cooperative Group (IGCCCG) für testikuläre Keimzelltumoren basiert auf dem histologischen Subtyp, der Lokalisation des Primärtumors und der Metastasen sowie der Serumkonzentrationen der Tumormarker vor Chemotherapie.

Fragestellung

Ziel der Arbeit war die Evaluation des Einflusses der Verwendung der Tumormarkerserumkonzentrationen vor Ablatio testis im Vergleich zu denen vor Chemotherapie im Hinblick auf die Eingruppierung entsprechend der IGCCCG-Klassifikation.

Material und Methoden

Wir führen eine retrospektive Datenanalyse an 135 Patienten mit metastasiertem testikulärem Keimzelltumor durch, die eine Primärtherapie mit einer Chemotherapie erhalten haben. Es erfolgte die Analyse von klinischen Parametern mit Fokus auf der Tumormarkerserumkonzentration vor Ablatio testis und vor Chemotherapie, die zur Eingruppierung in eine Prognosegruppe entsprechend der IGCCCG-Klassifikation führten.

Ergebnisse

Die Verwendung der Tumormarkerserumkonzentrationen zur Berechnung der IGCCCG-Klassifikation vor der Ablatio testis im Vergleich zu denen vor Chemotherapie führte bei 8 % (11/135) aller Patienten zu einer veränderten Prognosegruppe sowie daraus folgend nicht-leitliniengerechten Therapieschemata. Es zeigt sich ein „up-staging“ bei 8 der 11 Patienten und somit 6 % (8/135) der gesamten Patientenkohorte, d. h. die Serumkonzentrationen der Tumormarker sind nach Ablatio bis zum Beginn der Chemotherapie abgefallen. Bei 3 der 11 Patienten bzw. 2 % (3/135) der gesamten Patientenkohorte, kam es zu einem „down-staging“, d. h. die Tumormarker sind bis zum Beginn der Chemotherapie angestiegen.

Diskussion

Die Verwendung der Tumormarkerserumkonzentrationen vor Ablatio testis im Vergleich zu denen vor Chemotherapie kann zu einer signifikanten IGCCCG-Fehlklassifikation und somit inkorrekter Therapie führen. Für ein leitlinienkonformes „staging“ der Patienten sollten folglich die Tumormarker vor der Chemotherapie verwendet werden.

[What does the oncologist need from the pathologist in testicular cancer?]

BACKGROUND

Testicular type II germ cell tumours (GCTs) are an exemplar of a curable cancer and the most common malignancy in males aged ≤35 years. Even in metastatic stages, about 70% of patients can be cured by cisplatin-based chemotherapy and multimodal treatments. For patients failing platinum-based standard therapy, prognosis is poor and novel biomarkers and therapeutic options are urgently needed.

OBJECTIVES

Discussion of desired histopathological information to guide urologists' and oncologists' decision making in the treatment of male GCTs.

MATERIAL AND METHODS

A narrative review of histopathological key features of male GCT tissue samples for clinical decision making.

RESULTS

Histopathological workup is crucial to identify (i) a GCT origin in cancers of unknown primary based on isochromosome 12p (i(12p)) detection, (ii) the different type II GCT subtypes, and (iii) risk factors, i.e. lymphovascular or rete testis invasion, among others. Proper histopathological diagnosis is indispensable for guideline-endorsed, histology-driven, and risk-adapted treatment decisions, hereby helping to maintain treatment success while reducing the therapeutic burden and potential long-term sequelae of multimodal treatments. For refractory patients failing standard treatment options, prognosis remains poor and, so far, neither predictive or prognostic biomarkers nor novel therapeutic targets have been established.

CONCLUSIONS

Close interaction and interdisciplinary discussion of histopathologic and radiologic findings and established risk factors including serum tumour markers is crucial for successful treatment including intensified strategies, where necessary, or prevention of overtreatment, where possible.