Chromosome abnormalities of eighty-one pediatric germ cell tumors: Sex-, age-, site-, and histopathology-related differences?a Children's Cancer Group study

Extragonadal Germ Cell Tumors: A Single Institution Experience with Clinicopathological Correlation

Background. Extragonadal germ cell tumors (EGCTs) are a rare heterogeneous group of tumors without evidence of primary gonadal germ cell tumors. They account for 2%-5% of overall malignancies. EGCTs are often not clinically suspected, making them challenging for pathologists. In this retrospective observational study, we describe our institutional experience among EGCTs with clinicopathological correlation. Materials and methods. All patients diagnosed as EGCTs from January 2014 to April 2023 were collected. All relevant clinical data and serum markers were retrieved from hospital medical records. Histopathology and immunohistochemistry slides were reviewed. Results. The present study included a total of 56 patients; 34 (60%) men and 22 (40%) women with a men-to-women ratio of 1.5:1. Of them, 1 patient had congenital/neonatal EGCTs, 21 patients had prepubertal EGCTs, and 34 had post-pubertal EGCTs. The common sites included are mediastinum (45%), sacrococcyx (18%), retroperitoneum (14%), and central nervous system (12%). The other rare sites were the vagina, liver, colon, and duodenum. The common germ cell tumor included mature teratoma (34%), mixed germ cell tumor (27%), seminoma/germinoma (12%), pure yolk sac tumor (11%), immature teratoma (9%), mature teratoma with somatic tumor (5%), and embryonal carcinoma (2%). All histological diagnoses of germ cell tumors were confirmed with IHC markers like PLAP, CD117 (KIT), AFP, LIN28, CD30, and β-hCG. Pre and posttreatment serum tumor marker levels were available in 37 patients. All our treated patients had a decrease or normal tumor marker levels post-therapy. Conclusion. In our study, a heterogeneous group of germ cell tumors was seen. Most of them were seen in post-pubertal adolescents and young adults. Early intervention by platinum-based combination chemotherapy in seminoma and nonseminomatous germ cell tumors has significantly improved the prognosis of malignant EGCTs similar to their germ cell counterparts.

Differential Activation of Immune Effector Processes in Mature Compared to Immature Sacrococcygeal Teratomas

Objective: This study aims to characterize the molecular signatures of sacrococcygeal teratomas (SCTs). Methods: Three SCTs were analyzed with whole genome genotyping. RNA sequencing of 10 SCTs dominated by mature, immature and neuroglial elements was analyzed. Expression in SCT-samples with different elements were compared to each other and to a reference group of malignant pediatric tumors. Macrophages, T- and B-lymphocytes were detected by immunohistochemistry. Results: No chromosomal imbalances were detected. SCTs showed overexpression of genes involved in neurosignaling, DNA-binding molecules and pathways of early germ cells. Genes associated with immune effector processes were overexpressed in mature compared to immature SCTs, and immune cell infiltration was found predominantly around mature epithelial elements. Conclusion: The broad repertoire of histological elements in SCTs reflects differences in transcriptional regulation rather than differences in gene copy numbers. A paucity of immune response in immature SCTs may be a factor contributing to their uninhibited growth.

Primary Mediastinal and Testicular Germ Cell Tumors in Adolescents and Adults: A Comparison of Genomic Alterations and Clinical Implications

Simple Summary

The germ cell tumors (GCTs) family is a heterogeneous group of neoplasms that includes tumors affecting testis (TGCTs) and rarer cases occurring in extragonadal sites. Mediastinal germ cell tumors (MGCTs) are more aggressive and have poorer prognosis. Due to their rarity of MGCTs, few molecular and clinical studies are reported. MGCTs share biological similarities with TGCT, and international guidelines recommend use of the same therapies validated for TGCT. However, while high response rate is achieved in TGCT, MGCT tend to be resistant to therapy. This review resumes all molecular findings reported in MGCTs, summarizing molecular characteristics common with TGCT and highlighting the different molecular alterations that characterize mediastinal tumors. A deeper understanding of the MGCT biology will help in clinical management of these patients.

Abstract

Mediastinal germ cell tumors (MGCTs) share histologic, molecular and biomarkers features with testicular GCTs; however, nonseminomatous MGCTs are usually more aggressive and have poorer prognosis than nonseminomatous TGCTs. Most nonseminomatous MGCT cases show early resistance to platinum-based therapies and seldom have been associated with the onset of one or more concomitant somatic malignancies, in particular myeloid neoplasms with recent findings supporting a common, shared genetic precursor with the primary MGCT. Genomic, transcriptomic and epigenetic features of testicular GCTs have been extensively studied, allowing for the understanding of GCT development and transformation of seminomatous and nonseminomatous histologies. However, MGCTs are still lacking proper multi-omics analysis and only few data are reported in the literature. Understanding of the mechanism involved in the development, in the progression and in their higher resistance to common therapies is still poorly understood. With this review, we aim to collect all molecular findings reported in this rare disease, resuming the similarities and disparities with the gonadal counterparts.

Single nucleotide polymorphism array and cytogenetic analyses of ovarian teratomas in children

Teratomas are the most common tumors in the ovary during childhood. Previous studies suggested that they may be derived from germ cells at any developmental stage from premeiotic oogonia through meiotic oocytes to post-meiotic ova. The majority of mature teratomas reveal normal karyotypes and immature teratomas show higher frequency of chromosomal abnormalities. We analyzed fresh tissue samples from 25 primary ovarian teratomas and three extraovarian deposits using whole genome single nucleotide polymorphism (SNP) array and karyotype. SNP array detected five patterns of copy neutral loss of heterozygosity (CN-LOH): failure of meiosis I (type I) in 12 tumors, failure of meiosis II (type II) in six tumors, endoreduplication of a haploid ovum (type III) in two tumors, premeiotic error (type IV) in four tumors, and both meiotic I and meiotic II errors in one tumor (type V). Three tumors with type I error had a single chromosome showing meiotic II error, and two tumors with type II error had a single chromosome showing premature sister-chromatid separation in meiosis I. Lack of recombination in multiple chromosomes in meiosis I were common, chromosomes 17, 7, 8, 21, and 22 were most commonly involved. Abnormal karyotypes were observed in four teratomas including +3, del(3q), +7, +8, +12, and i(18q). The extraovarian deposits revealed the same CN-LOH pattern as the primary teratoma. In summary, SNP array reveals the origin of ovarian teratoma and we propose a new mechanism that consecutive meiotic I and II errors occur frequently in ovarian teratomas.

Extragonadal Yolk Sac Tumor Limited to the Myometrium: Report of a Case With Potential Fertility Preservation and Molecular Analysis Suggesting Germ Cell Origin

Extragonadal pelvic yolk sac tumor (YST) in postpubertal female patients is a rare malignant neoplasm with potentially 2 distinct histogenetic pathways, and no clear treatment algorithm, especially in young patients desiring future fertility. Here we report a case of extragonadal YST arising within the myometrium in a 30-yr-old nulligravid woman. The patient presented with heavy and irregular bleeding, and imaging studies showed an 8.2 cm uterine mass, most consistent with a degenerating uterine leiomyoma. The patient underwent abdominal myomectomy, and intraoperative frozen section evaluation revealed a high-grade malignancy. Because of the patient's strong desire for future fertility, a conservative wedge resection of the surrounding myometrium and surgical staging with uterine closure and retention of the ovaries were performed. On permanent sections the tumor showed an admixture of glandular, reticular, solid and papillary architectural patterns, moderate to marked nuclear atypia and clear cytoplasm with focal eosinophilic hyaline globules. Immunohistochemical stains were diffusely positive for SALL4, AFP, glypican3, and focally positive for CK20, and negative for EMA, and CK7, confirming the diagnosis of extragonadal YST. The endometrium displayed normal secretory phase morphology without involvement by YST, and the myometrial resection margins were negative. Short tandem repeat genotyping analysis of the tumor revealed allelic gains at 7 loci (involving chromosomes 2, 3, 4, 5, 8, 13, and 15) and allelic loss at one locus assessed on chromosome 11, while next-generation sequencing results showed no mutations in 155 genes tested, suggesting germ cell origin. The patient underwent 4 cycles of adjuvant chemotherapy with bleomycin, etoposide, and cisplatin, and she had 1 cycle of successful oocyte cryopreservation 6 months after completing chemotherapy. The clinical follow-up at 12 mo shows no evidence of disease.

Lack of genetic homozygosity in prepubertal teratomas: divergent pathogenesis distinct from that of teratomas in adolescents

In adults, both immature and mature ovarian teratomas show frequent genetic homozygosity consistent with tumorigenesis involving germ cells after meiosis I. Investigation into genetic zygosity of various teratomas in children has been limited. Thirteen sacrococcygeal, 12 ovarian, and 3 testicular teratomas in children 18 years or younger were retrieved from our departmental archives and histologically reviewed. Tumor and paired normal tissues were microdissected and subjected to short tandem repeat (STR) genotyping. DNA genotyping was informative in 12 sacrococcygeal teratomas, 8 ovarian teratomas, and 3 testicular teratomas. Sacrococcygeal teratomas included seven mature teratomas, four immature teratomas, and one mixed germ cell tumor with patient age ranging from 0 days to 3 years. All but two patients were female. Ovarian teratomas included five mature and three immature teratomas with patient age ranging from 2 to 18 years. Testicular teratomas included two mature teratomas and one immature teratoma with patient age ranging from 3 months to 3 years. All sacrococcygeal, testicular, and ovarian teratomas in patients younger than 4 years showed no evidence of genetic homozygosity by STR genotyping. In contrast, all four ovarian teratomas in patients older than 9 years showed either partial or complete homozygosity. In conclusion, unlike adolescent and adult ovarian teratomas, prepubertal sacrococcygeal and gonadal teratomas lack genetic homozygosity, supporting the hypothesis that teratomas before puberty develop at an early stage of germ cell development different from that of teratomas in adolescents and adults.

Age-Dependent Presentation and Clinical Course of 1465 Patients Aged 0 to Less than 18 Years with Ovarian or Testicular Germ Cell Tumors; Data of the MAKEI 96 Protocol Revisited in the Light of Prenatal Germ Cell Biology

OBJECTIVE

To evaluate prognostic factors in pediatric patients with gonadal germ cell tumors (GCT).

METHODS

Patients <18 years with ovarian and testicular GCT (respectively OGCT and TGCT) were prospectively registered according to the guidelines of MAKEI 96. After resection of the primary tumor, patients staged ≥II received risk-stratified cisplatin-based combination chemotherapy. Patients were analyzed in respect to age (six age groups divided into 3-year intervals), histology, stage, and therapy. The primary end point was overall survival.

RESULTS

Between January 1996 and March 2016, the following patients were registered: 1047 OGCT, of those, 630 had ovarian teratoma (OTER) and 417 had malignant OGCT (MOGCT); and 418 TGCT, of those, 106 had testicular teratoma (TTER) and 312 had malignant TGCT (MTGCT). Only in MTGCT, older age correlated with a higher proportion of advanced tumors. All 736 teratomas and 240/415 stage I malignant gonadal GCT underwent surgery and close observation alone. In case of watchful waiting, the progression rate of OGCT was higher than that of TGCT. However, death from disease was reported in 8/417 (1.9%) MOGCT and 8/312 (2.6%) MTGCT irrespective of adjuvant chemotherapy and repeated surgery.

CONCLUSIONS

The different pathogenesis and histogenesis of gonadal GCT reflects sex- and age-specific patterns that define clinically relevant risk groups. Therefore, gender and age should be considered in further research on the biology and clinical practice of pediatric gonadal GCT.

Klinefelter syndrome in males with germ cell tumors: A report from the Children's Oncology Group

BACKGROUND

Males with Klinefelter syndrome (KS) (47,XXY) may be more likely to develop germ cell tumors (GCTs), particularly mediastinal GCTs. To date, there are no reports characterizing the prevalence of KS among male GCT cases.

METHODS

The authors used array genotyping data from a Children's Oncology Group epidemiology study to estimate the prevalence of KS in males with GCTs (433 males aged birth-19 years). Using Fisher's exact tests, the authors examined differences in age at diagnosis, race/ethnicity, tumor location and histology, and several birth characteristics between cases of KS-GCT and GCT cases without chromosomal abnormalities. Using publicly available data, the authors estimated the 1-year risk, risk ratio, and corresponding 95% confidence interval of GCTs among KS cases.

RESULTS

Based on analysis of array genotyping data, 3% of male GCT cases (13 cases) had KS. The additional X chromosome was of maternal origin in 7 of the 13 cases. Of these 13 KS cases, 5 of 9 KS-GCT cases with parental questionnaire data (56%) reported a diagnosis of KS. No significant differences were observed with regard to patient or birth characteristics between KS-GCT and non-KS-GCT cases. KS-GCT cases were significantly more likely to be diagnosed with mediastinal tumors than non-KS-GCT cases (P<.01). The authors estimated the risk of developing a GCT among males with KS to be 0.00025, or 1 per 4000 males (risk ratio, 18.8; 95% confidence interval, 11.7-30.0).

CONCLUSIONS

Compared with males without chromosomal abnormalities, males with KS are more likely to be diagnosed with a mediastinal GCT. The presence of KS should be considered in males with a diagnosis of mediastinal GCT. In the current study, the authors report that approximately one-third of males with mediastinal germ cell tumors have Klinefelter syndrome, and therefore screening of these individuals for the syndrome may be warranted. Males with Klinefelter syndrome are 19 times as likely as males without Klinefelter syndrome to develop germ cell tumors.

Chemotherapy-Induced Depletion of OCT4-Positive Cancer Stem Cells in a Mouse Model of Malignant Testicular Cancer

Testicular germ cell tumors (TGCTs) are among the most responsive solid cancers to conventional chemotherapy. To elucidate the underlying mechanisms, we developed a mouse TGCT model featuring germ cell-specific Kras activation and Pten inactivation. The resulting mice developed malignant, metastatic TGCTs composed of teratoma and embryonal carcinoma, the latter of which exhibited stem cell characteristics, including expression of the pluripotency factor OCT4. Consistent with epidemiological data linking human testicular cancer risk to in utero exposures, embryonic germ cells were susceptible to malignant transformation, whereas adult germ cells underwent apoptosis in response to the same oncogenic events. Treatment of tumor-bearing mice with genotoxic chemotherapy not only prolonged survival and reduced tumor size but also selectively eliminated the OCT4-positive cancer stem cells. We conclude that the chemosensitivity of TGCTs derives from the sensitivity of their cancer stem cells to DNA-damaging chemotherapy.

Two Tumors in 1: What Should be the Therapeutic Target? Pediatric Germ Cell Tumor With Somatic Malignant Transformation

BACKGROUND

Germ cell tumors with somatic malignant transformation (GCT with SMT) are rare in children and poorly described. Data are missing to determine if therapies should target the GCT, the SMT compound, or both simultaneously.

PATIENTS AND METHODS

A retrospective national study was conducted in the Société Française des cancers de l'Enfant (SFCE) Centers. Medical records from patients aged 0 to 18 years diagnosed with GCT with SMT between 2000 and 2015 were analyzed. Any stages and primary sites were considered as well as synchronous and metachronous cases.

RESULTS

Fifteen patients were identified. Thirteen patients had synchronous GCT with SMT. In the latter cases, primaries were ovary (5), mediastinum (3), pineal gland (3), sacrococcyx (1), and parametrium (1). SMT histologies were central primitive neuroectodermal tumor (5), embryonal rhabdomyosarcomas (3) or thyroid papillary adenocarcinoma, leukemia, poorly differentiated carcinoma, mixed sarcomas, and miscellaneous histology (1 case each). Chemotherapy was targeted against the GCT (3), the SMT (6), or both components (3). The last patient received surgery exclusively. Partial or complete response to chemotherapy was observed in 5/10 assessable cases: 2/3 patients treated with GCT-dedicated chemotherapy, 3/6 patients treated with SMT-dedicated therapy, and 0/1 treated with combined therapy. In addition, 2 patients with mediastinal GCT primary had metachronous SMT, with acute myeloid leukemia and thyroid papillary adenocarcinoma, 8 months and 8 years, respectively, after the diagnoses of GCT. Two patients (1 synchronous and 1 metachronous) were cured with surgery exclusively. At the end of follow-up, 6 patients died of their disease including all 4 with postsurgical macroscopic residue.

CONCLUSIONS

GCT with SMT constitutes a very rare entity in children and adolescents. Surgical removal of the tumor is the cornerstone of the treatment and might be sufficient in selected cases. In the remaining cases, the best management is still unknown and should take into account both components and their respective chemosensitivity. Long-term surveillance is advised for patient with unresected teratoma as late transformation can occur.

The World Health Organization 2016 classification of testicular germ cell tumours: a review and update from the International Society of Urological Pathology Testis Consultation Panel

Since the last World Health Organization (WHO) classification scheme for tumours of the urinary tract and male genital organs, there have been a number of advances in the understanding, classification, immunohistochemistry and genetics of testicular germ cell tumours. The updated 2016 draft classification was discussed at an International Society of Urological Pathology Consultation on Testicular and Penile Cancer. This review addresses the main updates to germ cell tumour classification. Major changes include a pathogenetically derived classification using germ cell neoplasia in situ (GCNIS) as a new name for the precursor lesion, and the distinction of prepubertal tumours (non-GCNIS-derived) from postpubertal-type tumours (GCNIS-derived), acknowledging the existence of rare benign prepubertal-type teratomas in the postpubertal testis. Spermatocytic tumour is adopted as a replacement for spermatocytic seminoma, to avoid potential confusion with the unrelated usual seminoma. The spectrum of trophoblastic tumours arising in the setting of testicular germ cell tumour continues to expand, to include epithelioid and placental site trophoblastic tumours analogous to those of the gynaecological tract. Currently, reporting of anaplasia (seminoma or spermatocytic tumour) or immaturity (teratoma) is not required, as these do not have demonstrable prognostic importance. In contrast, overgrowth of a teratomatous component (somatic-type malignancy) and sarcomatous change in spermatocytic tumour indicate more aggressive behaviour, and should be reported.

Survival outcomes of adolescent and adult patients with non-seminomatous testicular germ-cell tumors: A population-based study

BACKGROUND

In adolescents, approximately 90% of testicular germ cell tumors (T-GCTs) are non-seminomas (NS T-GCTs). Few studies have evaluated the impact of age, specifically in adolescence, on outcomes of NS T-GCTs.

OBJECTIVE

The purpose of this study was to review all patients diagnosed with NS T-GCTs in the Surveillance, Epidemiology, and End Results (SEER) database to evaluate the association between age (adolescents vs. adults) and survival outcomes.

METHOD

The SEER database was queried for individuals ≥13 years old diagnosed with NS T-GCTs from 1995 to 2012. Patients were categorized into adolescent (13-19 years) and adult (≥20 years) cohorts. A Cox proportional hazards model was used for multivariate analysis (MVA).

RESULTS

A total of 13,963 patients (1496 adolescents, 12,467 adults) was included. Median follow-up was 71 months (range 1-215). Five-year overall survival (OS) for adolescent and adult patients was 94% and 92%, respectively (p = 0.007); 5-year cancer-specific survival (CSS) was 95% and 94%, respectively (p = 0.139). Under MVA, adolescent patients had improved OS (HR 0.61; 95% CI 0.50-0.75; p < 0.001) and CSS (HR 0.65; 95% CI 0.51-0.82; p < 0.001), when compared with adults (Table). In a logistic regression analysis adjusting for demographics, adolescent patients were more likely to present with regional or distant metastatic disease (OR 1.16; 95% CI 1.01-1.35; p = 0.039), undergo an orchiectomy (OR 2.44; 95% CI 1.50-4.00; p < 0.001) or tumor excision (OR 2.43; 95% CI 1.57-3.77; p < 0.001), and receive other adjuvant surgery (OR 5.87; 95% CI 2.25-15.30; p < 0.001).

CONCLUSIONS

To our knowledge, this is the largest population-based comparative analysis in NS T-GCTs comparing outcomes between these two age groups. Adolescent patients with NS T-GCTs had slightly improved survival compared with adults, despite presenting with more advanced disease. While adolescent patients present at more advanced stage, they achieve excellent survival outcomes possibly at the cost of a greater therapeutic burden.

Prognostic factors in children with extracranial germ cell tumors treated with cisplatin-based chemotherapy

Purpose

To evaluate the outcomes and prognostic factors in children with extracranial germ cell tumors (GCTs) treated at a single institution.

Methods

Sixty-six children diagnosed with extracranial GCTs between 1996 and 2012 were included in the study. Primary treatment was surgical excision, followed by six cycles of cisplatin-based chemotherapy. The survival rates were compared according to the International Germ Cell Cancer Cooperative Group classification used for GCTs in adults to validate the classification guidelines for GCTs in children.

Results

The median patient age was 4.4 years. In 34 patients (51.5%), the primary tumor site was the gonad. Extragonadal GCTs were detected in 32 patients. The 5-year overall survival and event-free survival (EFS) were 92.0%±3.5% and 90.4%±3.7%, respectively. In univariate analysis, tumor histology, metastasis, and elevated alpha-fetoprotein were not prognostic factors in children with extracranial GCTs. However, EFS was poorer in patients with mediastinal disease (n=12, 66.7%±13.6 %) than in those with nonmediastinal disease (n=54, 96.0%±2.8%) (P=0.001). The 5-year EFS was lower in patients older than 10 years, (n=21, 80.0%±8.9%) compared with those younger than 10 years (n=45, 95.2%±3.3%) (P=0.04). Multivariate analysis identified the mediastinal tumor site as the only independent prognostic factor.

Conclusion

The prognosis of children with extracranial GCTs was favorable. However, nongerminomatous mediastinal tumors were associated with poor survival in children. Further research is needed to improve the prognosis of children with malignant mediastinal GCTs.

Sacrococcygeal teratomas: clinico-pathological characteristics and isochromosome 12p status

The biological behavior of teratomas is highly variable, and morphologic features alone are insufficient to predict their clinical course. Prognostic factors that influence behavior include the following: patient sex, age, anatomic site, coincident neoplasm, and cytogenetic abnormalities. Gonadal teratomas have been well-characterized; postpubertal testicular teratomas are commonly associated with isochromosome 12p (i12p) and considered to nearly always carry a potential for malignant behavior, whereas ovarian and prepubertal testicular teratomas are i12p negative and predominantly benign in behavior. For extragonadal sites, such as sacrum and coccyx, clinical characteristics and i12p status are yet to be adequately characterized. As part of this study, we identified 19 sacrococcygeal teratomas in our surgical pathology archives from 1990 to 2012. Clinical records and slides were reviewed to confirm the original diagnosis. Gains in chromosome 12p, including i12p status were assessed in representative paraffin sections by fluorescence in situ hybridization. Our cases included 16 mature sacrococcygeal teratomas (11 prepubertal and 5 postpubertal) and three immature saccrococygeal teratomas (all prepubertal). Among mature teratomas, the average tumor size was larger in adults compared with prepubertal patients. A higher number of adult cases were recurrences (80% vs 21%), but only pediatric recurrences were managed with postoperative chemotherapy. All examined tumors were negative for i12p. 100% survival was documented in our cohort with a median follow-up of 6 years. We present a large series of sacrococcygeal teratomas and the first series to examine postpubertal adults at this anatomic site. All tumors lacked chromosome 12p gains, including i12p. Both pre- and postpubertal sacrococcygeal teratomas had a favorable outcome regardless of age or sex.

The prenatal origins of cancer

The concept that some childhood malignancies arise from postnatally persistent embryonal cells has a long history. Recent research has strengthened the links between driver mutations and embryonal and early postnatal development. This evidence, coupled with much greater detail on the cell of origin and the initial steps in embryonal cancer initiation, has identified important therapeutic targets and provided renewed interest in strategies for the early detection and prevention of childhood cancer.

A comparison of pediatric, adolescent, and adult testicular germ cell malignancy

BACKGROUND

Testicular germ cell tumors (T-GCTs) occur from infancy to adulthood, and are the most common solid tumor in adolescent and young adult males. Traditionally, pediatric T-GCTs were perceived as more indolent than adult T-GCTs. However, there are few studies comparing these groups and none that specifically evaluate adolescents.

METHODS

An institutional database of T-GCT patients was reviewed and patients were categorized into Pediatric, aged 0-12 years, Adolescent, aged 13-19 years, and Adult, older than 20 years, cohorts. Demographics, tumor characteristics, disease stage, treatment, event-free survival (EFS), and overall survival (OS) were compared between groups.

RESULTS

Overall, 413 patients (20 pediatric, 39 adolescent, 354 adult) met study criteria and were followed for a median of 2.0 years (0.1-23.6). Adolescents presented with more advanced stage than children (P = 0.018) or adults (P = 0.008). There was a higher rate of events in Adolescents (13, 33.3%) than in Adults (61, 17.2%) or Children (2, 10.0%). Three-year EFS was 87.2% in the Pediatric group, 59.9% in Adolescents and 80.0% in Adults (P = 0.011). In a multivariate analysis, controlling for stage, IGCCCG risk, and histology, the hazard ratio (HR) for an event was: 1 (Reference) for Adults, HR = 0.82 (95% CI 0.19-3.46; P = 0.33) for the Pediatric group, and HR = 2.22 (95% CI 1.21-4.07; P = 0.01) for Adolescents. Five-year OS was 100% in the Pediatric group, 84.8% in Adolescents, and 92.8% in Adults (P = 0.388).

CONCLUSION

Lower EFS in adolescent T-GCT patients was observed than in either children or adults. Elucidating factors associated with inferior outcomes in adolescents is an important focus of future research.

Salvage therapy for refractory or recurrent pediatric germ cell tumors: the French SFCE experience

PURPOSE

Some children with extracranial germ cell tumors (GCT) relapse after or do not respond to first-line treatment combining chemotherapy and surgery, of whom very few experience long-term survival despite multimodal salvage treatment.

METHODS

This prospective study, part of the French TGM95 Protocol for non-seminomatous GCT (NSGCT), included 19 (7%) children with malignant refractory or recurrent extracranial NSGCT who were studied to identify prognostic factors and determine the best salvage treatment.

RESULTS

At the end of the first-line treatment, 10 and 9 children were in complete and incomplete remission, respectively. Events occurred within 2 years (5-23 months) after initial diagnosis. A progression was observed in 13 patients at least in one site initially involved. Two patients had a purely biological relapse (increase in isolated markers), and four patients had a purely metastatic relapse (brain location in three cases). After salvage treatment combining surgery and various types of chemotherapy (including high-dose chemotherapy (HDCT) in 10 cases), the 5-year event-free survival and overall survival rates were of 26% (95%CI: 9.6-46.8%) and 32% (95%CI: 12.9-52.2%), respectively. Patients who underwent complete surgery (or without any detectable tumor) had higher survival rate than patients who underwent partial surgery or for whom surgery was not feasible (P = 0.0003) at first relapse while this rate was similar between patients treated or not with HDCT.

CONCLUSION

In pediatric recurrent or refractory NSGCT, complete excision of the tumor appears essential. The role of HDCT remains debated.

Brain metastases during follow-up of children and adolescents with extracranial malignant germ cell tumors: risk adapted management decision tree analysis based on data of the MAHO/MAKEI-registry

BACKGROUND

The overall risk for brain metastases among children and adolescents with extracranial malignant germ cell tumors (mGCT) is low but may vary between subgroups. Early identification of subgroups with an increased risk for brain metastasis is therefore important.

PROCEDURE

We analyzed 900/2,160 patients from the German MAHO/MAKEI registry on children and adolescents with malignant extracranial GCT (pure teratomas (grade 0-3) were not included). For follow-up evaluation, patients with brain metastases at diagnosis and those with a follow-up shorter than 32 months after diagnosis (longest interval to brain metastases in our cohort) were excluded. Patients were censored at detection of brain metastases or death due to other causes. A decision tree analysis considering age, gender, site of primary tumor, and presence of other metastases at diagnosis as risk factors for brain metastases was performed.

RESULTS

Among 838 eligible patients, 9 acquired brain metastases during follow-up, accounting for death in 5. There were no brain metastases in absence of extracranial metastases at diagnosis. If extracranial metastases were detected in absence of mediastinal mGCT the risk for brain metastases was 1.2% (95% CI: 0.2-3.5.%). In contrast, risk was increased to 37.5 (95% CI 15.2-64.6%) in patients with mediastinal GCTs and extracranial metastases.

CONCLUSION

A high-risk subgroup is detected with a decision tree analysis approach. These patients may benefit from an intensified chemotherapy. Close surveillance for CNS-metastases is warranted in this high-risk group while less close monitoring in low-risk patients is justified. Pediatr Blood Cancer 2013;60:217-223. © 2012 Wiley Periodicals, Inc.

Insights on neoplastic stem cells from gel-based proteomics of childhood germ cell tumors

BACKGROUND

Childhood germ cell tumors (cGCTs), believed to arise from transformed primordial germ cells by an unknown mechanism, provide a unique model system for investigating cell signaling, pluripotency, and the microenvironment of neoplastic stem cells (NSCs) in vivo. This is the first report of proteomics of cGCTs.

PROCEDURE

Four dysgerminomas (DYSs) and four childhood endodermal sinus tumors (cESTs), resembling self-renewing and differentiating NSCs, respectively, were selected. Proteomic studies were performed by 2-DE, SDS-PAGE, and cLC/MS/MS with protein database searching.

RESULTS

2-DE: 9 of 941 spots were differentially regulated with greater than a twofold change in spot volume for at least three of four gels in each group. Two of nine spots had P values for the t-test analysis of comparisons less than 0.001, while the remaining spots had P values from 0.013 to 0.191. Top-ranked proteins were identified in nine of nine spots with 4.0-38% sequence coverage. APOA1, CRK, and PDIA3 were up-regulated in cESTs. TFG, TYMP, VCP, RBBP, FKBP4, and BiP were up-regulated in DYSs. SDS-PAGE: Up-regulation of NF45 and FKBP4 was observed in four of four cESTs and DYSs, respectively. The fold-changes observed correspond with characteristic genetic changes.

CONCLUSION

Differential regulation of FKBP4 and NF45, combined with previous research on immunosuppressant binding, suggests that glucocorticoid receptor signaling merits further investigation in cGCTs and NSCs.

Association of JAK2 mutation status and cytogenetic abnormalities in myeloproliferative neoplasms and myelodysplastic/myeloproliferative neoplasms

Myeloproliferative neoplasms and myelodysplastic/myeloproliferative neoplasms are heterogeneous disorders. JAK2 mutation testing and karyotyping are routinely used for diagnosis but have not been incorporated into risk stratification in Philadelphia chromosome-negative myeloproliferative neoplasms. This study correlated cytogenetic abnormalities with disease stage and JAK2 status. A total of 179 cases were analyzed for the JAK2 mutation. Among them, cytogenetic data were available for 97 cases-45 of 106 JAK2+ and 52 of 73 JAK2-. The JAK2+ group showed a higher frequency of cytogenetic anomalies than the JAK2- group (23/45 [51%] vs 14/52 [27%]). Chromosome 9, chromosome 7, and 20q- were recurrent abnormalities in the JAK2+ group, whereas 13q- and trisomy 21 were common in the JAK2- group. In the JAK2+ group, chromosome 7 and complex cytogenetic abnormalities were associated with excess blasts/blastic transformation (P < .05), whereas no cases with 20q- underwent blastic transformation. Our results suggest that incorporation of JAK2 mutation testing and karyotyping allows for monitoring of disease progression with prognostic and therapeutic implications.

Analysis of the adenomatous polyposis coli (APC) gene in childhood and adolescent germ cell tumors

BACKGROUND

Aberrant Wnt signaling due to deregulation of Wnt regulators is implicated in the development and progression of numerous embryonal tumors. This study addresses the questions if activation of Wnt signaling in germ cell tumors (GCTs) arising during childhood and adolescence is associated with aberrations of the tumor suppressor adenomatous polyposis coli (APC), and whether APC aberrations might be responsible for progression from benign teratoma to malignant yolk sac tumor (YST).

PROCEDURE

Forty-eight GCTs were analyzed, including mature (n = 5) and immature (n = 7) teratomas, mixed malignant GCTs (n = 10), YSTs (n = 17) as well as dysgerminomas (n = 9). To screen APC for genetic aberrations, we conducted direct sequencing of the mutation cluster region (MCR), loss of heterozygosity analyses (LOH) and protein truncation test. Epigenetic analyses included methylation specific PCR and bisulfite genomic sequencing of the APC 1a promoter. Gene expression was determined by quantitative real-time PCR.

RESULTS

Aberrant promoter methylation was detected in YSTs, teratomas and mixed malignant GCTs, with a pronounced hypermethylation exclusively in YSTs (11/13) while dysgerminomas were not methylated (0/9). Teratomas (2/2) and YSTs (4/5) show LOH at the APC locus. However, neither mutations within the MCR nor truncated protein were detected. APC expression did not significantly vary between the different histological subgroups.

CONCLUSIONS

Methylation of APC and LOH 5q21-22 in YSTs and teratomas provide evidence for involvement of APC in the accumulation of β-catenin and activation of the WNT pathway. Our additional analyses suggest that APC is unlikely to be solely responsible for the formation and progression of childhood GCTs.

Trends in incidence and survival of pediatric and adolescent patients with germ cell tumors in the United States, 1975 to 2006

BACKGROUND

Pediatric germ cell tumors (GCTs) are rare and heterogeneous tumors with uncertain etiology. In the current study, data from the National Cancer Institute's Surveillance, Epidemiology and End Results (SEER) Program were used to evaluate trends in incidence and survival of GCTs in boys and girls ages ≤19 years. To the authors' knowledge, few studies to date have evaluated trends in pediatric GCTs. Results from these analyses may provide clues to the etiology of GCTs.

METHODS

Frequencies, incidence rates, and 5-year relative survival rates stratified by sex were evaluated overall and by demographic subgroups based on age (birth to 9 years and 10-19 years), race (white, black, and other), and ethnicity (non-Hispanic and Hispanic) as sample size permitted.

RESULTS

In whites, the incidence of GCTs was lower for females than males in the 10-year to 19-year age group (rate ratio [RR], 0.47; 95% confidence interval [95% CI], 0.42-0.53), whereas the rates were similar in the age group for birth to 9 years. In contrast, incidence rates were higher in black females than in black males in both age groups (RR, 2.01 [95%CI, 1.08-3.84] in those ages birth to 9 years; RR, 3.30 [95% CI, 2.13-5.28] in those ages 10-19 years). The incidence of ovarian GCT was significantly higher in Hispanic compared with non-Hispanic girls in the groups aged 10 to 19 years. Incidence rates increased during the study period in boys ages 10 to 19 years (annual percentage change [APC], 1.2; 95% CI, 0.4-2.1) and girls ages birth to 9 years (APC, 1.9; 95% CI, 0.3-2.5).

CONCLUSIONS

The incidence of pediatric GCTs in the United States appears to be increasing only in certain subgroups, suggesting that the etiology is not completely overlapping in all age groups. Differences in incidence patterns by race and ethnicity merit further investigation.

Inherited cancer syndromes in children and young adults

Geneticists estimate that 5% to 10% of all cancers diagnosed in the pediatric age range occur in children born with a genetic mutation that directly increases their lifetime risk for neoplasia. However, despite the fact that only a fraction of cancers in children occur as a result of an identified inherited predisposition, characterizing genetic mutations responsible for increased cancer risk in such syndromes has resulted in a profound understanding of relevant molecular pathways involved in carcinogenesis and/or resistance to neoplasia. Importantly, because most cancer predisposition syndromes result in an increased risk of a small number of defined malignancies, personalized prophylactic surveillance and preventive measures can be implemented in affected patients. Lastly, many of the same genetic targets identified from cancer-prone families are mechanistically involved in the majority of sporadic cancers in adults and children, thereby underscoring the clinical relevance of knowledge gained from these defined syndromes and introducing novel therapeutic opportunities to the broader oncologic community. This review highlights the clinical and genetic features of many of the known constitutional genetic syndromes that predispose to malignancy in children and young adults.

Constitutional aneuploidy and cancer predisposition

Constitutional aneuploidies are rare syndromes associated with multiple developmental abnormalities and the alterations in the risk for specific cancers. Acquired somatic chromosomal aneuploidies are the most common genetic aberrations in sporadic cancers. Thus studies of these rare constitutional aneuploidy syndromes are important not only for patient counseling and clinical management, but also for deciphering the mechanisms by which chromosomal aneuploidy affect cancer initiation and progression. Here we review the major constitutional aneuploidy syndromes and suggest some general mechanisms for the associated cancer predisposition.

Molecular Pathology of the Genitourinary Tract: Molecular Pathology of Kidney and Testes

With the advent of newer molecular technologies, our knowledge of cellular mechanisms with tumors of the kidney and testis has grown exponentially. Molecular technologies have led to better understanding of interplay between the von Hippel-Lindau gene and angiogenic cytokines in renal cancer and isochromosome 12p in testicular neoplasms. The result has been development of antiangiogenic-targeted therapy within recent years that has become the mainstay treatment for metastatic renal cell cancer. In the near future, classification and diagnosis of renal and testicular tumors through morphologic analysis will be supplemented by molecular information correlating to prognosis and targeted therapy. This article outlines tumor molecular pathology of the kidney and testis encompassing current genomic, epigenomic, and proteonomic findings.

Copy Number Changes in 1q21.3 and 1q23.3 have Different Clinical Relevance in Ovarian Tumors

Many studies have reported aberrations such as amplifications, deletions and translocations of 1q21-q23 in ovarian tumors. These findings increase the scientific interest in analyzing this region using specific gene probes. We investigated the frequency of copy number changes of two specific bacterial artificial chromosomes (BAC) clones in 1q21.3 and 1q23.3 by fluorescent in situ hybridization (FISH) on tissue microarrays consisting of 540 ovarian tumors of different malignancies, histology, stage and grade. Such changes in 1q21.3 were established in 9.64% of malignant (2.41% amplification), in 8.33% of low malignant potential (LMP) and in 13.13% of benign ovarian tumors. Copy number changes of 1q23.3 were found in 17.78% of malignant (1.48% amplification), in 16.67% of LMP and in 12.64% of benign ovarian tumors. We found a significantly higher gain of 1q23.3 in non epithelial (50%) compared to epithelial tumors (14.73%) (p <0.03). The gain of 1q21.3 prevailed in non serous malignant and LMP ovarian tumors in comparison to serous tumors. In non serous tumors, both gains were associated with higher grade. The frequency of gain in 1q23.3 was 2.5-times higher than that in 1q21.3 of ovarian cancers.

Hamartomas, teratomas and teratocarcinosarcomas of the head and neck: Report of 3 new cases with clinico-pathologic correlation, cytogenetic analysis, and review of the literature

Background

Germ-cell tumors (GCT) are a histologically and biologically diverse group of neoplasms which primarily occur in the gonads but also develop at different extragonadal sites in the midline of the body. The head and neck region including the upper respiratory tract is a very rare location for such tumors in both children and adults, which can cause diagnostic and therapeutic difficulties.

Methods

We describe here two new cases of multilineage tumors including sinonasal teratocarcinosarcoma [SNTCS], and congenital oronasopharyngeal teratoma (epignathus) and compare their features with those of a new case of a rare salivary gland anlage tumor [SGAT], an entity for which the pathogenesis is unclear (i.e. hamartoma versus neoplasm). We correlate their presenting clinico-pathological features and compare histologic and cytogenetic features in an attempt to elucidate their pathogenesis and biologic potentials.

Results and discussion

Cytogenetic analysis revealed chromosomal abnormalities only in the case of SNTCS that showed trisomy 12 and 1p deletion. Both cytogenetic abnormalities are characteristically present in malignant germ cell tumors providing for the first time evidence that this rare tumor type indeed might represent a variant of a germ cell neoplasm. The SGAT and epignathus carried no such cytogenetic abnormalities, in keeping with their limited and benign biologic potential.

Conclusion

The comparison of these three cases should serve to emphasize the diversity of multilineage tumors (hamartomas and GCT) of the upper respiratory tract in regards to their biology, age of presentation and clinical outcomes. Malignant tumors of germ cell origins are more likely to affect adults with insidious symptom development, while benign tumors can nevertheless cause dramatic clinical symptoms which, under certain circumstances, can be fatal.

Application of stem cell markers in search for neoplastic germ cells in dysgenetic gonads, extragonadal tumours, and in semen of infertile men

Germ cell tumours (GCTs) are a complex entity. Current areas of attention include early detection and avoidance of unnecessary over-treatment. Novel findings regarding diagnosis of GCTs located in various anatomical sites are described, particularly testicular GCTs and their common progenitor, carcinoma in situ (CIS). Recognition of CIS enables intervention before tumour development, but nevertheless, testicular GCTs are sporadically diagnosed at the pre-invasive stage where minimal treatment is necessary. As presence of CIS is asymptomatic, a simple screening method is needed when CIS is suspected (i.e. in males investigated for infertility). To develop approaches for early detection CIS gene expression studies have been performed showing many similarities with embryonic stem cells with confirmation of established markers (i.e. PLAP, OCT-3/4, KIT) and identification of novel markers (i.e. AP-2 gamma, NANOG). We have reported a very promising new approach of AP-2 gamma (or OCT3/4) based immunocytological semen analysis (specificity 93.6%, sensitivity 54.5%). Comparative studies of gonadal/extragonadal GCTs have revealed resemblance pointing towards similar, but not identical, origins. Moreover, infertility and testicular cancer are connected in the 'Testicular Dysgenesis Syndrome' and 25% of contralateral testes from testicular GCT patients harbour dysgenetic features, including impaired spermatogenesis. Thus, recent data have provided potential diagnostic tools including CIS detection in semen, microarray-based tumour classification, additional serological GCT markers, and novel stem cell markers for immunohistochemical diagnosis of gonadal and extragonadal GCTs. Many CIS candidate genes are yet uninvestigated, and information from these could increase knowledge about CIS tumour initiation/progression and be used for optimisation of a non-invasive detection method.

Genetic alterations of E-cadherin and beta-catenin in germinoma and teratoma: report of two central nervous system cases

The genetic basis as well as mechanisms of development of germ cell tumors of the CNS are still unexplained. In the present article changes of Ecadherin (CDH1) and beta-catenin (CTNNB1) genes in two CNS germ cell tumors are reported. Both gene products are components of adherens junctions, but are also involved in the Wnt signaling pathway. A case of germinoma of the central nervous system and a case of spinal channel teratoma were tested for loss of heterozygosity (LOH) of E-cadherin gene by PCR amplification of tetranucleotide polymorphism (D16S752). Changes of beta-catenin were tested by heteroduplex method. Both germ cell tumors analyzed demonstrated LOH of the CDH1 gene. Analysis of exon 3 of the CTNNB1 gene showed additional band in the germinoma, suggesting that this sample harbors mutation in the beta-catenin gene. Immunostaining showed that LOHs in our samples were accompanied with the absence of E-cadherin protein. We also investigated E-cadherin expression in four other germinomas, of which three were negative and one was mildly positive. Our findings may contribute to better understanding of the genetic profile of germ cell tumors.

Pediatric germ cell tumors

Pediatric germ cell tumors are a diverse group of neoplasms with variable clinical behaviors, depending upon the age and site of presentation. Most result from sporadic mutations, although environmental exposures and other genetic aberrations may play a role. Platinum-based chemotherapy has dramatically improved the event-free and overall survival outcomes of pediatric patients with malignant germ cell tumors over the past two decades. Prognosis is dependent on tumor stage and location. Patients with gonadal germ cell tumors have at least a 95% 5-year survival for early stage disease and at least a 85% 5-year survival for advanced stages. In general, extragonadal germ cell tumors carry a poorer prognosis with mediastinal location having the worst outcomes (70% 4-year survival). Current trials are focused on maintaining similar excellent outcomes while reducing morbidity by reducing the dose and duration of chemotherapy. Cytogenetic research studies have found chromosomal aberrations specific to some of these tumors that may serve as prognosticators and even direct therapy.

Extragonadal germ cell tumors: a review with emphasis on pathologic features, clinical prognostic variables, and differential diagnostic considerations

Extragonadal germ cell tumors (GCTs) are relatively uncommon, but represent 1% to 5% of all GCTs. Their morphology varies widely and includes mature teratoma, immature teratoma, seminoma, yolk sac tumor, embryonal carcinoma, choriocarcinoma, and mixed GCTs. Noncentral nervous system extragonadal GCTs are found in a variety of anatomic locations, but most commonly affect the mediastinum and sacrococcygeal region. Predicting behavior in these tumors can be confusing because it is based on a combination of varying factors including patient age, histologic subtype, anatomic site, and clinical stage. This review attempts to dissect these issues by separating the discussion into 3 age groups: neonatal (congenital), children (prepubertal), and adult (postpubertal). Within each individual age group, we cover the significance of anatomic site, morphology, and staging parameters. In addition, we discuss the spectrum of associated secondary malignancies and their impact on patient outcome. Finally, we provide a detailed survey of differential diagnostic considerations grouped by anatomic site.

Malignant germ cell tumours of childhood: new associations of genomic imbalance

Malignant germ cell tumours (MGCTs) of childhood are a rare group of neoplasms that comprise many histological subtypes and arise at numerous different sites. Genomic imbalances have been described in these tumours but, largely because of the paucity of cases reported in the literature, it is unclear how they relate to abnormalities in adult MGCTs and impact on potential systems for classifying GCTs. We have used metaphase-based comparative genomic hybridisation to analyse the largest series of paediatric MGCTs reported to date, representing 34 primary tumours (22 yolk sac tumours (YSTs), 11 germinomatous tumours and one metastatic embryonal carcinoma) occurring in children from birth to age 16, including 17 ovarian MGCTs. The large dataset enabled us to undertake statistical analysis, with the aim of identifying associations worthy of further investigation between patterns of genomic imbalance and clinicopathological parameters. The YSTs showed an increased frequency of 1p- (P=0.003), 3p+ (P=0.02), 4q− (P=0.07) and 6q− (P=0.004) compared to germinomatous tumours. Gain of 12p, which is invariably seen in adult MGCTs, was present in 53% of primary MGCTs of children aged 5–16 and was also observed in four of 14 YSTs affecting children less than 5. Two of these cases (14% of MGCTs in children less than 5) showed gain of the 12p11 locus considered to be particularly relevant in adult MGCTs. Gain of 12p showed a significant association with gain of 12q. Conversely, MGCTs without 12p gain displayed a significantly increased frequency of loss on 16p (P=0.04), suggesting that this imbalance may contribute to tumour development in such cases. This data provides new insight into the biology of this under-investigated tumour group and will direct future studies on the significance of specific genetic abnormalities.

Germ cell tumor showing partial trisomy 1 in a gonadectomized intersex child with monosomy X and double Y mosaicism

High incidence of germ cell tumors arising from dysgenetic gonads in patients with sexual chromosome abnormalities has been described, especially in patients with a Y chromosome bearing cell line. Here we report a 14-year-old patient with ambiguous genitalia. Constitutional karyotype showed 45,X/46,X,derY [?t(Yp;Yq)] mosaicism. The patient developed an abdominally located mixed malignant germ cell tumor 5 years after the removal of the dysgenetic gonads. Tumor karyotype showed partial trisomy 1q, a derivative 8q, and a hyperdiploidy with +X, +7, +12, +15, +19, +21, and an unidentified marker.

Screening for Intratubular Germ Cell Neoplasia of the Testis Using OCT4 Immunohistochemistry

Specific populations of patients are at high risk for the development of germ cell neoplasia. OCT4 has been shown to be a sensitive and specific marker for intratubular germ cell neoplasia of the testis. Whether or not OCT4 immunohistochemistry is a clinically useful screening tool in patients at risk for developing malignant germ cell tumors is not currently known. We undertook immunohistochemical staining for OCT4 in a large series of patients who underwent testicular biopsy or orchiectomy for reasons other than for management of a testicular mass suspicious for malignancy (infertility, cryptorchidism, atrophic testicle, etc.). OCT4 nuclear staining was identified in germ cells in 6 of 157 patients, all of whom had clinical risk factors for the development of testicular germ cell tumors. Two of the 6 patients were under 1.5 years of age, making the significance of OCT4 positivity less certain in these cases. The remaining patients with OCT4-positive germ cells consisted of 3 adults and 1 7-year-old child. Intratubular germ cell neoplasia was identified by light microscopy in only 1 of the 6 OCT4-positive cases. OCT4 immunostaining was negative in all patients who presented with infertility and who had no additional germ cell tumor risk factors. OCT4 immunohistochemistry may be useful in identifying early forms of preinvasive germ cell neoplasia in patients with risk factors for the development of malignant testicular germ cell tumors. The low incidence of OCT4 positivity in the adult infertility patients argues against the routine use of OCT4 immunostains in testicular biopsies for infertility unless additional risk factors are present.