Reduced and Compressed Cisplatin-Based Chemotherapy in Children and Adolescents With Intermediate-Risk Extracranial Malignant Germ Cell Tumors: A Report From the Children's Oncology Group

Characterizing Lymphovascular Invasion in Pediatric and Adolescent Malignant Ovarian Nongerminomatous Germ Cell Tumors: A Report from the Children's Oncology Group

BACKGROUND

Lymphovascular invasion (LVI) has been identified as a poor prognostic factor for a variety of tumors; however, its significance in malignant ovarian germ cell tumors (MOGCT) in pediatric and adolescent patients is not well described. We aim to clarify the significance of LVI in the subset of patients with nongerminomatous MOGCT.

METHODS

Records of patients 0-20 years of age with MOGCT enrolled on Children's Oncology Group study AGCT0132 were reviewed. Patients with documented presence or absence of LVI in either institutional or central review pathology reports were included.

RESULTS

Of 130 patients with MOGCTs, 83 patients had of the presence or absence of LVI documented in their pathology report. 42/83 patients (50.6%) were found to have LVI present. The estimated odds of having LVI was higher in patients with stage II and III disease, 11 years and older and with the presence of choriocarcinoma. Event-free survival (EFS) and overall survival (OS) remained high in patients with LVI. Approximately 50% of patients with a documented LVI status in either institutional pathology report or central review were found to have LVI.

CONCLUSIONS

The presence of LVI was higher in tumors with adverse risk factors including higher stage and age greater than 11 years. While LVI was not associated with EFS or OS in the intermediate risk group, further work is necessary to determine the effect of LVI on long-term disease-free survival. We, therefore, recommend routinely incorporating LVI status into institutional pathology reports for pediatric and adolescent patients with MOGCT.

LEVEL OF EVIDENCE

III.

Clinical characteristics of malignant germ cell tumors in adolescents: A multicenter 10-year retrospective study in Beijing

Background

The aim of this study was to review clinical features of adolescent malignant germ cell tumors (MGCTs) in Beijing and analyze the peculiar characteristics of this age group.

Methods

Clinical characteristics, pathological presentations, and survival outcomes of 34 patients were analyzed retrospectively.

Results

Of 34 patients, 12 girls and 22 boys, 18 (52.9%) had an extra-cranial tumor, including one testicular tumor, five ovarian tumors, one sacrococcygeal tumor, and 11 mediastinal tumors. Histologically, we found immature teratomas (n = 6), yolk sac tumors (n = 5), mixed malignant tumors (n = 5), an embryonic carcinoma (n = 1), and seminoma (n = 1). Three-year event-free survival (EFS) and overall survival (OS) were 48.8% and 62.9%, respectively. Another 16 (47.1%) patients had an intracranial tumor, including nine in the pineal region, five in the suprasellar region, one in basal ganglia, and one in cerebellopontine. All patients had localized disease and an excellent outcome with 3-year EFS and OS of 93.7% and 100%, respectively.

Conclusions

Adolescent MGCTs are rare with a strong dependence on gender, and the mediastina and pineal region are the most common tumor locations. The prognosis is promising compared with that of other adolescent tumors and MGCTs in other age groups. MGCTs in mediastina have a tendency to companion with other hematological malignancies, and the prognosis is extremely poor in these patients.

Outcome and late effects of patients treated for childhood vaginal malignant germ cell tumors

PURPOSE

Vaginal malignant germ cell tumors (MGCT) are rare, occurring in children less than 2 years old and raise the question of the optimal local treatment.

METHODS

We included children treated for vaginal MGCT according to the French TGM-95/2013 regimen. Patients were classified as standard risk (SR: localized disease and alpha-fetoprotein (AFP) < 10,000 ng/mL) or high risk (HiR: metastatic and/or AFP > 10,000 ng/mL) and were treated, respectively, with three to five VBP (vinblastine-bleomycin-cisplatin) or four to six VIP (etoposide-ifosfamide-cisplatin), followed by conservative surgery and/or brachytherapy in case of post-chemotherapy residuum.

RESULTS

Fourteen patients were included (median age = 12 months), of which six (43%) were classified as HiR. AFP levels were normalized after first-line chemotherapy in all cases but one. A vaginal post-chemotherapy residuum (median size = 8 mm, range: 1-24 mm) was observed in 13/14 patients, treated by complete resection in seven of 13 (viable cells in three of seven), incomplete resection in four of 13 (viable cells in two of four), with adjuvant brachytherapy in two of 13, and exclusive brachytherapy in two of 13 (viable cells in one of six). Among the six patients with viable disease, four patients received adjuvant chemotherapy. One patient (SR) experienced immediate postoperative relapse despite presenting no viable residual cells and was treated with four VIP cycles and brachytherapy. At last follow-up (median = 4.6 years, range: 0.5-16), all patients were alive in complete remission. Five patients suffered from vaginal sequelae with synechiae and/or stenosis (of whom four had undergone brachytherapy).

CONCLUSION

Childhood vaginal MGCTs show a highly favorable prognosis with risk-adapted chemotherapy and local treatment of post-chemotherapy residuum (preferably by conservative surgery with partial vaginectomy). Brachytherapy could be an alternative when conservative surgery is not deemed possible or in cases of incomplete resection with residual viable cells.

Extracranial Germ Cell Tumors in Children: Ten Years of Experience in Three Children's Medical Centers in Shanghai

OBJECTIVE

The aim was to describe the clinical features of extracranial germ cell tumors (GCTs) in pediatrics and study the clinical risk factors related to survival for malignant germ cell tumors (MGCTs) in order to optimize therapeutic options.

METHODS

The clinical data of children with extracranial GCTs in three children's medical centers in Shanghai were retrospectively analyzed.

RESULTS

In total, 1007 cases of extracranial GCTs diagnosed between 2010 and 2019 were included in this study, including teratomas (TERs) 706 (70.11%) and MGCTs 301 (29.89%). There were twice as many TER cases as MGCT cases. Approximately 50% of children with GCTs were <3 years old (43.39% for TERs, 67.13% for MGCTs). GCTs in children of different ages show differences in tumor anatomical locations and pathological subtypes. The 5-year event-free survival (EFS) and overall survival (OS) of all patients with MGCTs were 82.33% (95% CI, 77.32%, 86.62%) and 94.13% (95% CI, 90.02%, 96.69%), respectively. The multivariate Cox regression analysis identified a primary site in the mediastinum and alpha fetoprotein (AFP) levels ≥10,000 ng/mL as independent adverse prognostic factors (p < 0.0.0001, χ2 = 23.6638, p = 0.0225, χ2 = 5.2072.). There were no significant differences in OS among children receiving various chemotherapy regimens, such as the BEP, PEB, JEB and other regimens (VBP/VIP and AVCP/IEV) (p < 0.05).

CONCLUSIONS

The clinical features of GCTs in Chinese pediatrics are similar to those reported in children in Europe and America. The age distribution of pathological types and primary sites in GCTs reflect the developmental origin of type I and type II GCTs transformed from mismigration primordial germ cells (PGCs). Optimizing the current platinum-based chemotherapy regimens and exploring the treatment strategies for MGCTs of the mediastinum are future research directions.

Children's Oncology Group's 2023 blueprint for research: Germ cell tumors

Extracranial germ cell tumors (GCT) are a biologically diverse group of tumors occurring in children, adolescents, and young adults. The majority of patients have excellent outcomes, but treatment-related toxicities impact their quality of survivorship. A subset of patients succumbs to the disease. Current unmet needs include clarifying which patients can be safely observed after initial surgical resection, refinement of risk stratification to reduce chemotherapy burden in patients with standard-risk disease, and intensify therapy for patients with poor-risk disease. Furthermore, enhancing strategies for detection of minimal residual disease and early detection of relapse, particularly in serum tumor marker-negative histologies, is critical. Improving the understanding of the developmental and molecular origins of GCTs may facilitate discovery of novel targets. Future efforts should be directed toward assessing novel therapies in a biology-driven, biomarker-defined, histology-specific, risk-stratified patient population. Fragmentation of care between subspecialists restricts the unified study of these rare tumors. It is imperative that trials be conducted in collaboration with national and international cooperative groups, with harmonized data and biospecimen collection. Key priorities for the Children's Oncology Group (COG) GCT Committee include (a) better understanding the biology of GCTs, with a focus on molecular targets and mechanisms of treatment resistance; (b) strategic development of pediatric and young adult clinical trials; (c) understanding late effects of therapy and identifying individuals most at risk; and (d) prioritizing diversity, equity, and inclusion to reduce cancer health disparities and studying the impacts of social determinants of health on outcomes.

Surgical treatment confers prognostic significance in pediatric malignant mediastinal germ cell tumors

BACKGROUND

Primary malignant mediastinal germ cell tumors (GCTs) are rare pediatric tumors that have a poorer prognosis compared to GCTs occurring elsewhere in the body. The current study aimed to assess the prognostic factors and treatment outcomes of children with primary malignant mediastinal GCT in Taiwan.

METHODS

The authors retrospectively reviewed children 0-18 years old who were newly diagnosed with primary malignant mediastinal GCT between January 1, 2005 and December 31, 2019 and were registered in the Taiwan Pediatric Oncology Group patient registry. The impact of presenting characteristics, including sex, age, tumor stage, histology subtype, surgical treatment, and chemotherapy regimens of the patients were analyzed.

RESULTS

This study enrolled 52 children with malignant mediastinal GCT who had a median age of 16.0 (range, 6.0-17.9) years at diagnosis. The most common histological subtypes were mixed GCTs (n = 20) and yolk sac tumors (n = 15). Advanced disease stage and choriocarcinoma histology subtype were associated inferior outcomes. Children who received surgical treatment exhibited better outcomes compared to those who did not (5-year overall survival, 78% vs. 7%, p < .001). After comparing patients who received first-line cisplatin- and carboplatin-based chemotherapy, no difference in treatment outcomes was observed. Multivariate analysis showed that surgical management was the only independent predictor for superior OS.

CONCLUSIONS

Surgical treatment is recommended for mediastinal GCT. Cisplatin-based chemotherapy was not superior to carboplatin-based chemotherapy as first-line treatment and may be avoided due to toxicity concerns.

Update on pediatric testicular germ cell tumors

BACKGROUND

Testicular germ cell tumors are uncommon tumors that are encountered by pediatric surgeons and urologists and require a knowledge of appropriate contemporary evaluation and surgical and medical management.

METHOD

A review of the recommended diagnostic evaluation and current surgical and medical management of children and adolescents with testicular germ cell tumors based upon recently completed clinical trials was performed and summarized in this article.

RESULTS

In this summary of childhood and adolescent testicular germ cell tumors, we review the initial clinical evaluation, surgical and medical management, risk stratification, results from recent prospective cooperative group studies, and clinical outcomes. A summary of recently completed clinical trials by pediatric oncology cooperative groups is provided, and best surgical practices are discussed.

CONCLUSIONS

Testicular germ cell tumors in children are rare tumors. International collaborations, data-sharing, and enrollment of patients at all stages and risk classifications into active clinical trials will enhance our knowledge of these rare tumors and most importantly improve outcomes of patients with testicular germ cell tumors.

LEVEL OF EVIDENCE

This is a review article of previously published and referenced level 1 and 2 studies, but also includes expert opinion level 5, represented by the American Pediatric Surgical Association Cancer Committee.

Treatment and Survival of Malignant Extracranial Germ Cell Tumours in the Paediatric Population: A Systematic Review and Meta-Analysis

OBJECTIVE

This systematic review and meta-analysis was performed to explore overall survival (OS) and event free survival (EFS) rates internationally over the past two decades and to define specific subgroups with inferior outcomes which may demand different treatment strategies.

METHODS

The search focused on malignant extracranial germ cell tumours (GCTs) in the paediatric population. The initial database search identified 12,556 articles; 32 articles were finally included in this review, comprising a total of 5095 patients.

RESULTS

The studies were heterogeneous, varying from single institution reports to large prospective trials. Older studies, describing eras where non-platinum-based chemotherapy regimens were used, showed clearly worse outcomes. Survival for stage I-II gonadal disease is excellent. On the other hand, patients with an initial alpha-fetoprotein (AFP) > 10,000 ng/mL or kU/L, age > 11 years and stage IV disease confer a survival disadvantage. For testicular disease in particular, lymphovascular invasion and certain histopathological subtypes, such as embryonal carcinoma (EC) and mixed malignant GCTs, survival is poorer. Survival data for sacrococcygeal and mediastinal GCTs show a heterogeneous distribution across studies in this review, independent of year of publication. Patients > 12 years presenting with a mediastinal GCT pose a subpopulation which fares worse than GCTs in other locations or age groups. This is independent of AFP levels, stage of disease or treatment protocol, and these patients may demand a different treatment strategy.

CONCLUSIONS

This review describes the heterogeneous nature of GCTs in different anatomical locations, impacting on stage at presentation, treatment modalities used and survival data. Despite this heterogeneity, in line with the current developmental biology-based classification system, subpopulations can be defined which have an inferior EFS and OS and where future research and more individualised treatment would help to improve survival.

Imaging Appearance of Nongerminoma Pediatric Ovarian Germ Cell Tumors Does Not Discriminate Benign from Malignant Histology

STUDY OBJECTIVE

Pediatric ovarian neoplasms with imaging appearance suggestive of teratoma are often presumed to have low risk of malignancy. We assessed the pre-operative imaging appearance of pediatric malignant ovarian germ cell tumors (MOGCT) and the presence of associated teratoma in a series of MOGCT.

DESIGN

Retrospective review of clinical and pathology data.

SETTING

Multicenter trial for extracranial malignant germ cell tumors in young female individuals by the Children's Oncology Group (COG study AGCT0132) that included yolk sac tumor, embryonal carcinoma and choriocarcinoma.

PARTICIPANTS

Female individuals 0-20 years of age at enrollment with ovarian primary nonseminomatous malignant germ cell tumors.

INTERVENTIONS

Review of data forms, including prospectively collected surgical checklist documenting imaging characteristics of the tumor, and review of pathology reports.

MAIN OUTCOME MEASURES

Description of imaging appearance and frequency of mixed histology with benign teratoma elements.

RESULTS

A total of 138 female individuals (11 months to 20 years of age) had primary ovarian tumors. Imaging appearance and pathology information were available for 133 patients. Among the 133 patients, tumor appearance was solid (10.5%), solid with calcification (3.0%), mixed cystic and solid (58.7%), mixed cystic and solid with calcification (24.8%), and unknown (3.0%). In all, 54% had elements of teratoma in addition to malignant histology.

CONCLUSION

Mixed cystic and solid appearance with or without calcification was seen in 83.5% of pediatric ovarian malignant germ cell tumors. Associated benign teratoma was common. The presence of a mixed cystic and solid appearance on preoperative imaging should not dissuade the surgeon from obtaining preoperative serum markers and undertaking complete surgical staging.

Outcomes of adolescent males with extracranial metastatic germ cell tumors: A report from the Malignant Germ Cell Tumor International Consortium

BACKGROUND

Adolescents with extracranial metastatic germ cell tumors (GCTs) are often treated with regimens developed for children, but their clinical characteristics more closely resemble those of young adult patients. This study was designed to determine event-free survival (EFS) for adolescents with GCTs and compared them with children and young adults.

METHODS

An individual patient database of 11 GCT trials was assembled: 8 conducted by pediatric cooperative groups and 3 conducted by an adult group. Male patients aged 0 to 30 years with metastatic, nonseminomatous, malignant GCTs of the testis, retroperitoneum, or mediastinum who were treated with platinum-based chemotherapy were included. The age groups were categorized as children (0 to <11 years), adolescents (11 to <18 years), and young adults (18 to ≤30 years). The study compared EFS and adjusted for risk group by using Cox proportional hazards analysis.

RESULTS

From a total of 2024 individual records, 593 patients met the inclusion criteria: 90 were children, 109 were adolescents, and 394 were young adults. The 5-year EFS rate was lower for adolescents (72%; 95% confidence interval [CI], 62%-79%) than children (90%; 95% CI, 81%-95%; P = .003) or young adults (88%; 95% CI, 84%-91%; P = .0002). The International Germ Cell Cancer Collaborative Group risk group was associated with EFS in the adolescent age group (P = .0020). After adjustments for risk group, the difference in EFS between adolescents and children remained significant (hazard ratio, 0.30; P = .001).

CONCLUSIONS

EFS for adolescent patients with metastatic GCTs was similar to that for young adults but significantly worse than for that children. This finding highlights the importance of coordinating initiatives across clinical trial organizations to improve outcomes for adolescents and young adults.

LAY SUMMARY

Adolescent males with metastatic germ cell tumors (GCTs) are frequently treated with regimens developed for children. In this study, a large data set of male patients with metastatic GCTs across different age groups has been built to understand the outcomes of adolescent patients in comparison with children and young adults. The results suggest that adolescent males with metastatic GCTs have worse results than children and are more similar to young adults with GCTs. Therefore, the treatment of adolescents with GCTs should resemble therapeutic approaches for young adults.

Germ Cell Tumors in Adolescents and Young Adults

Germ cell tumors (GCTs) are rare in childhood, representing only 3.5% of childhood cancers, but a common malignancy in adolescents and young adults (AYAs), accounting for 13.9% of neoplasms in adolescents between age 15 and 19 years. The overall outcomes of patients treated for GCTs are excellent. However, as seen in other cancers, outcomes for AYA patients are significantly worse. Understanding the reasons for this observation has led to different approaches to diagnosis, staging, and treatment. The Malignant Germ Cell International Consortium was created to bring together pediatric, gynecologic, and testicular cancer specialists to promote research initiatives and provide evidence-based approaches in the management of GCTs across different age groups. Collaboration between multiple subspecialties is essential to further understand the disease continuum, the underlying biologic characteristics, and the development of appropriate therapeutic approaches. This review focuses on the unique characteristics of patients with extracranial GCTs in the AYA group.

Squamous Cell Carcinoma Malignantly Transformed From Frequent Recurrence of a Presacral Epidermoid Cyst: Report of a Case

Backgroud: Presacral tumors are rare space occupying lesions that arise in the presacral space. The incidence of presacral tumor has been reported to be 1 in 40,000 to 63,000 patients. An even rarer occurrence is the transformation of a presacral tumor into a squamous cell carcinoma (SCC).

Case Summary: A 61 years old man was referred to our hospital for a palpable mass near anus and appeared repeatedly in last 10 years. The patient previously underwent two surgeries at another hospital. A posterior approach was implemented in the first two surgeries, and the diagnosis was benign presacral epidermoid cyst. Two months before his admission to our department in 2017, the patient complained of a mass measuring ~2 cm around his anus. Physical examination revealed a 2 cm mass at the 12 o'clock direction in chest-knee position. A digital rectal examination indicated a rubbery lesion located in the presacral space. The Pre-operative pelvic magnetic resonance imaging (MRI) confirmed the presence of a 6.8 cm * 5.2 cm * 7.3 cm mass located at the presacral space. In contrast phase, the center of the lesion exhibited homogenous density without enhancement. The mass was then excised via posterior para-sacral approach with pathological report showing a benign epidermoid cyst after operation. The patient was discharged with full recovery without fecal incontinence. Fifteen months after being discharged from our hospital, the patient discovered a recurrence at the original site of where the mass previously appeared. Unlike the previous instance, the mass was accompanied with swelling, pain, and localized increased skin temperature. Pelvic MRI showed a 3.2 cm * 7.2 cm * 5.8 cm located at the same place, with no enhance in the core of mass. However, a speckled enhancement was observed on the margin of the lesion. The lesion was completely resected using the same procedure as before with a pathological diagnosis of SCC. The patient underwent chemoradiation therapy and remained disease free for more than 1 year.

Conclusion: Although very rare, benign cyst from presacral space can become malignant transformation. This highlights the importance of pre-operative diagnostic tests and evaluation to correctly identify the source of the primary cancer, which is crucial prior to starting adjuvant therapy.

Clinicopathologic Features and Chromosome 12p Status of Pediatric Sacrococcygeal Teratomas: A Multi-institutional Analysis

Chromosome 12p gains are typically present in postpubertal male patients with testicular malignant germ cell tumors, including most teratomas, and absent in pure ovarian teratomas, both mature and immature. We sought to evaluate the clinicopathologic features and chromosome 12p status of pediatric patients with sacrococcygeal teratomas (SCTs) using the institutional databases of 2 tertiary medical centers. Seven mature teratomas (3 pure, 2 with yolk sac tumor, 1 with medulloepithelioma, and 1 with ependymoma) and 3 immature teratomas (2 pure: grade 2 and grade 3 and 1 mixed: grade 3 with yolk sac tumor) were identified. All patients underwent surgery and 2 received adjuvant chemotherapy. Fluorescence in situ hybridization analysis was performed to elucidate chromosome 12p gains, including isochromosome 12p. All 10 tumors analyzed lacked 12p gains regardless of the components. No patient had evidence of disease at their most recent interval follow-up (mean: 30, range: 7-91 months), irrespective of margin status or of receiving chemotherapy. Overall, our study suggests an absence of chromosome 12p abnormalities in clinically nonaggressive SCTs. Additional data are required to confirm these findings before definitive patient care recommendations can be made.

Detection of Relapse by Tumor Markers Versus Imaging in Children and Adolescents With Nongerminomatous Malignant Germ Cell Tumors: A Report From the Children's Oncology Group

PURPOSE

To investigate relapse detection methods among children and adolescents with nongerminomatous malignant germ cell tumors (MGCTs) and to determine whether tumor markers alone might be sufficient for surveillance.

METHODS

We retrospectively reviewed all patients enrolled in a phase III, single-arm trial for low-risk and intermediate-risk MGCTs. The method used to detect relapse was assessed based on case report forms, tumor markers, imaging, and pathology reports. Relapses were classified into one of two categories on the basis of whether they were (1) detectable by tumor marker elevation or (2) not detectable by tumor markers.

RESULTS

A total of 302 patients were enrolled, and 284 patients had complete data for review. Seven patients had normal tumor markers at initial diagnosis, and none experienced a relapse. At a median follow-up of 5.3 years, 48 patients (16.9%) had experienced a relapse. After central review, 47 of 48 relapses (98%) were detected by tumor marker elevation. Of the 47 patients, 16 (33.3%) had abnormal tumor markers with normal/unknown imaging, 31 patients (64.6%) had abnormal tumor markers with abnormal imaging, and one patient (2.1%) had abnormal imaging with unknown marker levels at relapse.

CONCLUSION

Tumor marker elevation is a highly sensitive method of relapse surveillance, at least among children and adolescents with tumor marker elevation at initial diagnosis. Eliminating exposure to imaging with ionizing radiation may enhance the safety of relapse surveillance in patients treated for MGCT.

Malignant testicular germ cell tumors in children and adolescents: The AIEOP (Associazione Italiana Ematologia Oncologia Pediatrica) protocol

OBJECTIVES

We report the results of an Associazione Italiana Ematologia Oncologia Pediatrica (AIEOP) study on the treatment of testicular germ cell tumors (TGCT) with a pediatric PEB (pPEB) regimen (cisplatin 25 mg/m² daily on days 1-4; etoposide 100 mg/m² daily on days 1-4; bleomycin 15 mg/m² on day 2, once per cycle).

METHODS AND MATERIALS

Male patients under 18 years old with malignant TGCT were enrolled for a second national prospective protocol. All patients underwent orchiectomy at diagnosis. Those with Stage I received no chemotherapy; those with Stage II-III disease received three cycles of pPEB; and those with Stage IV received four cycles. After chemotherapy, resection of radiologically-evident residual disease was recommended. The main study end-points were overall survival and relapse-free survival.

RESULTS

Ninety-nine boys from 0.5 to 17.8 years old (median 15.4 years) were evaluable, and staged as follows: 58 Stage I (59%), 7 Stage II (7%), 14 Stage III (14%), and 20 Stage IV (20%). With a median follow-up of 59 months (range 4-165 months), 5-year relapse-free survival (95% CI) was 73% (65%-83%) for the whole sample, 65% (53%-79%) for Stage I patients, and 86% (75%-98%) for Stage II-IV patients. Five-year overall survival (95% CI) was 99% (97%-100%).

CONCLUSIONS

We confirmed a good prognosis for malignant TGCT in children and adolescents. Reducing the number of chemotherapy cycles for Stage II-III disease does not seem to negatively affect survival outcomes.

Gonadal dysgenesis is associated with worse outcomes in patients with ovarian nondysgerminomatous tumors: A report of the Children's Oncology Group AGCT 0132 study

PURPOSE

In this report, we characterize the timing and behavior of malignant ovarian germ cell tumors (GCTs) in pediatric patients with dysgenetic gonads compared to those with normal gonadal development.

PATIENTS AND METHODS

Patients from the Children's Oncology Group AGCT0132 with malignant ovarian GCTs were included. Within this population, we sought to identify patients with gonadoblastoma, streak ovaries, or other evidence of gonadal dysgenesis (GD). Patients with malignant GCTs containing one or more of the following histologies-yolk sac tumor, embryonal carcinoma, or choriocarcinoma-were included. Patients were compared with respect to event-free survival (EFS) and overall survival (OS).

RESULTS

Nine patients with GD, including seven with gonadoblastoma (mean age, 9.3 years), were compared to 100 non-GD patients (mean age, 12.1 years). The estimated 3-year EFS for patients with GD was 66.7% (95% CI 28.2-87.8%) and for non-GD patients was 88.8% (95% CI 80.2-93.8%). The estimated 3-year OS for patients with GD was 87.5% (95% CI 38.7-98.1%) and for non-GD patients was 97.6% (95% CI of 90.6-99.4%).

CONCLUSION

Patients presenting with nongerminomatous malignant ovarian GCTs in the context of GD have a higher rate of events and death than counterparts with normal gonads. These findings emphasize the importance of noting a contralateral streak ovary or gonadoblastoma at histology for any ovarian GCT and support the recommendation for early bilateral gonadectomy in patients known to have GD with Y chromosome material. In contrast to those with pure dysgerminoma, these patients may represent a high-risk group that requires a more aggressive chemotherapy regimen.

EGF Receptor and mTORC1 Are Novel Therapeutic Targets in Nonseminomatous Germ Cell Tumors

Germ cell tumors (GCT) are malignant tumors that arise from pluripotent embryonic germ cells and occur in children and young adults. GCTs are treated with cisplatin-based regimens which, while overall effective, fail to cure all patients and cause significant adverse late effects. The seminoma and nonseminoma forms of GCT exhibit distinct differentiation states, clinical behavior, and response to treatment; however, the molecular mechanisms of GCT differentiation are not fully understood. We tested whether the activity of the mTORC1 and MAPK pathways were differentially active in the two classes of GCT. Here we show that nonseminomatous germ cell tumors (NSGCT, including embryonal carcinoma, yolk sac tumor, and choriocarcinoma) from both children and adults display activation of the mTORC1 pathway, while seminomas do not. In seminomas, high levels of REDD1 may negatively regulate mTORC1 activity. In NSGCTs, on the other hand, EGF and FGF2 ligands can stimulate mTORC1 and MAPK signaling, and members of the EGF and FGF receptor families are more highly expressed. Finally, proliferation of NSGCT cells in vitro and in vivo is significantly inhibited by combined treatment with the clinically available agents erlotinib and rapamycin, which target EGFR and mTORC1 signaling, respectively. These results provide an understanding of the signaling network that drives GCT growth and a rationale for therapeutic targeting of GCTs with agents that antagonize the EGFR and mTORC1 pathways. Mol Cancer Ther; 17(5); 1079-89. ©2018 AACR.