Germ Cell Tumors Research Articles

Testicular cancer survivorship program at National Cancer Institute in Slovakia.

e13792 Background: Testicular germ cell tumors (GCTs) are highly curable malignancies. Survivors of GCTs represent a growing population with a long life expectancy after curative cancer treatment. GCT survivors may experience a variety of late adverse effects of treatment and reduced quality of life. Therefore, National Cancer Institute in Slovakia has developed a testicular cancer survivorship program with a long-term follow-up of GCT survivors aiming to evaluate late toxicities and their underlying molecular mechanisms. Methods: The long-term annual follow-up of GCT survivors is established per our institutional guidelines for testicular cancer survivorship program. GCT survivors are referred to our testicular survivorship outpatient clinic at least 5 years after completion of curative treatment, and are followed annually throughout their lives. During each visit, patient’s history is updated, physical examination is performed, blood and urine samples are collected, and survivors complete validated questionnaires for evaluation of late toxicities (peripheral neuropathy, sexual dysfunction, cognitive impairment) and quality of life. Complete blood count, metabolic panel, lipid panel, levels of serum tumor markers, testosterone, luteinizing hormone and follicle stimulating hormone are measured at each visit. Plasma aliquots and urine samples from every visit are prospectively collected and stored in the biobank of our Translational Research Unit. Data including age, medical history, histological type, stage, prognostic group, type of treatment, laboratory values, and questionnaire scores are collected and recorded in our electronic survivorship database. In addition, information on important survivorship topics is provided and healthy lifestyle changes are suggested to all survivors. Results: From August 2015 to January 2024 our testicular survivorship outpatient clinic performed 1733 follow-up visits in 407 GCT survivors treated at our institution from 1984 to 2019. Median age at the first follow-up visit at the survivorship clinic was 41 years (range 21 - 77). Median time from the curative treatment to the first follow-up visit at the survivorship clinic was 7 years (range 4 - 32). To date, 104 patients have had at least 7 follow-ups. Eighty-six (21.13 %) patients were treated with surgery only, 278 (68.3 %) with chemotherapy, 28 (6.88 %) with radiotherapy, and 15 (3.69 %) patients with both chemotherapy and radiotherapy. To date, 18 publications (including papers and abstracts) have been published using the data from our testicular survivorship database. Conclusions: Testicular cancer survivorship program with the long-term annual follow-up of GCT survivors has been established at National Cancer Institute in Slovakia. The ongoing prospective study for evaluation of late toxicities and their underlying mechanisms is part of the program. Our large database offers valuable data for the future research.

Real-world evidence of overall survival (OS) and treatment patterns of patients (pts) with testicular germ cell tumors (GCT) receiving palliative chemotherapy in the United States.

Real-world evidence of overall survival (OS) and treatment patterns of patients (pts) with testicular germ cell tumors (GCT) receiving palliative chemotherapy in the United States.

Molecular characterization of growing teratoma syndrome in patients with testicular germ cell tumor.

e17017 Background: Teratomas are unique neoplastic growths that encompass a diverse array of tissue types derived from multiple germ layers, often exhibiting varying degrees of differentiation. Among the phenomena associated with teratomas, the growing teratoma syndrome (GTS) stands out as a rare yet clinically significant occurrence. GTS, characterized by the persistence or regrowth of teratomatous elements despite initial treatment, poses challenges for both diagnosis and management. In this abstract, we present the results of our expression array analysis of teratomas, aiming to uncover novel insights into their molecular composition, heterogeneity, and potential implications for clinical management. Methods: This study included 53 patients with retroperitoneal teratoma (7 chemotherapy naïve and 46 with postchemotherapy teratoma) and 20 patients with viable postchemotherapy germ cell tumor from retroperitoneum that had surgery at National Cancer Institute in Slovakia and for whom formalin-fixed paraffin-embedded (FFPE) tumor tissue was available. Study also includes samples from 5 patients with normal testis as control group. Ten patients (18.9%) in this cohort had growing teratoma syndrome. Analysis was performed by HTG EdgeSeq Oncology Biomarker panel (HTG Molecular Diagnostics, Inc., Tucson, USA). Identified candidate genes associated with GTS were further validated by immunohistochemistry on FFPE. Results: Molecular profiling indicates no differences in expression profile in retroperitoneal teratomas regardless of previous chemotherapy. Expression analysis indicates 1586 genes being differently expressed with high significance ( p < 0.05) in teratomas compared to normal testis and 1571 genes differentially expressed compared postchemotherapy viable tumors. We identified 14 genes being differently expressed in growing teratoma syndrome compared to teratoma without growth (CYP4A22, IGFBP1, CXCL6, LTF, CYP2C8, CFTR, CCL20, PFKFB3, SLC2A3, LIPA, HMOX1, GPNMB, CCL18, DLK1. Pathway analysis revealed MAPK and PI3K−Akt signaling pathways are mostly dysregulated in GTS. Conclusions: This molecular profiling identify genes differentially expressed in teratomas that are potential biomarkers for prediction of teratoma element in postchemotherapy residues in testicular germ cell tumor patients. Moreover, inhibition of identified signaling pathways associated with GTS could represent potentially novel therapeutic targets in case of unresectable disease.

Prognostic reclassification and survival outcomes in intermediate- and poor-risk nonseminomatous germ cell tumors (NSGCT).

Prognostic reclassification and survival outcomes in intermediate- and poor-risk nonseminomatous germ cell tumors (NSGCT).

Management of relapsed stage I nonseminomatous germ-cell tumor with retroperitoneal only relapse.

Management of relapsed stage I nonseminomatous germ-cell tumor with retroperitoneal only relapse.

Feasibility of tumor-informed circulating tumor DNA (ctDNA) for molecular residual disease (MRD) assessment in pediatric patients with solid tumors.

10058 Background: Circulating Tumor DNA (ctDNA) is a noninvasive biomarker which has been validated as a prognostic tool in multiple adult cancers. There is evolving evidence that ctDNA may be prognostic in pediatric solid tumors, but experience with commercially available assays in pediatric patients is scarce. Signatera is a ctDNA assay which utilizes whole exome sequencing of tumor and whole blood to identify 16 tumor-specific, clonal, somatic variants. These variants are then monitored in plasma as a molecular residual disease (MRD) assessment. Methods: From November 2021 through August 2023, 30 patients were enrolled on a single center study evaluating the feasibility and utility of Signatera MRD monitoring in pediatric patients with solid tumors. Patients 6 months to 25 years of age with any malignant extracranial solid tumor including lymphoma were eligible. Peripheral blood has been collected every 3 weeks to 3 months while on therapy and every 3 to 6 months while off therapy for up to 2 years. A minimum of 22mL of blood was required for the first draw, and 16mL for subsequent draws. Timing of blood draws was aligned with standard of care blood draws when possible. Results of ctDNA MRD were compared with imaging obtained for disease response and surveillance as standard of care. Results: The cohort consisted of 6 cases of neuroblastoma, 6 osteosarcomas, 4 Wilms tumors, 4 carcinomas, 3 soft tissue sarcomas, 2 Ewing sarcomas, 2 germ cell tumors, 2 lymphomas, and one hepatoblastoma. Of 30 patients enrolled, a tumor-informed ctDNA assay was successfully created for 27 (90%). Of 25 patients who had radiographic evidence of disease at any time of monitoring, 23 (92%) had simultaneous detectable ctDNA. Seven patients have had disease recurrence, of whom all seven had detectable ctDNA at or preceding time of recurrence. Conclusions: Signatera tumor-informed ctDNA assay is a feasible noninvasive tool which may be utilized in parallel with standard of care imaging to monitor for disease recurrence in pediatric patients with extracranial solid tumors. Additional analysis of a larger patient cohort is needed to identify tumor types and clinical scenarios for which its application is most useful.

Emergency treatment for primary intracranial germ cell tumours (PICGCTs).

e17020 Background: PICGCTs arise de novo in children and young adults, most frequently in the pineal or suprasellar regions. Here, we evaluate the acute pathway for patients (pts) with PICGCTs managed at our Emergency Cancer Treatment Centre. Methods: Retrospective observational study from 1984-2022 at a single institution. Data was collected from paper and electronic patient records for all PICGCT pts, including pts treated with our intracranial regimen EP-OMB (Etoposide-Cisplatin alternating every week with Vincristine-Methotrexate-Bleomycin) administered with and without intrathecal Methotrexate. Results: To date, we have identified 43 pts with intracranial disease treated at our Centre over 38 years: 25 pts (58%) with PICGCT, 18pts (42%) with germ cell tumour brain metastases treated with EP-OMB and excluded from analysis. Most PICGCT pts are male (92%, n=23) with a median age 25 (range 17-50). The majority present with symptomatic disease (88%, n=22) confined to the pineal gland (72%, n=18), with hormone dysfunction in 24% ( n=6). Only two female pts (8%) have presented with suprasellar and pituitary midline lesions causing headache, progressive visual loss and hypothalamic failure including cranial diabetes insipidus. Eloquent areas in the brain cannot be biopsied so only 60% PICGCTs ( n=15) were confirmed histologically, 47% as germinoma ( n=7), 27% dysgerminoma ( n=4), 27% unclassified ( n=4). Tumour markers (TM) were elevated in all pts with cerebrospinal fluid (CSF) evaluation ( n=5) compared to elevated serum TM in under half (44%, n=12). 68% pts required emergency treatment for a new cancer diagnosis ( n=17): neurosurgery (59%, n=10), chemotherapy (35%, n=6) or radiotherapy (6%, n=1). 88% PICGCT pts received EP-OMB ( n=22) with intrathecal Methotrexate in 63% ( n=14). For all PICGCT pts, 72% pts remain alive ( n=18) with median follow-up 3.8 years (range 0.2-27.3). For 36% pts with TM relapse or radiological progression despite treatment ( n=9), 44.4% remain alive ( n=4) with median overall survival at 6.8 years (range 1.1-18.6). Conclusions: PICGCT pts frequently require emergency surgical treatment for a new cancer diagnosis. Although rare, accurate diagnosis will affect management and prognosis in this young patient group. CSF rather than serum TM analysis is crucial for diagnostic work-up. Consensus on optimal management is warranted given the potential toxicity from multiple therapeutic interventions administered with curative intent.

Staging and Restaging Pediatric Abdominal and Pelvic Tumors: A Practical Guide.

The most common abdominal malignancies diagnosed in the pediatric population include neuroblastoma, Wilms tumor, hepatoblastoma, lymphoma, germ cell tumor, and rhabdomyosarcoma. There are distinctive imaging findings and patterns of spread for each of these tumors that radiologists must know for diagnosis and staging and for monitoring the patient's response to treatment. The multidisciplinary treatment group that includes oncologists, surgeons, and radiation oncologists relies heavily on imaging evaluation to identify the best treatment course and prognostication of imaging findings, such as the image-defined risk factors for neuroblastomas, the PRETreatment EXtent of Disease staging system for hepatoblastoma, and the Ann Arbor staging system for lymphomas. It is imperative for radiologists to be able to correctly indicate the best imaging methods for diagnosis, staging, and restaging of each of these most prevalent tumors to avoid inconclusive or unnecessary examinations. The authors review in a practical manner the most updated key points in diagnosing and staging disease and assessing response to treatment of the most common pediatric abdominal tumors. ©RSNA, 2024 Supplemental material is available for this article.

Brain metastases in testicular cancer: A single-institution experience in Guatemala.

e17019 Background: Brain metastases secondary to germ cell tumors develop in 2 to 3% of patients, in addition to implying a poor prognosis, its incidence in advanced stages increases to 10-15%. The European Urology Association guidelines recommend performing imaging studies using MRI or brain contrasted tomography to rule out metastases in patients with multiple lung metastases, or high beta subunit of human Chorionic Gonadotropin (β-HCG) values, or those in the poor-prognosis International Germ Cell Cancer Collaborative Group (IGCCCG) risk group. Methods: Retrospective descriptive study in patients with brain metastasis for testicular cancer at the Liga Nacional Contra el Cáncer – INCAN Guatemala, from 2018 to 2022. From medical records, we obtained: demographic, clinico-pathological and treatment data. Median was calculated for age, while frequencies and percentages were computed for the categorical variables. Results: Of the 238 patients diagnosed with testicular cancer, 22% (52) presented a β-HCG above 5,000 IU/L, of which 27% (14) developed brain metastases with a mean age of 28 years. Corresponding to 6% of the total cases studied. Among histological subtypes the most common was choriocarcinoma (43%), follow by mixed germ cell cancer (36%), embrionary carcinoma (14%) and classic seminoma (7%). All of the patients belonged to prognostic group S2. Most patients reported first symptom was headache (42%), followed by seizures (21%), cognitive dysfunction (15%), motor dysfunction (10%) and others (12%). Management of these patients included: orchidectomy in all of them, 57% (8) of patients died, of them 50% (4) of patients died before any other therapy. The rest of them, received chemotherapy and none received radiotherapy or surgery for the brain metastases. Conclusions: The presence of brain metastases in testicular cancer increases the mortality produced by the disease as previously reported in other regions of the world, reason why the early suspicion of it, should prompt the evaluation with a brain MRI or computed tomography.

High dose chemotherapy in male patients with germ cell cancer: A population-based study by the SWENOTECA group.

High dose chemotherapy in male patients with germ cell cancer: A population-based study by the SWENOTECA group.

Multicenter analysis of high-dose chemotherapy (HDCT) regimens for the treatment of patients (pts) with recurrent germ cell tumors (GCTs).

Multicenter analysis of high-dose chemotherapy (HDCT) regimens for the treatment of patients (pts) with recurrent germ cell tumors (GCTs).

Fertility preservation in male adolescents with cancer (2011-2020): A retrospective study in China.

According to the studies, more than 80% of pediatric patients with cancer can achieve a survival rate greater than 5 years; however, long-term chemotherapy and/or radiation therapy may seriously affect their reproductive ability. Fertility preservation in adolescents with cancer in China was initiated late, and related research is lacking. Analyze data to understand the current situation and implement measures to improve current practices. From 2011 to 2020, data on 275 male adolescents with cancer whose age ranged from 0 to 19 years old were collected from 16 human sperm banks for this retrospective study. Methods include comparing the basic situation of male adolescents with cancer, the distribution of cancer types, and semen quality to analyze the status of fertility preservation. The mean age was 17.39 ± 1.46 years, with 13 cases (4.7%) aged 13-14 years and 262 cases (95.3%) aged 15-19 years. Basic diagnoses included leukemia (55 patients), lymphomas (76), germ cell and gonadal tumors (65), epithelial tumors (37), soft tissue sarcomas (14), osteosarcoma (7), brain tumors (5), and other cancers (16). There are differences in tumor types in different age stages and regions. The tumor type often affects semen quality, while age affects semen volume. Significant differences were found in sperm concentration and progressive motility before and after treatment (p < 0.001). Moreover, 90.5% of patients had sperm in their semen and sperm were frozen successfully in 244 patients (88.7%). The aim of this study is to raise awareness of fertility preservation in male adolescents with cancer, to advocate for fertility preservation prior to gonadotoxic therapy or other procedures that may impair future fertility, and to improve the fertility status of future patients.

STRIvE-02 Arm C: Phase 1 study of concurrent PD-1 inhibition with B7-H3 CAR T cell immunotherapy for recurrent/refractory pediatric solid tumors.

e14626 Background: B7-H3 expression by a broad range of pediatric solid tumors has led to development of B7-H3-directed chimeric antigen receptor (B7-H3-CAR) T cells. However, early phase clinical trials of B7-H3-CAR T cells in recurrent/refractory solid tumors demonstrated inconsistent CAR T cell expansion and limited anti-tumor activity. We subsequently developed a dual transduced CAR product expressing B7-H3-CAR and CD19-CAR (CARB7H3x19) to enhance CAR T cell expansion with antigenic stimulation by normal B cells (STRIvE-02 Arm B). Augmented expansion was observed but CAR T cell persistence was variable, leading to a hypothesis that concurrent use of pembrolizumab (pembro), a PD1-inhibitor, would help prolong persistence, leading to improved anti-tumor activity. Methods: Patients up to age 26 years with recurrent/refractory solid tumors (excluding primary CNS) enrolled onto Arm C of STRIvE-02 to examine safety and feasibility of CARB7H3x19 at a dose of 0.5 x 106 CD19-CAR T/kg followed by pembro 2 mg/kg (max 200 mg) either 7- (Dose regimen (DR) 1) or 21-days (DR 2) post-CAR T cell using a 3+3 statistical design. All subjects received lymphodepletion with fludarabine and cyclophosphamide prior to CAR T cells. CTCAEv5 was used for toxicity grading. Results: Of six patients (pts) enrolled (age range 11–25 yrs, median 20 yrs, four received CAR T cell+pembro; three received DR1 pembro (day (D)+7), and one received DR2 (D+21). A pt on DR2 with nonseminomatous germ cell tumor developed grade (gr) 5 immune effector cell-associated hyperinflammatory syndrome (IEC-HS) on D+17 prior to pembro, resulting in trial suspension. One pt did not receive CAR T cells and is unevaluable. Adverse effects occurring in pts who received pembro included gr 3 fever in setting of neutropenia (n=1), and gr 2 hyperthyroidism (n=1), with no dose limiting toxicity attributed to CAR T cell+pembro. Maximum circulating CAR T expansion for Arm C was 192.18 cells/uL (range 6.86 – 192.18 cells/uL) with median persistence of 28 days (range 28 - 84), compared to a maximum circulating CAR T expansion of 740.95 cells/uL (range 8.29 – 740.95 cells/uL) and median persistence of 65 days (range 21 - 274) in pts treated on Arm B receiving the same CAR dose level (n=8). D+28 disease restaging in the four Arm C pts who received CAR T cells+pembro demonstrated stable disease (n=1) and disease progression (n=3). Conclusions: Although we observed tolerable toxicity among patients who received CAR T cell+pembro, the small number of patients limit full toxicity assessment. T cell expansion and persistence was observed, but the effects of pembro on CAR T cell fitness are unclear. Phenotypic characterization of circulating CAR T cells is underway to further assess impact of pembro. Of note, this is the first reported death attributed to IEC-HS in a patient after receiving B7-H3-CAR T cells. Investigations into etiology are ongoing. Clinical trial information: NCT04483778 .

Impact of age on clinical trial availability for AYAs with cancer: A time-trend analysis.

1534 Background: Low participation of adolescents and young adults (AYAs, age 15-39 yrs at diagnosis) in cancer clinical trials (CCT) limits their access to novel therapies and hinders the ability to study disease biology and age-specific toxicities. Patient age may be an important barrier as younger and older AYAs may be excluded depending on the trial’s focus. In 2017, the American Society of Clinical Oncology and Friends of Cancer Research issued a joint statement encouraging removal of age as a CCT eligibility criterion unless there is specific biological rationale. To evaluate the impact of this statement, we undertook this analysis of CCT availability for AYAs. Our primary objective was to compare the number of CCT available for AYAs, overall and by tumor types, from 2019-2023 vs previously published data from 2007-2018. The availability of early phase trials and study sponsor was also assessed. Methods: We identified CCT registered on ClinicalTrials.gov from January 2019 to July 2023 enrolling patients with 10 malignancies relevant for AYAs (Hodgkin lymphoma, anaplastic large cell lymphoma, melanoma, extracranial germ cell tumors [GCT], medulloblastoma, thyroid cancer, Ewing sarcoma, osteosarcoma, rhabdomyosarcoma [RMS], and synovial sarcoma). Trials were categorized as adult (≥18 yrs), transitional (patients &lt; or ≥18 yrs), or pediatric (&lt;18 yrs). Transitional trials with an age range 12-18 to &lt;40 yrs were defined as AYA specific trials. Early phase included phase 1 and 1/2 trials; late phase included phase 2/3 and 3 trials. Trial availability from 2007-2018 was identified from a prior analysis by deRojas et al in 2019 (PMID:32337483). The proportion of trials in each category was compared between 2007-2018 and 2019-2023 using z-tests. Results: There were 1071 eligible trials registered on Clinicaltrials.gov: 840 (78%) adult, 226 (21%) transitional, and 5 (0.5%) pediatric. Four trials were AYA-specific. Compared to the prior 10 years, the proportion of transitional trials did not change overall (19% vs 21%, p=0.24) or within any disease. Whereas the proportion of trials available at age 17 has not significantly changed overall (20% vs 21%; p=0.48) or within any disease, the proportion of trials available at age 18 significantly increased (95% vs 98%; p&lt;0.001) in aggregate and specifically for Ewing sarcoma (93% vs 100%; p=0.003), GCT (96% vs 99%; p=0.002), medulloblastoma (86% vs 98%; p=0.006), RMS (87% vs 98%; p=0.007) and thyroid cancer (92% vs 98%; p=0.01). Time trends for transitional trials by phase and sponsor are summarized (Table). Conclusions: Availability of transitional trials for AYAs has not increased, particularly for those &lt;18 yrs. The 18-yr-old age limit continues to be an obstacle in CCT availability and enrollment. [Table: see text]

Primary intracranial germ cell tumors in adolescents and adults: Results of an international, multicenter, retrospective cohort study.

2061 Background: Primary Intracranial Germ Cell Tumors (iGCT) are rare. Previous prospective and retrospective studies mainly included pediatric patients (pts) with a median age of 10-14 years. The aim of this retrospective analysis was to evaluate characteristics, treatment and outcome of adolescents and adults with iGCT. Methods: Data were collected from 10 institutions in Germany and Switzerland. Pts aged &gt;/= 16 years at first diagnosis or at relapse with a primary iGCT were included. Objective responses were evaluated by local investigators. Statistics (Cox proportional hazard model, progression-free survival (PFS) and overall survival (OS) analyzed by Kaplan-Meier method) were performed with SPSS v29. Results: We identified 75 pts (92.0% male) with a median age of 23 years (range 16-60, 94.7% &gt;/= 18 years). At first diagnosis, histology was pure germinoma in 70.7%, pure teratoma in 10.7%, other non-germinomatous GCT (NGGCT) in 13.3%, unknown in 5.3% of pts. Localized, bifocal, and metastatic disease was found in 72.0, 6.7, and 21.3% of pts. As part of their first line (1L) treatment, 69.3%, 80.0%, and 62.7% received surgery, radiotherapy, and chemotherapy, respectively. High dose chemotherapy/ autologous stem cell transplantation (HDCT/ASCT) was part of 1L treatment in n=3 pts with NGGCT. Trimodal and bimodal treatment was performed in 48.0% and 32.0% of pts. Response to 1L therapy was complete remission (CR) in 61.3%, partial remission tumor marker negative (PRm-) in 16.0%, PRm+ in 4.0%, PR with tumor marker status unknown in 4.0%, progressive disease (PD) in 2.7%, and unknown in 12.0%. Relapse occurred in 13/75 pts (17.3%) with unknown histology (n=4), teratoma (n=2), other NGGCT (n=4), and germinoma (n=3). In 2 pts. in whom germinoma was diagnosed at time of first diagnosis, at time of recurrence PNET and Yolk sac tumor were histologically proven. Median time to relapse was 19.0 months (mo.; range 3-223). HDCT/ASCT as salvage treatment was performed in 5 pts with NGGCT and in one pt with germinoma as 2L (n=5) or 3L (n=1). NGGCT histology was associated with increased risk for recurrence or death (p=0.012 and 0.039).3-year PFS was 90.7% (germinoma: 98.1%, NGGCT: 73.9%) and 5-year OS was 92.0% (germinoma: 98.1%; NGGCT: 78.3%). Median follow-up time was 60 mo (range 0-339). Conclusions: Disease characteristics, treatment and outcomes of adolescent/ adult iGCT pts are comparable to those reported in pediatric pts. High cure rates are achieved in pts with pure germinoma and current treatment concepts. In pts with NGGCT further investigation is needed to improve survival outcomes.

Perioperative strategies and management of giant anterior mediastinal tumors: a narrative review.

Giant anterior mediastinal tumors sometimes may cause circulatory collapse and respiratory failure, known as mediastinal mass syndrome (MMS). The prediction and prevention of MMS is challenging. The aim of this study is to summarize the evaluation methods for MMS and formulate treatment strategies for giant anterior mediastinal tumors. We performed a thorough analysis of recent international literature on giant anterior mediastinal tumors (>10 cm in diameter) and MMS published in the PubMed database. The search spanned the duration of the preceding 10 years from August 19, 2023, and only studies published in English were included. Mature teratomas and liposarcomas are the most common giant anterior mediastinal tumors and MMS develops most frequently in case of malignant lymphomas. Here, we propose a new treatment strategy for giant anterior mediastinal tumors. Based on imaging findings, giant anterior mediastinal tumors can be classified as cystic or solid and further blood investigation data are useful for a definitive diagnosis. When malignant lymphoma or malignant germ cell tumor is highly suspected, the first choice of treatment is not surgery but chemotherapy and radiotherapy. Moreover, image-guided drainage may be effective if giant cystic anterior tumors develop into MMS. The risk classification of MMS is important for treating giant anterior mediastinal tumors. If the MMS risk classification is 'unsafe' or 'uncertain', the intraoperative management deserves special attention. The surgical approach should however be based on tumor localization and invasion of surrounding tissues. Multidisciplinary team coordination is indispensable in the treatment of giant anterior mediastinal tumors. When giant anterior mediastinal tumors are encountered, it is important to follow the appropriate treatment strategy, focusing on the development of MMS based on imaging findings and symptoms.

Overall survival and patterns of care for women with rare ovarian cancers: A prospective study from the Australian National Gynae-Oncology Registry (NGOR).

e17554 Background: Ovarian cancer (OC) is a heterogenous group of malignancies, most of which are rare. Data on patterns of care and survival of the most-rare sub-groups of OC (incidence rates &lt; 6 per 100,000) in the real-world setting is limited. This study aims to describe patterns of care and overall survival (OS) for women with rare ovarian cancers in Australia. Methods: Clinical data were sourced from the NGOR and assessed for accuracy and completeness. High grade serous and endometrioid OC subtypes were excluded. Due to incompleteness of survival follow-up data, 3-year OS was only calculated for the state of Victoria. Results: Data on 2812 women with newly diagnosed OC from 2017-2023 within NGOR were collected and 716 women were subsequently identified with rare subtypes of OC. The 5 sub-types with the highest incidences were clear cell (n = 168, 23.4%), mucinous (n=151, 21.1%), adult granulosa cell (n=111, 15.5%), low grade serous (n=98, 13.7%) and carcinosarcoma (n=59, 8.2%). A further 23 additional rare subtypes included germ cell tumours and sex cord stromal tumours. The median follow-up time was 2.6 years and median age at diagnosis was 55 years. Most women had an ECOG 0-1 performance status (n=551, 77.0%). The primary treatment modality was surgery only (n=360, 50%), followed by surgery and systemic therapy (n = 317, 44.2%), systemic therapy only (n=28, 3.9%) and no treatment (n=11, 1.5%). Most women were discussed at a multi-disciplinary meeting (n=701, 97.9%). The diagnosis was confirmed on histology for all women. The 30-day post-operative adverse events (Clavien-Dindo &gt;III severity) was 3.6 % (n=26), with the highest rate of post-operative events in the carcinosarcoma group of 12% (n=6). Using Fisher’s exact test across the 5 most common sub-types described above, there were significant differences in treatment modalities (p&lt;0.001), rates of 30-day post-operative events (p=0.002), age adjusted charlson comorbidity index (p&lt;0.001) and metropolitan versus remote regional status (p=0.007) between the sub-types. Survival at 3 years for these five sub-types of rare OC within the state of Victoria are summarised in the table. The highest 3-year OS was in adult granulosa and low grade serous sub-types. Conclusions: This is a large, real-world analysis of patterns of care and survival for women with rare sub-types of OC. Combining data with international sites will likely further enhance research on patterns of care and outcomes for women with rare OC. [Table: see text]

Metastatic right atrial mass in the presence of atrial septal defect: A rare clinical coincidence

Key Clinical MessageThe key takeaway from this clinical scenario is to choose the most appropriate and reasonable treatment plan when dealing with a patient who has atrial septal defect (ASD) and concurrent atrial and mediastinal masses. In such cases, a heart‐oncology team should make the therapeutic decision.AbstractRight atrial masses are not pretty rare and might be a diagnostic challenge. Thrombosis, tumors, and vegetations are primary differential diagnoses. Workup for these masses usually includes multimodality imaging and biopsy in selected cases. We report a case of a 37‐year‐old lady who presented with cough, dyspnea, and head and neck swelling after a cesarean section. Echocardiography revealed a right atrial mass accompanied by a secundum type atrial septal defect (ASD). Pulmonary CT Angiography was performed, in which a lobulated mass in the anterior mediastinum was detected, and a heart‐oncology team made the therapeutic decision. The patient was scheduled for surgical ASD closure and concomitant tissue biopsy. The pathology results were in favor of poorly differentiated germ cell tumors, and chemotherapy was started following the surgery. After two sessions of chemotherapy, the tumor did not respond to the primary regimen. Thus, an updated regimen was initiated. Compliance with the updated regimen was acceptable, and the patient is currently under treatment and follow‐up.

Yolk sac tumor of the liver: Presentation, diagnosis, and treatment review.

e16371 Background: Yolk Sac Tumor of the Liver (YSTL) is an extremely rare extragonadal germ cell tumor with gonadal origin and histology which presents in the liver. While uncommon, this tumor is often misdiagnosed due to the similarities between YSTL, HCC, and Hepatoblastoma (HB). As this cancer can present with serious mortality, our review aimed to evaluate clinical findings, diagnostic workup, and treatments in patients with YSTL. Methods: We performed a literature search in PubMed from 1950 to October 2023 using filters English language and full text with keywords “Yolk sac tumor of the liver”, “Endodermal Sinus tumor of liver”, “Hepatic Yolk sac tumor”, and “Hepatic Endodermal sinus tumor”. We also conducted a combined search query with all these search terms and “primary”. Patients were included in the study if they had primary YSTL and no other malignancy. Results: Our results looked at 19 patients ranging from 15 months to 64 years with median age being 27 years, including 13 female (68%) and 6 male (32%) patients, percentages reflect the total number of patients. The key presenting symptom in adults was abdominal pain (55%), while the key presenting symptom in children was abdominal distention (63%). All patients in the study had a diagnostic workup that included imaging and pathology. Imaging included CT Abdomen (68%) and MRI (37%), in 58% of patients a solitary mass was seen on imaging, while in 42% of patients multiple hepatic masses were seen. Histology workup mainly noted Shiller Duval Bodies(SDBs)(76%). Molecular Markers included AFP(42%), Alpha-1 anti-trypsin(A1AT)(26%), SALL4(21%), Pancytokeratin(PK)(11%), and Placental-like alkaline phosphatase(PALP)(11%). Treatment included chemotherapy(58%), surgery(47%), transplant(11%), and trans-arterial chemoembolization(5%). Out of the 11 patients who were treated with chemotherapy, 91% received the bleomycin, etoposide, and cisplatin (BEP) regimen. The remaining 9 % of patients received a regimen of cisplatin, adriamycin, and pepleomycin. Conclusions: YSTL is a unique tumor presenting in patients of all ages, tending to present vaguely often with abdominal pain or distension. Diagnostic workup often includes abdominal imaging (MRI and CT Abdomen) and pathology with a focus on SDBs on histologic examination and stains like AFP, A1AT, SALL4, etc. Treatment often focuses on surgery and chemotherapy, notably BEP. Though both HCC and HB traditionally present as a multifocal liver mass on imaging along with positive staining for AFP and PK, our study helps differentiate this tumor from others by emphasizing the importance of SDBs in diagnosis and highlighting new molecular markers to help make the diagnosis easier.

Utilization patterns and outcomes of radiotherapy for patients with germ cell tumor relapsing with brain metastases, with a focus on stereotactic radiosurgery.

Utilization patterns and outcomes of radiotherapy for patients with germ cell tumor relapsing with brain metastases, with a focus on stereotactic radiosurgery.