Pilot study of cisplatin, etoposide, bleomycin, and escalating dose cyclophosphamide therapy for children with high risk germ cell tumors: a report of the children's oncology group (COG)

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.

Excellent Outcomes in Children, Adolescents, and Young Adults with Ovarian Germ Cell Tumors Treated by Either Reduced- or Standard-Dose Bleomycin

To investigate the outcomes of children, adolescents, and young adults (AYAs) with malignant ovarian germ cell tumors (MOGCTs), we analyzed the data of 61 patients aged ≤39 years diagnosed with MOGCT between 2006 and 2022. Among 59 patients who received chemotherapy after initial diagnosis, 57 received BEP (standard dose of bleomycin with 30 units per week, n = 13) or bEP (reduced dose of bleomycin with 15 units/m2 on day 1, n = 44). The 5-year overall survival (OS) and event-free survival (EFS) rates were 98.3% and 84.9%, respectively. Reduced bleomycin dose did not adversely affect survival. Normalization of tumor markers within 3 months after surgery was significantly associated with better EFS (p < 0.01). Of the 59 surviving patients, 8 experienced surgery-related menopause, while 49 demonstrated menstrual recovery. After completion of chemotherapy, there was no significant difference in pulmonary function regarding bleomycin dose, and no overt nephrotoxicity. Approximately 60% and 25% of survivors experienced peripheral neuropathy at the end of chemotherapy and after 1 year, respectively (p < 0.01). Children and AYAs with MOGCT have favorable survival rates with minimal long-term toxicity, which are not influenced by a reduced bleomycin dose. Rapid normalization of tumor markers is associated with improved outcomes.

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.

The Nitrogen Mustards

The nitrogen mustards are powerful cytotoxic and lymphoablative agents and have been used for more than 60 years. They are employed in the treatment of cancers, sarcomas, and hematologic malignancies. Cyclophosphamide, the most versatile of the nitrogen mustards, also has a place in stem cell transplantation and the therapy of autoimmune diseases. Adverse effects caused by the nitrogen mustards on the central nervous system, kidney, heart, bladder, and gonads remain important issues. Advances in analytical techniques have facilitated the investigation of the pharmacokinetics of the nitrogen mustards, especially the oxazaphosphorines, which are prodrugs requiring metabolic activation. Enzymes involved in the metabolism of cyclophosphamide and ifosfamide are very polymorphic, but a greater understanding of the pharmacogenomic influences on their activity has not yet translated into a personalized medicine approach. In addition to damaging DNA, the nitrogen mustards can act through other mechanisms, such as antiangiogenesis and immunomodulation. The immunomodulatory properties of cyclophosphamide are an area of current exploration. In particular, cyclophosphamide decreases the number and activity of regulatory T cells, and the interaction between cyclophosphamide and the intestinal microbiome is now recognized as an important factor. New derivatives of the nitrogen mustards continue to be assessed. Oxazaphosphorine analogs have been synthesized in attempts to both improve efficacy and reduce toxicity, with varying degrees of success. Combinations of the nitrogen mustards with monoclonal antibodies and small-molecule targeted agents are being evaluated. SIGNIFICANCE STATEMENT: The nitrogen mustards are important, well-established therapeutic agents that are used to treat a variety of diseases. Their role is continuing to evolve.

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.

Feasibility and efficacy of gonadotropin-releasing hormone agonists for the prevention of chemotherapy-induced ovarian insufficiency in patients with malignant ovarian germ cell tumours (KGOG 3048R)

BACKGROUND

This study assessed the effects of gonadotropin-releasing hormone agonists (GnRHa) on the prevention of chemotherapy-induced ovarian insufficiency among young patients with malignant ovarian germ cell tumour (MOGCT) receiving chemotherapy.

METHODS

This multicentre, retrospective study was conducted at 15 sites affiliated with the Korean Gynecologic Oncology Group and enrolled 354 patients between January 1995 and September 2018. Among them, 227 patients were included in this study and divided into two groups according to the use of GnRHa during chemotherapy (GnRHa versus no GnRHa groups). The primary objective was to compare the rates of menstrual resumption between the two groups. We also assessed the clinical determinants affecting menstrual resumption among the study groups.

RESULTS

There were no significant differences between the GnRHa (n = 63) and no GnRHa (n = 164) groups regarding age at diagnosis, parity, ethnicity, age at menarche, body mass index, International Federation of Gynecology and Obstetrics stage, mode of surgery and surgery type. The rate of menstrual resumption after chemotherapy was 100% (63 of 63) in the GnRHa group and 90.9% (149 of 164) in the no GnRHa group (p = 0.013). The mean periods from last chemotherapy to menstrual resumption were 7.4 and 7.3 months in the GnRHa and no GnRHa groups, respectively. GnRHa co-administration during chemotherapy reduced the likelihood of amenorrhoea after chemotherapy, although statistical significance was not confirmed in the univariate analysis (odds ratio: 0.276; 95% confidence interval, 0.004-1.317; p = 0.077).

CONCLUSION

Temporary ovarian suppression with GnRHa during chemotherapy does not significantly increase the chances of menstrual resumption in young patients with MOGCT.

Pediatric mediastinal germ cell tumors

Mediastinal germ cell tumors (GCTs) are a rare and heterogeneous group of neoplasms. Although histologically resembling their gonadal counterparts, they differ considerably in their clinical characteristics, biological behavior and prognostic outcome. The rarity of mediastinal GCTs has hindered their meaningful analysis, with most studies and clinical trials including them along with other extragonadal GCTs, which has led to a lack of consensus on optimal treatment strategies, and a lull in improvement in patient outcomes. Diagnosis of mediastinal GCT requires a multipronged approach, and encompasses multidisciplinary treatment including chemotherapy followed by surgery, with or without radiotherapy. In view of sustained response rates to current management protocols, the focus needs to be shifted to identifying patients in whom treatment regimens can be downscaled with the aim of decreasing long term morbidity and improving quality of life in low risk patient groups, while improving survival rates in poor risk patient subsets. In this scenario, better understanding of the molecular pathogenesis of these tumors may lead to identification of novel biomarkers and therapeutic targets, as well as improved disease segmentation and risk stratification, thus helping to avoid the toxicity and morbidity associated with current one-fits-all treatment strategies. Multi-institutional collaborations across continents are necessary to generate meaningful data, and are the face of future developments in this arena.

Is carboplatin-based chemotherapy as effective as cisplatin-based chemotherapy in the treatment of advanced-stage dysgerminoma in children, adolescents and young adults?

OBJECTIVE

Dysgerminoma is the most common malignant ovarian germ cell tumor (GCT) with peak incidence during adolescence and young adulthood. Current standard of care for patients with disease that has spread outside of the ovary (advanced-stage) utilizes platin-based chemotherapy regimens. The study objective was to compare clinical outcomes between platin-based (carboplatin versus cisplatin) strategies across all age groups (children < 11 years (y), adolescents = 11-25 y and young adult women > 25 y) for advanced-stage dysgerminoma.

METHODS

The Malignant Germ Cell Tumor International Consortium (MaGIC) pooled data from six GCT trials (3 = pediatric, 3 = adult) conducted internationally by pediatric and gynecologic oncology clinical trial organizations (CTOs) between 1983 and 2009. Newly diagnosed patients, with advanced-stage (FIGO IC-IV) dysgerminoma, who received either carboplatin- or cisplatin-based chemotherapy were eligible for analysis.

RESULTS

126 eligible patients were identified; 56 patients (38 = pediatric, 18 = adult) received carboplatin-based and 70 patients (50 = pediatric, 20 = adult) received cisplatin-based chemotherapy. Mean age was 20 y (range = 6-46 y). The median follow-up was 10.3 y (range = 0.17-21.7 y). The five-year event-free survival (EFS₅) and overall survival (OS₅) was 0.94 (95%CI, 0.88-0.97) and 0.96 (95%CI, 0.91-0.99) respectively. Survival outcomes were comparable between carboplatin-(EFS₅ = 0.96 (95%CI, 0.85-0.99), OS₅ = 0.96 (95%CI, 0.85-0.99)) and cisplatin-(EFS₅ = 0.93 (95%CI, 0.83-0.97), OS₅ = 0.96 (95%CI, 0.87-0.99)) based regimens. Across three age groups, comparison of the EFS₅ (<11 y = 0.1, 11-25 y = 0.91 (95%CI, 0.82-0.96), >25 y = 0.97 (95%CI, 0.81-0.99)) and OS₅ (<11 y = 0.1, 11-25 y = 0.95 (95%CI, 0.87-0.99), >25 y = 0.97 (95%CI, 0.81-0.99)) did not demonstrate any statistically significant differences in outcomes.

CONCLUSIONS

Patients diagnosed with dysgerminoma have an excellent OS, across all ages, even in the context of metastatic disease. Data from three large CTOs supports the investigation of carboplatin-based regimens in the frontline treatment of all patients with advanced-stage dysgerminoma to minimize treatment-related toxicities.

Primary Central Nervous System Germ Cell Tumors: A Review and Update

IMPORTANCE

Primary central nervous system (CNS) germ cell tumors (GCT) are a heterogeneous group of tumors that are still poorly understood. In North America, GCTs comprise approximately 1% of primary brain tumors in pediatric and young adult patients. GCTs can occur as pure or mixed subtypes; they are divided into germinomas, which are the most common subtype, and non-germinomatous germ cell tumors (NGGCTs), which consist of approximately one-third of GCTs and include teratomas, embryonal carcinomas, choriocarcinomas, and yolk sac tumors.

OBSERVATIONS

While the etiology of primary CNS GCT is not entirely clear, the various subtypes are lineage-related and may involve progenitor germ cells that fail to migrate and become trapped in midline locations. Primary CNS GCT most commonly arises in the pineal region but also occur in other areas. Presenting symptoms can include headache, Parinaud syndrome, diabetes insipidus, precosious puberty, ataxia, or hemiparesis. Diagnosis of primary CNS GCTs can be difficult and is often delayed. Various imaging studies and tumor markers can assist in specific diagnosis. Treatment plans differ depending on the subtype of GCT and may vary among physicians and institutions. Germinomas have a favorable prognosis with a greater than 90% overall survival, while NGGCTs only have survival rates ranging from 40-70%.

CONCLUSIONS AND RELEVANCE

Germinomas seem to be most effectively treated with chemotherapy and radiation, while NGGCT usually require surgical resection, chemotherapy, and radiation with the exception of mature teratomas frequently curable with surgery alone. Gamma knife radiosurgery is a promising treatment that may be an effective additional treatment option. Cytogenic and molecular analyses are attempting to further specify the different GCT subtypes and are helping to direct the development of distinct therapeutic targets to improve treatment and prognosis.

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

Purpose To investigate whether event-free survival (EFS) can be maintained among children and adolescents with intermediate-risk (IR) malignant germ cell tumors (MGCT) if the administration of cisplatin, etoposide, and bleomycin (PEb) is reduced from four to three cycles and compressed from 5 to 3 days per cycle. Patients and Methods In a phase 3, single-arm trial, patients with IR MGCT (stage II-IV testicular, II-III ovarian, I-II extragonadal, or stage I gonadal tumors with subsequent recurrence) received three cycles of PEb. A parametric comparator model specified that the observed EFS rate should not be significantly < 92%. As recommended for trials that test a reduction of therapy, a one-sided P value ≤ .10 was used to indicate statistical significance. In a post hoc analysis, we also compared results to the EFS rate of comparable patients treated with four cycles of PEb in two prior studies. Results Among 210 eligible patients enrolled from 2003 to 2011, 4-year EFS (EFS₄) rate was 89% (95% confidence interval, 83% to 92%), which was significantly lower than the 92% threshold of the comparison model ( P = .08). Among 181 newly diagnosed patients, the EFS₄ rate was 87%, compared with 92% for 92 comparable children in the historical cohort ( P = .15). The EFS₄ rate was significantly associated with stage (stage I, 100%; stage II, 92%; stage III, 85%; and stage IV, 54%; P < .001). Conclusion The EFS rate for children with IR MGCT observed after three cycles of PEb was less than that of a prespecified parametric model, particularly for patients with higher-stage tumors. These data do not support a reduction in the number of cycles of PEb from four to three. However, further investigation of a reduction in the number of cycles for patients with lower-stage tumors is warranted.

Paediatric extracranial germ-cell tumours

Management of paediatric extracranial germ-cell tumours carries a unique set of challenges. Germ-cell tumours are a heterogeneous group of neoplasms that present across a wide age range and vary in site, histology, and clinical behaviour. Patients with germ-cell tumours are managed by a diverse array of specialists. Thus, staging, risk stratification, and treatment approaches for germ-cell tumours have evolved disparately along several trajectories. Paediatric germ-cell tumours differ from the adolescent and adult disease in many ways, leading to complexities in applying age-appropriate, evidence-based care. Suboptimal outcomes remain for several groups of patients, including adolescents, and patients with extragonadal tumours, high tumour markers at diagnosis, or platinum-resistant disease. Survivors have significant long-term toxicities. The challenge moving forward will be to translate new insights from molecular studies and collaborative clinical data into improved patient outcomes. Future trials will be characterised by improved risk-stratification systems, biomarkers for response and toxic effects, rational reduction of therapy for low-risk patients and novel approaches for poor-risk patients, and improved international collaboration across paediatric and adult cooperative research groups.

Pediatric and Adolescent Extracranial Germ Cell Tumors: The Road to Collaboration

During the past 35 years, survival rates for children with extracranial malignant germ cell tumors (GCTs) have increased significantly. Success has been achieved primarily through the application of platinum-based chemotherapy regimens; however, clinical challenges in GCTs remain. Excellent outcomes are not distributed uniformly across the heterogeneous distribution of age, histologic features, and primary tumor site. Despite good outcomes overall, the likelihood of a cure for certain sites and histologic conditions is less than 50%. In addition, there are considerable long-term treatment-related effects for survivors. Even modest cisplatin dosing can cause significant long-term morbidities. A particular challenge in designing new therapies for GCT is that a variety of specialists use different risk stratifications, staging systems, and treatment approaches for three distinct age groups (childhood, adolescence, and young adulthood). Traditionally, pediatric cancer patients younger than 15 years have been treated by pediatric oncologists in collaboration with their surgical specialty colleagues. Adolescents and young adults with GCTs often are treated by medical oncologists, urologists, or gynecologic oncologists. The therapeutic dilemma for all is how to best define disease risk so that therapy and toxicity can be appropriately reduced for some patients and intensified for others. Further clinical and biologic insights can only be achieved through collaborations that do not set limitations by age, sex, and primary tumor site. Therefore, international collaborations, spanning different cooperative groups and disciplines, have been developed to address these challenges.

Revised risk classification for pediatric extracranial germ cell tumors based on 25 years of clinical trial data from the United Kingdom and United States

PURPOSE

To risk stratify malignant extracranial pediatric germ cell tumors (GCTs).

PATIENTS AND METHODS

Data from seven GCT trials conducted by the Children's Oncology Group (United States) or the Children's Cancer and Leukemia Group (United Kingdom) between 1985 and 2009 were merged to create a data set of patients with stage II to IV disease treated with platinum-based therapy. A parametric cure model was used to evaluate the prognostic importance of age, tumor site, stage, histology, tumor markers, and treatment regimen and estimate the percentage of patients who achieved long-term disease-free (LTDF) survival in each subgroup of the final model. Validation of the model was conducted using the bootstrap method.

RESULTS

In multivariable analysis of 519 patients with GCTs, stage IV disease (P = .001), age ≥ 11 years (P < .001), and tumor site (P < .001) were significant predictors of worse LTDF survival. Elevated alpha-fetoprotein (AFP) ≥ 10,000 ng/mL was associated with worse outcome, whereas pure yolk sac tumor (YST) was associated with better outcome, although neither met criteria for statistical significance. The analysis identified a group of patients age > 11 years with either stage III to IV extragonadal tumors or stage IV ovarian tumors with predicted LTDF survival < 70%. A bootstrap procedure showed retention of age, tumor site, and stage in > 94%, AFP in 12%, and YST in 27% of the replications.

CONCLUSION

Clinical trial data from two large national pediatric clinical trial organizations have produced a new evidence-based risk stratification of malignant pediatric GCTs that identifies a poor-risk group warranting intensified therapy.