Phase II Study of Paclitaxel Plus Gemcitabine Salvage Chemotherapy for Germ Cell Tumors After Progression Following High-Dose Chemotherapy With Tandem Transplant

Management of recurrent and persistent malignant ovarian germ cell tumors: a narrative review

Approximately 10% of patients with malignant ovarian germ cell tumors will experience a tumor relapse. Given the rarity of malignant ovarian germ cell tumors, management of these patients is challenging. Secondary cytoreductive surgery can be considered for carefully selected patients with a goal to achieve complete gross or optimal resection. For patients with platinum sensitive disease who have already received platinum-based chemotherapy, standard dose chemotherapy with paclitaxel/ifosfamide/cisplatin or vinblastine/ifosfamide/cisplatin can be considered. High-dose chemotherapy protocols at specialized centers should be explored even for patients with platinum-resistant disease; however, optimal timing is under investigation. A subset of patients with malignant ovarian germ cell tumors harbors potentially actionable genomic alterations. Further research is required to identify novel therapeutic approaches for these patients.

Adolescent and Young Adult Germ Cell Tumors: Epidemiology, Genomics, Treatment, and Survivorship

Innovations in the care of adolescent and young adult (AYA) germ cell tumors (GCTs) are needed for one of the most common AYA cancers for which treatment has not significantly changed for several decades. Testicular GCTs (TGCTs) are the most common cancers in 15- to 39-year-old men, and ovarian GCTs (OvGCTs) are the leading gynecologic malignancies in women younger than 25 years. Excellent outcomes, even in widely metastatic disease using cisplatin-based chemotherapy, can be achieved since Einhorn and Donohue's landmark 1977 study in TGCT. However, as the severity of accompanying late effects (ototoxicity, neurotoxicity, cardiovascular disease, second malignant neoplasms, nephrotoxicity, and others) has emerged, efforts to deintensity treatment and find alternatives to cisplatin have taken on new urgency. Current innovations include the collaborative design of clinical trials that accrue GCTs across all ages and both sexes, including adolescents (previously on pediatric trials), and OvGCT (previously on gynecologic-only trials). Joint trials accrue larger sample sizes at a faster rate and therefore evaluate new approaches more rapidly. These joint trials also allow for biospecimen collection to further probe GCT etiology and underlying mechanisms of tumor growth, thus providing new therapeutic options. This AYA approach has been fostered by The Malignant Germ Cell International Consortium, which includes over 115 GCT disease experts from pediatric, gynecologic, and genitourinary oncologies in 16 countries. Trials in development incorporate, to our knowledge, for the first time, molecular risk stratification and precision oncology approaches on the basis of specific GCT biology. This collaborative AYA approach pioneering successfully in GCT could serve as a model for impactful research for other AYA cancer types.

Maintenance Oral Etoposide After High-Dose Chemotherapy (HDCT) for Patients With Relapsed Metastatic Germ-Cell Tumors (mGCT)

BACKGROUND

HDCT and peripheral-blood stem-cell transplant (PBSCT) can cure up to 60% of pts with relapsed mGCT. Maintenance daily oral etoposide after salvage therapy has demonstrated potential clinical benefit. We now evaluate the potential role of maintenance etoposide versus observation post HDCT+PBSCT in this nonrandomized retrospective analysis.

METHODS

The prospectively maintained Indiana University testicular cancer database was interrogated. Patients with relapsed non-seminoma who completed HDCT+PBSCT and achieved complete serologic remission and hematologic recovery were evaluated. Outcomes of pts who received maintenance etoposide (N = 141) were compared to pts who were observed (N = 242). In this retrospective study, Kaplan-Meier method was used to analyze progression-free survival (PFS) and overall survival (OS). Univariable and multivariable cox regression models were used to determine variables associated with PFS. We also performed an additional analysis to compare the survival outcomes in the platinum-refractory patients' subgroup based on maintenance etoposide treatment.

RESULTS

Two-year PFS in the maintenance etoposide vs observation group was 55% vs. 46% (P = .028). Two-year OS was 61% vs 54% (P = .04). A multivariable analysis was performed, including the factors: primary tumor site (testis vs. mediastinum), IGCCCG risk, platinum refractory, HDCT line of therapy (2nd vs ≥3rd), tumor marker amplitude at HDCT initiation, and receipt of maintenance etoposide post HDCT vs. observation. Maintenance etoposide was confirmed as an independent predictor of improved PFS with HR 0.51 [95% CI, 0.37-0.70] (P < .001). Two-year OS and PFS for platinum-refractory patients who received maintenance etoposide vs. observation group were 50.2% vs. 26.1% (P < .0001) and 44.2% vs.. 23.1% (P = .0003), respectively. There was no statistically significant difference in 2-year OS and PFS between the platinum-sensitive patients who received maintenance etoposide and those who were observed.

CONCLUSION

Daily oral etoposide therapy produced encouraging efficacy results in patients with relapsed non-seminoma GCT (NSGCT) who completed HDCT and PBSCT and achieved complete serologic remission and hematologic recovery. Patients with platinum-refractory disease and poor prognostic features are potential candidates for daily maintenance oral etoposide post HDCT. These data have led to an ongoing randomized phase II clinical trial (NCT04804007).

Dynamic regulation of P-TEFb by 7SK snRNP is integral to the DNA damage response to regulate chemotherapy sensitivity

Testicular germ cell tumors and closely related embryonal stem cells are exquisitely sensitive to cisplatin, a feature thought to be linked to their pluripotent state and p53 status. It remains unclear whether and how cellular state is coordinated with p53 to confer cisplatin sensitivity. Here, we report that positive transcription elongation factor b (P-TEFb) determines cell fate upon DNA damage. We find that cisplatin rapidly activates P-TEFb by releasing it from inhibitory 7SK small nuclear ribonucleoprotein complex. P-TEFb directly phosphorylates pluripotency factor estrogen-related receptor beta (ESRRB), and induces its proteasomal degradation to enhance pro-survival glycolysis. On the other hand, P-TEFb is required for the transcription of a substantial portion of p53 target genes, triggering cell death during prolonged cisplatin treatment. These results reveal previously underappreciated roles of P-TEFb to coordinate the DNA damage response. We discuss the implications for using P-TEFb inhibitors to treat cancer and ameliorate cisplatin-induced ototoxicity.

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P-TEFb regulates pro-survival and pro-death pathways during DNA damage response

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P-TEFb promotes ESRRB proteasomal degradation to enhance pro-survival glycolysis

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P-TEFb induces a substantial portion of p53 target genes to trigger cell death

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Chemical inhibitors of P-TEFb blocks cisplatin- or UV-induced cell death

Platinum-Based Chemotherapy 'Rechallenge' in Advanced Non-ovarian Solid Malignancies

Platinum-based chemotherapy forms the backbone of treatment for many solid cancers. However, resistance inevitably develops in those with advanced disease. Platinum rechallenge is a well-established concept in the management of ovarian cancer, small cell lung cancer and germ cell tumours. In other solid malignancies there is a lack of quality evidence to support platinum rechallenge, yet it is a widely adopted strategy. Often, patients are within the last year of life, making questions of efficacy, treatment-related toxicity and quality of life critical factors for treatment recommendations. In this overview we appraise the available evidence for platinum rechallenge and strategies being developed to attempt resensitisation of tumours to platinum-based chemotherapy.

Overcoming Chemotherapy Resistance in Germ Cell Tumors

Testicular germ cell tumors (GCTs) are highly curable malignancies. Excellent survival rates in patients with metastatic disease can be attributed to the exceptional sensitivity of GCTs to cisplatin-based chemotherapy. This hypersensitivity is probably related to alterations in the DNA repair of cisplatin-induced DNA damage, and an excessive apoptotic response. However, chemotherapy fails due to the development of cisplatin resistance in a proportion of patients. The molecular basis of this resistance appears to be multifactorial. Tracking the mechanisms of cisplatin resistance in GCTs, multiple molecules have been identified as potential therapeutic targets. A variety of therapeutic agents have been evaluated in preclinical and clinical studies. These include different chemotherapeutics, targeted therapies, such as tyrosine kinase inhibitors, mTOR inhibitors, PARP inhibitors, CDK inhibitors, and anti-CD30 therapy, as well as immune-checkpoint inhibitors, epigenetic therapy, and others. These therapeutics have been used as single agents or in combination with cisplatin. Some of them have shown promising in vitro activity in overcoming cisplatin resistance, but have not been effective in clinical trials in refractory GCT patients. This review provides a summary of current knowledge about the molecular mechanisms of cisplatin sensitivity and resistance in GCTs and outlines possible therapeutic approaches that seek to overcome this chemoresistance.

Salvage Resection of Mediastinal Nonseminomatous Germ Cell Tumor in a Patient with Extrathoracic Involvement upon Progression following High-Dose Chemotherapy

Primary mediastinal nonseminomatous germ cell tumor with extrathoracic metastases is associated with a very high mortality rate, and there is no consensus regarding optimal upfront therapy. Once patients fail the first-line treatment, salvage therapy often fails to effectively control the disease. Resection of the residual mediastinal mass does not appear to achieve long-term control in those who have extrathoracic metastases following conventional first-line systemic therapy. We report a case where a young man presented with symptomatic brain metastases as well as extensive visceral involvement of the liver, small intestine, and lungs. He was successfully managed with multimodality treatment including high-dose chemotherapy with hematopoietic stem cell support following standard first-line chemotherapy, resection of mediastinal disease, lung metastasectomy, and stereotactic brain radiation. He has achieved long-term survival.

Testicular cancer: Biology to bedside

Testicular cancer is the first solid tumor with a remarkably high cure rate. This success was only made possible through collaborative efforts of basic and clinical research. Most patients with distant metastases can be cured. However, the majority of these patients are diagnosed at a young age, leaving many decades for the development of treatment-related complications. This has magnified the importance of research into survivorship issues after exposure to platinum-based chemotherapy. This research, along with research into newer biomarkers that will aid in the diagnosis and surveillance of patients and survivors of testicular cancer, will continue to advance the field and provide new opportunities for these patients. There also remains the need for further therapeutic options for patients who unfortunately do not respond to standard treatment regimens and ultimately die from this disease, including a cohort of patients with late relapses and platinum-refractory disease. Here we discuss the advancements in management that led to a highly curable malignancy, while highlighting difficult situations still left to solve as well as emerging research into novel biomarkers.

Current Management of Refractory Germ Cell Tumors

PURPOSE OF REVIEW

Germ cell tumors (GCTs) are the most common solid tumors affecting men between ages of 20 and 34 years. Most of the cases, even in advanced disease, will have good prognosis. However, around 20-30% of advanced disease will be refractory or develop relapse after treatment. Herein, we review the current management of refractory/relapsed GCTs.

RECENT FINDINGS

Salvage treatment of GCTs has been a controversial topic for the last few decades. Conventional dose chemotherapy (CDCT), high-dose chemotherapy (HDCT) with stem cell infusion, and surgical salvage were proven to be effective and curative options in some cases. The international randomized trial (TIGER) will ultimately answer which chemotherapy approach may be optimal. Furthermore, the usage of immunotherapy is still under investigation with limited data so far in the setting of relapsed/refractory GCTs. Curative paradigms including with CDCT and HDCT are possible, although novel approaches beyond HDCT are still needed to eliminate mortality from this disease.

Gemcitabine, carboplatin and veliparib in multiple relapsed/refractory germ cell tumours: The GCT-SK-004 phase II trial

Background Patients with multiple relapsed/refractory germ cell tumours (GCTs) have an extremely poor prognosis. PARP (poly-ADP-ribose polymerase) is overexpressed in GCTs compared to normal testes, and PARP overexpression is an early event in GCT development. This study aimed to determine the efficacy and toxicity of gemcitabine, carboplatin and the PARP inhibitor veliparib in patients with multiple relapsed/refractory GCTs. Methods Fifteen patients with multiple relapsed/refractory GCTs were enrolled in this phase II study from October 2016 to October 2020. Gemcitabine was administered at a dose of 800 mg/m2 on days 1 and 8 every 3 weeks; carboplatin at a target AUC of 4 on day 1 every 3 weeks; and veliparib at a dose of 250 mg b.i.d. throughout. The primary end point was 12-month progression-free survival (PFS). Results The median number of treatment cycles was 4 (range 2-8). Twelve-month PFS was achieved in 1 (6.7 %) patient. The median PFS was 3.1 months (95 % CI 2.2-3.9), and the median overall survival was 10.5 months (95 % CI 8.9-11.1). Partial remission was achieved in 4 (26.7 %) patients, and disease stabilization was observed in 5 (33.3 %) patients. A favourable response was achieved in 3 (20.0 %) patients. Treatment was well tolerated; however, 11 (73.3 %) patients experienced grade 3/4 neutropenia, 10 (66.7 %) experienced thrombocytopenia, 5 (33.3 %) anaemia and 2 (13.3 %) febrile neutropenia. Conclusions This study failed to achieve its primary endpoint, and our data suggest limited efficacy of gemcitabine, carboplatin and veliparib for multiple relapsed/refractory GCTs. ClinicalTrials.gov Identifier: NCT02860819, registered August 9, 2016.

Salvage management of patients with relapsing testicular germ cell tumors

PURPOSE OF REVIEW

This review aims to summarize the latest evidence of medical and surgical treatment options for patients with relapsing testicular germ cell tumors.

RECENT FINDINGS

Depending on International Germ Cell Cancer Classification Group risk classification 10-50% of patients with metastatic TGCT develop relapse which needs further multimodality treatment. With regard to therapy, early relapses are stratified according to their prognostic risk profile which results in a 3-year overall survival between 6% in the very high to 77% in the very low risk group. Prognostic risk score dictates systemic therapy which might be second line chemotherapy (TIP, PEI) or high dose chemotherapy. Any residual masses following salvage chemotherapy need to be completely resected due the presence of viable cancer and/or teratoma in more than 50% of cases. Targeted therapy in men with druggable mutations is for individualized cases only. Patients with late relapses developing more than 2 years after first-line chemotherapy are best managed by surgery. Desperation surgery is reserved for those patients with rising markers during or immediately after chemotherapy and good risk factors such as rising alpha-fetoprotein, <3 metastatic sites and complete resectability. Multimodality treatment will result in long-term cure of 25% to 60%. Due to the complexity of treatment, chemotherapy as well as surgery should be performed in highly experienced centres only.

SUMMARY

Multimodality treatment to salvage relapsing patients with metastatic testis cancer requires extensive experience for both systemic therapy and surgery. If done properly, it will result in moderate to high cure rates. Personalized therapeutic options are currently evaluated in clinical trials.

Testicular Cancer, Version 2.2020, NCCN Clinical Practice Guidelines in Oncology

Testicular cancer is relatively uncommon and accounts for <1% of all male tumors. However, it is the most common solid tumor in men between the ages of 20 and 34 years, and the global incidence has been steadily rising over the past several decades. Several risk factors for testicular cancer have been identified, including personal or family history of testicular cancer and cryptorchidism. Testicular germ cell tumors (GCTs) comprise 95% of malignant tumors arising in the testes and are categorized into 2 main histologic subtypes: seminoma and nonseminoma. Although nonseminoma is the more clinically aggressive tumor subtype, 5-year survival rates exceed 70% with current treatment options, even in patients with advanced or metastatic disease. Radical inguinal orchiectomy is the primary treatment for most patients with testicular GCTs. Postorchiectomy management is dictated by stage, histology, and risk classification; treatment options for nonseminoma include surveillance, systemic therapy, and nerve-sparing retroperitoneal lymph node dissection. Although rarely occurring, prognosis for patients with brain metastases remains poor, with >50% of patients dying within 1 year of diagnosis. This selection from the NCCN Guidelines for Testicular Cancer focuses on recommendations for the management of adult patients with nonseminomatous GCTs.

Genomic landscape of platinum resistant and sensitive testicular cancers

While most testicular germ cell tumours (TGCTs) exhibit exquisite sensitivity to platinum chemotherapy, ~10% are platinum resistant. To gain insight into the underlying mechanisms, we undertake whole exome sequencing and copy number analysis in 40 tumours from 26 cases with platinum-resistant TGCT, and combine this with published genomic data on an additional 624 TGCTs. We integrate analyses for driver mutations, mutational burden, global, arm-level and focal copy number (CN) events, and SNV and CN signatures. Albeit preliminary and observational in nature, these analyses provide support for a possible mechanistic link between early driver mutations in RAS and KIT and the widespread copy number events by which TGCT is characterised.

Systemic therapy for primary and extragonadal germ cell tumors: prognosis and nuances of treatment

Testicular germ cell tumors are the most common solid tumors in young men. These cancers represent a success story of modern medicine in our ability to cure young patients and offer decades of life, with a 5-year survival rate of approximately 95%. This review outlines the staging and risk classification of testicular cancers, and reviews the current state of knowledge and standard of care for the systemic treatment of testicular germ cell tumors with chemotherapy, focusing on the relevant clinical data supporting each treatment regimen. This review also briefly highlights current areas of active investigation, notably in the relapsed and refractory setting, including ongoing clinical trials.

Current pharmacotherapy for testicular germ cell cancer

INTRODUCTION

With the implementation of platinum-based chemotherapy, germ cell tumors (GCTs) became a model for a curable solid tumor, with survival rates of 95% in all patients with >80% survival in metastatic stages.

AREAS COVERED

Herein, the authors review the current standards of adjuvant chemotherapy for stage I GCTs as well as first-line and salvage treatments for metastatic disease. Novel approaches for refractory disease are also reviewed.

EXPERT OPINION

Active surveillance should be considered for all stage I patients and is the preferred approach for stage I seminoma. In stage I non-seminomas with vascular invasion, one cycle of bleomycin, etoposide, and cisplatin (BEP) substantially reduces the relapse risk. For most advanced GCTs, BEP remains the first-line standard of care. For poor prognosis disease treatment, stratification according to tumor marker decline is recommended. The role of primary high-dose chemotherapy (HDCT) for selected very high-risk patients remains to be prospectively evaluated. Salvage HDCT at relapse seems superior to conventional chemotherapy, retrospectively. The treatment of multiply relapsed disease remains challenging. The gemcitabine/oxaliplatin/paclitaxel (GOP) protocol is considered the standard for refractory disease. However, overall, outcomes are poor and new treatment approaches are urgently needed with targeted therapies so far failing to yield relevant clinical activity.

Management of Refractory Germ Cell Cancer

Over the past 5 decades, the use of well-validated, guideline-based strategies has resulted in high cure rates in newly diagnosed patients with germ cell cancer. However, about 30% of those with metastatic disease at initial presentation will experience refractory disease. Salvage treatment is far more complex and less validated than first-line treatment because it is rare, patient cohorts are more heterogeneous, and prognostic factors seem to have greater impact. Prior to the initiation of any salvage treatment, several considerations must be made, including assessment of known prognostic factors and choice of the optimal salvage strategy. Evaluation of patients according to their disease biology, response to prior treatment, and the extent of their tumor burden at the time of salvage treatment is crucial for establishing the optimal salvage strategy. Patients with metastatic germ cell cancer in whom adequate cisplatin-based first-line chemotherapy fails should be included in the ongoing randomized TIGER trial comparing conventional-dose chemotherapy with high-dose chemotherapy as first salvage treatment. Outside this trial, patients may be treated with conventional or high-dose chemotherapy depending on the presence or absence of adverse prognostic factors, availability of resources, and patient and physician preferences.

Role of one, two and three doses of high-dose chemotherapy with autologous transplantation in the treatment of high-risk or relapsed testicular cancer: a systematic review

Approximately 20-30% of patients with metastatic germ cell cancers (GCCs) can develop relapsed or refractory (RR) disease, about 40-50% of patients who relapse after salvage chemotherapy may reach long-term remission. The goal of this review was to identify patients who appear to benefit from high-dose chemotherapy (HDCT) and autologous stem cell transplant (ASCT). To access this, we performed a systematic medical literature review to evaluate the effectiveness of HDCT in the frontline setting, as well as in patients with RR testicular cancer. We searched databases for interventional clinical studies and identified 5883 studies. We selected 49 studies for inclusion, which included a total of 5985 patients. Seventeen studies reported results of newly diagnosed poor-risk GCC patients and 32 studies reported results of RR patients. For newly diagnosed patients with poor prognostic predictors, a risk adjusted strategy using unfavorable tumor marker decline with initial standard chemotherapy regimen and upfront HDCT demonstrated improved outcomes. Our data suggest a minimum of two HDCT cycles with ASCT should be standard of care for patients with RR GCC. Failure of HDCT results in a poor prognosis with only 10% of patients achieving lasting remission with salvage therapy.

High-dose chemotherapy and stem-cell rescue for salvage therapy for relapsed malignant mixed ovarian germ cell tumor: A case report

Background

Malignant ovarian germ cell tumors are rare, and often treatable with surgery and chemotherapy. Few data are available for treatment of platinum-resistant tumors.

Case

A 31 year old gravida 0 with a 20 cm pelvic mass was found to have a malignant ovarian germ cell tumor after she underwent debulking surgery. She initially responded to chemotherapy; however her AFP began to rise before all cycles were completed. She underwent additional debulking surgery that was again suboptimal. She was then referred for salvage therapy with high-dose chemotherapy with stem cell transplant, which was successful and she has had no evidence of disease for over two years.

Conclusion

High-dose chemotherapy with stem cell transplant is a viable salvage therapy for patients with platinum-resistant germ cell tumors.

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Malignant ovarian germ cell tumors are rare.

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These tumors are often treatable with surgery and adjuvant chemotherapy.

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High-dose chemotherapy and stem cell rescue should be considered for platinum-resistant disease.

Prevalence of βIII-tubulin (TUBB3) expression in human normal tissues and cancers

Microtubules are multifunctional cytoskeletal proteins that are involved in crucial cellular roles including maintenance of cell shape, intracellular transport, meiosis, and mitosis. Class III beta-tubulin (βIII-tubulin, also known as TUBB3) is a microtubule protein, normally expressed in cells of neuronal origin. Its expression was also reported in various other tumor types, such as several types of lung cancer, ovarian cancer, and esophageal cancer. TUBB3 is of clinical relevance as overexpression has been linked to poor response to microtubule-targeting anti-cancer drugs such as taxanes. To systematically investigate the epidemiology of TUBB3 expression in normal and neoplastic tissues, we used tissue microarrays for analyzing the immunohistochemically detectable expression of TUBB3 in 3911 tissue samples from 100 different tumor categories and 76 different normal tissue types. At least 1 tumor with weak expression could be found in 93 of 100 (93%) different tumor types, and all these 93 entities also had at least 1 tumor with strong positivity. In normal tissues, a particularly strong expression was found in neurons of the brain, endothelium of blood vessels, fibroblasts, spermatogenic cells, stroma cells, endocrine cells, and acidophilic cells of the pituitary gland. In tumors, strong TUBB3 expression was most frequently found in various brain tumors (85%-100%), lung cancer (35%-80%), pancreatic adenocarcinoma (50%), renal cell carcinoma (15%-80%), and malignant melanoma (77%). In summary, these results identify a broad spectrum of cancers that can at least sporadically express TUBB3. Testing of TUBB3 in cancer types eligible for taxane-based therapies could be helpful to identify patients who might best benefit from this treatment.

Salvage Therapy for Patients With Germ Cell Tumor

The introduction of cisplatin combination chemotherapy, 40 years ago, transformed metastatic testicular germ cell tumors from an almost uniformly fatal disease into a model for a curable neoplasm. Before the era of platinum combination chemotherapy, the 5-year survival rate among men with metastatic testicular germ cell tumors was 5% to 10%. Currently, the 5-year survival rate is 80% for patients with metastatic disease and 95% overall. Despite the substantial advances in the treatment of germ cell tumors, 20% to 30% of patients will relapse after first-line chemotherapy and will require additional salvage therapies. Standard-dose or high-dose chemotherapy can cure ≤ 50% of these patients. Relapses after high-dose chemotherapy generally carry a poor prognosis; however, cure is still possible in a small percentage of patients by using further salvage chemotherapy or salvage surgery.

Current Management of Refractory Germ Cell Tumors and Future Directions

PURPOSE OF REVIEW

We review current management strategies for patients with relapsed and refractory germ cell tumors (GCTs), defined as relapsed or persistent disease following at least one line of cisplatin-based chemotherapy. Additionally, we discuss future directions in the management of these patients.

RECENT FINDINGS

Recent studies involving targeted therapies have been disappointing. Nevertheless, studies of the management of refractory germ cell cancer are ongoing, with a focus on optimal utilization of high-dose chemotherapy and autologous stem cell transplant, as well as the role of immune checkpoint inhibitors in refractory germ cell tumors. Studies aiming to identify those patients who may benefit from more intensive treatment up front to prevent the development of refractory disease are also in progress. Testicular germ cell tumors are among the most curable of all solid tumor malignancies, with cure being possible even in the refractory, metastatic setting. Treatment of refractory disease remains a challenging clinical scenario, but potentially practice changing studies are ongoing.

Consensus Recommendations from the Spanish Germ Cell Cancer Group on the Use of High-dose Chemotherapy in Germ Cell Cancer

BACKGROUND

High-dose chemotherapy (HDCT) has been studied in several clinical scenarios in advanced germ cell cancer (GCC).

OBJECTIVE

To establish a clinical practice guideline for HDCT use in the treatment of GCC patients.

DESIGN, SETTING, AND PARTICIPANTS

An expert panel reviewed information available from the literature. The panel addressed relevant issues concerning and related to HDCT. The guideline was externally reviewed by two international experts.

RESULTS AND LIMITATIONS

The efficacy of HDCT has been demonstrated in selected GCC patients. The most conclusive evidence comes from retrospective analyses that need to be interpreted with caution. HDCT can cure a significant proportion of heavily treated GCC patients. When indicated, sequential HDCT with regimens containing carboplatin and etoposide, as well as peripheral stem-cell support, is recommended. There is no conclusive evidence to recommend HDCT as first-line therapy. According to a multinational retrospective pooled analysis, HDCT might be superior to conventional CT as first salvage treatment in selected patients. There is an urgent need for prospective clinical trials addressing the value of HDCT in GCC patients who experience failure on first-line cisplatin-based CT. In patients who progress on conventional-dose salvage CT, HDCT should be considered. Treatment of these patients at experienced centers is strongly recommended.

CONCLUSIONS

It has been demonstrated that HDCT cures selected GCC patients who experience disease progression on conventional rescue regimens. The panel recommends the inclusion of GCC patients in randomized clinical trials including HDCT.

PATIENT SUMMARY

This consensus establishes clinical practice guidelines for the use and study of high-dose chemotherapy in patients with germ cell cancer.

Tailored therapy and long-term surveillance of malignant germ cell tumors in the female genital system: 10-year experience

OBJECTIVE

To explore the appropriate treatment of malignant germ cell tumor (MGCT) in the female genital system, and to analyze the factors influencing both therapeutic response and survival outcome.

METHODS

A cohort of 230-Chinese women diagnosed with MGCT of the genital system was retrospectively reviewed and prospectively followed. The demographic and pathological features, extent of disease and surgery, treatment efficiency, recurrence and survival were analyzed.

RESULTS

MGCTs from different genital origins shared a similar therapeutic strategy and response, except that all eight vaginal cases were infantile yolk sac tumors. The patients' cure rate following the initial treatment, 5-year overall survival and disease-free survival (DFS) were 85.02%, 95.00%, and 86.00%, respectively. Although more extensive excision could enhance the remission rate; it did not improve the patients' survival. Instead, the level of the medical institution, extent of surgery and disease were independent prognostic factors for relapse (p<0.05). Approximately 20% of patients had recurrent or refractory disease, more than half of whom were in remission following secondary cytoreductive surgery with salvage chemotherapy.

CONCLUSION

Fertility-sparing surgery with or without standardized PEB/PVB (cisplatin, etoposide/vincristine, and bleomycin) chemotherapy is applicable for female MGCTs of different origins. Comprehensive staging is not required; nor is excessive debulking suggested. Appropriate cytoreduction by surgery and antineoplastic medicine at an experienced medical institution can bring about an excellent prognosis for these patients.

Role of N-cadherin in proliferation, migration, and invasion of germ cell tumours

Germ cell tumors (GCTs) are the most common malignancies in young men. Most patients with GCT can be cured with cisplatin-based combination chemotherapy, even in metastatic disease. In case of therapy resistance, prognosis is usually poor. We investigated the potential of N-cadherin inhibition as a therapeutic strategy. We analyzed the GCT cell lines NCCIT, NTERA-2, TCam-2, and the cisplatin-resistant sublines NCCIT-R and NTERA-2R. Effects of a blocking antibody or siRNA against N-cadherin on proliferation, migration, and invasion were investigated. Mouse xenografts of GCT cell lines were analyzed by immunohistochemistry for N-cadherin expression. All investigated GCT cell lines were found to express N-cadherin protein in vitro and in vivo. Downregulation of N-cadherin in vitro leads to a significant inhibition of proliferation, migration, and invasion. N-cadherin-downregulation leads to a significantly higher level of pERK. N-cadherin-inhibition resulted in significantly higher rates of apoptotic cells in caspase-3 staining. Expression of N-cadherin is preserved in cisplatin-resistant GCT cells, pointing to an important physiological role in cell survival. N-cadherin-downregulation results in a significant decrease of proliferation, migration, and invasion and stimulates apoptosis in cisplatin-naive and resistant GCT cell lines. Therefore, targeting N-cadherin may be a promising therapeutic approach, particularly in cisplatin-resistant, therapy refractory and metastatic GCT.

Efficacy and safety of gemcitabine, oxaliplatin, and paclitaxel in cisplatin-refractory germ cell cancer in routine care--Registry data from an outcomes research project of the German Testicular Cancer Study Group

BACKGROUND

Chemotherapy (CTX) with gemcitabine, oxaliplatin, and paclitaxel (GOP) has demonstrated efficacy with an overall response rate (ORR) of approximately 50% in patients with multiply relapsed or cisplatin-refractory germ cell cancer (GCC) or both within a phase II study. We analyzed the efficacy and safety of GOP in routine clinical practice within a registry of the German Testicular Cancer Study Group.

METHODS

Overall, 63 patients with refractory GCC, who received GOP because of progression under cisplatin-based treatment or relapse after high-dose CTX, were included in this database. Patient characteristics, response rate, toxicity, progression-free and overall survival (OS) were analyzed. For further risk stratification, univariate and multivariate analyses were performed.

RESULTS

GOP was applied as second to eighth treatment line (median fourth) after cisplatin-based CTX. The ORR was 44% with complete remissions achieved in 8 patients (4 patients with CTX plus additional residual tumor resections and 4 patients with CTX alone) and partial remissions achieved in 19 of all for best response evaluable patients. The median progression-free survival and OS were 4.0 months (95% CI: 3.08-4.94) and 13.3 months (95% CI: 9.50-17.06), respectively. Long-term OS of>2 years was achieved in 13 (21%), and grade III and IV toxicities, mainly thrombocytopenia and leukopenia, occurred in 29 patients.

CONCLUSION

Our results were similar compared with the previous results from the phase II study with a distinct activity with an ORR of 44%, and a long-term OS in 21% of the patients. Our data support the recommendation to use GOP ± secondary surgery in patients with multiply refractory metastatic GCC.

Salvage therapy in patients with germ cell tumors

Testicular cancer is the most curable metastatic solid tumor. Initial chemotherapy is evidence based with risk stratification into three prognostic categories: good, intermediate, and advanced disease. Guidelines for disease management following progression after initial cisplatin combination chemotherapy are less clear. Options include salvage surgery for patients with anatomically confined relapse, standard-dose cisplatin combination chemotherapy, or high-dose chemotherapy with carboplatin plus etoposide with peripheral blood stem cell transplantation. Proper interpretation of a presumed relapse can be complicated. Growing masses on imaging studies might reflect a growing teratoma. Persistent elevations of serum human chorionic gonadotropin (hCG) or alpha fetoprotein (AFP) are only an indication for salvage therapy if there is a definitive rise in the tumor marker. Elevated and rising serum hCG as the only evidence of recurrence can be because of cross reactivity with luteinizing hormone or usage of marijuana rather than progressive cancer. Elevated liver function tests can cause rising serum AFP.

Cisplatin resistance in germ cell tumours: models and mechanisms

Recent years have led to a better understanding of the mechanisms underlying cisplatin response and resistance in germ cell tumours (GCT), and several promising targets have been identified. Two main mechanisms of the responsiveness to DNA damaging agents have been postulated. Firstly, GCT readily activate a DNA damage response, but show deficits in several damage repair pathways. In particular, they have been found to have defects in interstrand crosslink repair and in homologous recombination (HR). Secondly, GCT, especially embryonal carcinoma (EC) cells, show a hypersensitive apoptotic response to DNA damage, which activates p53, and leads to up-regulation of the pro-apoptotic factors Noxa, Puma and Fas in non-resistant EC. These cells fail to activate p21 which induces a G1/S arrest, but accumulate in G2/M phase. In the absence of functional p53, family members like p73 and GTAp63 might be important in initiating this response. Mechanisms involved in cisplatin resistance are as follows: down-regulation of Oct4 (e.g. as a result of hypoxia, treatment with retinoic acid or exposure to cisplatin) and failure to induce Puma and Noxa; changes in the expression levels of micro-RNAs such as miR-17/-106b, miR-302a, or miR-371 to -373; elevated levels of MDM2 and cytoplasmic translocation of p21 by phosphorylation; and activation of the PDGFRβ/PI3K/pAKT pathway. Several approaches to overcome resistance have been successfully examined in vitro and in vivo, including PARP inhibitors, especially in cells showing deficient HR-repair; stabilization of p53 using nutlin-3; inhibition of several components of the PI3K/pAKT pathway using small molecules; and DNA demethylation by 5-azacytidine or 5-aza-deoxy-cytidine, among others. Many of these substances deserve further exploration, alone or in combination with DNA damaging agents, and the most promising approaches should be taken forward to clinical testing. Targeted therapy based on mechanistic insights holds the promise to turn cisplatin-resistant GCT into a curable disease.

The impact of taxanes on the management of genitourinary cancers

Taxanes have had a profound impact on the management of genitourinary tumors. In the perioperative and metastatic setting in bladder cancer, taxanes such as paclitaxel have an established role in combination chemotherapy strategies to improve survival. In metastatic prostate cancer, docetaxel was the only treatment, until recently, shown to improve survival after the development of castration resistance. More recently, cabazitaxel, a synthetic taxane derivative, is an effective option after docetaxel failure. In advanced testicular cancer, taxanes play an important role in the management of relapsed disease with the ability to still achieve cure. This chapter will focus on the development and current role of taxanes in the treatment of genitourinary cancers including bladder, prostate, and testis cancers as well as the status of novel agents currently under investigation.

Current chemotherapeutic approaches for recurrent or refractory germ cell tumors

INTRODUCTION

Up to 25% of patients with metastatic testicular germ cell tumour (GCT) are not cured by first line therapy and require treatment for refractory or relapsed disease.

METHODS

A literature search was conducted through PubMed, Medline, Cochrane and EMBASE from January 1950 to April 2014 for articles relating to trials of chemotherapy for patients with relapsed or refractory germ cell tumours. Relevant review papers and conference proceedings were hand searched for additional references.

RESULTS

A range of conventional dose chemotherapy (CDCT) regimens can provide durable remissions in 20-30% of patients at first or subsequent salvage.

CONCLUSIONS

This article reviews the evidence underlying commonly used salvage CDCT based on ifosfamide and cisplatin such as TIP, VIP and VeIP; other active combinations; and single agent salvage regimens. The treatment of growing teratoma syndrome and malignant transformation of teratoma will also be discussed. Companion articles will explore the role of high dose chemotherapy (HDCT) and novel targeted agents.

Transplantation for refractory germ cell tumors: does it really make a difference?

High-dose chemotherapy (HDC) has been used over the past 25 years for germ-cell tumors in a variety of clinical scenarios. There is consensus at this point that its use as part of first-line treatment does not benefit patients with high-risk tumors. Long-term results of prospective trials in patients with relapsed or with refractory disease indicate that a fraction of them achieve long-term remissions consistent with cures. While HDC constitutes for many oncologists in the US an accepted treatment modality for relapsed or refractory GCT, controversy surrounds its use in those settings. Prognostic models have been developed that allow to prospectively identify poor prognosis patients that might benefit from novel HDC-based approaches.

Anti-tumour activity of two novel compounds in cisplatin-resistant testicular germ cell cancer

BACKGROUND

Resistance to cisplatin-based chemotherapy is associated with poor prognosis in testicular germ cell cancer, emphasising the need for new therapeutic approaches. In this respect, the therapeutic concept of anti-angiogenesis is of particular interest. In a previous study, we presented two novel anti-angiogenic compounds, HP-2 and HP-14, blocking the tyrosine kinase activity of angiogenic growth factor receptors, such as vascular endothelial growth factor receptor-2 (VEGFR-2), and related signalling pathways in testicular cancer. In this study, we investigated the efficacy of these new compounds in platinum-resistant testicular germ cell tumours (TGCTs), in vitro and in vivo.

METHODS AND RESULTS

Drug-induced changes in cell proliferation of the cisplatin-sensitive TGCT cell line 2102EP and its cisplatin-resistant counterpart 2102EP-R, both expressing the VEGFR-2, were evaluated by crystal violet staining. Both compounds inhibited the growth of cisplatin-resistant TGCT cells in a dose-dependent manner. In combination experiments with cisplatin, HP-14 revealed additive growth-inhibitory effects in TGCT cells, irrespective of the level of cisplatin resistance. Anti-angiogenic effects of HP compounds were confirmed by tube formation assays with freshly isolated human umbilical vein endothelial cells. Using TGCT cells inoculated onto the chorioallantoic membrane of fertilised chicken eggs (chicken chorioallantoic membrane assay), the anti-angiogenic and anti-proliferative potency of the novel compounds was also demonstrated in vivo. Gene expression profiling revealed changes in the expression pattern of genes related to DNA damage detection and repair, as well as in chaperone function after treatment with both cisplatin and HP-14, alone or in combination. This suggests that HP-14 can revert the lost effectiveness of cisplatin in the resistant cells by altering the expression of critical genes.

CONCLUSION

The novel compound HP-14 effectively inhibits the growth of cisplatin-resistant TGCT cells and suppresses tumour angiogenesis. Thus, HP-14 may be an interesting new agent that should be further explored for TGCT treatment, especially in TGCTs that are resistant to cisplatin.

Brief report: phase II multicenter study of temozolomide in patients with cisplatin-resistant germ cell tumors

PURPOSE

To determine the activity and toxicity of temozolomide in a phase II multicenter trial in patients diagnosed with relapsed or cisplatin-refractory germ cell tumors.

PATIENTS AND METHODS

During a recruitment period of 30 months, 20 patients received temozolomide 150 mg/m(2)/day p.o. for 5 days every 4 weeks, escalating to 200 mg/m(2)/day if grade II toxicity was not observed in the first cycle. Eligibility criteria were tumor progression or relapse after previous cisplatin and ifosfamide-containing chemotherapy, creatinine clearance of >40 ml/min, and a performance status of 0-2.

RESULTS

The median age was 38 years (range 27-56). Seventeen patients had nonseminomatous tumors, and 3 had seminomatous tumors. Six of the patients had extragonadal primary tumors (3 retroperitoneal and 3 mediastinal). The median number of prior cisplatin-containing cycles was 11 (range 7-20). Eight patients received prior high-dose chemotherapy and 14 were refractory or absolutely refractory to cisplatin. A total of 45 cycles were administered. Two partial responses lasting 9 and 3.5 months (overall response rate 10%, 95% CI 1.2-31.7) were observed. One of these responses was seen in a patient with a cisplatin-refractory tumor that had previously been treated with high-dose chemotherapy. The median time to progression and the median overall survival were 1.5 and 3.1 months, respectively. Grade III hematological toxicity consisted of thrombocytopenia in 2 patients and anemia in 1 patient. No grade IV toxicity was observed.

CONCLUSIONS

Temozolomide had some activity in heavily pretreated patients resistant to cisplatin-based chemotherapy.

Multidisciplinary management of malignant ovarian germ cell tumours

OBJECTIVES

Malignant ovarian germ cell tumours (MOGCT) are rare cancers of young women. Limited prospective trials exist from which evidence-based management can be developed. This review summarizes the available literature concerning MOGT in order to provide the clinician with information relevant to their multidisciplinary management.

METHODS

MEDLINE was searched between 1966 and 2010 for all publications in English where the studied population included women diagnosed with malignant ovarian germ cell tumours.

RESULTS

The majority of patients can be cured with fertility-preserving surgery with or without combination chemotherapy. Long term survival approaches 100% in early stage disease and is approximately 75% in advanced stage disease. Most studies suggest that the treatment has little, if any, effect on future fertility and limited data suggest that there is no adverse effect on the future quality of life.

CONCLUSION

MOGCTs are rare tumours of young women the majority of which can be successfully treated with fertility-preserving surgery with or without chemotherapy with preservation of reproductive function. Minimisation of chemotherapy in good prognostic groups and improved treatment in resistant and relapsed MOGCT are important goals for the future. Further studies are needed to quantify the late adverse effects of treatment in long term survivors.

[Result of treatment for advanced germ cell tumor in the last decade]

PURPOSE

We retrospectively analyzed our therapeutic results of advanced male germ cell tumors in terms of efficacy and feasibility of our treatment strategy.

PATIENTS AND METHODS

Fifty-one new cases were treated in Saitama Cancer Center between April 1997 and August 2007. Patients age ranged from 16 to 58 (median 33). Primary site of the tumor was testis in 41 (80%) patients, retroperitoneum in 6 (12%), and mediastinum in 4 (8%). Histology of the primary germ cell tumor was pure seminoma in 14 (27%), and non-seminoma in 30 (59%). Twenty (39%), 14 (27%) and 17 (33%) were classified as good-, intermediate-, and poor-risk, retrospectively, based on The International Germ Cell Consensus Classification (IGCCC) criteria. The initial treatment for good-risk patients was BEP x 3. Intermediate- or poor-risk patients were treated by VIP from 1997 to 2000, VIPVB from 2001 to 2004, and BEP from 2005 to 2007. Second line salvage treatments were high-dose VIP or ICE from 1997 to 2000. TIP x 4 has been employed since. Marker-negative cases with residual tumors underwent surgical resection of the mass lesion.

RESULTS

Five-year survival rate was 100%, 74%, and 76% in patients with good-, intermediate- and poor-risk characteristics, respectively. After two courses of initial chemotherapy, tumor marker decline was satisfactory in 37 patients (73%) and unsatisfactory in 14 (27%). Of these 14 patients, 12 (86%) had unsatisfactory hCG decline, 4 (29%) had unsatisfactory AFP decline, and 2 (14%) had unsatisfactory decline in both markers. Five-year overall survival was 94% in cases with satisfactory maker decline and 71% in those with unsatisfactory marker decline (p = 0.03).

CONCLUSIONS

In this IGCCCG era, 5 year survival rates of the advanced germ cell tumors have improved by the earlier administration of second line chemotherapies based on both the prognostic factor-based staging system and the tumor marker decline in initial chemotherapy. Development of effective treatment for cases with unfavorable tumor maker decline is the most challenging issue to be addressed.