A randomised phase 2 trial of intensive induction chemotherapy (CBOP/BEP) and standard BEP in poor-prognosis germ cell tumours (MRC TE23, CRUK 05/014, ISRCTN 53643604)

Application of Approved Cisplatin Derivatives in Combination Therapy against Different Cancer Diseases

The problems with anticancer therapy are resistance and toxicity. From 3000 Cisplatin derivatives tested as antitumor agents, most of them have been rejected, due to toxicity. The aim of current study is the comparison of therapeutic combinations of the currently applied in clinical practice: Cisplatin, Carboplatin, Oxaliplatin, Nedaplatin, Lobaplatin, Heptaplatin, and Satraplatin. The literature data show that the strategies for the development of platinum anticancer agents and bypassing of resistance to Cisplatin derivatives and their toxicity are: combination therapy, Pt IV prodrugs, the targeted nanocarriers. The very important strategy for the improvement of the antitumor effect against different cancers is synergistic combination of Cisplatin derivatives with: (1) anticancer agents—Fluorouracil, Gemcitabine, Cytarabine, Fludarabine, Pemetrexed, Ifosfamide, Irinotecan, Topotecan, Etoposide, Amrubicin, Doxorubicin, Epirubicin, Vinorelbine, Docetaxel, Paclitaxel, Nab-Paclitaxel; (2) modulators of resistant mechanisms; (3) signaling protein inhibitors—Erlotinib; Bortezomib; Everolimus; (4) and immunotherapeutic drugs—Atezolizumab, Avelumab, Bevacizumab, Cemiplimab, Cetuximab, Durvalumab, Erlotinib, Imatinib, Necitumumab, Nimotuzumab, Nivolumab, Onartuzumab, Panitumumab, Pembrolizumab, Rilotumumab, Trastuzumab, Tremelimumab, and Sintilimab. An important approach for overcoming the drug resistance and reduction of toxicity of Cisplatin derivatives is the application of nanocarriers (polymers and liposomes), which provide improved targeted delivery, increased intracellular penetration, selective accumulation in tumor tissue, and enhanced therapeutic efficacy. The advantages of combination therapy are maximum removal of tumor cells in different phases; prevention of resistance; inhibition of the adaptation of tumor cells and their mutations; and reduction of toxicity.

Standard versus high-dose chemotherapy in mediastinal germ cell tumors: a narrative review

OBJECTIVE

The aim of this review is to analyze feasibility and toxicities of high-dose chemotherapy (HDCT) in comparison to standard dose chemotherapy (SDCT) in patients affected by mediastinal germ cell tumors (MGCTs), discussing factors that may affect therapeutic choices, such as: management of residual disease, early response predictors for chemotherapeutic efficacy and determinants of chemotherapeutic resistance. In this review, we discuss the main clinical experiences with HDCT and SDCT in germ cell tumor (GCT) patients specifically in those affected by MGCT.

BACKGROUND

MGCTs represent a very small subset characterized by a poor prognosis, despite improvements in their clinical management and in understanding their biology. From early 1970s, HDCT has become an alternative to SDCT for both first-line and salvage therapeutic settings in advanced GCT patients. Several HDCT schedules-either cisplatin or carboplatin-based-have been tested so far, both in clinical randomized trial and in single-center experiences, with divergent results in terms of clinical outcomes and tolerability. Moreover, the majority of these studies included, but were not exclusively designed for, advanced MGCT patients, making difficult to infer data for this specific subset.

METHODS

an extended review of literature through PubMed was conducted using the keywords "mediastinal germinal cell tumors", "standard dose chemotherapy" and "high dose chemotherapy".

CONCLUSIONS

HDCT regimens could not be considered to date a standard option as first-line therapy in advanced MGCT patients, whilst they could be an alternative to SDCT regimens in relapsed tumors after proper patient selection.

Paclitaxel, Ifosfamide, and Cisplatin in Patients with Poor-prognosis Disseminated Nonseminomatous Germ Cell Tumors with Unfavorable Serum Tumor Marker Decline After First Cycle of Chemotherapy. The GCT-SK-003 Phase II Trial

Background

Germ cell tumors represent highly curable disease even in metastatic stage. However, poor-risk patients with an unfavorable serum tumor marker (STM) decline after the first cycle of chemotherapy represent a subgroup with dismal prognosis, with approximately 50% cure rate using bleomycin, etoposide, and cisplatin (BEP).

Objective

The aim of this study was to determine the efficacy and safety of paclitaxel, ifosfamide, and cisplatin (TIP) in this patient population.

Design, setting, and participants

This was an open-labeled, nonrandomized, single-center phase II trial to study the efficacy and toxicity of TIP in the first-line treatment of germ cell tumor patients with an unfavorable decline of STMs. Nineteen patients with a poor prognosis according to the International Germ Cell Cancer Collaboration Group classification and an unfavorable STM decline after the first cycle of chemotherapy were included in this phase II study (NCT02414685). The treatment regimen consisted of paclitaxel 250 mg/m² on day 1, ifosfamide 1200 mg/m² on days 1–5, and cisplatin 20 mg/m² on days 1–5, totally for four cycles.

Outcome measurements and statistical analysis

The primary endpoint was complete response (CR) rate. An optimal Simon two-stage design was used with a type I error of 5% and study power of 80%. If fewer than six CRs to study therapy have been observed among the first 19 patients, the study was to be terminated.

Results and limitations

A CR was achieved in four (21.1%) patients; therefore, the study was terminated in the first stage. A favorable response rate (CR or partial remission with negative tumor markers) was observed in 14 (78.9%) patients. At a median follow-up period of 35.2 mo (range, 5.6–62.1 mo), ten (52.6%) patients experienced disease progression and eight patients (42.1%) died. The 2-yr progression-free and overall survival was 41.2% (95% confidence interval [CI] 16.8–65.7) and 72.7% (95% CI 48.9–96.4), respectively. TIP was well tolerated, and no unexpected toxicity was observed. No informative biomarkers, including miR-371a-3p was identified.

Conclusions

Treatment modification from the BEP to the TIP regimen in patients with an unfavorable STM decline after the first cycle of chemotherapy was not associated with improved outcome, and four cycles of BEP remain the standard treatment option in this patient population.

Patient summary

Poor-risk patients with an unfavorable serum tumor marker decline after the first cycle of chemotherapy represent a subgroup with dismal prognosis, with an approximately 50% cure rate using bleomycin, etoposide, and cisplatin (BEP). Treatment modification from the BEP regimen to the paclitaxel, ifosfamide, and cisplatin regimen in patients with an unfavorable serum tumor marker decline after the first cycle of chemotherapy was not associated with improved outcome, and four cycles of BEP remain the standard treatment option in this patient population.

Challenging presentations of germ cell tumours in routine clinical practice

Testicular cancer is the most common malignancy in young men. We discuss four cases of germ cell tumours (GCTs) presenting to general practitioners and physicians where there were notable preventable delays in the diagnosis and management. This diagnostic delay is associated with a more advanced stage of disease, and subsequent increased treatment-related morbidity and decreased survival. Our series highlights the variety of ways in which GCTs may present and we discuss the importance of prompt diagnosis through a thorough history and examination, early measurement of serum tumour markers and appropriate multidisciplinary team discussion. GCTs are highly curable cancers in the majority of patients and delays in management can, therefore, have devastating consequences.

Predicting Outcomes in Men With Metastatic Nonseminomatous Germ Cell Tumors (NSGCT): Results From the IGCCCG Update Consortium

The classification of the International Germ Cell Cancer Collaborative Group (IGCCCG) plays a pivotal role in the management of metastatic germ cell tumors but relies on data of patients treated between 1975 and 1990.

The impact of a supranetwork multidisciplinary team (SMDT) on decision-making in testicular cancers: a 10-year overview of the Anglian Germ Cell Cancer Collaborative Group (AGCCCG)

BACKGROUND

The germ cell supranetwork multidisciplinary team (SMDT) for the Anglian Network covers a population of 7.5 million.

METHODS

We reviewed 10 years of SMDT discussion and categorised them into five domains ((1) overall outcome, (2) chemotherapy regimens-untreated disease and salvage therapy, (3) radiology, (4) pathology and (5) complex cases) to assess the impact of the SMDT.

RESULTS

A total of 2892 new cases were reviewed. In the first 5 years, patients with good prognosis disease had poorer survival in low-volume vs high-volume centres (87.8 vs 95.3, p = 0.02), but the difference was no longer significant in the last 5 years (93.3 vs 95.1, p = 0.30). Radiology review of 3206 scans led to rejection of the diagnosis of progression in 26 cases and a further 10 cases were down-staged. There were 790 pathology reviews by two specialised uropathologists, which lead to changes in 75 cases. 18F-fluorodeoxyglucose (18FDG) PET-CT was undertaken during this time period but did not help to predict who would have viable cancer. A total of 26 patients with significant mental health issues who were unable to give informed consent were discussed.

CONCLUSION

SMDT working has led to an improvement in outcomes and refining of treatment in patients with germ cell tumours.

Systemic anti-cancer treatment in malignant ovarian germ cell tumours (MOGCTs): current management and promising approaches

Malignant ovarian germ cell tumours (MOGCTs) are rare. Unlike epithelial ovarian cancer, MOGCTs typically occur in girls and young women. Fertility-sparing surgery and platinum-based chemotherapy remain the standard of care, providing high chance of cure at all stages. Given the lack of high-quality studies in this field, current practice guidelines recommend chemotherapy regimens adopted in testicular germ cell tumours. However, platinum-resistant/refractory MOGCTs retain a worse prognosis in comparison with their male counterpart. Herein, we focus on current systemic anti-cancer treatment options in MOGCTs and promising approaches. Future studies enrolling exclusively female participants or germ cell tumour trials allowing participation of MOGCT patients are strongly recommended in order to improve evidence on existing management and develop novel strategies.

Management of Late Relapses After Chemotherapy in Testicular Cancer: Optimal Outcomes with Dose-intense Salvage Chemotherapy and Surgery

BACKGROUND

Late relapse (LR) in testicular cancer is defined as disease recurrence more than 2yr after primary treatment. Optimal management for this rare group is unknown.

OBJECTIVE

To identify prognostic factors relevant to outcomes in a large LR series following primary treatment with platinum-based chemotherapy.

DESIGN, SETTING, AND PARTICIPANTS

We performed a retrospective analysis of all patients treated for advanced testicular cancer within the Anglian Germ Cell Cancer Network between 1995 and 2016. We identified 53 cases of LR following initial treatment for metastatic disease with platinum-based chemotherapy, and collected data on patient and tumour characteristics, treatments, and outcomes.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Progression-free survival (PFS) and overall survival (OS) were calculated for all patients. Survival curves were plotted according to the Kaplan-Meier method and univariate analysis of descriptive variables was performed using the log-rank method.

RESULTS AND LIMITATIONS

Across the cohort, PFS at 36 mo was 41% and OS was 61%. Multiple factors were correlated with PFS. Use of dose-intense or high-dose chemotherapy was associated with better PFS compared to conventional-dose chemotherapy (PFS 48 vs 9.8 mo; p=0.0036). Resection of residual disease post-relapse chemotherapy was associated with better PFS (hazard ratio 3.46; p=0.0076). There was a nonsignificant trend towards worse PFS in very late (>7 yr) relapses. The study is limited by its retrospective nature and selection bias cannot be excluded.

CONCLUSIONS

This study provides new insight into prognostic factors in LR. It confirms that surgery is critical to optimal outcomes, and suggests that dose-intense or high-dose chemotherapy in multisite nonresectable disease should be considered wherever feasible.

PATIENT SUMMARY

We studied patients with testicular cancer that recurred at least 2yr after initial treatment with chemotherapy. We found that patients who are able to have surgery to remove cancer and who have more intensive chemotherapy may be more likely to live longer.

Very unusual case of a primary sinonasal germ cell tumour

Sinonasal malignancies are a very rare diagnosis. We present a unique case of a 32-year-old man who presented with symptoms of worsening sinusitis and periorbital cellulitis. Investigation found a sinonasal malignancy and pathology confirmed this to be a primary germ cell tumour. The patient was managed with chemotherapy, surgery and consolidation radiotherapy and has remained well to date. This case report outlines an unusual presentation and diagnostic challenge for the primary care physician, ear, nose and throat surgeon, pathologist and oncologist with review of the surrounding literature.

Long-term outcomes with intensive induction chemotherapy (carboplatin, bleomycin, vincristine and cisplatin/bleomycin, etoposide and cisplatin) and standard bleomycin, etoposide and cisplatin in poor prognosis germ cell tumours: A randomised phase II trial (ISRCTN53643604)

Background

Up to 50% of men with poor prognosis, non-seminoma germ cell tumours (GCTs) die with standard BEP (bleomycin, etoposide and cisplatin) chemotherapy. An intensive regimen, CBOP/BEP (carboplatin, bleomycin, vincristine and cisplatin/BEP), met response targets in a randomised, phase II trial (74% complete response or partial response marker negative, 90% confidence interval (CI) 61%–85%).

Aim

To assess long-term outcomes and late toxicity associated with CBOP/BEP.

Methods

Patients with poor prognosis extracranial GCT were randomised to 4xBEP or CBOP/BEP (2xCBOP, 2xBO, 3xBEP with 15,000iu of bleomycin). Low-dose, stabilising chemotherapy before entry was permitted. Response rates (primary outcome) were reported previously. Here, we report secondary outcomes: progression-free survival (PFS), overall survival (OS) and late toxicity. Prognostic factors and the impact of marker decline are assessed in exploratory analysis.

Results

Eighty-nine patients (43 CBOP/BEP) were randomised. After median 63 months follow-up, 3-year PFS is 55.7% (95% CI: 39.7%, 69.0%) for CBOP/BEP and 38.7% (95% CI: 24.7%, 52.4%) for BEP (hazard ratio [HR]: 0.59 (0.33, 1.06), p = 0.079). Three-year OS is 65.0% (48.8%, 77.2%) and 58.5% (43.0%, 71.2%), respectively (HR: 0.79 (0.41, 1.52), p = 0.49). Twelve-month toxicity was affected by subsequent treatments, with no clear differences between arms. Stabilising chemotherapy was associated with poorer PFS (HR: 2.09 (1.14, 3.81), p = 0.017), whereas unfavourable marker decline, in 60 (70%) patients, was not.

Conclusion

Although not powered for PFS, results for CBOP/BEP are promising. Impact on OS was less clear (and will be affected by subsequent therapy). Further study in an international phase III trial is warranted.

Trial registration

ISRCTN 53643604.

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Intensive induction chemotherapy met response targets in poor prognosis germ cell tumours.

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Three-year progression-free survival was 56% for CBOP/BEP and 39% for BEP.

•

Impact on survival was less clear and will be affected by subsequent therapy.

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Further study in an international phase III trial is warranted.

ESMO Consensus Conference on testicular germ cell cancer: diagnosis, treatment and follow-up

The European Society for Medical Oncology (ESMO) consensus conference on testicular cancer was held on 3-5 November 2016 in Paris, France. The conference included a multidisciplinary panel of 36 leading experts in the diagnosis and treatment of testicular cancer (34 panel members attended the conference; an additional two panel members [CB and K-PD] participated in all preparatory work and subsequent manuscript development). The aim of the conference was to develop detailed recommendations on topics relating to testicular cancer that are not covered in detail in the current ESMO Clinical Practice Guidelines (CPGs) and where the available level of evidence is insufficient. The main topics identified for discussion related to: (1) diagnostic work-up and patient assessment; (2) stage I disease; (3) stage II-III disease; (4) post-chemotherapy surgery, salvage chemotherapy, salvage and desperation surgery and special topics; and (5) survivorship and follow-up schemes. The experts addressed questions relating to one of the five topics within five working groups. Relevant scientific literature was reviewed in advance. Recommendations were developed by the working groups and then presented to the entire panel. A consensus vote was obtained following whole-panel discussions, and the consensus recommendations were then further developed in post-meeting discussions in written form. This manuscript presents the results of the expert panel discussions, including the consensus recommendations and a summary of evidence supporting each recommendation. All participants approved the final manuscript.

[Management of metastatic testicular germ cell tumors]

Metastatic testicular germ cell tumors are rare entities with a high cure rate owing to their major chemosensitivity. Current guidelines should be strictly followed to ensure maximal cure rate. Germ cell tumor treatment requires multidisciplinary skills and is based on cisplatin-based chemotherapy. The current challenge for these patients with favorable prognosis is to limit over- or under-treatment. Centralization of care for patients with these rare cancers is a key point to achieve the best chance of cure.

Dose-reduced first cycle of chemotherapy for prevention of life-threatening acute complications in nonseminomatous germ cell tumor patients with ultra high tumor markers and/or poor performance status

PURPOSE

Patients with metastatic nonseminomatous germ cell tumors (mNSGCT) and a high tumor burden or a poor performance status at initial diagnosis are at risk from potentially life-threatening early complications during or after the first chemotherapy cycle. The outcomes with dose-reduced first cycle of chemotherapy in this population of patients are not well established.

METHODS

We performed a retrospective analysis of patients with mNSGCT and International Germ Cell Cancer Collaborative Group (IGCCCG) poor risk features. All patients received cisplatin and etoposide-based combinations as first-line treatment. Ultra high tumor marker levels were defined as α-fetoprotein ≥ 100,000 ng/ml or human chorionic gonadotropin ≥ 200,000 mIU/ml. Before 2005, the first treatment cycle was administered at a full dose in our center. After 2005, we used an abbreviated course of cisplatin and etoposide (EP) for the first cycle, followed by subsequent full-dose administration.

RESULTS

From 1987 to 2012, 265 patients with poor risk features according to IGCCCG received first-line chemotherapy. Among them, 63 out of 265 (24%) patients had ultra high tumor marker levels and/or ECOG performance status of 3-4. Dose reduction of the first chemotherapy cycle was associated with a significant decrease of life-threatening complications from 76 to 44% (p = 0.01), but not with the overall survival (HR 0.99, 95% CI 0.44-2.26).

CONCLUSIONS

Dose reduction of the first EP cycle by 40-60% in the subgroup of poor risk patients with ultra high tumor marker levels and/or ECOG performance status 3-4 is associated with significantly lowered acute complication rates but not with overall survival.

Dose intense chemotherapy in the management of poor prognosis and relapsed testicular cancer: experiences and controversies

INTRODUCTION

The treatment of poor prognosis chemotherapy naïve or relapsed testicular cancer is challenging. In poor prognosis treatment naïve disease, the outlook for patients with standard approaches utilising three weekly cisplatin based regimens, most commonly bleomycin, etoposide and cisplatin (BEP) is suboptimal, and one can expect more than half of patients to relapse or progress and need salvage treatment. Recent randomised studies have lent weight to the use of dose intensified treatments in these selected patient groups. In relapsed testicular cancer, post platinum based chemotherapy controversy exists as to the optimum relapse regimen as significant cure rates can be expected by re-treating with both conventional dose and high dose or dose intense regimens. Areas covered: This review seeks to outline the evidence for alternative approaches beyond standard three weekly cisplatin based regimens in poor risk metastatic disease. It also explores the evidence available for selection between conventional dose and high dose strategies on relapse. Expert commentary: An overview of the data is presented to support personalising therapy selection in both poor risk and relapsed metastatic germ cell tumors.

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.

The present and future of serum diagnostic tests for testicular germ cell tumours

Testicular germ cell tumours (GCTs) are the most common malignancy occurring in young adult men and the incidence of these tumours is increasing. Current research priorities in this field include improving overall survival for patients classified as being 'poor-risk' and reducing late effects of treatment for patients classified as 'good-risk'. Testicular GCTs are broadly classified into seminomas and nonseminomatous GCTs (NSGCTs). The conventional serum protein tumour markers α-fetoprotein (AFP), human chorionic gonadotrophin (hCG) and lactate dehydrogenase (LDH) show some utility in the management of testicular malignant GCT. However, AFP and hCG display limited sensitivity and specificity, being indicative of yolk sac tumour (AFP) and choriocarcinoma or syncytiotrophoblast (hCG) subtypes. Furthermore, LDH is a very nonspecific biomarker. Consequently, seminomas and NSGCTs comprising a pure embryonal carcinoma subtype are generally negative for these conventional markers. As a result, novel universal biomarkers for testicular malignant GCTs are required. MicroRNAs are short, non-protein-coding RNAs that show much general promise as biomarkers. MicroRNAs from two 'clusters', miR-371-373 and miR-302-367, are overexpressed in all malignant GCTs, regardless of age (adult or paediatric), site (gonadal or extragonadal) and subtype (seminomas, yolk sac tumours or embryonal carcinomas). A panel of four circulating microRNAs from these two clusters (miR-371a-3p, miR-372-3p, miR-373-3p and miR-367-3p) is highly sensitive and specific for the diagnosis of malignant GCT, including seminoma and embryonal carcinoma. In the future, circulating microRNAs might be useful in diagnosis, disease monitoring and prognostication of malignant testicular GCTs, which might also reduce reliance on serial CT scanning. For translation into clinical practice, important practical considerations now need addressing.

Effect of Bleomycin Administration on the Development of Pulmonary Toxicity in Patients With Metastatic Germ Cell Tumors Receiving First-Line Chemotherapy: A Meta-Analysis of Randomized Studies

BACKGROUND

Limited information is available about the effect of bleomycin administration on the development of pulmonary toxicity in metastatic germ cell tumors (GCT).

PATIENTS AND METHODS

A literature search was conducted to identify randomized trials of first-line chemotherapy for GCT. We conducted univariate and multivariate analyses using random effects models to evaluate the predictive role of bleomycin administration in the development of all Grade and Grade 3 to 4 (G3-4) pulmonary toxicity. The results were adjusted for length of follow-up, prognostic risk group, year of treatment, presence of lung metastases, and primary mediastinal GCT.

RESULTS

Fifty-three study arms of 25 phase II and III trials encompassing 6498 patients were selected: 40 that used bleomycin (n = 5093) and 13 that did not (n = 1405). The pooled probability of all-Grade pulmonary toxicity in the bleomycin and nonbleomycin arms was 11.7% (95% confidence interval [CI], 8.4%-16.0%) and 1.7% (95% CI, 0.7%-4.2%), respectively. Univariate analysis indicated that bleomycin administration was associated with the incidence of all-Grade (odds ratio [OR], 7.57; 95% CI, 2.84-20.18; Wald test P < .001) and G3-4 pulmonary toxicity (OR, 5.19; 95% CI, 1.57-17.16; P = .007). Multivariate analysis showed a significant association of bleomycin administration with the incidence of all-Grade pulmonary toxicity (OR, 4.14; 95% CI, 1.36-12.59; P = .012) and a trend toward significance for G3-4 toxicity (OR, 2.24; 95% CI, 0.91-5.51; P = .080).

CONCLUSION

We quantified the bleomycin-associated effect on the development of pulmonary toxicity in patients with GCT who received first-line chemotherapy. This information might be useful for planning clinical trials aimed at reducing chemotherapy as well as to inform patients in the clinic.

Update in germ cell tumours

PURPOSE OF REVIEW

The purpose of this study is to update the reader on advances in postpubertal male germ cell tumours (GCTs) over the last 18 months.

RECENT FINDINGS

Single nucleotide polymorphisms, including in four sex-determination genes, have been identified as additional genetic susceptibility loci to testicular GCT development. New insights into cisplatin resistance implicate the PDGFR-PIK3CA-AKT and RAS pathways. Circulating tumour cells and circulating microRNAs are potential new biomarkers. In clinical stage I (CS-I) GCT, two large studies have confirmed the excellent outcomes achieved with surveillance, which is now the management option of choice for CS I-A nonseminoma and all CS-I seminomas; CS I-B nonseminoma remains controversial. First-line trials of dose-dense multidrug regimens reported promising results but have not yet supplanted BEPx4. Survivorship issues, including secondary malignancies from chemotherapy, remain important in this disease and are a continuing focus of ongoing research.

SUMMARY

Important research questions remain across all aspects of GCT. The next decade is likely to produce many new and exciting discoveries that will benefit GCT patients.

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.