High-dose chemotherapy (HDCT) as second-salvage treatment in patients with multiple relapsed or refractory germ-cell tumors

Efficacy and safety of high-dose chemotherapy as the first or subsequent salvage treatment line in patients with relapsed or refractory germ cell cancer: an international multicentric analysis

BACKGROUND

In relapsed or refractory (RR) metastatic germ cell cancer (GCC), high-dose (HD) chemotherapy (CTX) plus autologous stem cell transplantation is considered the standard of care. Limited data exist regarding the efficacy of HD-CTX following conventionally dosed salvage regimens (CDRs). This analysis explores and contrasts the efficacy of HD-CTX as the first or subsequent salvage regimen.

PATIENTS AND METHODS

Data were retrospectively collected to explore the efficacy of HD-CTX administered as the first (group A) or subsequent salvage CTX (group B) after a CDR. The primary endpoint was OS from the time of HD-CTX. Associations of survival, overall response rate (ORR), and toxicity with clinical characteristics were explored using stratified Kaplan-Meier and Cox regression models.

RESULTS

Overall, 283 patients with GCC were included from 11 international centers, with 159 patients (56%) in group A and 124 patients (44%) in group B. The first salvage treatment was administered between 1998 and 2022, with a median follow-up of 27.0 [standard deviation (SD) 46.2] months for group A and 17.0 (SD 48.5) months for group B. The median OS from HD-CTX treatment initiation was not reached in group A, compared with 25 months in group B (P = 0.00027), associated with 2- and 5-year OS rates of 74% and 63% (group A) versus 53% and 37% (group B), respectively. When administered as the first salvage treatment, HD-CTX was associated with a higher ORR (79% versus 60%; P = 0.013) and lower nonhematologic grade ≥3 toxicity rate (78% versus 97%; P < 0.001). Concerning risk factor analysis for the total cohort, the International Prognostic Factors Study Group score was the only independent predictor of OS in multivariable analysis (P = 0.006).

CONCLUSIONS

When administered as the initial salvage treatment or after CDR, HD-CTX exhibits curative potential for patients with RR GCC. The efficacy and safety outcomes were more favorable when HD-CTX was conducted as the first salvage treatment line.

High-Dose Chemotherapy and Autologous Stem Cell Transplantation for Salvage Therapy of Relapsed/Refractory Germ Cell Tumors: A Single-Center Experience

INTRODUCTION

The optimal management of relapsed/refractory germ cell tumors remains unsettled. In this study, we aimed to evaluate the efficacy of high-dose chemotherapy (HDCT) and autologous stem cell transplantation (ASCT) as salvage therapy in patients who progressed after at least one line of cisplatin-based chemotherapy.

METHODS

We retrospectively reported the results of 133 patients who underwent HDCT and ASCT as salvage therapy from 2016 to 2021. Patients received 3 cycles of paclitaxel, ifosfomide and cisplatin (TIP) regimen as induction and 1 cycle of carboplatin 700 mg/m2 on days 1-3 plus etoposide 750 mg/m2 on days 1-3, followed by ASCT. Demographic and clinicopathological features of patients, the International Germ Cell Cancer Collaborative Group (IGCCCG) risk group at diagnosis, serum alpha-fetoprotein (AFP) and beta-human chorionic gonadotropin (HCG) levels before HDCT, treatment-related complications and survival outcomes were recorded.

RESULTS

The median age of the patients was 31 (range 18-62). The median follow-up was 31.1 months (95% CI, 28.9-33.3 months). During the median follow-up period, 74 of the 133 patients were still alive, and 63 of these were in complete remission. The median progression-free survival (PFS) was 25.8 months (95% CI, 8.1-43.4 months). The 2-year PFS rate was 50.3% and the 2-year overall survival (OS) rate was 60.8%. Variables that remained statistically significant in multivariable analysis and were associated with poor prognosis were mediastinal primary tumor location, presence of brain metastases, and higher AFP and HCG levels at baseline.

CONCLUSION

One course of HDCT and ASCT after induction with TIP is an effective and feasible treatment option for salvage treatment of relapsed/refractory germ cell tumors, with cure rates of up to 60%.

Pure testicular choriocarcinoma, a rare and highly malignant subtype with challenging treatment: A case report and review of the literature

Testicular choriocarcinoma (CC) is the rarest subtype of germ cell tumours (GCTs) of the testis, with a high malignant potential and early haematogenous metastasis. Radical surgical resection should be performed primarily for histological diagnosis, while chemotherapy remains the mainstay of therapy for advanced disease. In the present study, the case of a 65-year-old male patient diagnosed with metastatic testicular CC, who did not fully respond to chemotherapy is reported. This patient underwent surgical removal of the testicular tumour, chemotherapy with etoposide and cisplatin, and radiotherapy of the intracranial lesions. Although the serum human chorionic gonadotropin (HCG) levels of the patient and most of the metastases continued decreasing during chemotherapy, complete response was not achieved after six cycles of chemotherapy. The patient refused high-dose chemotherapy and autologous stem cell transplantation due to severe side effects, and eventually developed respiratory failure on maintenance therapy with oral etoposide. A literature review was then performed, aiming to summarize the characteristics and therapeutic principles of testicular CC. In addition, the emerging therapeutic agents that could be used in maintenance therapy for GCTs, particularly for testicular CC, were also discussed. The limited clinical trials of targeted treatments showed potential benefit for long survival of patients with selected GCTs with fewer side effects. In particular, immunotherapy showed unique potential for testicular CC in preclinical studies, offering new approaches of maintenance therapy for advanced disease. Further studies should shed light on the identification of prognostic factors that predict the response to immune-based therapy in GCTs.

The Use of Salvage Chemotherapy for Patients with Relapsed Testicular Germ Cell Tumor (GCT) in Canada: A National Survey

BACKGROUND

Although metastatic germ cell tumor (GCT) is highly curable with initial cisplatin-based chemotherapy (CT), 20-30% of patients relapse. Salvage CT options include conventional (CDCT) and high dose chemotherapy (HDCT), however definitive comparative data remain lacking. We aimed to characterize the contemporary practice patterns of salvage CT across Canada.

METHODS

We conducted a 30-question online survey for Canadian medical and hematological oncologists with experience in treating GCT, assessing treatment availability, patient selection, and management strategies used for relapsed GCT patients.

RESULTS

There were 30 respondents from 18 cancer centers across eight provinces. The most common CDCT regimens used were TIP (64%) and VIP (25%). HDCT was available in 13 centers (70%). The HDCT regimen used included carboplatin and etoposide for two cycles (76% in 7 centers), three cycles (6% in 2 centers), and the TICE protocol (11%, in 2 centers). "Bridging" CDCT was used by 65% of respondents. Post-HDCT treatments considered include surgical resection for residual disease (87.5%), maintenance etoposide (6.3%), and surveillance only (6.3%).

CONCLUSIONS

HDCT is the most commonly used GCT salvage strategy in Canada. Significant differences exist in the treatment availability, selection, and delivery of HDCT, highlighting the need for standardization of care for patients with relapsed testicular GCT.

Immune checkpoint inhibitor using in cases with gestational trophoblastic diseases

Gestational trophoblastic neoplasias (GTNs) are chemosensitive disorders with very high cure rates. However, individuals with chemoresistant diseases pass away as a result of their illness, necessitating the use of innovative medications. Immune checkpoint inhibitors (ICIs) are a critical component of the strategy for the management of drug-resistant GTD due to the high rate of PD-1 expression and the paternal genetic inheritance in GTNs. Immunotherapy is mentioned as a potential therapeutic approach for chemotherapy-resistant GTD in the most recent worldwide recommendations. However, multicenter worldwide collaborative studies are required to give additional evidence to detect and identify prognostic markers due to the rarity of GTDs and the dearth of data in the literature.

High-dose chemotherapy for relapsed testicular germ cell tumours

Relapsed testicular germ cell tumours (GCTs) might be cured with salvage chemotherapy. Accepted salvage treatment is conventional-dose chemotherapy (CDCT) or high-dose chemotherapy (HDCT). HDCT with peripheral blood stem cell transplant might produce a higher number of durable responses than CDCT. We discuss studies reporting on outcomes of salvage HDCT in relapsed GCTs. The most reproducible results were achieved with HDCT with two cycles of etoposide and carboplatin or three cycles of the paclitaxel, ifosfamide, carboplatin and etoposide regime. Using these two regimens, sustained cure rates of 50-66% were reported in phase I, phase II and retrospective studies published in the past two decades. Cure rates in patients with cisplatin-resistant disease are between 30% and 45%. Two phase III randomized studies were conducted with certain limitations and were unsuccessful in showing a survival benefit of HDCT. Thus, salvage treatment remains a controversial topic. Salvage HDCT with peripheral blood stem cell transplant and CDCT are two recommended treatment options for relapsed GCTs. Consistently reported cure rates from phase I, phase II and large retrospective studies support the use of HDCT in the hands of an experienced team of oncologists.

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.

Immunosenescence in Testicular Cancer Survivors: Potential Implications of Cancer Therapies and Psychological Distress

Testicular cancer (TC) is the most frequent solid tumor diagnosed in young adult males. Although it is a curable tumor, it is frequently associated with considerable short-term and long-term morbidity. Both biological and psychological stress experienced during cancer therapy may be responsible for stimulating molecular processes that induce premature aging and deterioration of immune system (immunosenescence) in TC survivors, leading to an increased susceptibility to infections, cancer, and autoimmune diseases. Immunosenescence is a remodeling of immune cell populations with inversion of the CD4:CD8 ratio, accumulation of highly differentiated memory cells, shrinkage of telomeres, shift of T-cell response to Th2 type, and release of pro-inflammatory signals. TC survivors exposed to chemotherapy show features of immunological aging, including an increase in memory T-cells (CD4+ and CD8+) and high expression of the senescence biomarker p16INK4a in CD3+ lymphocytes. However, the plethora of factors involved in the premature aging of TC survivors make the situation more complex if we also take into account the psychological stress and hormonal changes experienced by patients, as well as the high-dose chemotherapy and hematopoietic stem cell transplantation that some individuals may be required to undergo. The relatively young age and the long life expectancy of TC patients bear witness to the importance of improving quality of life and of alleviating long-term side-effects of cancer treatments. Within this context, the present review takes an in-depth look at the molecular mechanisms of immunosenescence, describing experimental evidence of cancer survivor aging and highlighting the interconnected relationship between the many factors modulating the aging of the immune system of TC survivors.

Nivolumab for the salvage treatment of desperate germ cell tumor: A case report

INTRODUCTION

Testicular germ cell tumors (GCT) are the most common tumor in young men. Their distinctive feature is the exceptional response to platin based combination chemotherapy.Since the prognosis is poor in relapsed and refractory patients, the immune checkpoint inhibitors are candidate agents in these patients although clinical trials are mostly lacking. Herein, we describe a patient with a refractory nonseminomatous GCT using nivolumab as a last resort therapy and provided long term response without any significant toxicity.

CASE REPORT

A 41-year-old male presented with the complaint of flank pain eleven years ago. The patient underwent a retroperitoneal lymph node excision and pathology reported as the mixed germ cell tumor. There were no mass in the testicles and the patient was diagnosed with a primary retroperitoneal GCT. Since the disease has progressed under multiple lines of chemotherapy and autologous stem cell transplantation, treatment was started with nivolumab.

MANAGEMENT AND OUTCOME

The patient started to treatment with nivolumab 3 mg/kg two weekly as a last resort treatment. The nivolumab was continued and the patient's response to this treatment is ongoing and has been stable for 13 months.

DISCUSSION

There are limited treatment options in platinum-refractory germ cell tumors. Recently, immune checkpoint inhibitors tried in this setting with some success in especially non-seminomatous GCTs. We see a good response and prolonged benefit with the use of nivolumab in our patient. Further research including prospective studies on the use of immune checkpoint inhibitors in platinum-resistant testicular cancer can further delineate the role of immunotherapy.

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.

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.

Biological basis and early clinical results of immunotherapy for cisplatin-resistant germ cell cancer

PURPOSE OF REVIEW

Prognosis of patients with refractory or multiply relapsed germ cell cancer (GCC) is dismal with a life expectancy of a few months only. Thus, new targets and treatment options are urgently needed. Here, we review and discuss the biological basis and first clinical results of immune-checkpoint inhibition by targeting programed death 1 (PD-1) or its ligand (PD-L1) in treatment-refractory GCCs.

RECENT FINDINGS

There is a biological rationale to evaluate immune-checkpoint inhibitors in refractory GCCs, as PD-L1 is often expressed and refractory tumors often display mismatch repair deficiency or microsatellite instability. However, the first published clinical phase II trial evaluating pembrolizumab in unselected refractory nonseminoma patients was closed early due to lacking clinical activity. On the contrary, single-case reports have shown meaningful activity in some patients.

SUMMARY

To date, targeted treatments, including current immunotherapy approaches, have only shown very limited activity. Although immune-checkpoint inhibition provides an effective treatment option for various malignancies based on large randomized clinical trials, data on the use of this immunotherapy in refractory GCC are scarce as results of ongoing trials are pending.

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.

The Role of Salvage High-Dose Chemotherapy in Relapsed Male Germ Cell Tumors

Germ cell tumors (GCT) are a unique tumor entity with excellent cure rates if guideline-endorsed treatment is thoroughly applied. Even patients with widespread metastatic disease can often be cured with cisplatin-based combination chemotherapy as part of a multimodal treatment approach. However, about 30% of patients with metastatic disease at initial presentation, corresponding to about 5-10% of all GCT patients, relapse or progress despite first-line treatment and therefore require salvage chemotherapy. Salvage systemic treatment either consists of conventional-dose cisplatin-based combination chemotherapy or sequential high-dose treatment with carboplatin and etoposide plus subsequent autologous stem cell support. This review is based on a comprehensive literature search of MEDLINE and conference proceedings of ESMO, ASCO, and EAU meetings until 2018 and provides an overview of current treatment options for germ cell cancer patients relapsing after or progressing during first-line cisplatin-based combination chemotherapy.

Survival outcomes of patients with germ cell tumors treated with high-dose chemotherapy for refractory or relapsing disease

Introduction

Male patients with metastatic germ cell tumors can be cured in up to 96% of cases depending on stage and IGCCCG prognosis group. Treatment in relapse consists of conventional or high-dose chemotherapy (HDCT) with autologous stem cell transplantation (ASCT) combined with local treatment modalities.

Results

Most patients were classified as poor risk according to IGCCCG (n = 24; 52%) and as intermediate (n = 12), high (n = 16), or very high risk (n = 9) at time of first relapse according to IPFSG criteria. In 67% of patients (n = 31) HDCT/ASCT was performed as first salvage treatment in relapse or for primary refractory disease following first line chemotherapy. In 46% of patients (n = 21) progressive disease was documented after mobilization and prior to HDCT/ASCT. Median progression free survival (mPFS) was 7.4 months (95% confidence interval (CI): 1.3-13.6) while median overall survival (mOS) was 22.2 months (95% CI: 8.9-35.5). When stratified for IPFSG risk group, mPFS (p < 0.001) and mOS (p = 0.009) differed significantly between risk groups (very low vs. low vs. intermediate vs. high vs. very high). Metastases to liver/bone/brain and platinum refractory disease were independent risk factors for inferior PFS (p = 0.024; p = 0.008) but not OS.

Materials and Methods

Forty-six patients treated with HDCT/ASCT at the university clinics in Heidelberg and Nuremberg between 2000-2016 were identified and analyzed. Data was collected retrospectively.

Conclusions

HDCT/ASCT offers a potential curative strategy for patients with relapsed GCT. Improvement is still needed in patients with intermediate, high, and very high IPFSG risk group.

Therapeutic approaches for refractory germ cell cancer

INTRODUCTION

Most germ cell cancer patients with metastatic disease are cured by cisplatin-based combination chemotherapy. 30% of metastatic patients will develop relapse or progress despite adequate first-line treatment and will require salvage therapy, with about 10% of metastasized patients ultimately developing platinum-resistant and fatal disease. Areas covered: Based on a comprehensive literature search of MEDLINE, EMBASE and conference proceedings of ESMO, ASCO and EAU meetings, this review provides an overview on current and potential future treatment options for platinum-refractory germ cell cancer patients including cytostatics and molecularly targeted therapies. Expert commentary: Treatment of platinum-refractory disease remains challenging and long-term survival is rarely achieved despite multimodal treatment approaches. Targeted treatment approaches do not yet play a role in the treatment of platinum-refractory disease due to lacking efficacy in small, unselected clinical trials. Inclusion of patients into clinical trials is strongly recommended.

High β-1,4-Galactosyltransferase-I expression in peripheral T-lymphocytes is associated with a low risk of relapse in germ-cell cancer patients receiving high-dose chemotherapy with autologous stem cell reinfusion

Survival of patients with germ-cell cancer (GCC) and primary progression or relapse after cisplatin-based first-line chemotherapy is highly heterogeneous, ranging from close to zero to more than 70%. We investigated β-1,4-Galactosyltransferase-I (B4GALT1) expression levels in peripheral lymphocytes in a cohort of 46 testicular cancer patients. B4GALT1 enhances immune cell crosstalk via glycosylation of surface molecules. A high expression level of B4GALT1 in T-lymphocytes, but not in monocytes, was associated with a lower risk of relapse with a hazard ratio (HR) of 0.66 (95% confidence interval (CI) of HR: 0.45-0.97; p = 0.02) upon multivariate Cox regression analysis. Correspondingly, interleukin 10 (IL10), a cytokine released by cytotoxic T-cells, was likewise significantly elevated in T-lymphocytes of non-relapse GCC patients (HR: 0.3; 95% CI of HR: 0.14-0.65; p = 0.002). Our data indicate that glycosylation and activation of T-lymphocytes may play a pivotal role in disease control in GCC patients with primary progressive or relapsed disease.

Treatment of CD30-Expressing Germ Cell Tumors and Sex Cord Stromal Tumors with Brentuximab Vedotin: Identification and Report of Seven Cases

BACKGROUND

Cytotoxic therapy for relapsed and refractory germ cell tumors or metastatic sex cord stromal tumors is rarely effective and is often accompanied by high adverse event rates. Expression of CD30 has been observed in testicular cancers, and patients with CD30-expressing embryonal carcinomas have worse progression-free survival and overall survival than those with CD30-negative tumors. The objective of this study (NCT01461538) was to characterize the antitumor activity of brentuximab vedotin in patients with CD30-expressing nonlymphomatous malignancies. Enrolled patients included seven patients with relapsed or refractory germ cell tumors or metastatic sex cord stromal tumors described in this case series.

MATERIALS AND METHODS

Forty patients with relapsed or refractory germ cell tumors, metastatic sex cord stromal tumors, or testicular tumors were screened for CD30 expression; 14 patients had tumors that expressed CD30. Seven patients with CD30-expressing testicular cancer were enrolled in the treatment study: five patients with germ cell tumors, one patient with a Leydig cell tumor, and one patient with a Sertoli cell tumor. Patients were treated with brentuximab vedotin at initial doses of 1.8 or 2.4 mg/kg every 3 weeks. Response assessments were performed at cycles 2 and 4 and every 4 cycles thereafter while the patient was receiving treatment.

RESULTS

Two of seven patients achieved an objective response, including one durable complete response and one partial response at a single time point. Both responding patients had germ cell tumors. Treatment with brentuximab vedotin was generally well tolerated.

CONCLUSION

Treatment of relapsed or refractory germ cell tumors with brentuximab vedotin can induce durable responses with a manageable toxicity profile.

IMPLICATIONS FOR PRACTICE

This case series of seven patients with relapsed or refractory CD30-expressing germ cell tumors (GCTs) or sex cord stromal tumors demonstrates that brentuximab vedotin has activity against GCTs and is well tolerated in heavily pretreated patients with these aggressive tumor types. One patient achieved a complete response that has been durable for almost 4 years since the discontinuation of treatment with brentuximab vedotin. Therefore, brentuximab vedotin may be a valuable option for physicians who care for this difficult-to-treat patient population.

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.

Platinum-refractory germ cell tumors: an update on current treatment options and developments

PURPOSE

In general, 50 % up to 80 % of metastasized germ cell tumor patients can be cured by platinum-based chemotherapy. However, 3-5 % of patients will still die of platinum-refractory disease and new systemic treatment options are needed to improve treatment success in this difficult setting. This review aims to give an overview on treatment options and current developments in the field of platinum-refractory male germ cell tumors.

METHODS

A comprehensive literature search was conducted searching PubMed, Medline, Cochrane and Embase to identify clinical trials regarding the treatment of platinum-refractory disease. ASCO, EAU and ESMO conference proceedings were searched to identify unpublished results of relevant trials. Comprehensive review papers were hand searched for additional references. Clinicaltrials.gov was checked for ongoing clinical trials in the field of platinum-refractory germ cell tumors.

RESULTS

Outcome of platinum-refractory disease remains poor. Single-agents with reasonable activity are gemcitabine, oxaliplatin and paclitaxel, but complete remissions resulting in long-term survival could not be achieved. The triple-combination of gemcitabine, oxaliplatin and paclitaxel followed by resection of residual masses provides the best outcomes with objective responses in 51 % of patients and long-term survival in approximately 10-15 %. To date, no molecularly targeted agent has shown reasonable activity.

CONCLUSIONS

Treatment options for platinum-refractory disease are limited, but a small subset of patients may achieve long-term disease-free survival by multimodal treatment. The potential of novel targeted agents, i.e. by immune-checkpoint-inhibition remains to be defined.

High dose chemotherapy with stem cell support in the treatment of testicular cancer

Testicular germ cell cancer (TGCC) is rare form of malignant disease that occurs mostly in young man between age 15 and 40. The worldwide incidence of TGCC is 1.5 per 100000 man with the highest rates in North Europe. After discovery of cisplatin cure rates of TGCC are very favorable between 90%-95% and unlike most solid tumors, cure rate for metastatic TGCC is around 80%. Metastatic TGCC is usually treated with 3-4 cycles of bleomycin, etoposide, cisplatinum chemotherapy with or without retroperitoneal surgery and cure rates with this approach are between 41% in poor risk group and 92% in good risk group of patients. Cure rates are lower in relapsed and refractory patients and many of them will die from the disease if not cured with first line chemotherapy. High dose chemotherapy (HDCT) approach was used for the first time during the 1980s. Progress in hematology allowed the possibility to keep autologous haematopoietic stem cells alive ex-vivo at very low temperatures and use them to repopulate the bone marrow after sub-lethal dose of intesive myeloablative chemotherapy. Despite the fact that there is no positive randomized study to prove HDCT concept, cure rates in relapsed TGCC are higher after high dose therapy then in historical controls in studies with conventional treatment. Here we review clinical studies in HDCT for TGCC, possibilities of mobilising sufficient number of stem cells and future directions in the treatment of this disease.

Intensive chemotherapy as salvage treatment for solid tumors: focus on germ cell cancer

Germ cell tumors present contrasting biological and molecular features compared to many solid tumors, which may partially explain their unusual sensitivity to chemotherapy. Reduced DNA repair capacity and enhanced induction of apoptosis appear to be key factors in the sensitivity of germ cell tumors to cisplatin. Despite substantial cure rates, some patients relapse and subsequently die of their disease. Intensive doses of chemotherapy are used to counter mechanisms of drug resistance. So far, high-dose chemotherapy with hematopoietic stem cell support for solid tumors is used only in the setting of testicular germ cell tumors. In that indication, high-dose chemotherapy is given as the first or late salvage treatment for patients with either relapsed or progressive tumors after initial conventional salvage chemotherapy. High-dose chemotherapy is usually given as two or three sequential cycles using carboplatin and etoposide with or without ifosfamide. The administration of intensive therapy carries significant side effects and can only be efficiently and safely conducted in specialized referral centers to assure optimum patient care outcomes. In breast and ovarian cancer, most studies have demonstrated improvement in progression-free survival (PFS), but overall survival remained unchanged. Therefore, most of these approaches have been dropped. In germ cell tumors, clinical trials are currently investigating novel therapeutic combinations and active treatments. In particular, the integration of targeted therapies constitutes an important area of research for patients with a poor prognosis.

High-dose chemotherapy for germ cell tumors: do we have a model?

INTRODUCTION

Since the late nineties, the intensification of chemotherapy doses with hematopoietic stem cell rescue held promise for patients with advanced and poor prognosis germ cell tumors (GCTs). High-dose chemotherapy (HDCT) has, nowadays, a recognized indication in the salvage setting of advanced GCTs and is steadily utilized worldwide.

AREAS COVERED

We evaluated the available data with the use of HDCT in these patients. In addition, we provided an original perspective on several issues as experts on behalf of the European Society for Blood and Marrow Transplantation and IGG, including peripheral blood stem cells mobilization and the use of HDCT in special subpopulations of GCT, with the aim to help clarify critical issues in the absence of available clear-cut information.

EXPERT OPINION

Despite HDCT being currently considered a therapeutic option in the salvage setting, critical questions regarding patient selection are still unanswered. Eligibility of patients with a chemoresistant disease, the use of available prognostic factors as well as tumor marker decline in clinical practice are pending issues. Moving forward, these are critical arguments in favor of further clinical research in the field of advanced GCTs.

A phase II trial of high-dose chemotherapy (HDCT) supported by hematopoietic stem-cell transplantation (HSCT) in germ-cell tumors (GCTs) patients failing cisplatin-based chemotherapy: the Multicentric TAXIF II study

BACKGROUND

High-dose chemotherapy (HDCT) is an effective salvage treatment of germ-cell tumors (GCTs) patients. In the first salvage setting, 30%-70% of patients may achieve durable remissions. Even when HDCT is administered as subsequent salvage treatment, up to 20% of patients may still be definitively cured. However, patients with refractory/relapsed disease still have a very poor long-term prognosis, requiring earlier intervention of HDCT.

PATIENTS AND METHODS

This phase II trial was addressed to nonrefractory patients failing Cisplatin-based chemotherapy. Inclusion criteria included seminomatous GCT in relapse after two lines of chemotherapy, nonseminomatous GCT in relapse after first or second lines, partial remission after first line, primary mediastinal GCT in first relapse. Patients received two cycles combining Epirubicin and Paclitaxel (Epi-Tax), followed by three consecutive HDCT, one using a Paclitaxel/Thiotepa (Thio-Tax) association and two using the 5-day Ifosfamide-Carboplatin-Etoposide regimen. The main objective was to determine the complete response rate.

RESULTS

Forty-five patients were included between September 2004 and December 2007: 44 received the first HDCT cycle, 39 two HDCT cycles, 29 could receive the whole protocol. Sixteen patients did not receive the entire protocol, including eight (17.7%) for toxic side-effects. Two patients (4.4%) died of toxicities, and 17 (37.7%) of disease progression. With a median follow-up time of 26 months (range, 4-51), the final overall response rate was 48.8% (including a complete response rate of 15.5% and a partial response/negative serum markers rate of 26.6%) in an intent-to-treat analysis. The median progression-free survival (PFS) and overall survival (OS) times were 22 months [95% confidence interval (CI) 2-not reached] and 32 months (95% CI 4-49), respectively. The 2-year PFS was a plateau setup at 50% (95% CI 32-67) and the 2-year OS was 66% (95% CI 44-81).

CONCLUSION

The TAXIF II protocol was effective in nonrefractory GCT patients failing Cisplatin-based chemotherapy. The toxic death rate remained acceptable in the field of HDCT regimens.

TRIAL REGISTRATION NUMBER

NCT00231582.

[Update on first-line and relapse chemotherapy for testicular cancer]

Germ-cell cancer (GCC) is still the most common cancer diagnosis in men between the ages of 20 and 45 years with an increasing incidence. Due to effective and standardized algorithms that have been developed to stratify patients into different risk groups, remarkable progress has been made in the medical treatment of testicular cancer with an overall cure rate of 88%. The application of surgery, radiotherapy and chemotherapy, the choice of chemotherapy agents as well as treatment duration is defined in international consensus guidelines. The guidelines are based on histology, tumor stages and presence or absence of already known and well-established risk factors. These stringent parameters guarantee the optimal curative treatment options for each GCC patient and can avoid overtreatment as well as undertreatment. For patients with early stage disease, careful consideration between possible side effects due to an adjuvant therapy and the expected relapse rate must be made, whereas in advanced tumor stages the optimal sequence of chemotherapy, surgery and radiotherapy is the focus. In patients who progress or relapse after first-line therapy, the issue of optimal treatment represents a particular challenge and is far more complex. It needs to take into account the analysis of special prognostic variables for a further risk-tailored therapy. A careful weighting between the chosen regimen and the often higher rate of treatment failure in contrast to increased toxic side-effects is mandatory.The disregard of accurate risk stratification and application of accepted treatment standards for patients with GCC at the time of initial diagnosis or at relapse is associated with developing more extensive disease and more intensive treatment. It also results in lower cure rates with the need for further therapy or leads to death of the patient without ever having had a chance for cure.

First salvage treatment in patients with advanced germ cell cancer after cisplatin-based chemotherapy: analysis of a registry of the German Testicular Cancer Study Group (GTCSG)

PURPOSE

We analyzed prognostic categories at first relapse according to the International Prognostic Factors Study Group (IPFSG) criteria as well as the efficacy of salvage treatment.

METHODS

143 patients with relapsed or refractory germ cell cancer undergoing first salvage treatment with conventional-dose (CD-CX, n = 48) or high-dose chemotherapy with autologous stem cell support (HD-CX, n = 95) contributed by nine centers were retrospectively analyzed.

RESULTS

Prognostic subgroups according to IPFSG criteria were: very low risk 13/143, low risk 36/143, intermediate risk 66/143, high risk 22/143, and very high risk 6/143 patients. The IPFSG categories significantly correlated with overall survival (OS) (p = 0.025) after 1st salvage treatment. After a median follow-up of 19 months, 55 % of all patients had relapsed and 33 % had died. For the entire cohort, progression-free survival (PFS) rate after 2 years was 43 %, and OS rate after 5 years was 52 %. Compared to the HD-CX group, vital carcinoma was found more often in secondarily resected lesions following CD-CX (22/29 vs. 22/45; p = 0.021). Second relapse rate was higher with 75 versus 44 %, resulting in a shorter median PFS with 8 versus 42 months (p < 0.001), but this did not translate into different OS (p = 0.931). At subsequent relapses, 26/36 patients received HD-CX as ≥2nd-salvage treatment.

CONCLUSION

This analysis confirms the prognostic value of the IPFSG prognostic score. HD-CX seemed superior to CD-CX as first salvage treatment with respect to PFS in this retrospective analysis.

Maintaining success, reducing treatment burden, focusing on survivorship: highlights from the third European consensus conference on diagnosis and treatment of germ-cell cancer

In November 2011, the Third European Consensus Conference on Diagnosis and Treatment of Germ-Cell Cancer (GCC) was held in Berlin, Germany. This third conference followed similar meetings in 2003 (Essen, Germany) and 2006 (Amsterdam, The Netherlands) [Schmoll H-J, Souchon R, Krege S et al. European consensus on diagnosis and treatment of germ-cell cancer: a report of the European Germ-Cell Cancer Consensus Group (EGCCCG). Ann Oncol 2004; 15: 1377-1399; Krege S, Beyer J, Souchon R et al. European consensus conference on diagnosis and treatment of germ-cell cancer: a report of the second meeting of the European Germ-Cell Cancer Consensus group (EGCCCG): part I. Eur Urol 2008; 53: 478-496; Krege S, Beyer J, Souchon R et al. European consensus conference on diagnosis and treatment of germ-cell cancer: a report of the second meeting of the European Germ-Cell Cancer Consensus group (EGCCCG): part II. Eur Urol 2008; 53: 497-513]. A panel of 56 of 60 invited GCC experts from all across Europe discussed all aspects on diagnosis and treatment of GCC, with a particular focus on acute and late toxic effects as well as on survivorship issues. The panel consisted of oncologists, urologic surgeons, radiooncologists, pathologists and basic scientists, who are all actively involved in care of GCC patients. Panelists were chosen based on the publication activity in recent years. Before the meeting, panelists were asked to review the literature published since 2006 in 20 major areas concerning all aspects of diagnosis, treatment and follow-up of GCC patients, and to prepare an updated version of the previous recommendations to be discussed at the conference. In addition, ∼50 E-vote questions were drafted and presented at the conference to address the most controversial areas for a poll of expert opinions. Here, we present the main recommendations and controversies of this meeting. The votes of the panelists are added as online supplements.

Sequential Versus Single High-Dose Chemotherapy in Patients With Relapsed or Refractory Germ Cell Tumors: Long-Term Results of a Prospective Randomized Trial

Purpose

To evaluate the long-term survival rates in patients with relapsed or refractory germ cell tumors (GCTs) after single or sequential high-dose chemotherapy (HDCT).

Patients and Methods

Between November 1999 and November 2004, 211 patients with relapsed or refractory GCT were randomly assigned to treatment with either one cycle of cisplatin 100 mg/m2, etoposide 375 mg/m2, and ifosfamide 6 g/m2 (VIP) plus three cycles of high-dose carboplatin 1,500 mg/m2 and etoposide 1,500 mg/m2 (CE, arm A) or three cycles of VIP plus one cycle of high-dose carboplatin 2,200 mg/m2, etoposide 1,800 mg/m2, and cyclophosphamide 6,400 mg/m2 (CEC, arm B) followed by autologous stem-cell reinfusion. Long-term progression-free survival (PFS) and overall survival (OS) 6 years after random assignment of the last patient were compared by using the log-rank test.

Results

Overall, 108 and 103 patients were randomly assigned to arms A and B, respectivelyl. The study was stopped prematurely because of excess treatment-related mortality in arm B (14%) compared with that in arm A (4%; P = .01). As of December 2010, nine (5%) of 211 patients were lost to follow-up; 94 (45%) of 211 are alive and 88 (94%) of 94 patients are progression free. Five-year PFS is 47% (95% CI, 37% to 56%) in arm A and 45% (95% CI, 35% to 55%) in arm B (hazard ratio [HR], 1.16; 95% CI, 0.79 to 1.70; P = .454). Five-year OS is 49% (95% CI, 40% to 59%) in arm A and 39% (95% CI, 30% to 49%) in arm B (HR, 1.42; 95% CI, 0.99 to 2.05; P = .057).

Conclusion

Patients with relapsed or refractory GCT achieve durable long-term survival after single as well as sequential HDCT. Fewer early deaths related to toxicity translated into superior long-term OS after sequential HDCT.

Intensified chemotherapy with stem-cell rescue in germ-cell tumors

BACKGROUND

Based on the high chemosensitivity of germ-cell tumors (GCTs), the concept of high-dose chemotherapy (HDCT) has been developed worldwide and investigated through many clinical trials. It has been carried out in different clinical settings, ranging from resistant or absolute refractory disease to chemosensitive relapse. HDCT with stem-cell support has been also explored as a part of first-line strategy for poor-prognosis patients.

PATIENTS AND METHODS

Our review summarized results from clinical trials evaluating the role of HDCT in patients with advanced GCTs. So far available data were obtained through a Medline search of English-language literature.

RESULTS

Several phase II trials and retrospective series have shown a possible benefit for GCT patients with recurrent disease as well as in first-line setting. Despite these results, data derived from randomized phase III studies failed to demonstrate any survival advantage for HDCT over conventional chemotherapy.

CONCLUSIONS

The role of HDCT in GCTs remains controversial. We need new prospective studies based on prognostic factors with multiple transplants of carboplatin and etoposide as the preferred high dose regimen. At present, based mainly on retrospective and phase II studies, HDCT may represent a therapeutic option for patients with primary refractory disease or for those with a second or further relapse.

[High-dose chemotherapy and residual tumor resection in male germ cell tumors]

As a consequence of the unsatisfactory results of conventional dose salvage regimens, in particular for patients with poor prognostic features at the time of relapse or in patients with refractory disease, high-dose chemotherapy (HDCT) was introduced into clinical practice in the late 1980s. The combination of carboplatin and etoposide (CE) still remains the backbone of most high-dose regimens. Multiple modifications with more dose escalations or addition of further drugs have been explored, most often with increased toxicity. With improved expertise in supportive care and the use of peripheral blood stem cells, hematopoetic recovery has been significantly shortened and the initial high treatment-related mortality reduced from more than 10% to about 3%. Since the incorporation of HDCT, even patients with unfavorable prognostic features or patients with second or subsequent relapses can achieve long-term remission. Following HDCT residual tumor resection plays a major role in achieving these long-term results. The proportion of vital residual tumor after HDCT is much higher than in patients after conventional chemotherapy. The role of HDCT remains controversial particularly as a first-line treatment and less so in the first salvage setting. As these patients are rare HDCT and residual tumor resection should only be be provided by high-volume centers with sufficient expertise in performing these complex procedures.

Conventional-dose versus high-dose chemotherapy as first salvage treatment in male patients with metastatic germ cell tumors: evidence from a large international database

PURPOSE

Conventional-dose chemotherapy (CDCT) and high-dose chemotherapy (HDCT) may both be successfully used as salvage treatment for patients with metastatic germ cell tumors (GCTs) who experience progression with first-line treatment.

PATIENTS AND METHODS

Data on 1,984 patients with GCTs who experienced progression after at least three cisplatin-based cycles and were treated with either cisplatin-based CDCT or carboplatin-based HDCT chemotherapy were collected from 38 centers or groups worldwide. Of 1,984 patients, 1,594 (80%) were eligible, and among the eligible patients, 1,435 (90%) could reliably be classified into one of the following five prognostic categories based on prior prognostic classification: very low (n = 76), low (n = 257), intermediate (n = 646), high (n = 351), and very high risk (n = 105). Within each of the five categories, the progression-free survival (PFS) and overall survival (OS) after CDCT and HDCT were compared using the Cox model adjusted for significant distributional differences between important variables.

RESULTS

Overall, 773 patients received CDCT, and 821 patients received HDCT. Both treatment modalities were used with similar frequencies within each prognostic category. The hazard ratio for PFS was 0.44 (95% CI, 0.39 to 0.51) stratified on prognostic category, and the hazard ratio for OS was 0.65 (95% CI, 0.56 to 0.75), favoring HDCT. These results were consistent within each prognostic category except among low-risk patients, for whom similar OS was observed between the two treatment groups.

CONCLUSION

This retrospective analysis suggests a benefit from HDCT given as intensification of first salvage treatment in male patients with GCTs and emphasizes the need for another prospective randomized trial comparing CDCT to HDCT in this patient population.

Testicular germ cell tumors: pathogenesis, diagnosis and treatment

Testicular germ cell tumors represent the most common solid malignancy of young men aged 15-40 years. Histopathologically, testicular germ cell tumors are divided into two major groups: pure seminoma and nonseminoma. The pathogenesis of testicular germ cell tumors remains unknown; however, cryptorchidism is the main risk factor, and molecular studies have shown strong evidence of an association between genetic alterations and testicular germ cell tumors. In cases of suspicion for testicular germ cell tumor, a surgical exploration with orchiectomy is obligatory. After completion of diagnostic procedures, levels of serum tumor markers and the clinical stage based on the International Union Against Cancer tumor-node-metastasis classification should be defined. Patients with early-stage testicular germ cell tumors are treated by individualized risk stratification within a multidisciplinary approach. The individual management (surveillance, chemotherapy or radiotherapy) has to be balanced according to clinical features and the risk of short-term and long-term toxic effects. Treatment for metastatic tumors is based on risk stratification according to International Germ Cell Cancer Collaborative Group classification and is performed with cisplatin-based chemotherapy and residual tumor resection in cases of residual tumor lesion. High-dose chemotherapy represents a curative option for patients with second or subsequent relapses.

Prognostic factors in patients with metastatic germ cell tumors who experienced treatment failure with cisplatin-based first-line chemotherapy

PURPOSE

To develop a prognostic model in patients with germ cell tumors (GCT) who experience treatment failure with cisplatin-based first-line chemotherapy.

PATIENTS AND METHODS

Data from 1,984 patients with GCT who progressed after at least three cisplatin-based cycles and were treated with cisplatin-based conventional-dose or carboplatin-based high-dose salvage chemotherapy was retrospectively collected from 38 centers/groups worldwide. One thousand five hundred ninety-four (80%) of 1,984 eligible patients were randomly divided into a training set of 1,067 patients (67%) and a validation set of 527 patients (33%). Seminomas were set aside for posthoc analyses. Primary end point was the 2-year progression-free survival after salvage treatment.

RESULTS

Overall, 990 patients (62%) relapsed and 604 patients (38%) remained relapse free. Histology, primary tumor location, response, and progression-free interval after first-line treatment, as well as levels of alpha fetoprotein, human chorionic gonadotrophin, and the presence of liver, bone, or brain metastases at salvage were identified as independent prognostic variables and used to build a prognostic model in the training set. Survival rates in the training and validation set were very similar. The estimated 2-year progression-free survival rates in patients not included in the training set was 75% in very low risk, 51% in low risk, 40% in intermediate risk, 26% in high risk, and only 6% in very high-risk patients. Due to missing values in individual variables, 69 patients could not reliably be classified into one of these categories.

CONCLUSION

Prognostic variables are important in patients with GCT who experienced treatment failure with cisplatin-based first-line chemotherapy and can be used to construct a prognostic model to guide salvage strategies.