TI-CE high-dose chemotherapy for patients with previously treated germ cell tumors: results and prognostic factor analysis

Clinical outcome and prognostic factors for immunotherapy-based treatments in patients with platinum-refractory germ cell tumor

BACKGROUND

Germ cell tumors (GCTs) are a heterogeneous group of cancers associated with a favorable prognosis when treated with platinum-based chemotherapy. However, patients with platinum-refractory GCTs face limited options and poorer outcomes, necessitating innovative treatment approaches. This study aims to evaluate the clinical outcomes and identify prognostic factors associated with immunotherapy-based treatments in this challenging patient population.

METHODS

This retrospective analysis included individuals with platinum-refractory GCTs treated with immunotherapy between 2017 and 2023. Clinical outcomes, safety, and biomarkers were analyzed.

RESULTS

The study included 37 male patients with a median age of 26 years (range: 18-65). The overall response rate was 24.32 %, with a median progression-free survival (PFS) and overall survival (OS) of 4.67 months and 22.67 months, respectively. Patients with both serum levels of alpha-fetoprotein (AFP) and human chorionic gonadotropin (hCG) below 100 (AFP & hCG < 100) demonstrated significantly better PFS and OS. Multivariate analysis indicated that lower serum tumor marker levels (AFP & hCG < 100) and treatment initiation at earlier lines were significantly associated with improved PFS. Notably, genomic analysis revealed that one patient with an MDM4 mutation experienced hyperprogression after the initiation of immunotherapy. Immune-related adverse events occurred in two patients: one developed grade 1 hyperthyroidism, and the other experienced grade 2 immune-related pneumonitis.

CONCLUSIONS

Immunotherapy offers a promising treatment option for selected patients with platinum-refractory GCTs, demonstrating moderate response rates and potential survival benefits in a real-world scenario. Identifying specific prognostic factors may help tailor treatment strategies and enhance outcomes in this challenging patient cohort.

SEOM-GG clinical guidelines for the management of germ-cell testicular cancer (2023)

Testicular germ cell tumors are the most common tumors in adolescent and young men. They are curable malignancies that should be treated with curative intent, minimizing acute and long-term side effects. Inguinal orchiectomy is the main diagnostic procedure, and is also curative for most localized tumors, while patients with unfavorable risk factors for recurrence, or those who are unable or unwilling to undergo close follow-up, may require adjuvant treatment. Patients with persistent markers after orchiectomy or advanced disease at diagnosis should be staged and classified according to the IGCCCG prognostic classification. BEP is the most recommended chemotherapy, but other schedules such as EP or VIP may be used to avoid bleomycin in some patients. Efforts should be made to avoid unnecessary delays and dose reductions wherever possible. Insufficient marker decline after each cycle is associated with poor prognosis. Management of residual masses after chemotherapy differs between patients with seminoma and non-seminoma tumors. Patients at high risk of relapse, those with refractory tumors, or those who relapse after chemotherapy should be managed by multidisciplinary teams in experienced centers. Salvage treatment for these patients includes conventional-dose chemotherapy (TIP) and/or high-dose chemotherapy, although the best regimen and strategy for each subgroup of patients is not yet well established. In late recurrences, early complete surgical resection should be performed when feasible. Given the high cure rate of TGCT, oncologists should work with patients to prevent and identify potential long-term side effects of the treatment. The above recommendations also apply to extragonadal retroperitoneal and mediastinal tumors.

High-dose chemotherapy as initial salvage chemotherapy in patients with relapsed or refractory testicular cancer: a systematic review and meta-analysis

Background

The role of high-dose chemotherapy followed by autologous hematopoietic cell transplantation in the management of patients with relapsed/refractory germ-cell tumors has not been established in prospective studies. Our aim was to estimate the benefits and harm of this treatment in men with relapsed/refractory germ-cell tumors.

Methods

Electronic databases, conference proceedings, and trial registers until April 30, 2023, were searched. Randomized and non-randomized prospective controlled trials were included. Risk of bias assessments were performed using either RoB2 or ROBINS-I tools. The certainty of evidence was assessed using the Grading of Recommendations, Assessment, Development, and Evaluations (GRADE) approach. Time-to-event data were analyzed using the hazard ratio. The primary outcome was overall survival, and a meta-analysis was not conducted to assess it because non-randomized trials were judged to have a critical risk of bias. Categorical data were analyzed using a risk ratio. All results are presented with the corresponding 95% confidence interval.

Results

Four out of 3,824 records met the inclusion criteria, and three out of four were used to assess primary and secondary outcomes. Based on the IT94 study (N = 263 participants), single high-dose chemotherapy followed by autologous hematopoietic cell transplantation may have little to no effect on overall survival [hazard ratio (HR) 0.98, 95%CI 0.68 to 1.42; p = 0.916]. Non-randomized trials (N = 43 participants) showed contrasting results, which may be explained by the number of cycles of high-dose chemotherapy administered in each study. Regarding secondary outcomes, information was only provided for event-free survival, response rate, and acute toxicities.

Conclusions

Based on prospective data, there is insufficient evidence to support or refute the proposal that high-dose chemotherapy with autologous hematopoietic cell transplantation improves survival in men with relapsed/refractory germ-cell tumors. If this treatment is considered essential, the choice should be made by experienced clinicians at high-volume cancer centers.

High-dose chemotherapy and peripheral blood stem cell transplantation as salvage therapy in primary mediastinal nonseminomatous germ cell tumors: The Indiana University experience

BACKGROUND

Patients with relapsed primary mediastinal nonseminomatous germ cell tumor have low cure rates with salvage chemotherapy or surgery. The authors report survival outcomes of patients who received high-dose chemotherapy (HDCT) and peripheral blood stem cell transplantation (PBSCT) at Indiana University.

METHODS

The prospectively maintained Indiana University germ cell tumor database identified 32 patients with primary mediastinal nonseminomatous germ cell tumor who progressed after first-line cisplatin-based combination chemotherapy and received HDCT and PBSCT between 2006 and 2021. Therapy included two consecutive courses of HDCT consisting of 700 mg/m2 carboplatin and 750 mg/m2 etoposide, each for 3 consecutive days, and each followed by PBSCT. A second course was not given if the patient experienced progressive disease or prohibitive toxicity. Progression-free survival and overall survival were analyzed using the Kaplan-Meier method. Medians with 95% confidence intervals were also calculated along with 2-year probabilities.

RESULTS

The median age at HDCT was 30 years (range, 18-61 years). With a median follow-up of 4.7 years (range, 1-14 years), the 2-year progression-free survival rate was 31% (95% confidence interval, 16%-47%), and the 2-year overall survival rate was 35% (95% confidence interval, 19%-52%). At last follow-up, nine patients (28%) remained without evidence of disease, including two platinum-refractory patients and two patients who were receiving HDCT as third-line therapy. There were three treatment-related deaths.

CONCLUSIONS

Salvage HDCT and PBSCT is an active combination in patients who have relapsed primary mediastinal nonseminomatous germ cell tumor with curative potential and prolonged survival, including in platinum-refractory and third-line settings. The authors recommend this approach for initial salvage chemotherapy in this patient population.

Paclitaxel, Ifosfamide, and Cisplatin as Initial Salvage Chemotherapy for Germ Cell Tumors: Long-Term Follow-Up and Outcomes for Favorable- and Unfavorable-Risk Disease

PURPOSE

Paclitaxel, ifosfamide, and cisplatin (TIP) is an established salvage regimen for germ cell tumors (GCT) on the basis of a phase II trial, but efficacy on a large patient cohort including patients with unfavorable risk features and long-term outcomes has not been reported. Herein, we report updated treatment efficacy and long-term follow-up with TIP.

PATIENTS AND METHODS

Patients with GCT who received TIP after cisplatin-based chemotherapy were eligible. Favorable response (complete response or partial response with negative tumor markers), overall survival (OS) and progression-free survival (PFS) rates, relapse, and toxicity were determined. Disease was reclassified according to the International Prognostic Factor Study Group (IPFSG) score.

RESULTS

Of the 104 patients, 87 had favorable risk factors and 17 had at least one unfavorable factor by Memorial Sloan Kettering Cancer Center (MSKCC) criteria. Ten patients were treated for a second gonadal primary GCT. With a median follow-up of 8.9 years, the 5-year PFS and OS rates were 66% (95% CI, 55 to 74) and 69% (95% CI, 59 to 77), respectively. Among 87 patients with favorable-risk disease, 69 (79%) achieved a favorable response with 5-year PFS and OS rates of 67% (95% CI, 56 to 76) and 72% (95% CI, 61 to 80), respectively. Among 17 patients with MSKCC unfavorable-risk disease, 13 (76%) achieved a favorable response with 5-year PFS and OS rates of 59% (95% CI, 33 to 78) and 56% (95% CI, 28 to 76), respectively. After IPFSG reclassification, 5-year PFS and OS rates for patients with ≤intermediate-risk disease were 75% (95% CI, 50 to 89) and 73% (95% CI, 55 to 85), respectively.

CONCLUSION

TIP is an effective second-line regimen for patients with GCT. Similar outcomes were observed in patients with favorable- and unfavorable-risk disease. The randomized TIGER trial (ClinicalTrials.gov identifier: NCT02375204) comparing TIP with high-dose chemotherapy will determine the optimal second-line treatment approach.

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.

High-dose chemotherapy with autologous stem cell transplants in adult primary non-seminoma mediastinal germ-cell tumors. A report from the Cellular Therapy and Immunobiology working party of the EBMT

BACKGROUND

Primary mediastinal germ-cell tumors (PMGCTs) account for 1%-3% of all germ-cell tumors (GCTs). Non-seminoma have a poorer prognosis compared to their gonadal counterpart and, according to the International Germ Cell Cancer Collaborative Group, they are considered 'poor risk' disease. Medical treatment is the same, with overall survival (OS) being ∼40%, declining to 10%-15% at 3 years in case of lung and non-visceral metastases. Patients failing first-line chemotherapy have a dismal prognosis, with only 5%-10% of cases being cured in the salvage setting. High-dose chemotherapy (HDC) with autologous stem cell transplantation (ASCT) has been successfully used to treat patients with relapsed or refractory gonadal GCTs.

PATIENTS AND METHODS

This retrospective study aimed to investigate the value of HDC with ASCT in the whole population and define primary mediastinal non seminoma germ cell tumor (PMNSGCT) patient subgroups, who were registered in the European Society for Blood and Marrow Transplantation database from January 2000 to January 2018. Sixty-nine adult male patients with PMNSGCT were included. HDC consisted mainly of carboplatin/etoposide doublet, and most patients received HDC as part of a multiple sequential HDC program.

RESULTS

OS was 43.3% at 2 years, and 34.7% at 5 and 10 years for the entire cohort. Analysis of outcomes showed that patients undergoing HDC as upfront therapy had a better progression-free survival (PFS) and OS compared to those treated in subsequent relapses (5-year PFS 51.8% versus 26.8% and 5-year OS 51.3% versus 25.9%). Better remission status before transplantation was predictive of the benefit of HDC. Three treatment-related deaths were recorded.

CONCLUSIONS

To our knowledge, this is the most extensive retrospective study of HDC in PMNSGCTs patients and the first to thoroughly investigate potential predictors of benefit from this treatment. HDC with ASCT may well represent a therapeutic option in patients with PMNSGCTs after the first relapse or even as a front-line program.

[Conventional versus high-dose salvage chemotherapy for relapsed testicular germ cell tumours]

Since the introduction of cisplatin-based combination chemotherapy, patients with metastatic germ cell tumours achieve very high cure rates of >80%. Nevertheless, about 30% of patients relapse despite guideline-endorsed first-line treatment. Of these, again about 50% of patients can still achieve cure with platinum-based salvage chemotherapy and eventually post-chemotherapy residual mass resection.Salvage chemotherapy generally involves platinum-based combination chemotherapy, either as conventional dose cisplatin-based combinations again or as high-dose chemotherapy with subsequent autologous stem cell transplantation.To date, high level evidence from randomised trials supporting the use of salvage high-dose chemotherapy for all patients relapsing after first-line treatment remains lacking, but a large international retrospective registry study had shown a 15% overall survival benefit for patients undergoing salvage high-dose chemotherapy.In this article, we summarise the available literature on the different salvage treatment approaches and discuss these in the light of current treatment guideline recommendations for the management of testicular cancer.

Current outstanding challenges in germ cell tumors

PURPOSE OF REVIEW

Despite the remarkable advances in the treatment of germ cell tumors (GCT), several challenges remain. This review aims to highlight some of these challenges and provide guidance on how to navigate through them.

RECENT FINDINGS

Patients with International Germ Cell Cancer Collaborative Group poor risk disease have worse prognosis and investigating novel therapeutic interventions are warranted in this population. Patients with brain metastases require a multidisciplinary approach by a group of clinicians experienced in the management of germ cell tumors. Patients with platinum refractory disease have poor prognosis and development of novel treatment options is urgently needed. Conventional tumor markers including alpha fetoprotein and human chorionic gonadotropin remain standard. Development of novel biomarkers to detect minimal residual disease or teratoma is needed.

SUMMARY

Management of patients with GCT requires a multidisciplinary approach. Patients should preferably be evaluated at tertiary care centers with expertise in the management of this disease.

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%.

High Dose Chemotherapy With Autologous Stem Cell Transplant for Patients With Advanced Germ Cell Tumors: Real-World Evidence From a Tertiary Cancer Center in Brazil

BACKGROUND

High-dose chemotherapy followed by stem cell transplant (HDCT) is potentially curative for patients with refractory germ cell tumors (rGCT). There is scarce real-world data supporting its implementation in low- and middle-income countries. We described the experience of our tertiary cancer center in Sao Paulo, Brazil.

METHODS

We identified male patients ≥18 years-old with rGCT referred to HDCT after board discussion. Clinical data, including delays in HDCT protocol, were extracted from medical records, and survival outcomes were estimated using the Kaplan-Meier method. The log-rank test and Cox proportional hazard were used to determine effects on overall survival (OS).

RESULTS

From January 2013 to January 2023, 34 patients were referred and considered eligible to receive 2 cycles of HDCT. Most patients had primary testicular tumors (82%), nonseminomatous histology (88%), and poor International Germ Cell Collaborative Group (IGCCCG) (79%). Twenty-three patients received HDCT (1 cycle, n = 8; 2 cycles, n = 15). Main reasons for not receiving any HDCT were death due to progressive disease (n = 1), performance deterioration (n = 7), and failure of stem cell mobilization (n = 3). OS at 2 years was 36.7% for the eligible population, 56.1% for patients who underwent at least 1 HDCT, and 77.1% for those who had ≥2 cycles. The 2-year OS rate for patients not given HDCT was 0%. All patients had delays in protocol, and poor-risk patients had longer intervals from referral to protocol initiation (0.7 vs. 1.8 month, P < .01).

CONCLUSION

Outcomes of patients who received ≥1 HDCT were encouraging; however, only 15 from 34 eligible patients were able to receive the planned 2 cycles of HDCT. Further strategies to minimize treatment delays in low- and middle-income countries are needed.

Testicular cancer in 2023: Current status and recent progress

Testicular germ cell tumor (GCT) is the most common solid tumor in adolescent and young adult men. Progress in the management of GCT has been made in the last 50 years, with a substantial improvement in cure rates for advanced disease, from 25% in the 1970s to nearly 80%. However, relapsed or platinum-refractory disease occurs in a proportion, 20% of whom will die from disease progression. This article reviews the current evidence-based treatments for extracranial GCT, the acute and chronic toxic effects that may result, and highlights contemporary advances and progress in the field.

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.

Primary germ cell tumours of the mediastinum: A review with emphasis on diagnostic challenges

This article will review current aspects of the histopathological, immunohistochemical and molecular analysis of primary mediastinal germ cell tumours (PMGCTs) as well as their aetiological, epidemiological, clinical and therapeutic features. PMGCTs represent an important differential diagnosis in the spectrum of mediastinal tumours, and their diagnosis is usually made on small tissue samples from core needle biopsies in combination with diagnostic imaging and serum tumour markers. As in lymphomas, a small biopsy is often the only viable tumour sample available from these patients, as they receive chemotherapy prior to eventual surgical resection. Pathologists therefore need to apply an efficient combination of immunohistochemical markers to confirm the diagnosis of a PMGCT and to exclude morphological mimics.

Ototoxicity associated with high-dose carboplatin for patients with previously treated germ cell tumors

BACKGROUND

High-dose carboplatin is an essential part of curative high-dose chemotherapy (HDCT) for patients with previously treated germ cell tumors (GCTs). Although hearing loss (HL) is a known side effect of HDCT, data on its severity and characteristics are limited.

METHODS

Eligible patients received HDCT for GCTs from 1993 to 2017 and had audiograms before and after HDCT. HL severity was classified by American Speech-Language-Hearing Association criteria, and mean change in hearing threshold at each frequency (0.25-8 kHz) was estimated from pre- to post-HDCT and between HDCT cycles.

RESULTS

Of 115 patients (median age, 32 years), 102 (89%) received three cycles of HDCT. Of 106 patients with normal hearing to mild HL in the speech frequencies (0.5-4 kHz) before HDCT, 70 (66%) developed moderate to profound HL in the speech frequencies after HDCT. Twenty-five patients (22%) were recommended for hearing aids after HDCT. Patients with moderate to profound HL isolated to the higher frequencies (6-8 kHz) before HDCT were more likely to develop moderate to profound HL in the speech frequencies after HDCT (94% vs. 61%; p = .01) and to be recommended for hearing aids (39% vs. 18%; p = .05).

CONCLUSIONS

HL was frequent after HDCT for GCTs, with most patients developing at least moderate HL in the speech frequencies and approximately one in five recommended for hearing aids. Moderate to profound HL isolated to high frequencies at baseline was predictive of more clinically significant hearing impairment after HDCT.

PLAIN LANGUAGE SUMMARY

Some patients with germ cell tumors, the most common malignancy in adolescent and young adult men, are not cured with standard-dose chemotherapy and require high-dose chemotherapy (HDCT). Using detailed hearing assessments of patients receiving HDCT, we found that most patients developed significant hearing loss and that one in five needed hearing aids. Thus, strategies to reduce this side effect are urgently needed, and all patients receiving HDCT should have a hearing test after therapy.

Analysis of prognostic factors and establishment of prognostic model for primary mediastinal germ cell tumors: a case controlled study

BACKGROUND

The overall prognosis of primary mediastinal germ cell tumors (PMGCTs) is poor and the associated prognostic factors are not fully understood. Our goal was to investigate the prognostic factors of PMGCTs and to develop a validated prognostic prediction model.

MATERIALS AND METHODS

A total of 114 PMGCTs with specific pathological types were included in this study. Clinicopathological characteristics of nonseminomatous PMGCTs and mediastinal seminomas were compared using the χ2 or Fisher's exact test. Independent prognostic factors of nonseminomatous PMGCTs screened using the univariate and multivariate Cox regression analysis were then used to generate a nomogram. The predictive performance of the nomogram was evaluated using the concordance index, decision curve, and the area under the receiver operating characteristic curve (AUC) and validated by bootstrap resampling. The Kaplan-Meier curves of independent prognostic factors were analyzed.

RESULTS

This study included 71 cases of nonseminomatous PMGCTs and 43 cases of mediastinal seminomas. The 3-year overall survival rates for nonseminomatous PMGCTs and mediastinal seminomas patients were 54.5 and 97.4%, respectively. The overall survival prognostic nomogram for nonseminomatous PMGCTs was established by integrating independent prognostic factors, including the Moran-Suster stage, white blood cell, hemoglobin, and platelet-lymphocyte ratio. The nomogram demonstrated good performance with a concordance index of 0.760 and the 1-year and 3-year AUC values of 0.821 and 0.833, respectively. These values were better than those of the Moran-Suster stage system. The bootstrap validation had an AUC of 0.820 (0.724-0.915) and showed a well-fitting calibration curve. Besides, patients with mediastinal seminomas showed favorable clinical outcomes and all the nine patients received neoadjuvant therapy and postoperative surgery achieved pathological complete response.

CONCLUSION

A nomogram based on staging and blood routine examination results was established to accurately and consistently predict the prognosis of patients with nonseminomatous PMGCTs.

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.

Challenges in the management of relapsed germ cell tumors

PURPOSE OF REVIEW

Despite the remarkable advances in the treatment of germ cell tumors (GCTs), a significant number of patients relapse after first line treatment. This review aims to highlight the challenges in management of relapsed GCT, discuss treatment options, and review novel therapeutics in development.

RECENT FINDINGS

Patients with relapsed disease after first line cisplatin-based chemotherapy can still be cured and should be referred to centers with expertise in GCTs. Patients with anatomically confined relapse should be considered for salvage surgery. The systemic treatment of patients with disseminated disease at the time of relapse after first line treatment remains unsettled. Treatment options include using salvage standard-dose cisplatin-based regimens with drugs not previously used or high-dose chemotherapy. Patients who relapse after salvage chemotherapy have poor outcomes and development of novel treatment options is required in this setting.

SUMMARY

Management of patients with relapsed GCT requires a multidisciplinary approach. Patients should be preferably evaluated at tertiary care centers with expertise in the management of these patients. There remains a subset of patients who relapse after salvage therapy and development of novel therapeutic approaches is needed in this setting.

Outcomes of relapsed/refractory extracranial germ cell tumors treated on conventional salvage chemotherapy without stem cell rescue: Experience from a tertiary cancer center

BACKGROUND AND AIMS

Data on the outcome and prognostic indicators in extracranial relapsed/refractory germ cell tumors (rel/ref-GCTs) in children are limited to a few studies. This study looks at remission rates and outcomes of rel/ref-GCTs treated with conventional salvage chemotherapy (SC) regimens without stem cell rescue at a single center in the developing world.

METHODS

Patients treated at our center from January 2009 to December 2018 were included. Risk at primary presentation was stratified as all completely excised teratomas and stage I gonadal tumors being low risk (LR); stage IV ovarian, stage III-IV extragonadal GCTs as high risk (HR), and the remaining as intermediate risk (IR). SC regimens were: vinblastine-ifosfamide-cisplatin/carboplatin or paclitaxel-ifosfamide-cisplatin/carboplatin, or cisplatin/carboplatin-etoposide-bleomycin. Local therapy was either surgery and/or radiotherapy.

RESULTS

The analyzable cohort comprised 50 patients (44 = rel-GCTs; 6 = ref-GCTs) with a median age of 3.8 years and male:female ratio of 1.27:1. Primary location was ovary in 16 (32%), testicular in 10 (20%), and extragonadal in the rest (48%). Local, metastatic, and combined progression was noted in 28 (56%), 14 (28%), and eight (16%) patients, respectively, at a median time of 8.5 months. At a median follow-up of 60 months, the 5-year event-free survival (EFS) and overall survival (OS) of the entire cohort (n = 50) were 42.4% and 50.0%, respectively. In patients previously exposed to platinum analogs (n = 38), 5-year-EFS and OS were 27.7% and 31.7%, respectively. Local relapses did better when compared to metastatic and combined relapses (5-year EFS: 64% vs. 23% vs. 0%; p = .009). LR and IR tumors did better compared to HR (5-year EFS: 81.5% vs. 49.3% vs. 6.5%; p = .002). Patients with normalization of tumor markers after two cycles had a superior EFS (57.6% vs. 0%; p < .001). Relapsed tumors fared better than primary refractory GCTs (5-year EFS: 48.6% vs. 0%; p < .001).

CONCLUSIONS

Primary refractory GCTs, extragonadal rel-GCTs, and rel/ref-GCTs with a poor biochemical response did poorly with conventional SC and need alternative treatment strategies. The rel/ref-testicular GCTs had the best chance of salvage despite a second recurrence (5-year EFS and OS: 28.60% and 42.90%, respectively).

Pediatric Extracranial Germ Cell Tumors: Review of Clinics and Perspectives in Application of Autologous Stem Cell Transplantation

Pediatric extracranial germ cell tumors (GCTs) are rare, accounting for approximately 3.5% of childhood cancers. Since the introduction of platinum-based chemotherapy, the survival rate of patients has improved to more than 80%. However, poor-risk subtypes of pediatric extracranial GCTs do not respond well to chemotherapy, leading to refractory or relapsed (R/R) diseases. For example, long-term survival rates of mediastinal GCTs or choriocarcinoma are less than 50%. According to reports in recent years for adult patients with R/R GCTs, the use of high-dose chemotherapy (HDCT) combined with autologous stem cell transplantation (ASCT) has clinical advantages; however, HDCT combined with ASCT has rarely been reported in pediatric GCTs. The R/R and poor-risk groups of pediatric GCTs could benefit from HDCT and ASCT.

High-dose chemotherapy with autologous stem cell transplantation for patients with extracranial germ cell tumors - experience of two Brazilian pediatric centers

Malignant extracranial germ cell tumors (GCTs) are rare in pediatric patients and are usually extremely sensitive to chemotherapy. Relapsed or refractory tumors, although rare, established the need for second-line therapies, including high-dose chemotherapy with autologous stem cell transplantation (HDCT/ASCT). However, there are few data on its use in children with GCTs. We present a retrospective analysis of all patients diagnosed with extracranial GCTs who received HDCT/ASCT at two Brazilian pediatric cancer centers from May 1999 to December 2019. We identified a total of 34 patients with a median age at diagnosis of 2.8 years (range, 0 to 18.8), who received HDCT/ASCT. Most patients (73%) received carboplatin, etoposide and melphalan (CEM) as a HDCT regimen. Fourteen patients received a second-line conventional dose chemotherapy (CDCT), 14 received a third-line CDCT and five received even a fourth-line CDCT prior to HDCT/ASCT. After a median follow-up of 22.7 months (range, 0.3 to 198.1), 16 patients had died after tumor relapse/progression and 2 patients died from HDCT/ASCT toxicity. We observed a 5-year OS of 47.1% and 5-year EFS of 44.1%. The 5-year OS for patients referred for HDCT/ASCT with progressive disease was 10% compared to 62.5% for those who achieved disease control before HDCT/ASCT (p = 0.001). In our experience, heavily pretreated children and adolescents with extracranial GCTs achieved considerable survival rates with HDCT/ASCT since, at least, partial control of their disease was possible before starting HDCT/ASCT. The role of HDCT/ASCT in pediatric patients with GCTs should be investigated in prospective trials.

Primary Mediastinal Germ Cell Tumors: A Thorough Literature Review

Primary mediastinal germ cell tumors (PMGCTs) are a rare type of cancer affecting young adults. They have different molecular and clinical features compared to testicular germ cell tumors. Non-seminoma PMGCTs have the shortest 5-year overall survival and the poorest prognosis among all of the germ cell tumor presentations, while seminomas share the same survival and prognosis as their testicular counterparts. There is an unmet need for better treatment options for patients with non-seminoma PMGCTs in both first-line and salvage therapy, as the available options are associated with underwhelming outcomes. Identifying biological and genetic factors to predict treatment responses would be helpful in improving the survival of these patients.

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).

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.

Advances in diagnosis and treatment of testicular cancer

Testicular cancer is a curable cancer. The success of physicians in curing the disease is underpinned by multidisciplinary advances. Cisplatin-based combination chemotherapy and the refinement of post-chemotherapy surgical procedures and diagnostic strategies have greatly improved long term survival in most patients. Despite such excellent outcomes, several controversial dilemmas exist in the approaches to clinical stage I disease, salvage chemotherapy, post-chemotherapy surgical procedures, and implementing innovative imaging studies. Relapse after salvage chemotherapy has a poor prognosis and the optimal treatment is not apparent. Recent research has provided insight into the molecular mechanisms underlying cisplatin resistance. Phase 2 studies with targeted agents have failed to show adequate efficacy; however, our understanding of cisplatin resistant disease is rapidly expanding. This review summarizes recent advances and discusses relevant issues in the biology and management of testicular cancer.

A phase II study assessing the safety and efficacy of ASP1650 in male patients with relapsed refractory germ cell tumors

Claudin6(CLDN6) is a tight junction protein of claudin-tetraspanin family and is of the earliest molecules expressed in embryonic epithelium. CLDN6 is frequently aberrantly expressed in testicular germ-cell tumors(GCT). ASP1650 is a chimeric-mouse/human-IgG1 antibody directed against CLDN6. Two-part, open-label, phase-II trial investigating ASP1650 in patients with relapsed/refractory GCT and no curable options. Part1 was a safety lead-in to establish the recommended-phase-II-dose(RP2D). Part2 was a phase-II study designed to evaluate the antitumor effects of ASP1650. CLDN6 expression was centrally assessed on archival tumor tissue using immunohistochemistry. The primary objectives were to establish the RP2D(safety lead-in) and the antitumor activity(phase-II) of ASP1650. Nineteen male patients were enrolled: 6 patients in 1000 mg/m2 safety lead-in group, and 13 in 1500 mg/m2 group. Median age 37.2 years(range,20-58). Histology was non-seminoma in 17/19 patients. Median number of previous chemotherapy regimens was 3. Thirteen patients had prior high-dose chemotherapy. No dose-limiting toxicity events were reported at any study drug dose. A RP2D of 1500 mg/m2 every 2 weeks was established. No partial or complete responses were observed. The study was stopped at the end of Simon Stage-I due to lack of efficacy. 15/16 subjects with available tissue had CLDN6 positive staining. The mean percent membrane staining was 71.6% and the mean membrane H score was 152.6(SD 76). ASP1650 did not appear to have clinically meaningful single-agent activity in relapsed/refractory GCT. CLDN6 expression seems ubiquitous in all elements of GCT and is worthy of investigation as a diagnostic biomarker and therapeutic target. (Clinical trial information: NCT03760081).

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.

Peri-treatment adverse events of primary mediastinal non-seminomatous germ cell tumors

Primary mediastinal non-seminomatous germ cell tumors (PMNSGCT) are rare but life-threatening thoracic cancers. We report our experience from eight patients with peri-treatment adverse events. By analyzing changes in tumor extent, serum tumor markers, and pathologies between diagnosis and transfer, those events could be attributed to postbiopsy respiratory insufficiency, growing teratoma syndrome, secondary histiocytic malignancy, and PMNSGCT progression. Subjecting patients to respiratory therapy, conventional or high-dose chemotherapy, and surgery controlled the disease, with five of the eight patients surviving disease free. These outcomes indicate that integrated appropriate and timely approaches are important in tackling peri-treatment adverse events.

The Nitrogen Mustards

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

Inflammatory Biomarkers for Outcome Prediction in Patients With Metastatic Testicular Cancer

Germ cell tumors are the most common malignant tumors in male young adults. Platinum-based chemotherapy has dramatically improved the outcome of metastatic germ cell tumor patients and overall cure rates now exceed 80%. The choice of medical treatment can be guided by the prognosis estimation which is an important step during the decision-making process. IGCCCG classification plays a pivotal role in the management of advanced disease. However, histological and clinical parameters are the available factors that condition the prognosis, but they do not reflect the tumor's molecular and pathological features and do not predict who will respond to chemotherapy. After first-line chemotherapy 20%-30% of patients relapse and for these patients, the issue of prognostic factors is far more complex. Validated biomarkers and a molecular selection of patients that reflect the pathogenesis are highly needed. The association between cancer-related systemic inflammation, tumorigenesis, and cancer progression has been demonstrated. In the last years, several studies have shown the prognostic utility of immune-inflammation indexes in different tumor types. This review analyzed the prognostic impact of inflammatory markers retrieved from routine blood draws in GCT patients.

Phase II trial of nivolumab monotherapy and biomarker screening in patients with chemo‐refractory germ cell tumors

Objectives

Germ cell tumors are highly susceptible to chemotherapy; however, there is a lack of established treatments for consistently relapsing germ cell tumor. Therefore, in this phase II study, we evaluated the efficacy and safety of nivolumab for relapsed germ cell tumor.

Methods

Seventeen adult patients (median age 34 years) with refractory primary germ cell tumor after second‐line or higher chemotherapy were enrolled. Nivolumab was administered over 30 min at 240 mg/body every 2 weeks until disease progression or intolerable adverse event occurrence. The primary endpoint was the overall response rate.

Result

We performed a biomarker analysis of programmed death ligand‐1 expression and genomic sequencing. Tumor histology revealed nonseminoma and seminoma in 14 and three patients, respectively. Patients were pretreated with a median of three chemotherapy lines, and three patients received high‐dose chemotherapy. The median number of nivolumab doses was 3 (range 2–46). One patient showed a partial response and three showed stable disease. Responses were durable in one patient with a partial response and one patient with stable disease (median 90 and 68 weeks, respectively). Nivolumab was well‐tolerated, with only two Grade 3 adverse events observed. Programmed death ligand‐1 expression was not associated with objective responses. Genomic sequencing revealed a high tumor mutation burden in a patient with a durable partial response. While a small subset of chemorefractory germ cell tumors may respond to nivolumab, programmed death ligand‐1 is unreliable to measure response.

Conclusions

Tumor mutation burden is a potential biomarker for future testing of germ cell tumor response.

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.

High-dose chemotherapy for relapsed germ cell tumours: outcomes in low-volume specialized centres

OBJECTIVE

To report treatment patterns and survival outcomes of patients with relapsed and refractory metastatic germ cell tumours (GCTs) treated with high-dose chemotherapy (HDCT) and autologous stem-cell transplantation in low-volume specialized centres within the widely dispersed populations of Australia and New Zealand between 1999 and 2019.

PATIENTS AND METHODS

We conducted a retrospective analysis of 111 patients across 13 institutions. Patients were identified from the Australasian Bone Marrow Transplant Recipient Registry. We reviewed treatment regimens, survival outcomes, deliverability and toxicities. Primary endpoints included overall (OS) and progression-free survival (PFS). Cox proportional hazards models were used to test the association of survival outcomes with patient and treatment factors.

RESULTS

The median (range) age was 30 (14-68) years and GCT histology was non-seminomatous in 84% of patients. International Prognostic Factors Study Group (IPFSG) prognostic risk category was very low/low, intermediate, high and very high in 18%, 36%, 25% and 21% of patients, respectively. Salvage conventional-dose chemotherapy (CDCT) was administered prior to HDCT in 59% of patients. Regimens included paclitaxel, ifosfamide, carboplatin and etoposide (50%), carboplatin and etoposide (CE; 28%), carboplatin, etoposide and ifosfamide (CEI; 6%), carboplatin, etoposide and cyclophosphamide (CEC; 5%), CEC-paclitaxel (6%) and other (5%). With a median follow-up of 4.4 years, the 1-, 2- and 5-year PFS rates were 62%, 57% and 52%, respectively, and OS rates were 73%, 65% and 61%, respectively. There were five treatment-related deaths. Progression on treatment occurred in 17%. In a univariable analysis, worse International Germ Cell Cancer Collaborative Group (IGCCCG) and IPFSG prognostic groups were associated with inferior survival outcomes. An association of inferior survival was not found with the number of high-dose cycles received nor when HDCT was delivered after salvage CDCT.

CONCLUSION

This large dual-national registry-based study reinforces the efficacy and deliverability of HDCT for relapsed and refractory metastatic GCT in low-volume specialized centres in Australia and New Zealand, with survival outcomes comparable to those found in international practice.

Current Status of Stem Cell Transplant in Treatment of Testicular Germ Cell Tumors

PURPOSE OF REVIEW

We aim to discuss the history of high-dose chemotherapy with autologous stem-cell transplant in testicular germ cell tumors, prognostic factors to consider prior to transplant, and issues both during and after transplant while also touching on the use of conventional-dose vs. high-dose chemotherapy for initial salvage treatment in patients with relapsed disease.

RECENT FINDINGS

The advancements in the treatment of testicular cancer have led to the majority of patients even with distant metastases being cured of their malignancy. Despite this, around 20% of patients with metastatic disease will relapse after first-line therapy, and the majority of these patients will go on to need further salvage chemotherapy, either with conventional-dose chemotherapy or high-dose chemotherapy. High-dose chemotherapy with autologous stem-cell transplant is an effective salvage therapy and will still remarkably result in cures for the majority of patients with relapsed disease. While patients receiving it as even third-line salvage therapy may achieve cures, earlier administration likely results in greater efficacy.

First-line salvage treatment options for germ cell tumor patients failing stage-adapted primary treatment : A comprehensive review compiled by the German Testicular Cancer Study Group

PURPOSE

In this review, we summarize and discuss contemporary treatment standards and possible selection criteria for decision making after failure of adjuvant or first-line cisplatin-based chemotherapy for primarily localized or metastatic germ cell tumors.

METHODS

This work is based on a systematic literature search conducted for the elaboration of the first German clinical practice guideline to identify prospective clinical trials and retrospective comparative studies published between Jan 2010 and Feb 2021. Study end points of interest were progression-free (PFS) and overall survival (OS), relapse rate (RR), and/or safety.

RESULTS

Relapses of clinical stage I (CS I) patients irrespective of prior adjuvant treatment after orchiectomy are treated stage adapted in accordance for primary metastatic patients. Surgical approaches for sole retroperitoneal relapses are investigated in ongoing clinical trials. The appropriate salvage chemotherapy for metastatic patients progressing or relapsing after first-line cisplatin-based chemotherapy is still a matter of controversy. Conventional cisplatin-based chemotherapy is the international guideline-endorsed standard of care, but based on retrospective data high-dose chemotherapy and subsequent autologous stem cell transplantation may offer a 10-15% survival benefit for all patients. Secondary complete surgical resection of all visible residual masses irrespective of size is paramount for treatment success.

CONCLUSIONS

Patients relapsing after definite treatment of locoregional disease are to be treated by stage-adapted first-line standard therapy for metastatic disease. Patients with primary advanced/metastatic disease failing one line of cisplatin-based combination chemotherapy should be referred to GCT expert centers. Dose intensity is a matter of ongoing debate, but sequential high-dose chemotherapy seems to improve patients' survival.

High dose chemotherapy followed by autologous hematopoietic stem cell transplantation for advanced germ cell tumors: State of the art and a single-center experience

BACKGROUND

Evidence for the choice of second line, standard vs high dose chemotherapy, (SDCT, HDCT) for patients with relapsed germ cell tumors (GCTs) comes mainly from retrospective studies.

MATERIAL AND METHODS

relevant literature was reviewed, considering as endpoints both survival and long term quality of life (QoL). Patients with metastatic GCT progressing after first-line treatment at our Institution were retrospectively evaluated.

RESULTS

HDCT seems to achieve a higher rate of long-term remissions. QoL data for this group of patients are lacking. Our experience on 29 patients was in line with these results. Two-year OS for the 18 patients treated with one or two HDCT/PBSCT procedures was 47.5 %, while 2-year PFS was 44 %. For the 11 receiving SDCT 2-year OS was 36.4 %, and 2-year PFS was 32.7 %.

CONCLUSIONS

HDCT/PBSCT confirmed to be effective in treating patients with relapsed GCT, but prospective studies are needed.

Outcomes After Multidisciplinary Management of Primary Mediastinal Germ Cell Tumors

OBJECTIVE

We examined management strategies, overall survival (OS), and progression-free survival (PFS) among patients with PMNSGCTs undergoing resection and multidisciplinary management at a high-volume institution.

SUMMARY OF BACKGROUND DATA

Outcomes after resection of PMNSGCTs are not well-characterized, with limited data on factors associated with survival.

METHODS

We reviewed patients with PMNSGCT who underwent resection between 1980 and 2019. Median follow-up was 3.4 years. Preoperative therapy (including use of bleomycin), surgical management, recurrence, and survival were examined. Factors associated with survival were analyzed using Cox regression.

RESULTS

In total, 113 patients were included [median age, 28 years (range, 16-65)]. Preoperative serum tumor markers (STMs) normalized/decreased in 74% of patients. Pathology included necrosis only (25%), teratoma +/- necrosis (20%), viable nonteratomatous germ cell tumor +/- teratoma (41%), and secondary somatic-type malignancy +/- teratoma (20%). Bleomycin chemotherapy was not associated with pulmonary complications or 90-day mortality. Patients receiving second-line chemotherapy followed by resection had significantly worse OS and PFS than patients receiving first-line chemotherapy followed by resection. On multivariable analysis, R1/R2 resection (HR, 3.92; P < 0.001) and increasing postoperative STMs (HR, 4.98; P < 0.001) were associated with shorter PFS; necrosis on pathology (HR, 0.42, P = 0.043) was associated with longer PFS.

CONCLUSIONS

In patients with PMNSGCT undergoing resection, completeness of resection, postoperative pathology, and postoperative STMs were associated with PFS. Induction bleomycin was not associated with pulmonary complications or mortality in patients undergoing resection. Patients undergoing second-line chemotherapy followed by resection have a poor prognosis, with long-term survival of 22%.

Autologous Stem Cell Transplantation in Testicular Germ Cell Tumor-Preliminary Experience from a Single Center

Background Germ cell tumor (GCT) of the testis is one of the highly curable solid organ malignancies. Those who experience relapse after platinum-based chemotherapy can be salvaged with systemic therapy followed by high-dose chemotherapy (HDCT) and autologous stem cell transplantation (ASCT). Complete remission can be obtained in approximately 50 to 60% of patients treated with HDCT. Our experience reports the efficacy and safety of HDCT followed by ASCT in relapsed GCT.

Methods Analysis of patient records (2012–2019) showed that three patients had received HDCT and ASCT.

Results All the three patients were treated with BEP (bleomycin, etoposide, and cisplatin) as first-line therapy. HDCT was done in Case 1 after third-line salvage and in other two patients after second-line salvage chemotherapies. High-dose carboplatin and etoposide were used as conditioning regimen. Granulocyte colony-stimulating factor was used for the mobilization of stem cells. After ASCT, complete remission was documented in all the patients. All were alive and disease-free till the last follow-up. Grade ¾ toxicities including myelosuppression, diarrhea, and mucositis were observed in all three patients.

Conclusion This is the first report from India on HDCT with ASCT in GCT. HDCT/ASCT seems to be feasible, safe, and effective in relapsed testicular GCTs.

Hematopoietic stem cell mobilization strategies to support high-dose chemotherapy: A focus on relapsed/refractory germ cell tumors

High-dose chemotherapy (HDCT) with autologous hematopoietic stem cell transplantation has been explored and has played an important role in the management of patients with high-risk germ cell tumors (GCTs) who failed to be cured by conventional chemotherapy. Hematopoietic stem cells (HSCs) collected from the peripheral blood, after appropriate pharmacologic mobilization, have largely replaced bone marrow as the principal source of HSCs in transplants. As it is currently common practice to perform tandem or multiple sequential cycles of HDCT, it is anticipated that collection of large numbers of HSCs from the peripheral blood is a prerequisite for the success of the procedure. Moreover, the CD34+ cell dose/kg of body weight infused after HDCT has proven to be a major determinant of hematopoietic engraftment, with patients who receive > 2 × 10⁶ CD34+ cells/kg having consistent, rapid, and sustained hematopoietic recovery. However, many patients with relapsed/refractory GCTs have been exposed to multiple cycles of myelosuppressive chemotherapy, which compromises the efficacy of HSC mobilization with granulocyte colony-stimulating factor with or without chemotherapy. Therefore, alternative strategies that use novel agents in combination with traditional mobilizing regimens are required. Herein, after an overview of the mechanisms of HSCs mobilization, we review the existing literature regarding studies reporting various HSC mobilization approaches in patients with relapsed/refractory GCTs, and finally report newer experimental mobilization strategies employing novel agents that have been applied in other hematologic or solid malignancies.

Recent advances in testicular germ cell tumours

Testicular germ cell tumours (TGCTs) are the most common solid tumours in young men and have an excellent overall cure rate and prognosis. In most patients, localised disease is cured by surgery alone, and a minority of patients receive short-course adjuvant chemotherapy to reduce the risk of further relapse. Also, in about 80% of patients, metastatic disease can be cured by systemic cisplatin-based chemotherapy. Unfortunately, for a proportion of patients, the disease exhibits platinum resistance and relapse occurs. Despite further lines of systemic treatment, cure can be difficult to achieve in these patients and ultimately about 20% of them will die from disease progression. Addressing the mechanisms underpinning platinum resistance is critical to improving the survival and chances of cure for these patients. This review describes the latest advances in TGCT research, focusing on the identification of novel biomarkers, genetic characteristics and exploring novel treatments.

Pearls and perils in the management of germ cell tumors

PURPOSE OF REVIEW

Research and innovation over the past half century have rendered testicular cancer a highly curable malignancy. Challenges and uncertainty remain in several aspects related to the management and surveillance of patients with germ cell tumors (GCT). Long-term effects of treatment on survivors of testicular cancer remain as continued areas of interest. This review aims to highlight pearls and perils in the management of patients with GCT.

RECENT FINDINGS

Uncertainty remain regarding complex aspects of first-line and salvage treatments of GCT, interpretation of tumor markers in cases of α-fetoprotein levels less than 25 ng/ml, plateau of β-human chorionic gonadotropin (hCG) levels in patients with initial hCG greater than 50 000 mIU/ml, supportive therapies throughout chemotherapy regimens, and long-term survivorship of patients who underwent surgery or received platinum-based chemotherapy. This review aims to highlight challenges that remain in GCT, review the emerging data in these areas, and provide our institutional opinion on the management in several aspects of GCT.

SUMMARY

Testicular cancer continues to present challenging clinical scenarios with respect to treatment, surveillance, and long-term management of patients. We review the data and share our institutional knowledge in several challenging areas related to the management of GCT.

Hematopoietic Cell Transplantation, Version 2.2020, NCCN Clinical Practice Guidelines in Oncology

Hematopoietic cell transplantation (HCT) involves the infusion of hematopoietic progenitor cells into patients with hematologic disorders with the goal of re-establishing normal hematopoietic and immune function. HCT is classified as autologous or allogeneic based on the origin of hematopoietic cells. Autologous HCT uses the patient's own cells while allogeneic HCT uses hematopoietic cells from a human leukocyte antigen-compatible donor. Allogeneic HCT is a potentially curative treatment option for patients with certain types of hematologic malignancies, and autologous HCT is primarily used to support patients undergoing high-dose chemotherapy. Advances in HCT methods and supportive care in recent decades have led to improved survival after HCT; however, disease relapse and posttransplant complications still commonly occur in both autologous and allogeneic HCT recipients. Allogeneic HCT recipients may also develop acute and/or chronic graft-versus-host disease (GVHD), which results in immune-mediated cellular injury of several organs. The NCCN Guidelines for Hematopoietic Cell Transplantation focus on recommendations for pretransplant recipient evaluation and the management of GVHD in adult patients with malignant disease.

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.

Survival outcomes and toxicity in patients 40 years old or older with relapsed metastatic germ cell tumors treated with high-dose chemotherapy and peripheral blood stem cell transplantation

BACKGROUND

High-dose chemotherapy (HDCT) plus peripheral blood stem cell transplantation (PBSCT) is effective salvage therapy for relapsed metastatic germ cell tumors (GCTs) but has potential toxicity. Historically, an age of ≥40 years has been associated with greater toxicity and worse outcomes.

METHODS

This is a retrospective analysis of 445 consecutive patients with relapsed GCT treated with HDCT and PBSCT with tandem cycles at Indiana University from between 2004-2017 per our institutional regimen. Kaplan-Meier methods and log-rank tests were used for progression-free survival (PFS) and overall survival (OS) analysis.

RESULTS

A total of 329 patients were <40 years of age, whereas 116 patients were ≥40 years of age; HDCT was used as second-line therapy in 85% and 79%, respectively. Median follow-up time was 42.5 months (range, 0.3-173.4 months). Grade ≥3 toxicities were similar between either group, except for greater pulmonary (P = .02) and renal toxicity (P = .01) in the ≥40-years-of-age group. Treatment-related mortality was similar between both age groups: 10 patients (3%) in the <40-years-of-age group and 4 patients (3.5%) in ≥40-years-of-age group died from complications of HDCT. Two-year PFS for <40 years of age versus ≥40 years of age was 58.7% versus 59.6% (P = .76) and 2-year OS was 63.9% versus 61.5% (P = .93). Factors predicting worse PFS included Eastern Cooperative Oncology Group performance status ≥1, platinum refractory disease, nonseminoma histology, and not completing 2 cycles of HDCT. Age was not an independent predictor of worse outcomes.

CONCLUSIONS

HDCT plus PBSCT is effective salvage therapy in patients ≥40 years of age with relapsed metastatic GCT. Patients ≥40 years of age experience similar rates of toxicity and treatment-related mortality as those <40 years of age.

Successful Treatment with High-Dose Chemotherapy Followed by Autologous Stem-Cell Transplantation in a Patient with Metastatic Germ Cell Tumor

Although testicular germ cell tumors (GCTs) are known to curable disease even in cases with metastatic disease, patients in intermediate or poor-risk group may experience disease progression or refractory to the initial chemotherapy and needed second-line therapy. Long-term disease-free survival was unsatisfactory in relapsed/refractory patients with poor-risk factors and clinical trials for those patients are still insufficient. High-dose chemotherapy (HDCT) with stem-cell rescue may be an effective alternative for conventional chemotherapy-resistant patients who are eligible for transplantation. Herein, we present successful treatment experience with HDCT followed by autologous stem-cell transplantation in a severely ill patient with heavily pretreated metastatic GCT.

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.

Phase II trial of brentuximab vedotin in relapsed/refractory germ cell tumors

Background CD-30 is highly expressed in some patients with non-seminomatous germ-cell tumors. Brentuximab vedotin is an antibody-drug conjugate directed to CD-30. We report a phase 2 trial of brentuximab vedotin in patients with chemo-refractory GCT. Patients and methods This is a single arm, two cohort phase 2 trial investigating brentuximab vedotin 1.8 mg/kg IV every 3 weeks until disease progression or intolerable toxicities in patients with relapsed GCT who have no curative options. Patients with mGCT who progressed after first line cisplatin-based chemotherapy and after at least 1 salvage regimen (high-dose or standard-dose chemotherapy) were eligible. CD30 expression was assessed and two cohorts defined: CD30 positive and CD30 negative/unknown. Results 18 patients were enrolled. Median age 34.7 (range, 23-56). All patients had non-seminoma. Median AFP 4.9 (range, 1-219,345) and hCG 282 (range, 0.6-172,064). Five patients had late relapse (> 2 years). Median number of previous chemotherapy regimens was 3 (range, 2-7). Ten patients received prior high-dose chemotherapy. Seven patients had positive CD30 staining. There were two grade 3 treatment-related adverse events. No partial or complete responses were observed. 6 patients achieved radiographic stable disease (range, 9-14.9 weeks), 5 had elevated AFP or hCG at trial entry and all 5 had transient > 50% decline in baseline AFP/hCG: 4 had CD30 -ve and 2 had CD30 + ve staining; 10 patients had progression of disease as their best response; 2 were not evaluable for response. Conclusion Brentuximab vedotin does not appear to have clinically meaningful single-agent activity in patients with refractory GCT.

Targeting of Deregulated Wnt/β-Catenin Signaling by PRI-724 and LGK974 Inhibitors in Germ Cell Tumor Cell Lines

The majority of patients with testicular germ cell tumors (GCTs) can be cured with cisplatin-based chemotherapy. However, for a subset of patients present with cisplatin-refractory disease, which confers a poor prognosis, the treatment options are limited. Novel therapies are therefore urgently needed to improve outcomes in this challenging patient population. It has previously been shown that Wnt/β-catenin signaling is active in GCTs suggesting that its inhibitors LGK974 and PRI-724 may show promise in the management of cisplatin-refractory GCTs. We herein investigated whether LGK-974 and PRI-724 provide a treatment effect in cisplatin-resistant GCT cell lines. Taking a genoproteomic approach and utilizing xenograft models we found the increased level of β-catenin in 2 of 4 cisplatin-resistant (CisR) cell lines (TCam-2 CisR and NCCIT CisR) and the decreased level of β-catenin and cyclin D1 in cisplatin-resistant NTERA-2 CisR cell line. While the effect of treatment with LGK974 was limited or none, the NTERA-2 CisR exhibited the increased sensitivity to PRI-724 in comparison with parental cell line. Furthermore, the pro-apoptotic effect of PRI-724 was documented in all cell lines. Our data strongly suggests that a Wnt/β-catenin signaling is altered in cisplatin-resistant GCT cell lines and the inhibition with PRI-724 is effective in NTERA-2 CisR cells. Further evaluation of Wnt/β-catenin pathway inhibition in GCTs is therefore warranted.