High-dose chemotherapy and stem-cell rescue for metastatic germ-cell tumors

Follow-Up of Patients Diagnosed With Germinal Testicular Tumors (Seminomas and Non-seminomatous) Treated With a Bone Marrow Transplant and a High Dose of Chemotherapy

INTRODUCTION

Germinal testicular tumors are the most common malignant neoplasm in men around 20 to 34 years. Even though they are unusual, they have increased incidence in the last decade; they have an excellent prognosis and overall survival at five years, approximately 95%. Divergent data exists regarding treatment options in patients with first, second, and third relapses with conventional therapy. Some studies describe the possible benefit of using high-dose chemotherapy associated with a bone marrow transplant with variable results.

METHODS

 The present study describes clinical outcomes, clinical response, mortality, overall survival, and progression-free survival to two years in a group of patients with germinal malignant tumors, seminoma versus non-seminomatous with evidence of progression of the disease at first, second, or third conventional chemotherapy regimens, and who received high dose chemotherapy and bone marrow transplantation at the National Cancer Institute between 2010 and 2021.

RESULTS

A retrospective observational study of case series showed that 57% of patients in third-line therapy received high-dose chemotherapy and bone marrow transplantation, with progression disease median time from diagnosis more than two years. Patients in the post-graft period presented infectious complications (71%). The most common were febrile neutropenia (29%) with a mortality rate of 71% (n=5), progression-free survival of 2.3 months, and overall survival of 7.4 months.

CONCLUSIONS

 These results show that in this group of patients, regimens with high-dose chemotherapy associated with bone marrow transplants, have a worse prognosis compared to other cohorts of patients, and may not be the best candidates for this rescue therapy.

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.

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.

Therapeutic efficacy of high-dose chemotherapy with autologous stem-cell transplantation in 44 relapsed or refractory germ-cell tumor patients: A retrospective cohort study

Despite having a higher mortality risk than conventional chemotherapeutics, high-dose chemotherapy (HDCT) has the potential to be curative in relapsed/refractory germ-cell tumors. Therefore, selecting the best patient group for this treatment is critical. This study aimed to determine the factors that affect survival in our relapsed/refractory GCT cohort who received HDCT and autologous stem-cell transplantation. Between September 2010 and 2020, we included in the study 44 relapsed/refractory male patients with GCT treated with HDCT plus autologous stem-cell transplantation. The patients' demographic features, clinical characteristics, and treatment outcomes were evaluated. Statistical analyses were performed to identify risk factors associated with survival. The median age of all cohorts was 28 years. Thirty-six patients had nonseminomatous tumors, and 8 patients had seminomatous tumors. The most common primary tumor sites were the gonads (75%), followed by the mediastinum (15.9%) and the retroperitoneum (9.1%). After HDCT, 11 patients had a complete response, 12 patients had a partial response, and 17 patients had a progressive disease, respectively. About 23 patients (52.3%) experienced at least 1 treatment-related grade 3 to 4 nonhematological toxicity. About 4 patients (10%) died due to HDCT-related toxicity. The total group's median progression-free survival (PFS) was 7 months, and the median overall survival (OS) was 14.9 months. Primary tumor site (hazard ratio [HR]: 1.84; P = .028), type of HDCT regimen (HR: 0.35; P = .010), and best response to HDCT (HR: 11.0; P < .0001) were independent prognostic risk factors for PFS. The only independent prognostic risk factor associated with OS was the best response to HDCT (HR: 6.62; P = .001). The results of the study promise the best response to HDCT as a primary measure for predicting survival in relapsed/refractory GCT. In contrast, primary mediastinal GCT is not a good candidate for HDCT. Furthermore, a carboplatin-etoposide regimen in combination with cyclophosphamide and paclitaxel may improve PFS.

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.

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.

Integrated genomic analysis reveals aberrations in WNT signaling in germ cell tumors of childhood and adolescence

Germ cell tumors (GCTs) are neoplasms of the testis, ovary and extragonadal sites that occur in infants, children, adolescents and adults. Post-pubertal (type II) malignant GCTs may present as seminoma, non-seminoma or mixed histologies. In contrast, pre-pubertal (type I) GCTs are limited to (benign) teratoma and (malignant) yolk sac tumor (YST). Epidemiologic and molecular data have shown that pre- and post-pubertal GCTs arise by distinct mechanisms. Dedicated studies of the genomic landscape of type I and II GCT in children and adolescents are lacking. Here we present an integrated genomic analysis of extracranial GCTs across the age spectrum from 0-24 years. Activation of the WNT pathway by somatic mutation, copy-number alteration, and differential promoter methylation is a prominent feature of GCTs in children, adolescents and young adults, and is associated with poor clinical outcomes. Significantly, we find that small molecule WNT inhibitors can suppress GCT cells both in vitro and in vivo. These results highlight the importance of WNT pathway signaling in GCTs across all ages and provide a foundation for future efforts to develop targeted therapies for these cancers.

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.

Triplet Strategies in Metastatic Clear Cell Renal Cell Carcinoma: A Worthy Option in the First-Line Setting?

Significant strides have been made in the frontline treatment of patients with advanced clear cell renal cell carcinoma (ccRCC). There are multiple standard-of-care doublet regimens consisting of either the combined dual immune checkpoint inhibitors, ipilimumab and nivolumab, or combinations of a vascular endothelial growth factor receptor tyrosine kinase inhibitor and an immune checkpoint inhibitor. Currently, there is an emergence of clinical trials examining triplet combinations. In COSMIC-313, a randomized phase III trial for patients with untreated advanced ccRCC, the triplet combination of ipilimumab, nivolumab, and cabozantinib was compared with a contemporary control arm of ipilimumab and nivolumab. While patients receiving the triplet regimen demonstrated improved progression-free survival, these patients also experienced greater toxicity and the overall survival data are still maturing. In this article, we discuss the role of doublet therapy as standard of care, the current data available for the promise of triplet therapy, the rationale to continue pursuing trials with triplet combinations, and factors for clinicians and patients to consider when choosing among frontline treatments. We present ongoing trials with an adaptive design that may serve as alternative methods for escalating from doublet to triplet regimens in the frontline setting and explore clinical factors and emerging predictive biomarkers (both baseline and dynamic) that may guide future trial design and frontline treatment for patients with advanced ccRCC.

Cardiovascular Risks in Testicular Cancer: Assessment, Prevention, and Treatment

PURPOSE OF REVIEW

Testicular cancer (TC) is the leading cancer in men between 18 and 39 years of age. Current treatment involves tumor resection followed by surveillance and/or one or more lines of cisplatin-based chemotherapy (CBCT) and/or bone marrow transplant (BMT). Ten years after treatment, CBCT has been associated with significant atherosclerotic cardiovascular disease (CVD) including myocardial infarction (MI), stroke, and heightened rates of hypertension, dyslipidemia, diabetes mellitus, and metabolic syndrome (MetS). Additionally, low testosterone levels and hypogonadism contribute to MetS and may further drive CVD.

RECENT FINDINGS

CVD in TCS has been associated with worse physical functioning accompanied by role limitations, decreased energy, and decreased overall health. Exercise may play a role in ameliorating these effects. Systematic CVD screening practices are needed at TC diagnosis and in survivorship. We encourage a multidisciplinary partnership between primary care physicians, cardiologists, cardio-oncologists, medical oncologists, and survivorship providers to address these needs.

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.

Predicting outcomes in female germ cell tumors using a modified International Germ Cell Cancer Collaborative Group classification system to guide management

OBJECTIVE

We previously developed preoperative and pre-chemotherapy modified versions of the male International Germ Cell Cancer Collaborative Group (IGCCCG) prognostic model and assessed it in female patients with germ cell tumors (GCTs). We sought to validate these modified IGCCCG (mIGCCCG) models in a new cohort.

METHODS

We queried institutional databases for female patients with GCTs treated at Memorial Sloan Kettering Cancer Center from 1/1/1990-6/1/2020. The mIGCCCG model classifies patients with non-dysgerminomas as good, intermediate, or poor risk based on tumor markers using male IGCCCG cutoffs and absence/presence of non-pulmonary/peritoneal visceral metastasis. In dysgerminomas, good- and intermediate-risk groups are defined by absence/presence of non-pulmonary/peritoneal visceral metastasis. Progression-free survival (PFS) and overall survival (OS) were estimated for each group in the validation and combined original and validation cohorts. Associations between individual clinical factors and outcomes were evaluated.

RESULTS

Among 183 female patients with GCTs, clinical characteristics and outcomes were similar between the original (n = 93) and validation (n = 90) cohorts. In multivariable models, higher stage, older age, and non-dysgerminoma histology predicted worse PFS and OS (p < 0.05). Among 162 patients who received chemotherapy, preoperative and pre-chemotherapy mIGCCCG models were significantly associated with PFS and OS (p < 0.001 for all groups). With the preoperative model, 3-year PFS rates were 94%, 76%, and 50% in the good-, intermediate-, and poor-risk patients, respectively; OS rates were 96%, 86%, and 52%, respectively. Even within stage groups, mIGCCCG risk classifications were associated with clinical outcomes.

CONCLUSIONS

A female-specific mIGCCCG risk model effectively stratifies patients and should be incorporated into clinical trials.

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.

Surgical treatment confers prognostic significance in pediatric malignant mediastinal germ cell tumors

BACKGROUND

Primary malignant mediastinal germ cell tumors (GCTs) are rare pediatric tumors that have a poorer prognosis compared to GCTs occurring elsewhere in the body. The current study aimed to assess the prognostic factors and treatment outcomes of children with primary malignant mediastinal GCT in Taiwan.

METHODS

The authors retrospectively reviewed children 0-18 years old who were newly diagnosed with primary malignant mediastinal GCT between January 1, 2005 and December 31, 2019 and were registered in the Taiwan Pediatric Oncology Group patient registry. The impact of presenting characteristics, including sex, age, tumor stage, histology subtype, surgical treatment, and chemotherapy regimens of the patients were analyzed.

RESULTS

This study enrolled 52 children with malignant mediastinal GCT who had a median age of 16.0 (range, 6.0-17.9) years at diagnosis. The most common histological subtypes were mixed GCTs (n = 20) and yolk sac tumors (n = 15). Advanced disease stage and choriocarcinoma histology subtype were associated inferior outcomes. Children who received surgical treatment exhibited better outcomes compared to those who did not (5-year overall survival, 78% vs. 7%, p < .001). After comparing patients who received first-line cisplatin- and carboplatin-based chemotherapy, no difference in treatment outcomes was observed. Multivariate analysis showed that surgical management was the only independent predictor for superior OS.

CONCLUSIONS

Surgical treatment is recommended for mediastinal GCT. Cisplatin-based chemotherapy was not superior to carboplatin-based chemotherapy as first-line treatment and may be avoided due to toxicity concerns.

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.

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.

Approaches of stem cell mobilization in a large cohort of metastatic germ cell cancer patients

High-dose chemotherapy (HD-Cx) in refractory germ cell cancer (GCC) is effective but limited data are available concerning the optimal approach for stem cell mobilization (SCM) in these patients. In this analysis 102 patients undergoing SCM during first (n = 25) or subsequent treatment lines (n = 77) were analyzed. Subcutaneous injections of granulocyte colony-stimulating factor (G-CSF) were given once daily (group 1) in 52 patients (51%), twice daily (group 2) in 39 patients (38%) or one injection Pegylated-G-CSF (PegG-CSF) (group 3) in eleven patients (11%) after one cycle of mobilization chemotherapy. Plerixafor was administered 13 times in group 1, seven times in group 2 and once in group 3. Overall, 77 (75%) patients achieved successful SCM defined as ≥8*10⁶ CD34+ cells/kg body weight for three consecutive HD-Cx plus one backup dose. In group 1, 40 of 52 patients (77%) achieved successful SCM with a median of 11 G-CSF injections, in group 2, 27 of 39 patients (69%) with a median of 14 G-CSF injections and in group 3, 10 of 11 patients (91%) with one injection of PegG-CSF. SCM was more successful if conducted during first-line chemotherapy (p = 0.016) and associated with a beneficial outcome concerning overall survival (p = 0.02) if performed satisfactorily.

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.

Racial disparities in hematopoietic stem cell transplant: a systematic review of the literature

Background

Hematopoietic stem cell transplant (HSCT) is an expensive and complex treatment regimen that can be curative in many diseases of the bone marrow, including malignant and non-malignant conditions. The introduction of the Affordable Care Act increased access to potential candidates and removed or reduced many barriers previously identified in the literature, however, racial disparities continue to persist. As HSCT expands its utilization and indications, there is a continued need to understand the multifactorial barriers which lead to inequalities in transplant referral, utilization, and survival. The objective of this systematic review is to summarize these racial disparities, expand the current understanding of the literature, and determine whether the increases in insurance status from Medicaid expansion have played a role in HSCT utilization and survival rates by race.

Methods

We explored studies based on retrospective reviews, literature reviews, and focus groups with the key-terms of 'race', 'hematopoietic stem cell transplant', and 'disparities'. The included studies were extracted from Cochrane and Medline databases. After screening for relevancy to research aims and objectives, 10 articles were utilized for background information and discussion, while 30 articles were categorized into main groups of outcomes, chiefly, (I) access/referral to transplant and (II) survival.

Results

Eight of the eleven retrospective reviews found substantial variation in access to HSCT by ethnic minorities (Black, Hispanic, or Asian) when compared to their Caucasian counterparts. Thirteen of the fourteen publications found racial disparities in either overall survival, progression free survival, treatment related mortality, relapse, or combinations of these outcomes. The majority of the studies evaluated African American patients with six of eight studies showing significantly elevated mortality compared to Caucasian patients.

Discussion

Substantial variation exists in access to HSCT, particularly in black patients. Having less generous insurance coverage was previously hypothesized to reduce the likelihood of HSCT utilization. Studies performed after full implementation of the Affordable Care Act continue to show poorer survival among ethnic minorities, particularly black patients, despite this increased coverage. Perceived racial bias and health-related stigma, as well as physician decisions and delay in referral process are likely contributing factors.

A 26-year old young male with severe anemia

Testicular choriocarcinoma is a subset of Non-Seminomatous Germ Cell Tumors (NSGT) which is considered the rarest and most aggressive testicular cancer. It primarily affects males between the ages of 25–30 years. Unlike other testicular neoplasms that carry a cure rate of 95%, choriocarcinoma has significantly lower rate of cure. Therefore, early detection and prompt treatment is necessary to improve survival. We present an unusual case of Choriocarcinoma presenting as severe anemia along with distant metastases to lung and brain. We also discuss diagnostic approach and treatment challenges in patients with Choriocarcinoma.

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.

Successful "on-demand" plerixafor for autologous peripheral blood stem-cells transplantation for relapsed/refractory germ cell tumors

Background

Germ cell tumors represent, among solid cancers, a potentially curable disease even if up to 20% to 30% of patients (pts) relapse after first‐line treatment especially considering intermediate and poor prognosis groups. In this scenario, patients are candidates for high‐dose chemotherapy and autologous stem‐cells transplantation as second‐line treatment even though stem‐cells mobilization potential can be affected by several cycles and regimens of chemotherapy. To date, plerixafor is authorized in poor mobilizer adult pts diagnosed with lymphoma or multiple myeloma and in pediatric solid tumors or lymphoma. Therefore, the use of plerixafor in adult pts with relapsing/refractory GCT is still off label.

Materials and methods

In our study, we describe mobilization and collection of peripheral blood stem cells for 10 pts with germ cell tumors. Six patients underwent plerixafor administration since classified as poor mobilizers based on WBC count (>5.000/μL) and CD34+ cell count (<15/μL) the day before apheresis procedure.

Results

On the first day of apheresis, plerixafor administration in poor mobilizers made possible a remarkable boost of CD34+ cells in such a way to overlap that of good mobilizers' (32/μL vs 35/μL, respectively, P > .05).

Conclusion

Therefore, in our experience, plerixafor made a good fraction of poor mobilizer patients eligible for mobilization and collection and able to undergo the predicted autologous stem‐cells transplantation; thus, the lack of access to the use of plerixafor in this setting of patients risks jeopardizing an effective treatment, especially in case of poor prognosis.

Primary Mediastinal and Testicular Germ Cell Tumors in Adolescents and Adults: A Comparison of Genomic Alterations and Clinical Implications

Simple Summary

The germ cell tumors (GCTs) family is a heterogeneous group of neoplasms that includes tumors affecting testis (TGCTs) and rarer cases occurring in extragonadal sites. Mediastinal germ cell tumors (MGCTs) are more aggressive and have poorer prognosis. Due to their rarity of MGCTs, few molecular and clinical studies are reported. MGCTs share biological similarities with TGCT, and international guidelines recommend use of the same therapies validated for TGCT. However, while high response rate is achieved in TGCT, MGCT tend to be resistant to therapy. This review resumes all molecular findings reported in MGCTs, summarizing molecular characteristics common with TGCT and highlighting the different molecular alterations that characterize mediastinal tumors. A deeper understanding of the MGCT biology will help in clinical management of these patients.

Abstract

Mediastinal germ cell tumors (MGCTs) share histologic, molecular and biomarkers features with testicular GCTs; however, nonseminomatous MGCTs are usually more aggressive and have poorer prognosis than nonseminomatous TGCTs. Most nonseminomatous MGCT cases show early resistance to platinum-based therapies and seldom have been associated with the onset of one or more concomitant somatic malignancies, in particular myeloid neoplasms with recent findings supporting a common, shared genetic precursor with the primary MGCT. Genomic, transcriptomic and epigenetic features of testicular GCTs have been extensively studied, allowing for the understanding of GCT development and transformation of seminomatous and nonseminomatous histologies. However, MGCTs are still lacking proper multi-omics analysis and only few data are reported in the literature. Understanding of the mechanism involved in the development, in the progression and in their higher resistance to common therapies is still poorly understood. With this review, we aim to collect all molecular findings reported in this rare disease, resuming the similarities and disparities with the gonadal counterparts.

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.

Testicular cancer: Biology to bedside

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

High-dose Chemotherapy in Germ Cell Cancer Patients With Brain Metastases: Experience of an Expert Center

OBJECTIVES

Germ cell tumor (GCT) patients with brain metastases (BM) have a poor prognosis and high risk of treatment failure. Optimal therapies for these patients remain controversial. The aim of this study was to report the outcomes of all GCT patients with BM treated with high-dose chemotherapy (HDCT) in our French expert center for GCT.

METHODS

We carried out a retrospective study of 35 GCT patients with BM who were treated from 2003 to 2019 with HDCT, followed by infusions of autologous peripheral blood hematopoietic stem cells.

RESULTS

The overall survival at 2 years was 36.9% (95% confidence interval, 19.7-54). The median overall survival was 12 months and the median progression-free survival was 8 months. No variables were associated with better survival in the univariable analysis. Among the 35 patients included in our study, 31 completed HDCT and 4 stopped treatments after mobilization. Eleven patients (11) showed favorable responses (complete, partial, or stable disease) to HDCT and 20 patients died of disease progression (17) or toxicities (3). Among the 11 patients with favorable responses to HDCT, 8 (72.7%) had metachronous BM, mostly isolated. The majority of these patients did not receive local treatment at diagnosis or at relapse.

CONCLUSIONS

Together, our study reveals that GCT patients can experience long-term survival even in the presence of BM. Metachronous BM can also be cured with HDCT even in the absence of local treatment. Biological and radiologic responses to mobilization could be a predictor of favorable responses to HDCT.

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.

Using mitochondrial activity to select for potent human hematopoietic stem cells

Hematopoietic cell transplantation is a critical curative approach for many blood disorders. However, obtaining grafts with sufficient numbers of hematopoietic stem cells (HSCs) that maintain long-term engraftment remains challenging; this is due partly to metabolic modulations that restrict the potency of HSCs outside of their native environment. To address this, we focused on mitochondria. We found that human HSCs are heterogeneous in their mitochondrial activity as measured by mitochondrial membrane potential (MMP) even within the highly purified CD34+CD38-CD45RA-CD90+CD49f+ HSC population. We further found that the most potent HSCs exhibit the lowest mitochondrial activity in the population. We showed that the frequency of long-term culture initiating cells in MMP-low is significantly greater than in MMP-high CD34+CD38-CD45RA-CD90+ (CD90+) HSCs. Notably, these 2 populations were distinct in their long-term repopulating capacity when transplanted into immunodeficient mice. The level of chimerism 7 months posttransplantation was >50-fold higher in the blood of MMP-low relative to MMP-high CD90+ HSC recipients. Although more than 90% of both HSC subsets were in G0, MMP-low CD90+ HSCs exhibited delayed cell-cycle priming profile relative to MMP-high HSCs. These functional differences were associated with distinct mitochondrial morphology; MMP-low in contrast to MMP-high HSCs contained fragmented mitochondria. Our findings suggest that the lowest MMP level selects for the most potent, likely dormant, stem cells within the highly purified HSC population. These results identify a new approach for isolating highly potent human HSCs for further clinical applications. They also implicate mitochondria in the intrinsic regulation of human HSC quiescence and potency.

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.