Patterns of relapse in poor-prognosis germ-cell tumours in the GETUG 13 trial: Implications for assessment of brain metastases

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

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

Immune-related genes play an important role in the prognosis of patients with testicular germ cell tumor

Background

Testicular cancer is a very common malignancy in young men. Although testicular cancer has a high cure rate, patients have a high long-term risk of secondary malignant tumors and cardiovascular disease. In addition, for patients resistant to traditional treatment methods, new treatment methods and methods for predicting prognosis are also urgently needed.

Methods

Gene expression profiles of 165 normal testicular tissues and 156 testicular germ cell tumor (TGCT) tissues from GTEx database and TCGA database were used to obtain differentially expressed genes (DEGs) in TGCT. Through the ImmPort database, we obtained immune-related genes (IRGs). Univariate Cox regression analysis was used to identify prognostic IRGs. A transcription factor regulatory network was constructed to clarify the possible regulatory mechanism for the differential expression of these IRGs. Multivariate Cox regression analysis was used to establish a prognostic model. Gene expression data and related survival data of 108 TCGT patients from GEO database were used for external validation. Survival analysis, receiver operating characteristic curves (ROC) curve analysis, independent prognostic analysis, principal component analysis (PCA) and clinical correlation analysis were performed to evaluate this model.

Results

Three hundred and thirty-three IRGs were differentially expressed between TGCT and normal testicular tissues. We established a prognostic model (riskScore) based on 5 risk genes (SEMA6B, SEMA3G, OBP2B, INSL6 and RETN). Whether in the training cohort, the testing cohort or the entire TCGA cohort, this model could accurately stratify patients with different survival outcomes. The prognostic value of riskScore and 5 risk genes was also confirmed in the GEO database. GSEA analysis showed that DEGs in patients with better prognosis were enriched in immune-related pathways, while DEGs in patients with poorer prognosis were enriched in cancer-related pathways and cardiovascular disease-related pathways. Finally, a new Nomogram with higher prognostic value was constructed to better predict the 1-year PFS, 3-year PFS and 5-year PFS of TCGT patients.

Conclusions

We successfully established an immune-related risk model with high prognostic value and created a new Nomogram. We found that different immune status in tumor microenvironment may be responsible for the different survival outcomes among TGCT patients.

Brain metastases from germ cell tumor: time to reconsider radiotherapy?

The presence of brain metastases (BMs) from germ cell tumor (GCT) remains a rare situation. BMs predominantly occur among patients with testis primary tumor site, and are almost exclusively associated with non-seminomatous (NS) histologies. Two situations must be distinguished, which differ in terms of clinical presentation, overall prognostic and management. At diagnosis, BMs are almost systematically associated with extra-cerebral metastases and the cornerstone of treatment is chemotherapy, while the role of local treatment remains controversial. In the metachronous setting, BMs more frequently constitute an isolated site of relapse, the outcome is poorer, and the role of local treatment is more consensual. However, all these data widely come from old reports, with outdated radiation techniques. The recent advances in radiation oncology, especially the rising use of stereotactic radiotherapy, could lead to the reconsideration of ancient dogmas regarding the "radiosensitivity" of (NS)GCT and the role of radiotherapy among patients with BMs.

Prognosis of Patients With Testicular Carcinoma Is Dependent on Metastatic Site

Background: Existing data on the association of metastatic sites and prognosis of patients with metastatic testicular malignancy are limited. In this study, the association of survival outcome and the prognostic value of different metastatic sites in patients with metastatic testicular cancer was investigated.

Methods: A dataset from the Surveillance, Epidemiology and End Results (SEER) survey was selected for a retrospective metastatic testicular cancer cohort study. Patients with different metastatic sites were divided into corresponding groups for further analysis. Kaplan-Meier analysis with log-rank test was implemented for comparison of the survival distribution of cases. Multivariate Cox regression models were then applied to analyze the association of distant metastases with survival for all selected patients and subgroup based on different histological type with a single metastatic site.

Results: A total of 1,661 patients treated for metastatic testicular malignant tumors between 2010 to 2016 were enrolled in this cohort study. Upon initial diagnosis, 61.9, 15.2, 6.7, 6.4, and 36.2% of patients were found to have lung, liver, bone, brain, and distant lymph nodes metastatic sites, respectively. Patients with lung, liver, or bone metastases showed more undesirable prognosis for overall survival (OS) and cancer-specific survival (CSS), in contrast with those with distant lymph node metastases (all P < 0.05). In comparison with patients with more than one metastatic site, those with a single metastasis had extended OS and CSS (both P < 0.001). In patients with a single metastatic site, Kaplan-Meier analysis and multivariate Cox regression demonstrated the association of bone and liver with the worst two groups of OS and CSS. Multivariate Cox models based on histological type showed different prognostic values of metastases in patients with seminoma or non-seminomatous germ cell tumors.

Conclusion: There is much heterogeneity in the oncological outcome of site-specific metastatic patients. Metastatic profiles and the prognostic value of metastases are dependent on the histological type in TC patients. Distant lymph nodes and lung metastases indicate favorable prognostic factors, while bone and liver metastases indicate negative survival outcomes in TC.

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

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

[Relapse surveillance of patients with testicular germ cell tumor]

Germ-cell tumors are the most common solid tumors in young men. The follow-up of these patients is very important in their management. In stage I testicular cancer, surveillance is the standard for low-risk disease. In addition to the early detection of relapse, follow-up should be directed towards prevention, detection and treatment of late toxicity, and secondary malignancies. Follow up consists in physical examination, laboratory analysis and radiological imaging. Recently, guidelines recommend risk-adapted surveillance strategy, with a reduction of CT scans numbers, due to the recognition of the risk of ionizing radiation exposure. However, efforts to maintain adequate compliance with follow up are required.

[Management of metastatic testicular germ cell tumors]

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

Current medical management of patients with poor-risk metastatic germ-cell tumors

PURPOSE OF REVIEW

Despite the high cure rate of germ-cell tumors (GCTs), the 5-year survival rate for those patients with metastatic poor-risk GCT rarely exceeds 50%. The purpose of this review is to highlight past and recent discoveries in the treatment of patients with poor-risk GCT.

RECENT FINDINGS

Multiple clinical trials to optimize the management of poor-risk germ-cell cancer are ongoing. First-line phase II clinical trials of dose-dense multidrug and paclitaxel-based regimens such as accelerated bleomycin, etoposide, and cisplatin (BEP), dose-dense chemotherapy and paclitaxel, ifosfamide, and cisplatin (TIP) reported promising results. Positive phase III data are still lacking.

SUMMARY

Four cycles of BEP or Etoposide (VP16), ifosfamide, cisplatin (VIP) continue to be the standard of care in patients with poor-risk GCT. A significant disparity in patient outcome exists between high-volume and low-volume centers. Referral for centers of excellence should be considered in the management of poor-risk GCT.

Managing seminomatous and nonseminomatous germ cell tumors

PURPOSE OF REVIEW

In the present review, we summarize the recent developments in the management of germ cell tumors (GCTs).

RECENT FINDINGS

Treatment-related acute and late-onset toxicity remains a key challenge in the management of GCTs, with recent evidence showing that the adverse health outcomes of etoposide and cisplatin for four cycles in comparison to bleomycin, etoposide, and cisplatin for three cycles appear to be similar. Recent data showed that multidisciplinary clinic approach and management in experienced academic centers were associated with improved overall survival in GCT patients. There are currently multiple conventional-dose chemotherapy options for salvage therapy in patients with refractory or recurrent disease. In addition, more efficacious high-dose chemotherapy regimens continue to be developed. The role of salvage conventional-dose chemotherapy versus high-dose chemotherapy is currently being investigated prospectively. Recent reports suggested that brentuximab vedotin could be a potential salvage option for cluster of differentiation 30 positive refractory GCTs. On the other hand the results of the first phase II clinical trial investigating pembrolizumab in refractory GCTs were disappointing showing no clinical activity.Finally, deep exploration of the immune profile of GCTs using immunohistochemistry and gene expression profiling has identified that advanced GCT stage was associated with decreased T-cell and Natural killer-cell signatures, whereas T regulatory, neutrophil, mast cell, and macrophage signatures increased with advanced stage. Even though these results indicated that activated T-cell infiltration correlated with seminoma histology and good prognosis, and could be used in the future as a biomarker, this approach needs to be validated in a large cohort.

SUMMARY

Remaining challenges to be addressed include minimizing therapeutic toxicity, and improving outcomes in patients with refractory/recurrent GCTs.

Management of residual masses in testicular germ cell tumors

INTRODUCTION

About 50% of all patients with advanced testicular cancer demonstrate residual retroperitoneal or extraretroperitoneal masses. About two thirds of the masses harbour necrosis/fibrosis only whereas as about 10% and 40% harbour vital cancer or teratoma. Appropriate therapy will result in a high cure rate if performed properly. Areas covered: This review article covers the indication, the surgical technique and the oncological outcome of PC-RPLND and resection of extraretroperitoneal residual masses following chemotherapy in patients with advanced testis cancer. Expert commentary: Postchemotherapy retroperitoneal lymph node dissection (PC-RPLND) plays an integral part of the multimodality treatment in patients with advanced testicular germ cell tumours. Patients with nonseminomas, residual masses < 1cm and good prognosis can undergo active surveillance. In all other cases, PC-RPLND with or without resection of adjacent organs needs to be performed for curative intent. PC-RPLND requires a complex surgical approach and should be performed in experienced, tertiary referral centres only.

Emerging Prognostic Biomarkers in Testicular Germ Cell Tumors: Looking Beyond Established Practice

Testicular germ cell tumors are unique among solid cancers. Historically, this disease was deadly if progressed beyond the stage I. The implementation of cisplatin-based chemotherapy regimens has drastically changed the clinical outcome of metastatic testicular cancer. Several biomarkers were established to refine the prognosis by International Germ Cell Collaborative Group in 1997. Among these, the most significant were primary tumor site; metastatic sites, such as non-pulmonary visceral metastases; and the amplitude of serum tumor markers α-fetoprotein, β-chorionic gonadotropin, and lactate dehydrogenase. Since then, oncology has experienced discoveries of various molecular biomarkers to further refine the prognosis and treatment of malignancies. However, the ability to predict the prognosis and treatment response in germ cell tumors did not improve for many years. Clinical trials with novel targeting agents that were conducted in refractory germ cell tumor patients have proven to have negative outcomes. With the recent advances and developments, novel biomarkers emerge in the field of germ cell tumor oncology. This review article aims to summarize the current knowledge in the research of novel prognostic biomarkers in testicular germ cell tumors.

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

INTRODUCTION

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