Clinical Response of a Patient to Anti-PD-1 Immunotherapy and the Immune Landscape of Testicular Germ Cell Tumors

Biomarkers for Salvage Therapy in Testicular Germ Cell Tumors

The outcome of metastatic testicular germ cell tumor patients has been dramatically improved by cisplatin-based chemotherapy combinations. However, up to 30% of patients with advanced disease relapse after first-line therapy and require salvage regimens, which include treatments with conventional-dose chemotherapy or high-dose chemotherapy with autologous stem cell transplantation. For these patients, prognosis estimation represents an essential step in the choice of medical treatment but still remains a complex challenge. The available histological, clinical, and biochemical parameters attempt to define the prognosis, but they do not reflect the tumor's molecular and pathological features and do not predict who will exhibit resistance to the several treatments. Molecular selection of patients and validated biomarkers are highly needed in order to improve current risk stratification and identify novel therapeutic approaches for patients with recurrent disease. Biomolecular biomarkers, including microRNAs, gene expression profiles, and immune-related biomarkers are currently under investigation in testicular germ cell tumors and could potentially hold a prominent place in the future treatment selection and prognostication of these tumors. The aim of this review is to summarize current scientific data regarding prognostic and predictive biomarkers for salvage therapy in testicular germ cell tumors.

Identification of testicular cancer immune infiltrates and novel immune cell subtypes

Testicular germ cell tumors (TGCT) are the most common type of testicular cancer, comprising 90-95% of cases and representing the most prevalent solid malignancy in young adult men. Immune infiltrates play important regulatory roles in tumors, but their role in TGCT remains unclear. Molecular subtyping is a promising way to provide precisely personalized treatment and avoid unnecessary toxicities. This study investigated immune infiltrates, key biomarkers, and immune subtyping of TGCT. In GSE3218, 24 differentially expressed immune genes (immDEGs) were identified. A new risk signature consisting of six immDEGs was developed using these genes. Individuals in the high-risk group had poor overall survival (OS; hazard ratio of 4.61 and P-value < 0.001). We validated the six-immDEGs risk signature in pure seminoma and mixed TGCT types. Two distinct immune patterns (Cluster 1 and Cluster 2) were identified using the consensusclusterplus, and Cluster 1 possessed an unfavorable OS compared with Cluster 2 (hazard ratio, 2.56; P < 0.001). Cluster 1 patients had significantly lower naive B cells, memory B cells, plasma cells, naive CD4 T cells, gamma delta T cells, and activated dendritic cells than Cluster 2 patients. Genes relating to the WNT signaling pathway, TGF-β signaling pathway, antigen processing and presentation, and NK cell-mediated cytotoxicity were associated with TGCT. STC1 was elevated in TGCT tissues, and its high expression showed advanced clinicopathological characteristics and poor prognosis of TGCT. Our findings may contribute to an increased understanding of the onset and progression of TGCT.

Immune checkpoint inhibitors and Chimeric Antigen Receptor (CAR)-T cell therapy: Potential treatment options against Testicular Germ Cell Tumors

Germ cell tumors (GCTs) represent a heterogeneous neoplasm family affecting gonads and rarely occurring in extragonadal areas. Most of patients have a good prognosis, often even in the presence of metastatic disease; however, in almost 15% of cases, tumor relapse and platinum resistance are the main challenges. Thus, novel treatment strategies with both improved antineoplastic activity and minor treatment-related adverse events compared with platinum are really expected. In this context, the development and the high activity demonstrated by immune checkpoint inhibitors in solid tumors and, subsequently, the interesting results obtained from the use of chimeric antigen receptor (CAR-) T cell therapy in hematological tumors, have stimulated research in this direction also in GCTs. In this article, we will analyze the molecular mechanisms underlying the immune action in the development of GCTs, and we will report the data from the studies that tested the new immunotherapeutic approaches in these neoplasms.

Long-term response to camrelizumab in a pretreated metastatic mixed testicular germ-cell tumor patient with co-mutations in DNA damage-repair genes

Little information is available regarding the therapeutic efficacy of immune checkpoint inhibitors and the prediction of DNA damage-repair (DDR) genes in mixed testicular germ-cell tumors (TGCTs). Here we report a pretreated patient with metastatic mixed TGCT harboring variations of three important DDR genes - BRCA2, MSH6 and PMS2 - identified by next-generation sequencing using plasma-based circulating tumor DNA. He obtained stable clinical benefit from PD-1 blockade. At the latest follow-up, he had a progression-free survival of more than 28 months and had survived 6.75 years since diagnosis. To our knowledge, this case is the first report of long-term clinical outcome obtained from immune checkpoint inhibitor therapy in a pretreated patient with mixed metastatic TGCT harboring co-mutations in DDR genes.

Inflammatory Biomarkers for Outcome Prediction in Patients With Metastatic Testicular Cancer

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

Long Non-Coding RNA RFPL3S Functions as a Biomarker of Prognostic and Immunotherapeutic Prediction in Testicular Germ Cell Tumor

The incidence of testicular germ cell tumor (TGCT) is currently on the rise worldwide, of which 15%-30% of patients have occur recurrence and metastasis. However, clinical methods for diagnosing TGCT and judging its prognosis remained inadequate. In this study, we aimed to explore the possibility of testis-specific long-chain non-coding RNA (lncRNA) Ret finger protein-like 3S (RFPL3S) as a biomarker for TGCT diagnosis, prognosis, and treatment response by reviewing the TGCT gene expression data in Gene Expression Omnibus (GEO) and The Cancer Genome Atlas (TCGA) databases. The cohort data and DNA methylation data of TGCT in TCGA were downloaded from TGCA, UCSC XENA, and GEO. The bioinformatic tools were used, including GEPIA2, Kaplan-Meier Plotter, LinkedOmics, UCSC XENA, Sangerbox Tools, GSCA, and Tumor Immune Dysfunction and Exclusion. Compared with normal testicular tissues, the RFPL3S expression was significantly reduced in TGCT, and was significantly negatively correlated with the patient’s Tumor, Node, Metastasis stage. Hypermethylation and low copy number of RFPL3S were present in TGCT, and low RFPL3S was associated with short disease-free and progression-free intervals. Silencing RFPL3S significantly enhanced the invasion ability and proliferation ability of TGCT cells as evaluated by Transwell and CCK-8 experiments. Additionally, RFPL3S expression was positively correlated with the infiltration of immune-activating cells such as B cells, CD8+ T cells, cytotoxic T cells, and natural killer cells, and negatively correlated with the infiltration of immunosuppressive cells such as Th17 and Th2. Higher RFPL3S expression was present in patients with immunotherapy benefits. In conclusion, we determined that the testis-specific lncRNA RFPL3S functioned as a tumor suppressor in TGCT and could be used as a prognostic predictor of TGCT, as well as a marker to predict the effect of TGCT immunotherapy.

An RNA-binding protein-related risk signature can predict the prognosis and tumor immunity of patients with testicular germ cell tumors

BACKGROUND

The functions of RNA-binding proteins (RBPs) in the occurrence and development of tumors remain largely unexplored. We established a risk signature based on RBPs to predict the prognosis, tumor-related immunity, and treatment benefits of patients with testicular germ cell tumors (TGCTs).

METHODS

A risk signature was built based on RBPs closely related to survival obtained from TGCT data in The Cancer Genome Atlas (TCGA) database. The ability of the signature to predict prognosis was analyzed by survival curves and Cox regression. The risk signature was validated using the Gene Expression Omnibus (GEO) database. The connection between tumor immunity and the risk score was evaluated. Risk score-related drug sensitivity and biofunctions were also explored.

RESULTS

A risk signature including four selected RBP genes (PARP12, USB1, POLR2E and EED) was established. The prognosis of high-risk TGCT patients was worse than that of low-risk TGCT patients. The risk score was considered a critical factor closely related to prognosis, as determined via Cox regression, and was also closely associated with multiple characteristics of tumor immunity, chemotherapy drugs and biofunctions.

CONCLUSION

The established risk signature including four selected RBPs in TGCTs could predict the prognosis, tumor-related immunity and treatment benefits of patients with TGCTs. Utilization of this signature could help clinicians make personalized treatment decisions.

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.

TcellInflamedDetector: an R package to distinguish T cell inflamed tumor types from non-T cell inflamed tumor types

A major issue in the use of immune checkpoint inhibitors is their lack of efficacy in many patients. Previous studies have reported that the T cell inflamed signature can help predict the response to immunotherapy. Thus, many studies have investigated mechanisms of immunotherapy resistance by defining the tumor microenvironment based on T cell inflamed and non–T cell inflamed subsets. Although methods of calculating T cell inflamed subsets have been developed, valid screening tools for distinguishing T cell inflamed from non–T cell inflamed subsets using gene expression data are still needed, since general researchers who are unfamiliar with the details of the equations can experience difficulties using extant scoring formulas to conduct analyses. Thus, we introduce TcellInflamedDetector, an R package for distinguishing T cell inflamed from non–T cell inflamed samples using cancer gene expression data via bulk RNA sequencing.

Multi-Level Analysis and Identification of Tumor Mutational Burden Genes across Cancer Types

Tumor mutational burden (TMB) is considered a potential biomarker for predicting the response and effect of immune checkpoint inhibitors (ICIs). However, there are still inconsistent standards of gene panels using next-generation sequencing and poor correlation between the TMB genes, immune cell infiltrating, and prognosis. We applied text-mining technology to construct specific TMB-associated gene panels cross various cancer types. As a case exploration, Pearson’s correlation between TMB genes and immune cell infiltrating was further analyzed in colorectal cancer. We then performed LASSO Cox regression to construct a prognosis predictive model and calculated the risk score of each sample for receiver operating characteristic (ROC) analysis. The results showed that the assessment of TMB gene panels performed well with fewer than 500 genes, highly mutated genes, and the inclusion of synonymous mutations and immune regulatory and drug-target genes. Moreover, the analysis of TMB differentially expressed genes (DEGs) suggested that JAKMIP1 was strongly correlated with the gene expression level of CD8⁺ T cell markers in colorectal cancer. Additionally, the prognosis predictive model based on 19 TMB DEGs reached AUCs of 0.836, 0.818, and 0.787 in 1-, 3-, and 5-year OS models, respectively (C-index: 0.810). In summary, the gene panel performed well and TMB DEGs showed great potential value in immune cell infiltration and in predicting survival.

Immune Checkpoint Inhibitors for Genitourinary Cancers: Treatment Indications, Investigational Approaches and Biomarkers

Cancers of the genitourinary (GU) tract are common malignancies in both men and women and are a major source of morbidity and mortality. Immune checkpoint inhibitors (ICI) targeting CTLA-4, PD-1 or PD-L1 have provided clinical benefit, particularly in renal cell and urothelial carcinoma, and have been incorporated into standard of care treatment in both localized and metastatic settings. However, a large fraction of patients do not derive benefit. Identification of patient and tumor-derived factors which associate with response have led to insights into mechanisms of response and resistance to ICI. Herein, we review current approvals and clinical development of ICI in GU malignancies and discuss exploratory biomarkers which aid in personalized treatment selection.

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.

Rapid Response to Pembrolizumab in a Chemo-Refractory Testicular Germ Cell Cancer with Microsatellite Instability-High

Testicular germ cell tumor (TGCT) is highly chemo-sensitive cancer; however, there is no established treatment for TGCT relapsed after multiple chemotherapy. Although pembrolizumab showed durable stable disease in some patients, no reliable biomarker for predicting response is available. High microsatellite instability (MSI) is rare in chemo-naïve TGCT. We report a TGCT patient with a rapid response to pembrolizumab. A 34-year-old Japanese male diagnosed with advanced TGCT underwent PCR-based testing of the primary site; it did not reveal MSI. He relapsed after four chemotherapy regimens: bleomycin, etoposide and cisplatin; paclitaxel, ifosfamide and cisplatin; vinblastine, ifosfamide and cisplatin; and irinotecan+nedaplatin with a total of 20 treatment cycles. Chemotherapy was thus discontinued. Re-examination by a CT-guided needle biopsy for progressing retroperitoneal lymph node (RPLN) metastases showed MSI-high; pembrolizumab was initiated. After only two doses, the human chorionic gonadotropin level decreased from 6500 to <1.0 IU/L. PET-CT showed shrinkage of the RPLN metastases with diminished metabolism. The patient is currently free from disease progression for 6 months from the start of pembrolizumab. This is the first report of refractory TGCT with MSI-high responding to pembrolizumab. We emphasize the utility of a metastatic-site biopsy to check the MSI status for refractory TGCT even when primary site is MSI-negative.

Expression of programmed death ligand-1 (PD-L1) in metastatic and postchemotherapy viable testicular germ cell tumors

INTRODUCTION

Chemotherapy for testicular germ cell tumors (GCT) is highly effective, with few patients who do not respond. Clinical studies to evaluated novel treatments are challenging given the rarity of these patients. Therefore, we sought to evaluate PD-L1 staining on metastatic and postchemotherapy viable testicular GCTs as a surrogate for potential benefit for immunotherapy targeting the PD-1/PD-L1 axis.

METHODS

Ethics research committee approval for this retrospective study was obtained by four participating institutions (CHU de Québec, St. Joseph's Health Care, Halifax Health Science Centre, Johannes Gutenberg University). Patients with viable metastatic testicular GCTs pathology samples were included. Patients with pure teratoma were excluded. PD-L1 staining with the 22C3 clone was evaluated on samples with >100 viable tumor cells using the combined positive score (CPS).

RESULTS

From 51 patients identified at participating institutions, 24 postchemotherapy and 18 chemotherapy-naive metastatic samples were available for PD-L1 staining, with 9 matched prechemotherapy samples and 7 matched orchiectomy pathology samples, respectively. The median CPS score was 55.6 (IQR 16-100) for all metastatic samples, 44.9 (IQR 13-100) for postchemotherapy metastatic samples, and 68.8 (IQR 38-100) for chemotherapy-naïve metastatic samples, with the median number of viable tumor cells at 545, 500, and 550, respectively. Differences were not significant between chemotherapy-naïve and postchemotherapy samples (P = 0.07), though among non-seminoma GCT metastatic samples, CPS scores were significantly lower postchemotherapy (P = 0.02). Significant differences among postchemotherapy metastatic tumors were also seen according to predominant subtype, with lower CPS scores for predominant yolk sac and higher values for predominant seminoma and choriocarcinoma. In 7 patients with matched specimens pre- and postchemotherapy, a significant increase in CPS was observed for seminoma (26.7 vs. 81.7, P = 0.045), but not nonseminoma GCTs. Comparing all chemotherapy naïve-samples, PD-L1 expression was higher in metastatic samples versus testicular samples (mean CPS 68.8 vs. 39.8, P = 0.02). This was also seen in matched chemotherapy-naïve samples (mean CPS 77.9 vs. 33.1, P = 0.01).

CONCLUSION

Our results suggest that most patients with refractory GCTs postchemotherapy will not benefit from PD-1/PD-L1 immunotherapy. However, the high PD-L1 expression in patients with predominant or pure seminoma post-chemotherapy suggests this may represent a subgroup for whom further trials may be considered.

Pembrolizumab in Patients with Advanced Metastatic Germ Cell Tumors

LESSONS LEARNED

Advanced germ cell tumors are aggressive and associated with poor prognosis. Pembrolizumab was overall well tolerated in 12 heavily pretreated patients. Three patients had radiographic stable disease that lasted for 10.9 months, 5.5 months, and 4.5 months, respectively. Published data of immunotherapeutic agents in patients with advanced germ cell tumors are confirmed. The limited antitumor activity of immunotherapy in germ cell tumors is, at least partially, attributed to tumor biology (low tumor mutational burden; low PD-1 expression) and other poor-risk features. Tumor profiling to understand the mechanisms of resistance to pembrolizumab and innovative clinical trials that may include immunotherapy are warranted.

BACKGROUND

Advanced germ cell tumors are associated with poor prognosis. We investigated the role of pembrolizumab in patients with advanced germ cell tumors.

METHODS

We analyzed a prespecified cohort of an open-label, phase II clinical trial in which patients with advanced germ cell tumors were treated with pembrolizumab (200 mg) intravenously every 21 days. The endpoints of the study were the non-progression rate (NPR) at 27 weeks, safety, and tolerability. An NPR >20% was considered successful and worthy of further pursuit.

RESULTS

From August 2016 to February 2018, 12 patients (10 men, 2 women) were treated (median age, 35 years [range, 22-63 years]; median number of prior systemic therapies, 3.5 [range, 2-7]; median number of metastatic sites, 3 [range, 2-8]). Overall, pembrolizumab was well tolerated. One patient experienced both grade 1 immune-related skin rash and grade 3 immune-related pneumonitis. No patient died from toxicity. Three patients had radiographic stable disease that lasted for 10.9 months, 5.5 months, and 4.5 months, respectively. No objective response was noted. The median progression-free survival was 2.4 months (95% confidence interval [CI], 1.5-4.5 months), and the median overall survival was 10.6 months (95% CI, 4.6-27.1 months). The 27-week NPR was 9.0% (95% CI, 0.23-41.2%).

CONCLUSION

Overall, pembrolizumab was safe and had limited antitumor activity in these patients. In the advanced, metastatic setting, tumor profiling to understand the mechanisms of resistance to immunotherapy and innovative clinical trials to identify efficacious combination regimens rather than off-label use of pembrolizumab are warranted.

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

INTRODUCTION

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

CASE REPORT

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

MANAGEMENT AND OUTCOME

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

DISCUSSION

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

Promising novel therapies for relapsed and refractory testicular germ cell tumors

INTRODUCTION

Germ cell tumors (GCTs) are the most common solid malignancies in young men. The overall cure rate of GCT patients in metastatic stage is excellent, however; patients with relapsed or refractory disease have poor prognosis. Attempts to treat refractory disease with novel effective treatment to improve prognosis have been historically dismal and the ability to predict prognosis and treatment response in GCTs did not sufficiently improve in the last three decades.

AREAS COVERED

We performed a comprehensive literature search of PubMed/MEDLINE to identify original and review articles (years 1964-2020) reporting on current improvement salvage treatment in GCTs and novel treatment options including molecularly targeted therapy and epigenetic approach. Review articles were further searched for additional original articles.

EXPERT OPINION

Despite multimodal treatment approaches the treatment of relapsed or platinum-refractory GCTs remains a challenge. High-dose chemotherapy (HDCT) regimens with autologous stem-cell transplant (ASCT) from peripheral blood showed promising results in larger retrospective studies. Promising results from in vitro studies raised high expectations in molecular targets. So far, the lacking efficacy in small and unselected trials do not shed a light on targeted therapy. Currently, wide inclusion of patients into clinical trials is highly advised.

Immune checkpoints and their inhibitors: Reappraisal of a novel diagnostic and therapeutic dimension in the urologic malignancies

Advances in molecular immunology have unveiled some of the complexity of the mechanisms regulating cellular immune responses and led to the successful targeting of immune checkpoints in attempts to enhance antitumor T cell responses. Surgery, chemotherapy, and radiation therapy have been the mainstay of treatment in urologic malignancies. Immune checkpoint molecules such as cytotoxic T-lymphocyte associated protein-4, programmed cell death protein-1, and programmed death-ligand 1 have been shown to play central roles in evading cancer immunity. Thus these molecules have been targeted by inhibitors for the management of cancers forming the basis of immunotherapy. Immunotherapy is now among the first line therapeutic options for metastatic renal cell carcinomas. In advanced bladder cancer, immunotherapy is the standard of care in the second line and the first line for cisplatin ineligible patients. There continues to be ongoing research to identify the role if any of immunotherapy in testicular, prostatic, and penile cancers. The ideal biomarker for response to immunotherapy is still elusive. Although programmed death-ligand 1 immunohistochemical testing has been widely used across the globe as a biomarker for immunotherapy, companion diagnostic tests have inherent issues with testing and reporting and cannot have universal applicability. Additional biomarkers including, tumor mutational burden, deficient mismatch repair, high microsatellite instability, and immune gene expression profiling are being evaluated in various clinical trials. This review appraises the data of immunotherapy in the management of urologic malignancies.

Immunotherapy in Testicular Germ Cell Tumors

Testicular germ cell tumors (TGCTs) are malignancies with very high curative potential even in metastatic settings, mainly due to the introduction of cisplatin in the treatment of this disease. However, in a group of patients with cisplatin-refractory disease or with progressive disease despite high-dose salvage chemotherapy treatment, the prognosis is typically dismal. The triple combination of gemcitabine, oxaliplatin, and paclitaxel (GOP) has reasonable efficacy and is considered to be standard care for this group of patients. It remains to be seen, however, whether refractory TGCTs may represent a potential target for immune checkpoint inhibition. This review will focus on the rationale of the use of immunotherapy for platinum-refractory TGCTs and summarize data reporting experiences with immune checkpoint inhibitor treatment for this malignancy.

Tumour biomarkers: association with heart failure outcomes

BACKGROUND

There is increasing recognition that heart failure (HF) and cancer are conditions with a number of shared characteristics.

OBJECTIVES

To explore the association between tumour biomarkers and HF outcomes.

METHODS

In 2,079 patients of BIOSTAT-CHF cohort, we measured six established tumour biomarkers: CA125, CA15-3, CA19-9, CEA, CYFRA 21-1 and AFP.

RESULTS

During a median follow-up of 21 months, 555 (27%) patients reached the primary end-point of all-cause mortality. CA125, CYFRA 21-1, CEA and CA19-9 levels were positively correlated with NT-proBNP quartiles (all P < 0.001, P for trend < 0.001) and were, respectively, associated with a hazard ratio of 1.17 (95% CI 1.12-1.23; P < 0.0001), 1.45 (95% CI 1.30-1.61; P < 0.0001), 1.19 (95% CI 1.09-1.30; P = 0.006) and 1.10 (95% CI 1.05-1.16; P < 0.001) for all-cause mortality after correction for BIOSTAT risk model (age, BUN, NT-proBNP, haemoglobin and beta blocker). All tumour biomarkers (except AFP) had significant associations with secondary end-points (composite of all-cause mortality and HF hospitalization, HF hospitalization, cardiovascular (CV) mortality and non-CV mortality). ROC curves showed the AUC of CYFRA 21-1 (0.64) had a noninferior AUC compared with NT-proBNP (0.68) for all-cause mortality (P = 0.08). A combination of CYFRA 21-1 and NT-proBNP (AUC = 0.71) improved the predictive value of the model for all-cause mortality (P = 0.0002 compared with NT-proBNP).

CONCLUSIONS

Several established tumour biomarkers showed independent associations with indices of severity of HF and independent prognostic value for HF outcomes. This demonstrates that pathophysiological pathways sensed by these tumour biomarkers are also dysregulated in HF.

Immune checkpoint inhibitors in genitourinary malignancies

Although immune-mediated therapies have been used in genitourinary (gu) malignancies for decades, recent advances with monoclonal antibody checkpoint inhibitors (cpis) have led to a number of promising treatment options. In renal cell carcinoma (rcc), cpis have been shown to have benefit over conventional therapies in a number of settings, and they are the standard of care for many patients with metastatic disease. Based on recent data, combinations of cpis and antiangiogenic therapies are likely to become a new standard approach in rcc. In urothelial carcinoma, cpis have been shown to have a role in the second-line treatment of metastatic disease, and a number of clinical trials are actively investigating cpis for other indications. In other gu malignancies, such as prostate cancer, results to date have been less promising. Immunotherapies continue to be an area of active study for all gu disease sites, with several clinical trials ongoing. In this review, we summarize the current evidence for cpi use in rcc, urothelial carcinoma, prostate cancer, testicular germ-cell tumours, and penile carcinoma. Ongoing clinical trials of interest are highlighted, as are the challenges that clinicians and patients will potentially face as immune cpis become a prominent feature in the treatment of gu cancers.

TP53 and PTEN mutations were shared in concurrent germ cell tumor and acute megakaryoblastic leukemia

Background

The occurrence of a mediastinal germ cell tumor (GCT) and hematological malignancy in the same patient is very rare. Due to its rarity, there have been only two reports of the concurrent cases undergoing detailed genetic analysis with whole-exome sequencing (WES), and the possible clonal relationship between the both tumors remained not fully elucidated.

Methods

We performed whole-exome sequencing analysis of mediastinal GCT and acute myeloid leukemia (AML) samples obtained from one young Japanese male adult patient with concurrent both tumors, and investigated the possible clonal relationship between them.

Results

Sixteen somatic mutations were detected in the mediastinal GCT sample and 18 somatic mutations in the AML sample. Mutations in nine genes, including TP53 and PTEN both known as tumor suppressor genes, were shared in both tumors.

Conclusions

All in our case and in the previous two cases with concurrent mediastinal GCT and AML undergoing with whole-exome sequencing analysis, TP53 and PTEN mutations were commonly shared in both tumors. These data not only suggest that these tumors share a common founding clone, but also indicate that associated mediastinal GCT and AML harboring TP53 and PTEN mutations represent a unique biological entity.

Detailed Characterization of Immune Cell Infiltrate and Expression of Immune Checkpoint Molecules PD-L1/CTLA-4 and MMR Proteins in Testicular Germ Cell Tumors Disclose Novel Disease Biomarkers

Background: The immune infiltrate plays an important part in testicular germ cell tumors, but it remains scarcely studied. We aimed at thoroughly characterizing the immune infiltrate and expression of immune checkpoints PD-L1/CTLA-4 and mismatch repair (MMR) proteins in these neoplasms, seeking for associations with patient outcome. Methods: A total of 162 consecutively diagnosed patients (2005–2018) were included. Immunostaining for PD-L1, CTLA-4 and MMR proteins was independently assessed both in immune cells (ICs) and tumor cells (TCs) of primary tumors and metastases, and characterization of IC populations was pursued. Results: PD-L1 and CTLA-4 positivity in ICs was frequent (85.5% and 96.3%). Patients with absent PD-L1 positive ICs exhibited significantly worse relapse-free survival (hazard ratio = 4.481, 95% CI 1.366–14.697, p = 0.013), both in univariable and multivariable analysis. Lower CD20 and CD3 IC infiltration in seminomas associated with higher disease stage (p = 0.0216, p = 0.0291). CTLA-4 TC intensity was significantly higher in yolk sac tumor, choriocarcinoma and teratoma, while PD-L1 TC positivity was significantly more frequent in choriocarcinoma. Both PD-L1 and CTLA-4 immunoexpression in ICs of metastatic samples was frequent (100% and 88.2%). MMR proteins were differentially expressed among the different tumor subtypes. Conclusions: Immune infiltrate/checkpoints associate with patients’ outcome, constituting novel (potentially targetable) disease biomarkers.

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

PURPOSE OF REVIEW

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

RECENT FINDINGS

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

SUMMARY

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

Testicular germ cell tumor: a comprehensive review

Testicular tumors are the most common tumors in adolescent and young men and germ cell tumors (TGCTs) account for most of all testicular cancers. Increasing incidence of TGCTs among males provides strong motivation to understand its biological and genetic basis. Gains of chromosome arm 12p and aneuploidy are nearly universal in TGCTs, but TGCTs have low point mutation rate. It is thought that TGCTs develop from premalignant intratubular germ cell neoplasia that is believed to arise from the failure of normal maturation of gonocytes during fetal or postnatal development. Progression toward invasive TGCTs (seminoma and nonseminoma) then occurs after puberty. Both inherited genetic factors and environmental risk factors emerge as important contributors to TGCT susceptibility. Genome-wide association studies have so far identified more than 30 risk loci for TGCTs, suggesting that a polygenic model fits better with the genetic landscape of the disease. Despite high cure rates because of its particular sensitivity to platinum-based chemotherapy, exploration of mechanisms underlying the occurrence, progression, metastasis, recurrence, chemotherapeutic resistance, early diagnosis and optional clinical therapeutics without long-term side effects are urgently needed to reduce the cancer burden in this underserved age group. Herein, we present an up-to-date review on clinical challenges, origin and progression, risk factors, TGCT mouse models, serum diagnostic markers, resistance mechanisms, miRNA regulation, and database resources of TGCTs. We appeal that more attention should be paid to the basic research and clinical diagnosis and treatment of TGCTs.

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.

Epigenetic treatment combinations to effectively target cisplatin-resistant germ cell tumors: past, present, and future considerations

BACKGROUND

Type II germ cell tumors represent the most common solid malignancy in men aged 15-45 years. Despite high cure rates of >90% over all stages, 10-15% of advanced patients develop treatment resistance and potentially succumb to their disease. Treatment of refractory germ cell tumors remains unsatisfactory, and new approaches are needed to further improve outcomes.

OBJECTIVES

With this narrative review, we highlight epigenetic mechanisms related to resistance to standard systemic treatment, which may act as promising targets for novel combined epigenetic treatment approaches.

MATERIALS AND METHODS

A comprehensive literature search of PubMed and MEDLINE was conducted to identify original and review articles on resistance mechanisms and/or epigenetic treatment of germ cell tumors in vitro and in vivo. Review articles were hand-searched to identify additional articles.

RESULTS

Distinct epigenetic phenomena have been linked to chemotherapy resistance in germ cell tumors, among which DNA hypermethylation, histone acetylation, and bromodomain proteins appear as promising targets for therapeutic exploitation. Inhibitors of key regulators, for example DNA methyltransferases (e.g. decitabine, guadecitabine), histone deacetylases (e.g. romidepsin), and bromodomain proteins (e.g. JQ1) decreased cell viability, triggered apoptosis, and growth arrest. Additionally, these epigenetic drugs induced differentiation and led to loss of pluripotency and re-sensitization towards cisplatin in cell lines and animal models.

DISCUSSION

Epigenetic treatments hold promise to (i) reduce the treatment burden of and (ii) overcome resistance to standard cisplatin-based chemotherapy. Combined approaches may enhance activity, while the ideal target and treatment combination of epigenetic drugs, either with another epigenetic agent or conventional cytotoxic agents need to be defined.

CONCLUSION

Epigenetic (combination) treatment for germ cell tumors should be further explored in pre-clinical and clinical research for its potential to further improve germ cell tumor treatment.

Immunotherapy: last bullet in platinum refractory germ cell testicular cancer

Testicular germ cell tumors are chemosensitive with very high cure-rates even in the metastatic setting. However, patients with platinum-refractory and relapsing tumors after autologous stem cell transplant have very poor outcomes despite salvage treatments, and with no effective alternative therapies. Immunotherapy, notably with PD-1 inhibitors, has proven to be very effective in treating various solid tumors. This review summarizes the experience with anti-PD-1 agents (pembrolizumab, nivolumab) in the treatment of testicular germ cell tumor relapsing after multiple lines of treatment, and exposes future trials evaluating newer checkpoint inhibitors in this setting.

Management of extraretroperitoneal masses in germ cell tumor

PURPOSE OF REVIEW

Management of extraretroperitoneal (ERP) germ cell tumor (GCT) is a complex clinical scenario faced by urologic oncologists. This article reviews the indications and approach to management of ERP GCT masses.

RECENT FINDINGS

ERP GCT management starts with chemotherapy, and for any residual masses, a careful consideration of surgical intervention versus salvage chemotherapy. Decision-making regarding residual ERP masses hinges on tumor markers, and also the anatomical location. These factors should be contextualized by the patient's risk for teratoma or active GCT, which will impact outcome and thus weigh on decision-making conversations with patients who have advanced disease. Technical challenges of surgical management in the postchemotherapy setting also apply in ERP mass resection. The risks of surgical management in the lung and liver, in particular, add special considerations for morbidity. Surgical resection is often the only recourse for a patient who may have chemoresistant disease and may be an important step in achieving cure.

SUMMARY

Surgical management of ERP GCT requires multidisciplinary input, and the urologic oncologist can help guide management with particular emphasis on the indication, timing, and approach to surgical resection.

Genomic Characterization of Testicular Germ Cell Tumors Relapsing After Chemotherapy

BACKGROUND

Although both seminomatous and nonseminomatous testicular germ cell tumors (TGCTs) have favorable outcomes with chemotherapy, a subset is chemorefractory, and novel therapeutic options are needed.

OBJECTIVE

To molecularly characterize chemotherapy-refractory TGCTs.

DESIGN, SETTING, AND PARTICIPANTS

Archival tissues from 107 chemotherapy-treated and relapsed TGCT patients (23 seminomas; 84 nonseminomas) underwent hybrid-capture-based genomic profiling to evaluate four classes of genomic alterations (GAs). Tumor mutational burden (TMB) and microsatellite instability (MSI) were also measured.

INTERVENTION

Genomic profiling on tumor samples from chemotherapy-refractory TGCTs.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Descriptive analyses and differences between seminoma and nonseminoma subgroups were reported.

RESULTS AND LIMITATIONS

The mean GA/tumor was 2.9 for seminomas and 4.0 for nonseminomas (p=0.04). KRAS alterations (mainly amplifications) were the most common GAs at the single-gene level (47.8% of seminomas and 51.2% of nonseminomas). RAS-RAF pathway (56.5% vs 52.3%) and cell-cycle pathway (52.2% vs 56.0%) were the most common GA classes in seminomas and nonseminomas, respectively. Receptor tyrosine kinase pathway and PI3K pathway GAs were more frequent in seminomas (p=0.02). Median TMB was 1.8 mutations/Mb for seminomas and 2.7 mutations/Mb for nonseminomas (p=0.098), and MSI-high status was found in one nonseminoma only (1.2%). A lack of clinical outcome correlation is a limitation of the present analyses.

CONCLUSIONS

In chemotherapy-refractory TGCTs, trials with agents targeting the KRAS pathway may be pursued due to the high frequency of KRAS GAs. Overall, the GAs found in refractory seminomas and nonseminomas differ significantly. Considering the frequency of high TMB or MSI-high status, immunotherapy may benefit a small subset of nonseminomas.

PATIENT SUMMARY

Testicular cancers that are resistant to or relapse after standard chemotherapy may harbor genomic alterations that are potentially druggable, particularly in the clinical trial setting, and genomic profiling can guide clinical research and disclose therapeutic opportunities for these patients.

Impact of oncogenic pathways on evasion of antitumour immune responses

Immunotherapeutic interventions are showing effectiveness across a wide range of cancer types, but only a subset of patients shows clinical response to therapy. Responsiveness to checkpoint blockade immunotherapy is favoured by the presence of a local, CD8+ T cell-based immune response within the tumour microenvironment. As molecular analyses of tumours containing or lacking a productive CD8+ T cell infiltrate are being pursued, increasing evidence is indicating that activation of oncogenic pathways in tumour cells can impair induction or execution of a local antitumour immune response. This Review summarizes our current knowledge of the influence of oncogenic effects on evasion of antitumour immunity.

Future perspectives in melanoma research "Melanoma Bridge", Napoli, November 30th-3rd December 2016

Major advances have been made in the treatment of cancer with targeted therapy and immunotherapy; several FDA-approved agents with associated improvement of 1-year survival rates became available for stage IV melanoma patients. Before 2010, the 1-year survival were quite low, at 30%; in 2011, the rise to nearly 50% in the setting of treatment with Ipilimumab, and rise to 70% with BRAF inhibitor monotherapy in 2013 was observed. Even more impressive are 1-year survival rates considering combination strategies with both targeted therapy and immunotherapy, now exceeding 80%. Can we improve response rates even further, and bring these therapies to more patients? In fact, despite these advances, responses are heterogeneous and are not always durable. There is a critical need to better understand who will benefit from therapy, as well as proper timing, sequence and combination of different therapeutic agents. How can we better understand responses to therapy and optimize treatment regimens? The key to better understanding therapy and to optimizing responses is with insights gained from responses to targeted therapy and immunotherapy through translational research in human samples. Combination therapies including chemotherapy, radiotherapy, targeted therapy, electrochemotherapy with immunotherapy agents such as Immune Checkpoint Blockers are under investigation but there is much room for improvement. Adoptive T cell therapy including tumor infiltrating lymphocytes and chimeric antigen receptor modified T cells therapy is also efficacious in metastatic melanoma and outcome enhancement seem likely by improved homing capacity of chemokine receptor transduced T cells. Tumor infiltrating lymphocytes therapy is also efficacious in metastatic melanoma and outcome enhancement seem likely by improved homing capacity of chemokine receptor transduced T cells. Understanding the mechanisms behind the development of acquired resistance and tests for biomarkers for treatment decisions are also under study and will offer new opportunities for more efficient combination therapies. Knowledge of immunologic features of the tumor microenvironment associated with response and resistance will improve the identification of patients who will derive the most benefit from monotherapy and might reveal additional immunologic determinants that could be targeted in combination with checkpoint blockade. The future of advanced melanoma needs to involve education and trials, biobanks with a focus on primary tumors, bioinformatics and empowerment of patients and clinicians.

Recent developments in the management of 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. Recent data show that patients with large retroperitoneal lymph node metastases are at increased risk of venous thromboembolism and may benefit from prophylactic anticoagulation. Predictive models have been developed to identify patients with residual retroperitoneal lymph node masses who are more likely to benefit from surgical resection. However, their clinical use remains hampered by relatively low accuracy. There are currently multiple conventional-dose chemotherapy (CDCT) options for salvage therapy in patients with refractory or recurrent disease. In addition, more efficacious high-dose chemotherapy (HDCT) regimens continue to be developed. The role of salvage CDCT versus HDCT is currently being prospectively investigated.Finally, intratumoral heterogeneity is a common finding in cancer and an obvious observation in GCTs. Despite intratumoral heterogeneity, recent studies on nonseminomatous GCT have identified distinct histological subgroups and a potentially lethal clinical phenotype. Importantly, comprehensive molecular profiling so far has not elucidated the biologic basis or the clinical underpinnings of intratumoral heterogeneity in GCTs.

SUMMARY

Remaining challenges to be addressed include minimizing therapeutic toxicity and improving outcomes in patients with refractory/recurrent GCTs or malignant transformation of teratomas.

Deep exploration of the immune infiltrate and outcome prediction in testicular cancer by quantitative multiplexed immunohistochemistry and gene expression profiling

Platinum-based chemotherapy is usually curative for patients with testicular germ cell tumors (TGCT), but a subset of patients experience disease progression and poor clinical outcomes. Here, we tested whether immune profiling of TGCT could identify novel prognostic markers and therapeutic targets for this patient cohort. We obtained primary and metastatic TGCT samples from one center. We performed immune profiling using multiplexed fluorescence immunohistochemistry (FIHC) for T-cell subsets and immune checkpoints, and targeted gene expression profiling (Nanostring nCounter Immune panel). Publically available data sets were used to validate primary sample analyses. Nearly all samples had some degree of T-cell infiltration and immune checkpoint expression. Seminomas were associated with increased CD3⁺ T-cell infiltration, decreased Regulatory T-cells, increased PD-L1, and increased PD-1/PD-L1 spatial interaction compared with non-seminomas using FIHC. Gene expression profiling confirmed these findings and also demonstrated increased expression of T-cell markers (e.g., IFNγ, and LAG3) and cancer/testis antigens (e.g., PRAME) in seminomas, whereas non-seminomas demonstrated high neutrophil and macrophage gene signatures. Irrespective of histology, advanced TGCT stage was associated with decreased T-cell and NK-cell signatures, while Treg, neutrophil, mast cell and macrophage signatures increased with advanced stage. Importantly, cancer/testis antigen, neutrophil, and CD8⁺/regulatory T-cell signatures correlated with recurrence free survival. Thus, deep immune characterization of TGCT using IHC and gene expression profiling identified activated T-cell infiltration which correlated with seminoma histology and good prognosis. These results may provide a rationale for testing of anti-PD-1/PD-L1 agents and suggest prognostic markers.

[Immunotherapy for the treatment of patients with genitourinary cancers: Review and perspectives]

Management of genitourinary (GU) cancers is improving rapidly with the development of immunotherapy agents, especially anti-PD-1/anti-PD-L1 therapies. Large studies have shown better outcomes for the treatment of these patients, leading to new drug approvals and recent changes in standards of care in renal, prostate and bladder cancer. We performed a review of recent studies assessing efficacy of immuno-oncology therapies in GU cancers. New results are summarized and next ways of development of clinical research are discussed as the use of such therapies will soon be assessed in first-line or adjuvant settings.