Immune-checkpoint status in penile squamous cell carcinoma: a North American cohort

Impact of TP53 Alterations on Clinical Outcomes in Penile Squamous Cell Carcinoma

BACKGROUND

Penile squamous cell carcinoma (PSCC) is a rare, aggressive malignancy with a high risk of mortality due to metastasis. A comprehensive understanding of its mutational landscape is critical for improving early detection and therapeutic strategies.

METHODS

We analyzed tissue samples from 28 patients with PSCC treated at the Cancer Hospital of the Chinese Academy of Medical Sciences between January 2019 and March 2023. DNA from primary tumors and/or matched inguinal lymph nodes underwent targeted sequencing. Somatic mutations were profiled to compare primary and metastatic lesions. Statistical analyses assessed associations between mutational features, clinical outcomes, and treatment responses.

RESULTS

A total of 980 mutations were identified across 354 genes. Frequently mutated genes included TP53 (67.5%), TERT (45%), CDKN2A (40%), FAT1 (37.5%), and NOTCH1 (30%). Copy number variations (CNVs) revealed amplifications in EGFR, SOX2, and MSH6 and deletions in CDKN2B and CDKN2A. A strong correlation was observed between mutational profiles of primary and metastatic lesions (r = 0.61, P < .001). Metastatic tumors exhibited higher tumor mutational burden (TMB) than primary tumors (38.9% vs. 9.5%, P = .030) and displayed a greater prevalence of mismatch repair deficiency-associated mutational signatures. Patients with higher TP53 mutation frequencies responded more favorably to immune checkpoint inhibitors (P = .024), with treatment efficacy strongly correlated (AUC = 0.938).

CONCLUSION

Key mutational alterations in PSCC, including high TMB and TP53 mutations, have significant implications for early diagnosis and personalized therapies. These findings support the potential use of specific genetic markers to guide targeted therapeutic approaches.

Molecular Pathology and Biomarkers of Penile Squamous Cell Carcinoma: Implications for Classification and Management

This review explores the current understanding and management of penile squamous cell carcinoma, emphasizing recent advances in molecular pathology and treatment strategies. The article discusses the importance of human papillomavirus status in tumor classification and prognosis, highlighting the 2022 WHO classification. The article underscores the need for a multidisciplinary approach to penile cancer management and identifies areas for future research, including refining molecular classification systems and developing predictive biomarkers. It concludes by emphasizing the rapid evolution of penile cancer management and the potential for more personalized treatment strategies.

Molecular characterization of metastatic penile squamous cell carcinoma in developing countries and its impact on clinical outcomes: LACOG 2018 translational study

BACKGROUND

Penile squamous cell carcinoma (PSCC) is a rare malignancy. However, in developing countries the incidence rate is higher. The understanding of molecular alterations is essential for evaluating possible targets for more effective systemic therapies.

METHODS

We retrospectively collected clinical data of metastatic PSCC (mPSCC) patients who had received at least one prior systemic treatment from 3 Brazilian hospitals. Tumor samples were evaluated using the next-generation sequencing (NGS) Foundation One DX and immunohistochemistry (IHC). The objective was to identify and describe somatic genomic alterations known to be functional or pathogenic and their association with survival outcomes.

RESULTS

Twenty-three patients were identified, 22 and 18 patients had tumor samples analyzed by IHC and NGS, respectively. PD-L1 expression (CPS ≥ 1%) was positive in 14 patients (63.6%). Regarding the genomic alterations, 16 patients (88.9%) had some clinically relevant genomic alterations. TP53, TERT, CDKN2A, PIK3CA, NOTCH1, and CDKN2B loss were identified in 66.7%, 50%, 50%, 33.3%, 27.8%, and 22.2% of the patients, respectively. No MSI or TMB high (≥10 mutations/MB) cases were identified. NOTCH1 mutation was identified only in HPV-negative patients and it was associated with worse OS (yes: 5.5 vs no: 12.8 months, P = .049) and progression-free survival (yes: 5.5 vs no: 11.7 months, P = .032).

CONCLUSION

This study demonstrated that molecular alterations in mPSCC from developing countries are similar to those from developed countries. Predictive biomarkers for immunotherapy response such as TMB high or MSI were not identified. Specific gene mutations may identify patients with worse prognoses and open new avenues for therapeutic development.

Tumor-infiltrating plasma cells are a prognostic factor in penile squamous cell carcinoma

Penile cancer (PeCa) is a rare disease with poor prognosis in the metastatic stage. Neither effective adjuvant nor palliative therapeutic options are available. Research efforts in this field have so far failed to establish robust predictors of survival. To identify prognostic targets in PeCa, the current project focused on characterizing the tumor microenvironment (TME). A study cohort of 93 men with PeCa was used for the construction of a tissue microarray and immunohistochemical staining for CD3, CD4, CD8, CD20, CD56, CD138, FoxP3, and PD-L1. The quantity and spatial distribution of tumor-infiltrating immune cells were analyzed using digital image analysis. PD-L1 staining of tumor and immune cells was manually scored (combined positivity score (CPS)). T cells, T helper cells, cytotoxic T cells (CTLs), and regulatory T cells were detected in > 90% of PeCa and B cells in 88%, plasma cells in 85%, and NK cells in 23%. Approximately 50% of the PeCa samples were PD-L1 positive. In the univariate survival analysis, high PD-L1 CPS, plasma cells, CTLs, and B cells were significantly associated with favorable overall survival (OS), and the latter two with adverse recurrence-free survival. In multivariate analysis, plasma cells remained a significant factor for favorable OS (p = 0.04). In this study, the immune cells in the TME, especially plasma cells, were favorably associated with patient survival compared to other established prognostic factors in PeCa. Contemporarily, plasma cells have been discussed in the light of contributing to responses to modern immunotherapies. The results of this study support this notion.

Relationship between NLR and penile squamous cell carcinoma: a systematic review and meta-analysis

OBJECTIVE

We conducted this study to summarize the results of studies reporting the role of NLR (neutrophil to lymphocyte ratio) in PSCC (penile squamous cell carcinoma).

METHODS

This meta-analysis was conducted using the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) criteria. A systematic search was conducted on PubMed, Scopus, and web of science up to March 10, 2023. Fourteen studies were included in the review. The NOS (Newcastle-Ottawa Scale) was used to determine the quality of the included studies. This meta-analysis was conducted on the studies reporting the relationship between NLR and survival using HR (hazard ratio) and 95% CI (confidence interval).

RESULTS

There was a significant association between NLR levels and the prognosis, nodal stage, and anatomical tumor stage of PSCC patients. In the meta-analysis of the association of NLR with survival, NLR level was significantly associated with lower cancer-specific survival (HR = 3.51, 95% CI = 2.07-5.98, p < 0.001) and lower disease-free survival (HR = 2.88, 95% CI = 1.60-5.20, p < 0.001). However, NLR was found to have no association with the stage, grade, location, and size of the tumor.

CONCLUSION

NLR has a significant diagnostic and prognostic value in PSCC.

Immune-based Therapies for Penile Cancer

This article reviews penile squamous cell carcinoma (PSCC), a rare genitourinary cancer that has been increasing in prevalence. It discusses emerging therapies, focusing on immunotherapy, vaccine therapy, and cell-based treatments, especially in the context of human papillomavirus-related PSCC. Factors influencing these therapies are discussed. These include the immune microenvironment, programmed cell death ligand-1 expression, and tumor immune cell infiltration. This article also highlights immune checkpoint inhibitors and related clinical trials. This review supports the use of personalized medicine in treating PSCC. It stresses the need for collaborative studies and data sharing to create specific treatment plans and achieve better outcomes.

Advances in molecular basis of response to immunotherapy for penile cancer: better screening of responders

Penile cancer is a rare malignant tumor of the male urinary system. The treatment benefit of standard first-line chemotherapy is not ideal for patients with locally advanced or metastatic lymph nodes. Immunotherapy has brought new treatment strategies and opportunities for patients with penile cancer. At present, clinical studies on immunotherapy for penile cancer have been reported, and the results show that it is effective but not conclusive. With the development of immunotherapy and the progress of molecular research technology, we can better screen the immunotherapy response population and explore new combination treatment regimens to evaluate the best combination regimen and obtain the optimal treatment options, which is also an important research direction for the immunotherapy of penile cancer in the future.

Penile cancer: ESMO-EURACAN Clinical Practice Guideline for diagnosis, treatment and follow-up

•This ESMO CPG provides recommendations for diagnosis, staging, pathology, treatment and follow-up of penile cancer. •Algorithms for the management of primary penile tumours and inguinal lymph nodes are provided. •The author group encompasses a multidisciplinary group of experts from different institutions and countries in Europe. •Recommendations are based on available scientific data and the authors’ collective expert opinion. •In clinical practice, all recommendations provided need to be discussed with patients in a shared decision-making approach.

High tumour mutational burden is associated with strong PD-L1 expression, HPV negativity, and worse survival in penile squamous cell carcinoma: an analysis of 165 cases

Penile squamous cell carcinoma (pSCC) is a rare tumour with a variable prognosis. More prognostic markers linked to mutational signatures and the tumour immune microenvironment are needed. A cohort made up of 165 invasive pSCC was retrospectively analysed using formalin-fixed, paraffin-embedded tumour tissue, focusing on tumour mutational burden (TMB), programmed death ligand 1 (PD-L1) expression, microsatellite instability (MSI), the number of tumour infiltrating lymphocytes (TILs) expressing cytotoxic T-lymphocyte-associated protein 4 (CTLA4), HPV status determined by p16 immunohistochemistry, and several traditional histopathological variables. High TMB (>10 mut/Mb) was associated with high PD-L1 expression (TPS 50-100%), and HPV-negative status. High PD-L1 expression was linked to HPV negativity, a high number of intratumoural CTLA4+ cells, and brisk lymphocytic infiltrate. High TMB was a significant predictor of shorter overall survival (OS) in both univariate and multivariate analysis when using a median cut-off value of 4.3 mut/Mb, but not when using an arbitrary cut-off of 10 mut/Mb. Low CTLA4+ cell infiltration at the tumour invasion front was a marker of shorter OS and cancer-specific survival in both univariate and multivariate analysis. PD-L1 expression had no significant impact on prognosis. Only two cases were MSI high. The results support the hypothesis of two aetiological pathways in pSCC cancerogenesis: (1) SCC linked to HPV infection characterised by low TMB, less common PD-L1 expression, and a lower number of TILs; and (2) SCC linked to chronic inflammation leading to a high number of acquired mutations (high TMB), HPV negativity, increased neoantigen production (i.e., PD-L1), and high immune cell infiltration.

Insights into the management of penile squamous cell carcinoma: from conventional approaches to emerging novel therapies

INTRODUCTION

Penile squamous cell carcinoma (PSCC), a rare genitourinary cancer, is associated with poor outcomes due to limited treatment effectiveness, especially in advanced stages.

AREAS COVERED

While chemotherapy and/or surgery remain the standard of care, emerging therapies like immunotherapy, targeted therapy, and human papillomavirus (HPV) directed therapies show promise. Key to advancing treatment is understanding the immune microenvironment to gain insights into tumor resistance mechanisms and potential therapeutic targets. The scarcity of data on PSCC is a major obstacle in advancing research for this rare cancer.

EXPERT OPINION

Future research should prioritize collaborative efforts across various research centers and countries. Enhancing data sharing and pooling resources can lead to a more comprehensive understanding of PSCC, ultimately supporting the development of precision medicine strategies tailored to this specific cancer type. This collaborative approach is essential for making significant strides in PSCC treatment and care.

Comprehensive genomic profiling of penile squamous cell carcinoma and the impact of human papillomavirus status on immune-checkpoint inhibitor-related biomarkers

BACKGROUND

Advanced penile squamous cell carcinoma (pSCC) is a rare and aggressive malignancy with limited success of immune-checkpoint inhibitors (ICIs). Approximately half of pSCC cases are associated with human papillomavirus (HPV) infection.

METHODS

Evaluation was done retrospectively of the landscape of somatic alterations and ICI-related biomarkers in pSCC by using the Caris Life Sciences data set with the aim to establish signatures for HPV-dependent oncogenesis. The pSCC tumors were analyzed by using next-generation sequencing (NGS) of DNA and RNA. Programmed death ligand 1 (PD-L1) expression was evaluated by immunohistochemistry (IHC). Microsatellite instability (MSI) was tested by fragment analysis, IHC (SP142; ≥1%), and NGS. Tumor mutational burden (TMB)-high was defined as ≥10 mutations/Mb. HPV16/18 status was determined by using whole-exome sequencing (WES) when available. Significance was adjusted for multiple comparisons (q value < .05).

RESULTS

NGS of the overall cohort (N = 108) revealed TP53 (46%), CDKN2A (26%), and PIK3CA (25%) to be the most common mutations. Overall, 51% of tumors were PD-L1+, 10.7% had high TMB, and 1.1% had mismatch repair-deficient (dMMR)/MSI-high status. Twenty-nine patients had their HPV status made available by WES (HPV16/18+, n = 13; HPV16/18-, n = 16). KMT2C mutations (33% vs. 0%) and FGF3 amplifications (30.8% vs. 0%) were specific to HPV16/18+ tumors, whereas CDKN2A mutations (0% vs. 37.5%) were exclusive to HPV16/18- tumors. TMB-high was exclusively found in the HPV16/18+ group (30.8%). The two groups had comparable PD-L1 and dMMR/MSI-H status.

CONCLUSIONS

In a large and comprehensive NGS-based evaluation of somatic alterations in pSCC, HPV16/18+ versus HPV16/18- pSCCs were molecularly distinct tumors. Our finding that TMB-high is exclusive to HPV16/18+ tumors requires confirmation in larger data sets.

PLAIN LANGUAGE SUMMARY

Penile squamous cell carcinoma (pSCC) is a rare and aggressive malignancy in the advanced setting, with poor prognosis and little success with immune-checkpoint inhibitors (ICIs) in an unselected patient approach. Human papillomavirus (HPV) infection is a known risk factor for pSCC; its impact on genomic tumor profiling is less defined. Using next-generation sequencing, we explored the genetic landscape and ICI-related biomarkers of pSCC and HPV-driven oncogenic molecular signatures. Our results indicate that HPV-positive and HPV-negative pSCCs are molecularly distinct tumors. Increased tumor mutational burden is associated with HPV-positive tumors, and could serve as a biomarker for predicting therapeutic response to ICI-based therapies. Our results support the growing literature indicating that HPV status in pSCC can be used to guide patient stratification in ICI-based clinical trials.

Safety and efficacy of immune checkpoint inhibitors in advanced penile cancer: report from the Global Society of Rare Genitourinary Tumors

BACKGROUND

Treatment options for penile squamous cell carcinoma are limited. We sought to investigate clinical outcomes and safety profiles of patients with penile squamous cell carcinoma receiving immune checkpoint inhibitors.

METHODS

This retrospective study included patients with locally advanced or metastatic penile squamous cell carcinoma receiving immune checkpoint inhibitors between 2015 and 2022 across 24 centers in the United States, Europe, and Asia. Overall survival and progression-free survival were estimated using the Kaplan-Meier method. Objective response rates were determined per Response Evaluation Criteria in Solid Tumours 1.1 criteria. Treatment-related adverse events were graded per the Common Terminology Criteria for Adverse Events, version 5.0. Two-sided statistical tests were used for comparisons.

RESULTS

Among 92 patients, 8 (8.7%) were Asian, 6 (6.5%) were Black, and 24 (29%) were Hispanic and/or Latinx. Median (interquartile range) age was 62 (53-70) years. In all, 83 (90%) had metastatic penile squamous cell carcinoma, and 74 (80%) had received at least second-line treatment. Most patients received pembrolizumab monotherapy (n = 26 [28%]), combination nivolumab-ipilimumab with or without multitargeted tyrosine kinase inhibitors (n = 23 [25%]), or nivolumab (n = 16 [17%]) or cemiplimab (n = 15 [16%]) monotherapies. Median overall and progression-free survival were 9.8 months (95% confidence interval = 7.7 to 12.8 months) and 3.2 months (95% confidence interval = 2.5 to 4.2 months), respectively. The objective response rate was 13% (n = 11/85) in the overall cohort and 35% (n = 7/20) in patients with lymph node-only metastases. Visceral metastases, Eastern Cooperative Oncology Group (ECOG) performance status of 1 or higher, and a higher neutrophil/lymphocyte ratio were associated with worse overall survival. Treatment-related adverse events occurred in 27 (29%) patients, and 9.8% (n = 9) of the events were grade 3 or higher.

CONCLUSIONS

Immune checkpoint inhibitors are active in a subset of patients with penile squamous cell carcinoma. Future translational studies are warranted to identify patients more likely to derive clinical benefit from immune checkpoint inhibitors.

Assessment of PD-L1, TROP2, and nectin-4 expression in penile squamous cell carcinoma

OBJECTIVES

There is an unmet need for therapeutically relevant biomarkers for advanced penile squamous cell carcinoma (pSCC). Proposed immunohistochemistry (IHC)-based biomarkers include programmed death-ligand 1 (PD-L1), trophoblast cell-surface antigen 2 (TROP2), and nectin-4; however, there is a paucity of data pertaining to these biomarkers. Herein, we investigated the expression of PD-L1, TROP2, and nectin-4 in a well-annotated cohort of pSCCs.

METHODS

A single-institution pathology archive was queried for patients who had a partial or total penectomy for pSCC between January 2000 and December 2022. Whole-slide sections were stained with antibodies against PD-L1 (22C3), TROP2, and nectin-4. Expression in tumor cells was quantified using H-scores (0-300). Associations between IHC expression, human papilloma virus (HPV) status, clinicopathologic findings, and outcome parameters were evaluated.

RESULTS

This study included 121 patients. For PD-L1, the median combined positive and H-scores were 1 and 0, respectively; 32.7 % of the cases had an H-score>0. Compared to PD-L1-negative tumors, PD-L1-positive tumors had higher pT stage and grade. The median TROP2 and nectin-4 H-scores were 230 and 140, respectively, with high TROP2 and nectin-4, defined by an H-score>200, noted in 80.7 % and 10.9 % of cases, respectively. High-risk HPV-positive cases had higher TROP2 and nectin-4 scores compared to HPV-negative cases. Patients with high TROP2 expression had significantly more disease progression, and patients with high nectin-4 expression had significantly fewer deaths due to disease.

CONCLUSIONS

High expression of TROP2 and nectin-4 in pSCC support evaluation of these markers as therapeutic targets pending validation of our findings.

Immune cell infiltration, tumour budding, and the p53 expression pattern are important predictors in penile squamous cell carcinoma: a retrospective study of 152 cases

Penile squamous cell carcinoma (pSCC) is a rare malignancy with a slowly increasing incidence and variable prognosis. Regional lymph node involvement signifies poor prognosis but represents a late sign, and more prognostic markers for effective patient risk stratification are urgently needed. In this retrospective study, 152 tumour samples with formalin-fixed, paraffin-embedded tissue were analysed for traditional pathological variables, tumour budding, p53, p16, and mismatch repair proteins (MMR) immunohistochemistry. The density of tumour lymphocytic infiltrate was also determined, using subjective evaluation by two pathologists (brisk/non-brisk/absent) and also using the immunoscore method, which categorised the cohort into five immunoscore groups according to the number of CD3+ and CD8+ T-cells in both the tumour centre and tumour invasion front. Only one case (0.6%) was MMR-deficient. Tumour budding count ≥5 tumour buds/20× power field and non-brisk/absent lymphocytic infiltrate were significant negative predictors of both the overall survival (OS) and cancer-specific survival (CSS), whereas a low immunoscore was a significant marker of shorter OS but not CSS. Advanced pT stage (3+4) was a significant marker of shorter CSS but not OS. In the multivariate analysis, high-grade budding was a significant parameter if adjusted for the patient's age and associated variables, except for the pN stage. The lymphocytic infiltrate retained its prognostic significance if adjusted for age and associated variables. The negative prognostic significance of the previously described parameters (lymphatic, venous, and perineural invasion, regional lymph node metastasis, and p53 mutated profile) were confirmed in our study. Grade, histological subtype, and HPV status (as determined by p16 immunohistochemistry) showed, surprisingly, little or no prognostic significance.

Penile squamous cell carcinoma exclusive to the shaft, with a proposal for a novel staging system

Penile squamous cell carcinomas (SCC) originating in the shaft are rare. pT1/pT2 categories in the American Joint Committee on Cancer (AJCC) staging manual (8th edition) are poorly defined for SCCs arising in the dorsal shaft as anatomic structures differ between the glans and dorsal shaft (corpus spongiosum vs dartos/Buck's fascia, respectively). We reviewed six penile SCC cases exclusive to the shaft, an unusual presentation, identified amongst 120 patients treated with penectomy. We propose a novel pT staging system for dorsal shaft tumors tailored to its anatomic landmarks, where tumors extending to Buck's fascia are considered pT2 instead of pT1. The mean age at penectomy, average duration of follow-up, and mean depth of invasion were 64 years, 45 months, and 9.8 mm, respectively. Four cases were moderately differentiated, HPV-negative SCCs of the usual type and two cases were HPV-positive basaloid and warty-basaloid carcinomas. Three cases had nodal or distant metastasis at the time of penectomy, and histologic assessment in these cases showed invasion into the Buck's fascia or deeper. According to the current AJCC system, only one of these three cases would be staged as ≥ pT2. In contrast, all three metastatic tumors would be staged as ≥ pT2 in the proposed model. At last follow-up, one patient died of disease-related complications. Based on this limited series, the proposed staging model appears to suggest better patient stratification for pT1/pT2 stages. This model incorporates Buck's fascia, which has been postulated as a pathway of tumor infiltration. Additional studies are needed to validate this model.

PD-L1 is associated with the prognosis of penile cancer: A systematic review and meta-analysis

BACKGROUND

Previous studies have explored the role of PD-L1 in the survival outcomes of penile cancer patients with controversies existed. Thus, the meta-analysis was conducted to report and review the association between PD-L1 and survival in penile cancer patients.

METHODS

PubMed, Cochrane Library, EMBASE, and Web of Science were all searched, screened, and reviewed by June 1, 2022. Hazard ratio (HR) was used to evaluate the relationship between PD-L1 and survival outcome, and odds ratio (OR) was for tumor features.

RESULTS

Nine retrospective studies (1,003 patients) were incorporated. The prevalence of PD-L1 in patients with penile cancer was 51.4% (95% CI = 42.1%-60.8%, I 2 = 88.5%). Higher PD-L1 on tumor cells was related to shorter cancer-specific survival (CSS) in patients (HR = 1.578, 95% CI = 1.227-2.029, I 2 = 23.3%), but had no associations with overall survival (OS) (HR = 1.123, 95% CI = 0.511-2.465, I 2 = 0.0%). Subgroup analysis indicated that higher PD-L1 was related to shorter CSS in Caucasus (HR = 1.827, 95% CI = 1.355-2.465, I 2 = 0.0%) only. Furthermore, PD-L1 had associations with tumor stage (pT1 vs. pT2-4, OR = 0.480, 95% CI = 0.346-0.667, P = 0.001) and tumor grade (Well and moderate vs. Poor, OR = 0.377, 95% CI = 0.264-0.538, P < 0.001). PD-L1 positivity was also related to lymph node (LN) status (pN0/NX vs. pN1-3, OR = 0.541, 95% CI = 0.385-0.759, P = 0.001) and HPV status (Positive vs. Negative, OR = 0.510, 95% CI = 0.322-0.810, P = 0.003). A trend toward statistical significance between PD-L1 and histological types was also observed (Usual SCC vs. Others, OR = 1.754, 95% CI = 0.984-3.124, P = 0.070).

CONCLUSIONS

PD-L1 over-expression was related to worse survival outcomes and several clinicopathological features of penile cancer. PD-L1 expression can be applied to select appropriate treatment strategies for penile malignancies.

SYSTEMATIC REVIEW REGISTRATION

https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=343041, identifier CRD42022343041.

Immune landscape and immunotherapy for penile cancer

Penile cancer is a rare malignancy and usually refers to penile squamous cell carcinoma (PSCC), which accounts for more than 95% of all penile malignancies. Although organ-sparing surgery is an effective treatment for early-stage PSCC, surgical intervention alone is often not curative for advanced PSCC with metastases to the inguinal and/or pelvic lymph nodes; thus, systemic therapy is required (usually platinum-based chemotherapy and surgery combined). However, chemotherapy for PSCC has proven to be of limited efficacy and is often accompanied by high toxicity, and patients with advanced PSCC usually have poor prognosis. The limited treatment options and poor prognosis indicate the unmet need for advanced PSCC. Immune-based therapies have been approved for a variety of genitourinary and squamous cell carcinomas but are rarely reported in PSCC. To date, several studies have reported high expression of PDL1 in PSCC, supporting the potential application of immune checkpoint inhibitors in PSCC. In addition, human papillomavirus (HPV) infection is highly prevalent in PSCC and plays a key role in the carcinogenesis of HPV-positive PSCC, suggesting that therapeutic HPV vaccine may also be a potential treatment modality. Moreover, adoptive T cell therapy (ATC) has also shown efficacy in treating advanced penile cancer in some early clinical trials. The development of new therapeutics relies on understanding the underlying biological mechanisms and processes of tumor initiation, progression and metastasis. Therefore, based on the interest, we reviewed the tumor immune microenvironment and the emerging immunotherapy for penile cancer.

Sintilimab-Induced Diabetic Ketoacidosis in a Patient with Radiation and Multichemorefractory Penile Cancer: A Case Report and Literature Review

Penile squamous cell carcinoma (PSCC) is a rare disease. The treatment options for advanced penile cancer are often limited, and the prognosis remains poor. We reported a 52-year-old male recurrent and metastatic PSCC patient with high PD-L1 expression (90%) and TMB (14.4 muts/Mb). He had undergone penectomy, bilateral inguinal lymph node dissection, and excision of the abdominal wall mass. Despite cisplatin-based concurrent chemoradiotherapy and sequential chemotherapy with docetaxel plus cisplatin then being carried out, the carcinoma still progressed. The patient then obtained progression-free survival with continuous sintilimab, although he experienced the new onset of ICI-induced diabetes after 24 cycles of sintilimab and required sustained insulin treatment. He had negative type 1 diabetes-associated autoantibodies and the susceptible HLA genotype DR3-DQ2 haplotype. This is the first patient with radiation and multichemorefractory PSCC who has obtained the remarkable anti-tumor effect of partial regression exceeding 32 months during continuous sintilimab and anlotinib treatment.

Interplay Between Immune and Cancer-Associated Fibroblasts: A Path to Target Metalloproteinases in Penile Cancer

Extracellular matrix (ECM) remodeling and inflammation have been reported in penile carcinomas (PeCa). However, the cell types and cellular crosstalk involved in PeCa are unexplored. We aimed to characterize the complexity of cells and pathways involved in the tumor microenvironment (TME) in PeCa and propose target molecules associated with the TME. We first investigated the prognostic impact of cell types with a secretory profile to identify drug targets that modulate TME-enriched cells. The secretome analysis using the PeCa transcriptome revealed the enrichment of inflammation and extracellular matrix pathways. Twenty-three secreted factors were upregulated, mainly collagens and matrix metalloproteinases (MMPs). The deregulation of collagens and MMPs was confirmed by Quantitative reverse transcription - polymerase chain reaction (RT-qPCR). Further, the deconvolution method (digital cytometry) of the bulk samples revealed a high proportion of macrophages and dendritic cells (DCs) and B cells. Increased DCs and B cells were associated with better survival. A high proportion of cancer-associated fibroblasts (CAFs) was observed in low-survival patients. Patients with increased CAFs had decreased immune cell proportions. The treatment with the MMP inhibitor GM6001 in CAF cells derived from PeCa resulted in altered cell viability. We reported a crosstalk between immune cells and CAFs, and the proportion of these cell populations was associated with prognosis. We demonstrate that a drug targeting MMPs modulates CAFs, expanding the therapeutic options of PeCa.

Immunotherapy in Penile Squamous Cell Carcinoma: Present or Future? Multi-Target Analysis of Programmed Cell Death Ligand 1 Expression and Microsatellite Instability

BACKGROUND

Penile cancer (PC) is an extremely rare malignancy, and the patients at advanced stages have currently limited treatment options with disappointing results. Immune checkpoint inhibitors anti-programmed cell death 1 (PD-1)/programmed cell death ligand 1 (PD-L1) are currently changing the treatment of several tumors. Furthermore, the microsatellite instability (MSI) and the deficient mismatch repair system (dMMR) proteins represent predictive biomarkers for response to immune checkpoint therapy. Until present, few data have been reported related to PD-L1 expression and MSI in PC. The main aim of our study was the evaluation of PD-L1 expression in tumor cells (TCs) and tumor-infiltrating lymphocytes (TILs) in immune cells and the analysis of dMMR/MSI status in a large series of PCs.

METHODS

A series of 72 PC, including 65 usual squamous cell carcinoma (USCC), 1 verrucous, 4 basaloid, 1 warty, and 1 mixed (warty-basaloid), was collected. Immunohistochemistry (IHC) was performed to assess PD-L1 expression using two different anti-PD-L1 antibodies (clone SP263 and SP142 Ventana) and MMR proteins expression using anti-MLH1, anti-PMS2, anti-MSH2, and anti-MSH6 antibodies. PCR analysis was performed for the detection of MSI status.

RESULTS

Of the 72 PC cases analyzed by IHC, 45 (62.5%) cases were TC positive and 57 (79%) cases were combined positive score (CPS) using PDL1 SP263. In our cohort, TILs were present in 62 out of 72 cases (86.1%), 47 (75.8%) out of 62 cases showed positivity to PDL1 clone SP142. In our series, 59 cases (82%) had pMMR, 12 cases (16.7%) had lo-paMMR, and only 1 case (1.3%) had MMR. PCR results showed that only one case lo-paMMR was MSI-H, and the case dMMR by IHC not confirmed MSI status.

CONCLUSION

Our findings showed that PD-L1 expression and MSI status represent frequent biological events in this tumor suggesting a rationale for a new frontier in the treatment of patients with PC based on the immune checkpoint inhibitors.

A global approach to improving penile cancer care

Rare tumours such as penile carcinoma have been largely neglected by the urology scientific community in favour of more common - and, therefore, more easily fundable - diseases. Nevertheless, penile cancer represents a rising burden for health-care systems around the world, because a lack of widespread expertise, ineffective centralization of care and absence of research funds have hampered our ability to improve the global care of these patients. Moreover, a dichotomy has arisen in the field of penile cancer, further impeding care: the countries that are mainly supporting research on this topic through the development of epidemiological studies and design of clinical trials are not the countries that have the highest prevalence of the disease. This situation means that randomized controlled trials in developed countries often do not meet the minimum accrual and are intended to close before reaching their end points, whereas trials are almost completely absent in those areas with the highest disease prevalence and probability of successful recruitment, such as Africa, South America and South Asia. The scientific and organizational inaction that arises owing to this mismatch translates into a burdensome cost for our patients. A global effort to gather experts and pull together scientific data from around the world may be the best way to boost clinical research, to change clinical practice and, ultimately, to improve care for patients and their families.

Pembrolizumab for advanced penile cancer: a case series from a phase II basket trial

BACKGROUND

Treatment options for unresectable, locally advanced or metastatic penile squamous cell carcinoma (SCC) are limited. Previous studies have shown that 40-62% of patients with penile SCC express PD-L1. We report three cases of locally advanced or metastatic penile SCC treated with pembrolizumab.

CASE PRESENTATIONS

Herein, we present three patients with recurrent, locally advanced or metastatic penile SCC who progressed on a platinum-based chemotherapy triplet and were treated with pembrolizumab, administered as part of a phase II clinical trial for rare tumors (NCT02721732). One patient with a microsatellite instability high (MSI-H) tumor experienced a durable partial response to pembrolizumab, underwent surgical consolidation, and remains disease-free 38.7 months later. Two patients experienced progressive disease within 3 months of beginning pembrolizumab. No one experienced a grade 3 or worse treatment-related adverse event.

CONCLUSION

In sum, single-agent pembrolizumab was well tolerated as salvage therapy in a small cohort of patients with unresectable, locally advanced or metastatic penile SCC. Pembrolizumab produced an objective response in an MSI-H tumor, yet it did not control disease in two patients with MSS penile SCC. Rationale combination therapies, including pembrolizumab, warrant further investigation.

TRIAL REGISTRATION

ClinicalTrials.gov identifier: NCT02721732 . Registered March 23, 2016.

Squamous cell carcinoma with sarcomatous transformation of the penis

Malignant tumors of the penis are rare, most of them being squamous cell carcinomas (SCCs). We report the case of a 75-year-old man with a large penile mass submitted to partial penectomy. The specimen showed an exophytic mass involving the glans, coronal sulcus, and prepuce. Microscopic examination showed a carcinoma with two distinct areas: a mixed SCC and a sarcomatoid carcinoma. The SCC component had areas of verrucous carcinoma and areas of classical invasive SCC. The tumor cells expressed p63 with the absence of p16 expression. Vimentin and p53 were positive in the sarcomatous component. The morphology and immunohistochemistry were compatible with mixed SCC (verrucous hybrid-sarcomatoid carcinoma). Additionally, the tumor cells also expressed 3 different clones of PDL1 (22C3, SP263, and SP142). Two months later, the patient presented local recurrence with multiple lymph nodes and lung metastases, dying 7 weeks later. Mixed tumors represent diagnostic challenges. The correct identification of adverse prognostic factors can be the first step to implement the treatment with a higher probability of success.

The peri- and intratumoral immune cell infiltrate and PD-L1 status in invasive squamous cell carcinomas of the penis

INTRODUCTION

Penile carcinomas are rare tumors throughout Europe. Therefore, little attention is drawn to this disease. That makes it important to study tumor-associated key metrics and relate these to known data on penile neoplasias.

MATERIALS AND METHODS

A cohort of 60 well-defined penile invasive carcinomas with known human papillomavirus (HPV) infection status was investigated. Data on tumor type, grading and staging were recorded. Additionally, data on the peri- and intratumoral immune cell infiltrate in a semiquanititave manner applying an HE stain were assessed.

RESULTS

Our study showed a significant correlation of immune cell infiltrate and pT stage with overall survival. Therefore, in a subset of tumors, PD-L1 staining was applied. For tumor proportion score (TPS), 26 of 30 samples (87%) were scored >0%. For the immune cell score (IC), 28 of 30 samples (93%) were defined as >0% and for CPS, 29 of 30 samples (97%) scored >0. PD-L1 expression was not associated with overall survival.

CONCLUSION

PD-L1 is expressed in penile carcinomas, providing a rationale for targeted therapy with checkpoint inhibitors. We were able to show that immune reaction appears to be prognostically relevant. These data enhance the need for further studies on the immune cell infiltrate in penile neoplasias and show that PD-L1 expression is existent in our cohort, which may be a potential target for checkpoint inhibitor therapy.

A 25-year perspective on advances in an understanding of the biology, evaluation, treatment and future directions/challenges of penile cancer

Squamous cell carcinoma of the penis (SCCP) is uncommon in some countries (including the U.S.), but is an important malignancy elsewhere. As a rare disease, progress has been slow compared to more common tumor types discussed in this anniversary issue and most often limited to single-center or retrospective datasets.  In this section we describe developments leading to the current standard approach with current research questions.

Cemiplimab for Cisplatin Resistant Metastatic Penile Cancer

We report on a 75-year old man who presented with metastatic, squamous-cell carcinoma (SCC) of the penis whose disease had progressed after radiotherapy (RT) and cisplatin-based chemotherapy (CT). A strong PD-L1 expression as well as a CDKN2A mutation was documented, and he was given cemiplimab every 3 weeks at time of disease progression. Complete response (CR) was demonstrated after 10 cycles, and no toxicity was reported. However, this treatment was stopped after 13 cycles when the patient developed moderate severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) pneumonitis which required a 2-week hospitalization for oxygen support. Six months later, he remains in CR. To our knowledge, this is the first demonstration of a CR with cemiplimab in a metastatic penile SCC patient previously treated with CT and RT for relapse. Furthermore, the patient remains disease-free despite cemiplimab was withdrawn due to SARS-CoV-2 pneumonitis.

Penile Cancer-Derived Cells Molecularly Characterized as Models to Guide Targeted Therapies

Penile cancer (PeCa) is a common disease in poor and developing countries, showing high morbidity rates. Despite the recent progress in understanding the molecular events involved in PeCa, the lack of well-characterized in vitro models precludes new advances in anticancer drug development. Here we describe the establishment of five human primary penile cancer-derived cell cultures, including two epithelial and three cancer-associated fibroblast (CAF) cells. Using high-throughput genomic approaches, we found that the epithelial PeCa derived- cells recapitulate the molecular alterations of their primary tumors and present the same deregulated signaling pathways. The differentially expressed genes and proteins identified are components of key oncogenic pathways, including EGFR and PI3K/AKT/mTOR. We showed that epithelial PeCa derived cells presented a good response to cisplatin, a common therapeutic approach used in PeCa patients. The growth of a PeCa-derived cell overexpressing EGFR was inhibited by EGFR inhibitors (cetuximab, gefitinib, and erlotinib). We also identified CAF signature markers in three PeCa-derived cells with fibroblast-like morphology, indicating that those cells are suitable models for PeCa microenvironment studies. We thus demonstrate the utility of PeCa cell models to dissect mechanisms that promote penile carcinogenesis, which are useful models to evaluate therapeutic approaches for the disease.

Management of Advanced Penile Cancer

Penile squamous cell carcinoma (PSCC) is a rare cancer, with approximately 2000 new cases in the United States and 35,000 globally every year. Multiple risk factors are involved in PSCC, but most importantly, the high-risk human papillomavirus infection is thought to be present in approximately 50% of cases. Penile squamous cell carcinoma presents as localized or locally advanced disease. Multiple prognostic markers have been explored over the past 3 decades, but lymph node status remains the strongest predictor of clinical outcomes. Surgical decisions are based on the primary tumor pathologic findings, nodal clinical examination, and imaging results. Most patients with high-risk advanced PSCC benefit from a multimodal treatment approach combining chemotherapy with consolidation surgical treatment. The role of neoadjuvant chemotherapy with radiation therapy has not been well explored in PSCC. Prospective clinical studies, like the International Penile Advanced Cancer Trial, have been launched to provide high-level evidence for multimodal treatment. The International Penile Advanced Cancer Trial is the first randomized clinical trial among patients with PSCC and is currently accruing, with the expectation to generate results in 2023. Unfortunately, most patients with high-risk locally advanced PSCC will have relapsed or refractory cancer after cisplatin-based combination chemotherapy. These patients have dismal outcomes with salvage chemotherapy, highlighting the major unmet need to expand our knowledge of the disease's biology and develop clinical trials that use novel systemic agents. This narrative review synthesizes relevant publications retrieved from PubMed. Our aim is to discuss current approaches in the management of PSCC, summarize ongoing efforts to improve care, and identify future areas for enhancing our understanding of the disease.

Penile cancer

Penile squamous cell carcinoma (PSCC) is a rare cancer with orphan disease designation and a prevalence of 0.1-1 per 100,000 men in high-income countries, but it constitutes up to 10% of malignancies in men in some African, Asian and South American regions. Risk factors for PSCC include the absence of childhood circumcision, phimosis, chronic inflammation, poor penile hygiene, smoking, immunosuppression and infection with human papillomavirus (HPV). Several different subtypes of HPV-related and non-HPV-related penile cancers have been described, which also have different prognostic profiles. Localized disease can be effectively managed by topical therapy, surgery or radiotherapy. As PSCC is characterized by early lymphatic spread and imaging is inadequate for the detection of micrometastatic disease, correct and upfront surgical staging of the inguinal lymph nodes is crucial in disease management. Advanced stages of disease require multimodal management. Optimal sequencing of treatments and patient selection are still being investigated. Cisplatin-based chemotherapy regimens are the mainstay of systemic therapy for advanced PSCC, but they have poor and non-durable responses and high rates of toxic effects, indicating a need for the development of more effective and less toxic therapeutic options. Localized and advanced penile cancers and their treatment have profound physical and psychosexual effects on the quality of life of patients and survivors by altering sexual and urinary function and causing lymphoedema.

Penile Lymphoepithelioma-Like Carcinoma: A Rare Case With PD-L1 Expression

Most malignant tumors of the penis are squamous cell carcinomas (SCC), being divided in 2 groups, one human papillomavirus (HPV)-related and another non-HPV-related, with lymphoepithelioma-like carcinoma (LELC) being one of the rarest HPV-related SCC. In this article, we report a case of a 50-year-old man who presented testicular swelling and pain for the past 3 months. A penile mass was identified, and the patient was submitted to a total penectomy. The penectomy specimen showed an ulcerated lesion at the glans reaching the cavernous bodies. Microscopic examination showed undifferentiated epithelial cells with syncytial growth pattern mix with a dense lymphoplasmacytic infiltrate, consistent with LELC. The tumor cells expressed p16 and all 3 different clones of PDL1 (22C3, SP263, and SP142). The patient is alive and well with a follow-up of 3 months. To our knowledge, this is the third LELC of the penis reported in literature and the first case reported with PDL1 expression.

Case Report: Two Cases of Chemotherapy Refractory Metastatic Penile Squamous Cell Carcinoma With Extreme Durable Response to Pembrolizumab

BACKGROUND

Penile squamous cell carcinoma (PSCC) is a rare malignancy, and those patients with metastatic disease have limited treatment options. Treatment is largely comprised of platinum-based chemotherapy; however, patients progressing after initial chemotherapy have a median overall survival (OS) of less than 6 months. Based on a high percentage of PD-L1 expression in patients with PSCC, and its biological similarities to other squamous cell carcinomas, we present two patient cases treated with pembrolizumab with extraordinary durable treatment response far beyond treatment with standard therapy.

MAIN BODY

The first patient is a 64 year old male with PSCC who was treated with neoadjuvant chemotherapy, partial penectomy, and adjuvant radiation prior to developing metastatic disease. He had a high TMB (14 mutations/Mb) and was started on pembrolizumab with a complete response, which has been maintained for 38 months. The second patient is an 85 year old male with PSCC who was treated with partial penectomy and adjuvant chemotherapy and radiation prior to developing metastatic disease. He had positive PD-L1 expression CPS 130) and was started on pembrolizumab with a partial response, which has been maintained for 18 months after starting treatment.

CONCLUSIONS

These two cases of extreme durable response with pembrolizumab (with molecular data including TMB and PD-L1 status) represent a significant clinical benefit in this patient population. With limited treatment options that result in a median OS of less than 6 months, along with the toxicity profile of chemotherapy which may not be tolerated in elderly patients with comorbidities, this survival benefit with pembrolizumab, along with advances in tumor sequencing and clinical trials shows that there is a potentially significant benefit with novel therapies in this patient population.

Progress on Management of Penile Cancer in 2020

OPINION STATEMENT

Management of penile cancer represents a challenge to urologic oncologists due to the disease's rarity and sparse data in the literature. Squamous cell carcinoma represents the most common histologic subtype of penile cancer. Penile cancer has a disastrous effect on patients' psychological and physical health. Penile cancer accounts for approximately 1% of cancer deaths in the USA annually. However, in recent years, the management of penile cancer has achieved marked progress in both diagnostic and therapeutic approaches with the intent to avoid radical surgeries. The traditional total penile amputation has been replaced by penile preserving procedures in many patients. Nowadays, total penile amputation (total penectomy) is preserved only for patients with proximal lesions. The introduction of minimally invasive surgical techniques in the management of penile cancer-infiltrated lymph nodes has been reported. Given the dismal prognosis with conventional cytotoxic therapies, new systemic therapies have been investigated in patients with locally advanced or metastatic penile cancer. Multiple studies have shown promising outcomes. All these efforts have resulted in a remarkable improvement in patient quality of life. The objectives of our review are to update clinicians on the advances in the management of penile cancer and to summarize the recent guidelines and recommendations.

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.

Status of Programmed Death Ligand 1 (PD-L1) by Immunohistochemistry and Scoring Algorithms

The detection of the Programmed Death Ligand 1 (PD-L1) protein by immunohistochemistry is currently the only approved test predictive of response to drugs targeting the PD1/PDL1 axis. The role of this test is debated since several reagents have been used as companion diagnostics for different drugs on diverse immunostaining platforms. In addition, different scoring systems for PD-L1 immunohistochemistry have been applied in the registration studies regarding single drugs. This review deals with the various issues that are related to the immunohistochemical test for PD-L1. We discuss currently unsolved problems such as the advantages and the flaws of PD-L1 immunohistochemistry; the choice of the best reagents and the best scoring system. Finally, we review the current experiences on the role of immunohistochemistry for PD-L1 in clinical trials with immune checkpoint inhibitors.

Second line salvage systemic therapy for advanced penile cancer

Most patients with advanced penile cancer will have relapsed disease after cisplatin-based combination chemotherapy. Unfortunately, these patients have dismal outcomes with salvage chemotherapy, surgery, or radiation. In this review we will discuss the available chemotherapy and targeted therapies for salvage second line systemic treatment for patients with penile cancer. We will also summarize the ongoing interventional clinical trials using immune and human papilloma virus-based therapies.

A risk calculator predicting recurrence in lymph node metastatic penile cancer

OBJECTIVES

To develop and externally validate a risk calculator for prediction of any cancer recurrence in patients with penile squamous cell carcinoma (pSCC) and inguinal lymph node metastases (ILNM), as to date no validated prognostic tool is available for patients with pSCC and ILNM.

PATIENTS AND METHODS

The development cohort included 234 patients from seven referral centres. The external validation cohort included 273 patients from two additional referral centres. Cox regression identified predictors of any recurrence, which were used to develop a risk calculator. The risk-calculator grouped the development and the validation cohorts according to the individual risk of any recurrence at 24 months (24m-R). Adjuvant treatment effects were tested on overall survival (OS) according to the derived tertiles, within the development and validation cohorts.

RESULTS

Positive surgical margins, pN₃ , and ILNM ratio were associated with higher recurrence rate. The 2-year OS rates were lower for patients with high (>37%) and intermediate (19-37%) compared to low (<19%) 24m-R risk of recurrence, for both the development (43% and 58% vs 83%, P < 0.001) and validation cohort (44% and 50% vs 85%, P < 0.001). Results were confirmed in the subgroup of patients who did not receive adjuvant treatment (P < 0.001), but not in patients who did receive adjuvant treatments in both the development and validation cohorts (P > 0.1).

CONCLUSION

Adjuvant treatment planning is crucial in patients with pSCC with ILNM, where only weak evidence is available. The current tool proved to successfully stratify patients according to their individual risk, potentially allowing better tailoring of adjuvant treatments.

Immunophenotypes Based on the Tumor Immune Microenvironment Allow for Unsupervised Penile Cancer Patient Stratification

The tumor immune microenvironment (TIME) plays an important role in penile squamous cell carcinoma (peSCC) pathogenesis. Here, the immunophenotype of the TIME in peSCC was determined by integrating the expression patterns of immune checkpoints (programmed cell death-1 (PD-1)/programmed cell death ligand-1 (PD-L1), cytotoxic T lymphocyte antigen 4 (CTLA-4), and Siglec-15) and the components of tumor-infiltrating lymphocytes, including CD8⁺ or Granzyme B⁺ T cells, FOXP3⁺ regulatory T cells, and CD68⁺ or CD206⁺ macrophages, in 178 patients. A high density of Granzyme B, FOXP3, CD68, CD206, PD-1, and CTLA-4 was associated with better disease-specific survival (DSS). The patients with diffuse PD-L1 tumor cell expression had worse prognoses than those with marginal or negative PD-L1 expression. Four immunophenotypes were identified by unsupervised clustering analysis, based on certain immune markers, which were associated with DSS and lymph node metastasis (LNM) in peSCC. There was no significant relationship between the immunophenotypes and high-risk human papillomavirus (hrHPV) infection. However, the hrHPV–positive peSCC exhibited a higher density of stromal Granzyme B and intratumoral PD-1 than the hrHPV–negative tumors (p = 0.049 and 0.002, respectively). In conclusion, the immunophenotypes of peSCC were of great value in predicting LNM and prognosis, and may provide support for clinical stratification management and immunotherapy intervention.

Genetics and penile cancer: recent developments and implications

PURPOSE OF REVIEW

We summarize the recent developments in the molecular landscape of penile squamous cell carcinoma (PSCC).

RECENT FINDINGS

Recent genomic studies have demonstrated a molecular convergence of PSCC with other squamous cell carcinomas (SCCs) from different organ sites. Similarly, human papillomavirus (HPV)-related PSCCs appear to have epigenetic and genomic similarities with other HPV-related cancers. This could have implications on future HPV-related cancer trial design. Growing efforts to characterize recurrent gene alterations in PSCC have expanded our understanding over the past years, showing a predominance of tumor suppressor gene alterations such as TP53 and NOTCH1. In addition, these studies have demonstrated that at least 30% of PSCC cases have targetable gene alterations. Further, the similar tumor mutational burden with other SCCs and the relatively high rates of programmed death-1 (PD-1) positive expression in PSCC constitute the rationale for investigation of PD-1 inhibition in ongoing clinical trials. Multiple studies have identified potential epigenetic and RNA signatures predictive of metastasis or survival, but these still require validation in larger cohorts.

SUMMARY

PSCC appears to be genomicaly similar to other SCCs and HPV-related cancers. This provides the rationale and opportunity to include a rare tumor like PSCC in future 'basket type' trials using novel agents targeting multiple SCCs that may exhibit similar biology.

A phase II trial of cabazitaxel as second line chemotherapy in relapsed locally advanced and/or metastatic carcinoma of the penis

Objectives

To assess the efficacy and tolerability of cabazitaxel in relapsed penile cancer.

Methods

This Phase II single-arm trial was designed to recruit 17 patients with relapsed penile cancer. The primary endpoint was objective (complete + partial) response rate (ORR; Response Evaluation Criteria in Solid Tumours [RECIST] v1.1). Treatment comprised six 21-day cycles of cabazitaxel with restaging after cycles 2 and 4. The planned interim analysis was based upon the premise that if none of the first nine patients achieved ORR, trial would be stopped (α = 0.05, Simon’s 2-stage design).

Results

Nine patients were recruited from four UK centres between December 2014 and August 2016. The median age was 61 (range, 27–73.6) years, and seven patients had metastases. Patients received a median of two chemotherapy cycles (range, 2–5). None of the nine patients achieved ORR and the trial was stopped. Cabazitaxel was well tolerated with no dose reductions or delays. Three patients had grade 3/4 adverse events (anaemia, vomiting, or neutropenic sepsis). The median progression-free and overall survival were 1.3 and 5.6 months, respectively.

Conclusions

The trial did not reach the threshold for further continuation of single-agent cabazitaxel. However, the observed tolerability profile supports its further investigation in combination with other agents to improve patient outcomes.

Treating Penile Cancer in the Immunotherapy and Targeted Therapy Era

While localized penile cancers are typically treated surgically and metastatic penile cancers benefit from standard chemotherapy, there have been studies on the horizon demonstrating immunotherapy as a novel approach to metastatic penile cancers that have failed standard chemotherapy. We report a case series of two patients who improved on immunotherapy after progressing with standard chemotherapy regimens. The first case describes a 64-year-old male with a penile mass and significant lymphadenopathy who had surgical resection and adjuvant chemotherapy prior to continued disease progression. He was started on anti-EGFR treatment and improved initially, but he eventually had progression of disease. The second case describes a 79-year-old male with a penile mass who was treated with surgical resection and started on adjuvant chemoradiation, but he developed recurrence and nodal involvement. Therefore, second-line therapy of the PD-L1 inhibitor was started in this patient. There were no available clinical trials for penile cancer patients who progressed beyond the standard surgical therapy and chemotherapy.

Defining the Tumor Microenvironment of Penile Cancer by Means of the Cancer Immunogram

Current chemotherapeutic treatment for advanced penile squamous cell carcinoma has substantial side effects and no randomized data to support an overall survival benefit. Immunotherapy with checkpoint blockade is currently being tested in penile cancer patients in clinical trials. The high PD-L1 expression and CD8⁺ T-cell infiltration in penile cancer represent a promising prospect for immunotherapy response in the treatment of locally advanced disease. For efficacious immunotherapy treatment, a better understanding of the tumor microenvironment (TME) is critical. Here we use the structure revealed by cancer immunograms to define current knowledge of the penile cancer TME as a backbone for future research. PATIENT SUMMARY: Advanced penile cancer has a poor prognosis with a need for more effective therapy. In this manuscript we describe the potential of immunotherapy as a new treatment modality in penile cancer.

PD-L1 Expression in Men with Penile Cancer and its Association with Clinical Outcomes

BACKGROUND

It has been hypothesized that PD-L1 expression in tumor cells and tumor-infiltrating immune (TII) cells may contribute to tumor progression by inhibiting antitumor immunity.

OBJECTIVE

To investigate the association between PD-L1 expression in tumor cells and TII cells and clinical outcomes in penile cancer.

DESIGN, SETTING, AND PARTICIPANTS

A cohort of 222 men treated for penile squamous cell carcinoma (SqCC) at Örebro University Hospital between 1984 and 2008 with long-term follow-up (median 34 mo) was evaluated for PD-L1 expression in tumor cells and TII cells via immunohistochemistry.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Association between clinicopathological features and PD-L1 expression was estimated using χ² and Fisher's exact tests. For survival analyses, Kaplan-Meier curves with log-rank tests and multivariate Cox proportional hazards regression models were used.

RESULTS AND LIMITATIONS

We found that 32.1% of the tumors and 64.2% of the TII cells expressed PD-L1. Our data demonstrate that penile SqCC patients with PD-L1-positive tumor cells or TII cells are at significant risk of lower cancer-specific survival and that the prognostic value of PD-L1 expression was strongest for tumor cell positivity. The use of tissue microarrays rather than whole sections may be viewed as a limitation.

CONCLUSIONS

Tumor PD-L1 expression independently identifies penile SqCC patients at risk of poor clinical outcomes.

PATIENT SUMMARY

We investigated how many patients with penile cancer had tumors that manufactured PD-L1, a protein that decreases the ability of the immune system to fight cancer. We found that up to one-third of penile tumors make this protein. Patients whose tumors make PD-L1 have more aggressive penile cancer and worse clinical outcomes.