Relationship between human papillomavirus and penile cancer-implications for prevention and treatment

Penile cancer: potential target for immunotherapy?

PURPOSE

Penile cancer (PeCa) is a rare malignancy with a poor prognosis in advanced disease. There is still a limited understanding of the biological mediators that are important in the prognosis and therapy of the disease. This review aims to provide a summary of the immune micro-environment, molecular oncogenesis and the role of HPV in the disease applying to the potential of the use of immunotherapy.

METHODS

Narrative, non-systematic review based on publications retrieved by PubMed and EMBASE search.

RESULTS

The molecular mechanisms underlying penile carcinogenesis are complex, and human papillomavirus (HPV) infection is a well-characterized driver of penile cancer. Up to 50% of the penile carcinomas are HPV related. There is potential to improve prevention, treatment and follow-up strategies pertaining to the role of HPV in penile cancer. Immune response modifiers such as toll-like receptor agonists are being used in a topical fashion for penile intraepithelial neoplasia while immune checkpoint inhibitors are currently under clinical investigation for its application in penile cancer.

CONCLUSIONS

The knowledge of prognosis-relevant biological pathways in penile cancer is expanding. HPV plays an important role in the carcinogenesis. This can lead to the identification of therapeutic targets which could significantly influence the prognosis of advanced penile cancer. Clinical trials are being conducted to pave the way for immune-modifying treatment modalities.

Risk factors and molecular characterization of penile cancer: impact on prognosis and potential targets for systemic therapy

PURPOSE OF REVIEW

To provide a comprehensive summary of risk factors, molecular machinery as well as potential therapeutic targets with a particular focus on literature published in the last 2 years on prognosis and treatment of penile cancer (PeCa).

RECENT FINDINGS

E2F, LAMC2, MAML2, ID1 and IGFBP2 proteins were demonstrated to play a critical role for aggressive tumor behavior and might predict poor survival in PeCa. PD-L1 axis was confirmed as a promising pathway to serve as a therapeutic target. A number of genetic alterations were illuminated. In clinical testing, pan-HER tyrosine kinase inhibitor dacomitinib provided promising results in chemo-naïve and EGFR monoantibody nimotuzumab in chemotherapy-failed PeCa patients.

SUMMARY

Knowledge of prognosis-relevant altered molecular pathways in PeCa is expanding paving the way for identification of potential therapeutic targets. Multicenter clinical trials in the setting of centralized PeCa care are warranted to foster effective marker-based individualized treatment strategies.

An update on systemic therapy for penile cancer

PURPOSE OF REVIEW

Whereas substantial advances have been made in systemic tumour therapy in the past decade, the prognosis of advanced squamous cell carcinoma (SCC) of the penis remains disproportionally poor. In this review, we aimed to present an update on systemic therapy of penile SCC highlighting the most recent data and future perspectives.

RECENT FINDINGS

Lymph node metastases play a key role in treating and assessing the prognosis of patients with penile SCC. Data show longer overall survival with the use of adjuvant chemotherapy in patients with pelvic lymph node metastases and recent analyses lead to the development of a nomogramm predicting overall survival in connection with the use of perioperative chemotherapy. There are two pathways in the pathogenesis of penile cancer, including human papilloma virus related and unrelated, leading to many possible novel therapeutic targets. Other targeted therapies have been evaluated, which show promising results with the use of tyrosine kinase inhibitors.

SUMMARY

Chemotherapy has shown moderate activity in advanced stages of the disease, however, the ideal timing of chemotherapy in patients with lymph node metastases is not entirely clear. Potential targets for future therapies exist, and are already being tested in other malignancies. Owing to the rarity of this condition, a robust evidence is lacking and it is of great importance to pursue further research to unveil several aspects of this disease, particularly in patients with recurrence, lymph node metastases or metastatic disease.

Current management and future perspectives of penile cancer: An updated review

Penile cancer (PeCa) is a rare disease worldwide, accounting for less than one percent of all malignancies in men. It usually presents as a painless ulcer or lump on the head of the penis. Squamous cell carcinoma represents the most common histological subtype of PeCa, with pathogenesis intimately linked to chronic Human Papilloma Virus (HPV) infection. Surgery is the cornerstone for the treatment of primary PeCa with potential mutilating outcome depending on the nodal extension of the disease. However, in case of extensive lymph node involvement, multidisciplinary treatment including perioperative chemotherapy and inclusion in clinical trial should be considered. To date, advanced or metastatic disease still have poor prognosis and are a therapeutic challenge with limited options, highlighting the need of new treatments and further investigations. Growing efforts to identify molecular alterations, understand the role of HPV and characterize immune contexture have expanded over the past years, providing further perspectives in prognostication, predictive biomarkers and therapeutic intervention. In this review, we provide an updated overview of current management of PeCa focusing on perioperative strategy. We discuss about new insights of the biology of PeCa and comment future directions in the field.

[Systemic treatment of locally advanced or metastatic penile cancer]

Penile cancers are rare, the vast majority is represented by squamous cell carcinoma, with HPV virus being found in 30 to 40% of cases. At a locally advanced or metastatic stage, first-line treatment relies on platinum and taxane based polychemotherapy. The prognosis for advanced or metastatic penile cancer remains poor, with overall survival ranging from 13.9 to 17.1 months. After the first line, guidelines recommend various chemotherapy treatments or targeted anti-EGFR therapies whose results as well as the level of evidence are limited. A better understanding of the oncogenic pathways involved in penile cancer and a frequent expression of PD-L1 are the rationale for the elaboration of new strategies. This review article presents the data, guidelines and ongoing studies in locally advanced or metastatic penile cancer.

Beyond MicroRNAs: Emerging Role of Other Non-Coding RNAs in HPV-Driven Cancers

Persistent infection with high-risk Human Papilloma Virus (HPV) leads to the development of several tumors, including cervical, oropharyngeal, and anogenital squamous cell carcinoma. In the last years, the use of high-throughput sequencing technologies has revealed a number of non-coding RNA (ncRNAs), distinct from micro RNAs (miRNAs), that are deregulated in HPV-driven cancers, thus suggesting that HPV infection may affect their expression. However, since the knowledge of ncRNAs is still limited, a better understanding of ncRNAs biology, biogenesis, and function may be challenging for improving the diagnosis of HPV infection or progression, and for monitoring the response to therapy of patients affected by HPV-driven tumors. In addition, to establish a ncRNAs expression profile may be instrumental for developing more effective therapeutic strategies for the treatment of HPV-associated lesions and cancers. Therefore, this review will address novel classes of ncRNAs that have recently started to draw increasing attention in HPV-driven tumors, with a particular focus on ncRNAs that have been identified as a direct target of HPV oncoproteins.

Genomic profiling reveals the pivotal role of hrHPV driving copy number and gene expression alterations, including mRNA downregulation of TP53 and RB1 in penile cancer

The incidence of penile cancer (PeCa) is increasing worldwide, however, the highest rates are reported in underdeveloped countries. The molecular mechanisms that underly the onset and progression of these tumors are still unclear. Therefore, our goal was to determine the genome-wide copy number alterations and the involvement of human papiloma virus (HPV) (TP53 and RB1), inflammatory (COX2 and EGFR), and PI3K/AKT pathway (AKT1, AKT2, EGFR, ERBB3, ERBB4, PIK3CA, and PTEN) associated genes in patients with PeCa from a high incidence region in Brazil (Maranhão). HPV genotyping was performed by nest-PCR and genome sequencing, copy number alterations (CNAs) by array comparative genomic hybridization and gene copy number status, gene, and protein expression by quantitative polymerase chain reaction, reverse transcriptase-quantitative polymerase chain reaction, and immunohistochemistry, respectively. HPV genotyping revealed one of the highest frequencies of HPV reported in PeCa, affecting 96.4% of the cases. The most common CNAs observed were located at the HPV integration sites, such as 2p12-p11.2 and 14q32.33, where ADAM 6, KIAA0125, LINC00226, LINC00221, and miR7641-2, are mapped. Increased copy number of ERBB3 and EGFR genes were observed in association with COX2 and EGFR overexpression, reinforcing the role of the inflammatory pathway in PeCa, and suggesting anti-EGFR and anti-COX2 inhibitors as promising therapies for PeCa. Additionally, TP53 and RB1 messenger RNA downregulation was observed, suggesting the occurrence of other mechanisms for repression of these oncoproteins, in addition to the canonical HPV/TP53/RB1 signaling pathway. Our data reinforce the role of epigenetic events in abnormal gene expression in HPV-associated carcinomas and suggest the pivotal role of HPV driving CNAs and controlling gene expression in PeCa.

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.

From Ancient to Emerging Infections: The Odyssey of Viruses in the Male Genital Tract

The male genital tract (MGT) is the target of a number of viral infections that can have deleterious consequences at the individual, offspring, and population levels. These consequences include infertility, cancers of male organs, transmission to the embryo/fetal development abnormalities, and sexual dissemination of major viral pathogens such as human immunodeficiency virus (HIV) and hepatitis B virus. Lately, two emerging viruses, Zika and Ebola, have additionally revealed that the human MGT can constitute a reservoir for viruses cleared from peripheral circulation by the immune system, leading to their sexual transmission by cured men. This represents a concern for future epidemics and further underlines the need for a better understanding of the interplay between viruses and the MGT. We review here how viruses, from ancient viruses that integrated the germline during evolution through old viruses (e.g., papillomaviruses originating from Neanderthals) and more modern sexually transmitted infections (e.g., simian zoonotic HIV) to emerging viruses (e.g., Ebola and Zika) take advantage of genital tract colonization for horizontal dissemination, viral persistence, vertical transmission, and endogenization. The MGT immune responses to viruses and the impact of these infections are discussed. We summarize the latest data regarding the sources of viruses in semen and the complex role of this body fluid in sexual transmission. Finally, we introduce key animal findings that are relevant for our understanding of viral infection and persistence in the human MGT and suggest future research directions.

A Review of Viral-Related Malignancies and the Associated Imaging Findings

OBJECTIVE. Imaging plays an important role in the diagnosis and staging of malignancies. Many common lymphoproliferative and other solid tumor malignancies can be viral-related. CONCLUSION. This review discusses the imaging findings that can be associated with common viral-induced malignancies. Knowledge of these imaging presentations can help narrow the differential diagnosis to reach a specific diagnosis through a precise workup and proper management.

Superficial penile cancer treated with complete excision of the glans epithelium and coverage with a tissue sealant matrix (TachoSil®)

Introduction

The aim of our work was to demonstrate the feasibility and clinical outcomes after partial excision of the epithelial and subepithelial layer of the glans with subsequent tissue sealant matrix coverage (TachoSil®).

Material and methods

We enrolled 11 consecutive patients with superficial penile cancer. Under the microscopic guidance, the tumor in the glans area was excised continuously with a minimal lateral margin of 5 mm. The cosmetic result was accessed using a 5-graded scale ranging from very dissatisfied to very satisfied.

Results

The median patient's age at the presentation was 46 years (range 38-53). Histopathological examination of the specimen confirmed squamous cell carcinoma and tumor-free surgical margins were obtained in all cases. Overall, the tumors were TaG1 in 3 patients, TaG2 in 1 patient, TisG1 in 2 patients, TisG2 in 2 patient, T1aG1 in 2 patients, and T1aG2 in 1 patient. All patients had clinically negative lymph-node status - cN0 (confirmed by aabdominopelvic computed tomography (CT) scan with contrast). During the follow-up of 6 to 36 months (median 18), local recurrence occurred in 1 patient with carcinoma in situ six months after surgery, which was managed by a second glans-preserving surgery without recurrence. The others showed no signs of local recurrence or metastasis during the period of observation.

Conclusions

These preliminary data suggests that glans-preserving surgical technique using TachoSil® as a defect coverage is technically feasible, functionally safe and cosmetically satisfying. However, well-designed prospective-randomized trial is warranted, to further confirm the clinical utility of our approach.

Recent advances in the management of penile cancer

Penile cancer is a rare condition and can be very complex to manage. Advances in surgical techniques, imaging, pathological classification and patient pathways have led to improved patient care. The diagnosis of pre-malignant change, penile cancer and metastatic disease along with advances in their treatment are detailed in this review which aims to update clinicians from multiple specialties and countries on penile cancer.

Nuclear loss and cytoplasmic expression of androgen receptor in penile carcinomas: role as a driver event and as a prognosis factor

Androgen receptor (AR) is a member of the steroid and nuclear family receptor that acts as transcription factor. AR signaling plays pivotal role in the development and progression of prostate cancer. However, the role of AR in penile cancer (PeCa) is poorly explored. Our previous molecular studies unveiled frequent AR mRNA loss in PeCa, which was further predicted as a major driver alteration in this neoplasm. Herein, we assessed the AR protein expression in 59 usual PeCa tissues and 42 surrounding normal tissues (SNT) by immunohistochemistry using a tissue microarray. In a paired analysis, we found a total absence of nuclear AR expression in PeCa while 95.2% of SNT samples presented strong nuclear AR expression (P < 0.001). Interestingly, 17 of 42 PeCa presented weak or moderate cytoplasmic AR staining, contrasting with 5 of 42 SNT (P = 0.008). Increased levels of AR cytoplasmic expression were related with poor prognosis features including advanced clinical staging (P = 0.044), compromised surgical margins (P = 0.005), and pathological inguinal node status (P = 0.047). Furthermore, AR cytoplasmic expression was also related with shorter overall survival (P = 0.032). In conclusion, the frequent loss of nuclear AR protein levels suggests a potential function in PeCa development. Based on this result, the androgen deprivation therapy is not indicated for PeCa patients. In addition, the AR cytoplasmic expression found in a significant number of cases (40.5%) showed prognostic value and pathways activated by the non-genomic AR signaling may represent a promising therapeutic strategy.

Human papillomavirus (HPV) genotype distribution in penile carcinoma: Association with clinic pathological factors

Background

Penile carcinoma (PC) is a rare, highly mutilating disease, common in developing countries. The evolution of penile cancer includes at least two independent carcinogenic pathways, related or unrelated to HPV infection.

Objectives

To estimate the prevalence, identify HPV genotypes, and correlate with clinicopathological data on penile cancer.

Methods

A retrospective cohort study involving 183 patients with PC undergoing treatment in a referral hospital in Goiânia, Goiás, in Midwestern Brazil, from 2003 to 2015. Samples containing paraffin embedded tumor fragments were subjected to detection and genotyping by INNO-LiPA HPV. The clinicopathological variables were subjected to analysis with respect to HPV positivity and used prevalence ratio (PR), adjusted prevalence ratio (PRa) and 95% confidence interval (CI) as statistical measures.

Results

The prevalence of HPV DNA in PC was 30.6% (95% CI: 24.4 to 37.6), high-risk HPV 24.9% (95% CI: 18.9 to 31.3), and 62.5% were HPV 16. There was a statistical association between the endpoints HPV infection and HPV high risk, and the variable tumor grade II-III (p = 0.025) (p = 0.040), respectively. There was no statistical difference in disease specific survival at 10 years between the HPV positive and negative patients (p = 0.143), and high and low risk HPV (p = 0.325).

Conclusions

The prevalence of HPV infection was 30.6%, and 80.3% of the genotypes were identified as preventable by anti-HPV quadrivalent or nonavalent vaccine. HPV infections and high-risk HPV were not associated with penile carcinoma prognosis in this study.