Updates in the molecular epidemiology and systemic approaches to penile cancer

Upregulated miRNAs on the TP53 and RB1 Binding Seedless Regions in High-Risk HPV-Associated Penile Cancer

Cancer development by the human papillomavirus (HPV) infection can occur through the canonical HPV/p53/RB1 pathway mediated by the E2/E6/E7 viral oncoproteins. During the transformation process, HPV inserts its genetic material into host Integration Sites (IS), affecting coding genes and miRNAs. In penile cancer (PeCa) there is limited data on the miRNAs that regulate mRNA targets associated with HPV, such as the TP53 and RB1 genes. Considering the high frequency of HPV infection in PeCa patients in Northeast Brazil, global miRNA expression profiling was performed in high-risk HPV-associated PeCa that presented with TP53 and RB1 mRNA downregulated expression. The miRNA expression profile of 22 PeCa tissue samples and five non-tumor penile tissues showed 507 differentially expressed miRNAs: 494 downregulated and 13 upregulated (let-7a-5p, miR-130a-3p, miR-142-3p, miR-15b-5p miR-16-5p, miR-200c-3p, miR-205-5p, miR-21-5p, miR-223-3p, miR-22-3p, miR-25-3p, miR-31-5p and miR-93-5p), of which 11 were identified to be in HPV16-IS and targeting TP53 and RB1 genes. One hundred and thirty-one and 490 miRNA binding sites were observed for TP53 and RB1, respectively, most of which were in seedless regions. These findings suggest that up-regulation of miRNA expression can directly repress TP53 and RB1 expression by their binding sites in the non-canonical seedless regions.

Innovative systemic therapies for penile cancer

PURPOSE OF REVIEW

The purpose of this review is to look at recent advancements and treatment options of systemic therapies to treat penile squamous cell carcinoma (PSCC). PSCC is a rare cancer that remains with limited funding for research and systemic therapy development. This review aims to discuss the most recent advancements in systemic treatments and our understanding of PSCC.

RECENT FINDINGS

Neoadjuvant chemotherapy (NAC) and adjuvant therapy remain integral parts of treatment in locally advanced PSCC. New potential drug regimens are being studied to expand on the availability of first-line regimen options. There has been a large development in discoveries of cellular pathways and immune system targets as potential treatment options but these therapies as of today have limited trial evidence and currently have no support to be used in a clinical setting.

SUMMARY

PSCC is a rare genitourinary cancer with limited treatment options for patients with advanced disease that is refractory to chemotherapy. Although many new therapies targeting the immune system and cellular pathways are being developed for other studies, clinical and translational research for PSCC are still understudied and underfunded.

Association Between Human Papillomavirus Infection and Outcome of Perioperative Nodal Radiotherapy for Penile Carcinoma

BACKGROUND

Data on the impact of human papillomavirus (HPV) infection status and outcomes for perioperative treatments for patients with lymph node-involved penile squamous-cell carcinoma (PSCC) are lacking.

OBJECTIVE

To analyze the benefit from perioperative radiotherapy (RT) for PSCC according to HPV infection status.

DESIGN, SETTING, AND PARTICIPANTS

In an international multicenter database of 1254 patients with PSCC who received inguinal lymph node dissection (ILND), 507 had suitable clinical information.

INTERVENTION

ILND, with or without chemotherapy or RT for involved lymph nodes.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Kaplan-Meier and restricted mean survival time (RMST) analyses for overall survival (OS) were performed for all patients and after propensity score-matching (PSM; n = 136), for which patient age, histology, type of penile surgical procedure, pathological tumor and nodal stage, ILND laterality, pelvic LND, and perioperative treatment were taken into account when assessing differences between HPV⁺ and HPV- patients. Finally, we looked at genomic alterations in PSCC using data from the Foundation Medicine database (n = 199) to characterize HPV⁺ PSCC.

RESULTS AND LIMITATIONS

Patients with HPV⁺ PSCC (n = 86; 17%) had lower clinical N stage (p < 0.001) and inguinal lymph node metastasis density (p < 0.001). Perioperative RT was delivered in 49 patients (9.7%), with the vast majority receiving adjuvant RT (n = 40). HPV⁺ patients had similar median OS (p = 0.1) but longer RMST than HPV- patients at different time points. Nevertheless, HPV⁺ patients treated with perioperative RT exhibited longer median OS (p = 0.015) and longer RMST compared to HPV- patients. In the PSM cohorts, HPV⁺ status remained significantly associated with longer OS after RT. The HPV- PSCC group had a higher frequency of TP53 mutations compared to HPV⁺ PSCC (75% vs 15%; p < 0.001). The results are limited by the retrospective nature of the data.

CONCLUSIONS

Perioperative RT was more effective in the HPV⁺ PSCC subgroup. Reasons for the enhanced radiosensitivity may be related to the lack of TP53 mutations.

PATIENT SUMMARY

We analyzed data from a large multicenter database for patients with penile cancer who had received inguinal lymph node dissection, with or without chemotherapy or radiotherapy. We found that for tumors positive for human papillomavirus (HPV), use of radiotherapy resulted in prolonged survival compared to HPV-negative tumors. On the basis of these results we are inspired to design studies on the use of radiotherapy in HPV-selected patients.

Neoadjuvant chemotherapy for lymph node-positive penile cancer: current evidence and knowledge

PURPOSE OF REVIEW

To review the latest in penile cancer treatment focusing on neoadjuvant chemotherapy in patients with regional lymph node involvement.

RECENT FINDINGS

Patients with regional lymph node involvement from penile cancer still suffer from a poor prognosis, and the chances to achieve cure are primarily dependent on the extent of the disease. Despite multiple lines of research are indicating the need for a multimodal management of the disease upfront, the search for newer effective systemic therapies is ongoing. The available guidelines currently suggest the use of combination chemotherapy regimens including taxanes and cisplatin as induction therapy before lymphadenectomy in patients with locally advanced disease (i.e., fixed or bulky inguinal lymph nodes or pelvic lymph node involvement). Research in the field will aim to provide more effective systemic therapies also in patients with a more limited disease spread to further improve the outcomes. Data from the literature also indicate the possibility to effectively administer postoperative chemotherapy in selected high-risk patients.

SUMMARY

We aimed to provide the evidence from the literature and the new avenues that would help delineating the optimal therapeutic pathway for these complex patients, commenting on the new opportunities that may come from the ongoing research.

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.