Systemic Therapy for Penile Cancer

piRNAs and PIWI Proteins as Diagnostic and Prognostic Markers of Genitourinary Cancers

piRNAs (PIWI-interacting RNAs) are small non-coding RNAs capable of regulation of transposon and gene expression. piRNAs utilise multiple mechanisms to affect gene expression, which makes them potentially more powerful regulators than microRNAs. The mechanisms by which piRNAs regulate transposon and gene expression include DNA methylation, histone modifications, and mRNA degradation. Genitourinary cancers (GC) are a large group of neoplasms that differ by their incidence, clinical course, biology, and prognosis for patients. Regardless of the GC type, metastatic disease remains a key therapeutic challenge, largely affecting patients’ survival rates. Recent studies indicate that piRNAs could serve as potentially useful biomarkers allowing for early cancer detection and therapeutic interventions at the stage of non-advanced tumour, improving patient’s outcomes. Furthermore, studies in prostate cancer show that piRNAs contribute to cancer progression by affecting key oncogenic pathways such as PI3K/AKT. Here, we discuss recent findings on biogenesis, mechanisms of action and the role of piRNAs and the associated PIWI proteins in GC. We also present tools that may be useful for studies on the functioning of piRNAs in cancers.

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.

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.

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.

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.

Nomogram-based prediction of overall survival after regional lymph node dissection and the role of perioperative chemotherapy in penile squamous cell carcinoma: A retrospective multicenter study

OBJECTIVES

To improve the prognostic allocation of patients with penile squamous-cell carcinoma (PSCC) receiving regional lymph node dissection (LND).

PATIENTS AND METHODS

An international, multicenter, retrospective study was performed on patients with PSCC who received regional LND, with or without perioperative therapy, from 1980 to 2017. We first used a random forest (RF) method with missing data imputation. Additionally, data were modeled using Cox proportional hazard regression, and a Cox model was also fit including prespecified variables. Based on the latter model, a nomogram for estimating 12-month and 24-month overall survival (OS) was developed.

RESULTS

There were 743 patients who received LND at 7 referral centers from Europe, the USA, Brazil, and China. Of these patients, 689 were analyzed: 86 (12.5%) received neoadjuvant chemotherapy (NAC); 171 (24.8%) received adjuvant chemotherapy (AC), and 74 (10.7%) received adjuvant radiotherapy. The variables significantly associated with OS were age (P < 0.001), the pathologically involved/total removed LN ratio (P < 0.001), pN stage (overall P < 0.001), and NAC (P = 0.013). NAC and AC were ineffective in N1-2 patients (clinical and pathological, respectively), whereas they provided OS improvements in N3 patients. Finally, we developed a nomogram predicting 12- and 24-month OS based on prespecified variables (c-index: 0.75). The study is limited by its retrospective nature.

CONCLUSIONS

We propose a tool that can be offered as an aid to physicians to enhance decision-making, clinical research, and patient counseling whenever LND is needed for PSCC. Administration of NAC and AC should be restricted to clinical and pathological N3 patients, respectively.