Imaging for the Initial Staging and Post-Treatment Surveillance of Penile Squamous Cell Carcinoma

Although relatively rare in the United States, penile squamous cell carcinoma is encountered worldwide at a higher rate. Initial diagnosis is often made on clinical exam, as almost all of these lesions are externally visible and amenable to biopsy. In distinction to other types of malignancies, penile cancer relies heavily on clinical nodal staging of the inguinal lymph node chains. As with all cancers, imaging plays a role in the initial staging, restaging, and surveillance of these patients. The aim of this manuscript is to highlight the applications, advantages, and limitations of different imaging modalities in the evaluation of penile cancer, including ultrasound, computed tomography, magnetic resonance imaging, and positron emission tomography.

Pathogenesis of Penile Squamous Cell Carcinoma: Molecular Update and Systematic Review

Penile squamous cell carcinoma (PSCC) is a rare but aggressive neoplasm with dual pathogenesis (human papillomavirus (HPV)-associated and HPV-independent). The development of targeted treatment is hindered by poor knowledge of the molecular landscape of PSCC. We performed a thorough review of genetic alterations of PSCC focused on somatic mutations and/or copy number alterations. A total of seven articles have been identified which, overall, include 268 PSCC. However, the series are heterogeneous regarding methodologies employed for DNA sequencing and HPV detection together with HPV prevalence, and include, in general, a limited number of cases, which results in markedly different findings. Reported top-ranked mutations involve TP53, CDKN2A, FAT1, NOTCH-1 and PIK3CA. Numerical alterations involve gains in MYC and EGFR, as well as amplifications in HPV integration loci. A few genes including TP53, CDKN2A, PIK3CA and CCND1 harbor both somatic mutations and copy number alterations. Notch, RTK-RAS and Hippo pathways are frequently deregulated. Nevertheless, the relevance of the identified alterations, their role in signaling pathways or their association with HPV status remain elusive. Combined targeting of different pathways might represent a valid therapeutic approach in PSCC. This work calls for large-scale sequencing studies with robust HPV testing to improve the genomic understanding of PSCC.

Low level of interobserver concordance in assessing histological subtype and tumor grade in patients with penile cancer may impair patient care

Differentiation between penile squamous cell carcinoma patients who can benefit from limited organ-sparing surgery and those at significant risk of lymph node metastasis is based on histopathological prognostic factors including histological grade and tumor histological subtype. We examined levels of interobserver and intraobserver agreement in assessment of histological subtype and grade in 207 patients with penile squamous cell carcinoma. The cases were assessed by seven pathologists from three hospitals located in Sweden and Italy. There was poor to moderate concordance in assessing both histological subtype and grade, with Fleiss kappas of 0.25 (range: 0.02–0.48) and 0.23 (range: 0.07–0.55), respectively. When choosing HPV-associated and non-HPV-associated subtypes, interobserver concordance ranged from poor to good, with a Fleiss kappa value of 0.36 (range: 0.02–0.79). A re-review of the slides by two of the pathologists showed very good intraobserver concordance in assessing histological grade and subtype, with Cohen’s kappa values of 0.94 and 0.91 for grade and 0.95 and 0.84 for subtype. Low interobserver concordance could lead to undertreatment and overtreatment of many patients with penile cancer, and brings into question the utility of tumor histological subtype and tumor grade in determining patient treatment in pT1 tumors.

Genome-Wide Profiling Reveals HPV Integration Pattern and Activated Carcinogenic Pathways in Penile Squamous Cell Carcinoma

Human papillomavirus (HPV) is a significant etiologic driver of penile squamous cell carcinoma (PSCC). The integration pattern of HPV and its carcinogenic mechanism in PSCC remain largely unclear. We retrospectively reviewed 108 PSCC cases who received surgery between 2008 and 2017. Using high-throughput viral integration detection, we identified 35 HPV-integrated PSCCs. Unlike cervical cancer, the HPV E2 oncogene was not prone to involvement in integration. Eleven of the 35 (31.4%) HPV-integrated PSCCs harbored intact HPV E2; these tumors had lower HPV E6 and E7 expression and higher expression of p53 and pRb proteins than those with disrupted E2 did (p < 0.001 and p = 0.024). Integration breakpoints are preferentially distributed in or near host genes, including previously reported hotspots (KLF5, etc.) and newly identified hotspots (CADM2, etc.), which are mainly involved in oncogenic signaling pathways (MAPK, JAK/STAT, etc.). Regarding the phosphorylation levels of JNK, p38 was higher in HPV-positive tumors with MAPK-associated integration than those in HPV-positive tumors with other integration and those in HPV-negative tumors. In vitro, KLF5 knockdown inhibited proliferation and invasion of PSCC cells, while silencing CADM2 promoted migration and invasion. In conclusion, this study enhances our understanding of HPV-induced carcinogenesis in PSCC, which may not only rely on the E6/E7 oncogenes, but mat also affect the expression of critical genes and thus activate oncogenic pathways.

Warthy-Basaloid Squamous Cell Carcinoma of Penile – Case Report

ObjectiveThe aim of the study was to present a case of penile squamous cell carcinoma and immunohistochemical identification and evaluation of E-cadherin and β-catenin expression.MethodsWe are presenting a 70-year old man with a variant of penile squamous cell carcinoma with mixed warty and basaloid features. After diagnosis, the patient underwent partial penectomy. Samples taken from the material after surgery were subjected to basic histological staining and immunohistochemical identification of E-cadherin and β-catenin. A Real-time PCR study was conducted to investigate the expression of E-cadherin and β-catenin.ResultsRoutine histopathological examinations revealed the characteristic features of warty-basaloid squamous cell carcinoma. In the case studied, a positive immunohistochemical reaction was observed for E-cadherin and β-catenin. QRT-PCR analysis showed a statistically significant decrease in E-cadherin expression in tumor samples compared to healthy tissue. In contrast, expression of the gene encoding β-catenin was slightly higher in tumor samples compared to normal tissue.ConclusionsThe reduced level of the complex of adhesive elements, E-cadherin-β-catenin, disturbs cell differentiation, promotes a more invasive phenotype-stromal infiltration and the formation of distant metastases. In the described case of the penile tumor, a decrease in E-cadherin expression was noted, which could be related to the occurrence of neoplastic infiltration of the spongy body space. In summary, E-cadherin and β-catenin expression and the immunoreactivity of these proteins are expressed at different levels in tumor cells and in penile interstitial cells. Regulation of expression during various physiological and pathophysiological processes indicates a potentially important role of E-cadherin and β-catenin in cell proliferation and adhesion.

Tislelizumab Combination With Chemotherapy Successfully Converted Unresectable Advanced Penile Cancer Into Complete Surgical Excision: a Case Report and Literature Review

Background: Locally advanced Penile squamous cell carcinoma (PSCC) with unresectable inguinal lymph nodes has a poor prognosis, and benefits from surgical treatment alone. Effective conversion therapy regimens are urgently needed.Case Presentation: We report a locally advanced PSCC patient with bulky, fixed inguinal lymph node metastasis complicated within genial skin ulcers, who completed inguinal lymph node dissection and achieved pathologically complete response via conversion therapy by immunotherapy plus chemotherapy.Conclusion: For unresectable locally advanced PSCC, neoadjuvant immunotherapy combined with chemotherapy is a potential treatment approach. Biomarkers of immune efficacy need to be explored. At the same time, clinical trials are needed to test the notions.