Evaluation of Prognostic Parameters to Identify Aggressive Penile Carcinomas.

BACKGROUND: Advanced penile carcinoma is characterized by poor prognosis. Most data on prognostic factors are based on small study cohorts, and even meta-analyses are limited in patient numbers. Therefore, there is still a lack of evidence for clinical decisions. In addition, the most recent TNM classification is questionable; in line with previous studies, we found that it has not improved prognosis estimation. METHODS: We evaluated 297 patients from Germany, Russia, and Portugal. Tissue samples from 233 patients were re-analyzed by two experienced pathologists. HPV status, p16, and histopathological parameters were evaluated for all patients. RESULTS: Advanced lymph node metastases (N2, N3) were highly significantly associated with reductions in metastasis-free (MFS), cancer-specific (CS), and overall survival (OS) rates (p = <0.001), while lymphovascular invasion was a significant parameter for reduced CS and OS (p = 0.005; p = 0.007). Concerning the primary tumor stage, a significant difference in MFS was found only between pT1b and pT1a (p = 0.017), whereas CS and OS did not significantly differ between T categories. In patients without lymph node metastasis at the time of primary diagnosis, lymphovascular invasion was a significant prognostic parameter for lower MFS (p = 0.032). Histological subtypes differed in prognosis, with the worst outcome in basaloid carcinomas, but without statistical significance. HPV status was not associated with prognosis, either in the total cohort or in the usual type alone. CONCLUSION: Lymphatic involvement has the highest impact on prognosis in penile cancer, whereas HPV status alone is not suitable as a prognostic parameter. The pT1b stage, which includes grading, as well as lymphovascular and perineural invasion in the T stage, seems questionable; a revision of the TNM classification is therefore required.

[Importance of HPV status and p16 for the prognosis of penile carcinoma]. / Bedeutung von HPV-Status und p16 für die Prognose des Peniskarzinoms.

BACKGROUND: Penile cancer is a rare but often lethal tumour disease, especially in the metastatic stage. Most data on prognostic factors for penile cancer are based on small patient cohorts, and even meta-analyses are mostly limited in terms of patient numbers. There is a lack of sufficient parameters to predict the metastatic risk of these tumours. Furthermore, the role of the HPV status for the prognosis, and, in this regard, of p16INK4a is still unclear. MATERIAL AND METHODS: In this study, 236 patients from an international multicentre cohort were analysed with regard to histological subtypes, HPV and p16 status, and other clinical parameters. The HPV status was only graded as HPV-positive if HPV was detected by PCR and the p16 status defined by immunochemistry was positive. The statistical analysis was carried out using the Kaplan-Meier method as well as the log-rank test and a univariable and multivariable analysis using the Cox regression model. RESULTS: A positive HPV status was not a significant parameter for either metastasis-free (MFS), tumour-specific (CSS) or overall survival (OS). p16-positive tumours showed a significantly better MFS (p=0.026), which was also confirmed in the subgroup analysis of HPV-negative tumours (p=0.037) without differences in CSS or OS. In the usual type, there was also a trend towards an improved MFS, but without statistical significance (p=0.070). p16-positive tumours were associated with a highly significantly better MFS (hazard ratio 0.3; p=0.004) in the multivariable Cox regression, while patients with a pT1b tumour stage or advanced lymph node metastasis showed a significantly worse survival. In the multivariable analysis of HPV-negative tumours, p16 status was also confirmed as an independent predictor of MFS (Hazard ratio 0.2; p=0.007). CONCLUSION: HPV status alone seems to be lacking prognostic relevance. In contrast, p16 status was confirmed as an independent prognostic factor. Thus, the expression of p16INK4a is associated with a significantly better MFS. Especially in HPV-negative tumours, the p16 status should be evaluated with regard to the prognostic value and thus also with a view to the treatment decision.

The prominent role of the S100A8/S100A9-CD147 axis in the progression of penile cancer.

Currently, no established biomarkers are recommended for the routine diagnosis of penile carcinoma (PeCa). The rising incidence of this human papillomavirus (HPV)-related cancer entity highlights the need for promising candidates. The Calprotectin subunits S100A8 and S100A9 mark myeloid-derived suppressor cells in other HPV-related entities while their receptor CD147 was discussed to identify patients with PeCa at a higher risk for poor prognoses and treatment failure. We thus examined their expression using immunohistochemistry staining of PeCa specimens from 74 patients on tissue microarrays of the tumor center, the invasion front, and lymph node metastases. Notably, whereas the tumor center was significantly more intensively stained than the invasion front, lymph node metastases were thoroughly positive for both S100 subunits. An HPV-positive status combined with an S100A8+S100A9+ profile was related with an elevated risk for metastases. We observed several PeCa specimens with S100A8+S100A9+-infiltrating immune cells overlapping with CD15 marking neutrophils. The S100A8+S100A9+CD15+ profile was associated with dedifferentiated and metastasizing PeCa, predominantly of HPV-associated subtype. These data suggest a contribution of neutrophil-derived suppressor cells to the progression of HPV-driven penile carcinogenesis. CD147 was elevated, expressed in PeCa specimens, prominently at the tumor center and in HPV-positive PeCa cell lines. CD147+HPV+ PeCa specimens were with the higher-frequency metastasizing cancers. Moreover, an elevated expression of CD147 of HPV-positive PeCa cell lines correlated negatively with the susceptibility to IgA-based neutrophil-mediated tumor cell killing. Finally, stratifying patients regarding their HPV/S100A8/S100A9/CD15/CD147 profile may help identify patients with progressing cancer and tailor immunotherapeutic treatment strategies.

Accounting for B-cell Behavior and Sampling Bias Predicts Anti-PD-L1 Response in Bladder Cancer.

Cancer immunotherapy is predominantly based on T cell-centric approaches. At the same time, the adaptive immune response in the tumor environment also includes clonally produced immunoglobulins and clonal effector/memory B cells that participate in antigen-specific decisions through their interactions with T cells. Here, we investigated the role of infiltrating B cells in bladder cancer via patient dataset analysis of intratumoral immunoglobulin repertoires. We showed that the IgG1/IgA ratio is a prognostic indicator for several subtypes of bladder cancer and for the whole IMVigor210 anti-PD-L1 immunotherapy study cohort. A high IgG1/IgA ratio associated with the prominence of a cytotoxic gene signature, T-cell receptor signaling, and IL21-mediated signaling. Immunoglobulin repertoire analysis indicated that effector B-cell function, rather than clonally produced antibodies, was involved in antitumor responses. From the T-cell side, we normalized a cytotoxic signature against the extent of immune cell infiltration to neutralize the artificial sampling-based variability in immune gene expression. Resulting metrics reflected proportion of cytotoxic cells among tumor-infiltrating immune cells and improved prediction of anti-PD-L1 responses. At the same time, the IgG1/IgA ratio remained an independent prognostic factor. Integration of the B-cell, natural killer cell, and T-cell signatures allowed for the most accurate prediction of anti-PD-L1 therapy responses. On the basis of these findings, we developed a predictor called PRedIctive MolecUlar Signature (PRIMUS), which outperformed PD-L1 expression scores and known gene signatures. Overall, PRIMUS allows for reliable identification of responders among patients with muscle-invasive urothelial carcinoma, including the subcohort with the low-infiltrated "desert" tumor phenotype.

DKK1 inhibits canonical Wnt signaling in human papillomavirus-positive penile cancer cells.

Penile squamous cell cancer (PSCC) is the most frequent penile malignant disease. Infections with human papillomaviruses (HPV) are a major etiologic driver of PSCC. However, the molecular details of the underlying carcinogenesis are understudied because of rare clinical specimens and missing cell lines. Here, we investigated if the expression of high-risk HPV16 oncogenes causes an augmentation of the Wnt pathway using unique HPV-positive penile cancer (PeCa) cell lines in monolayer and organotypic 3D raft cultures as well as tissue micro arrays containing clinical tissue specimens. The HPV oncoproteins enhanced the expression of Leucine-rich repeat-containing G-protein coupled receptor 6 (LGR6) and the HPV-positive PeCa cells expressed a signature of Wnt target and stemness-associated genes. However, the notable lack of nuclear ß-catenin in vitro and in situ raised the question if the enhanced expression of Wnt pathway factors is tantamount to an active Wnt signaling. Subsequent TOP-flash reporter assays revealed Wnt signaling as absent and not inducible by respective Wnt ligands in PeCa cell lines. The HPV-positive PeCa cells and especially HPV-positive PeCa specimens of the tumor core expressed the Wnt antagonist and negative feedback-regulator Dickkopf1 (DKK1). Subsequent neutralization experiments using PeCa cell line-conditioned media demonstrated that DKK1 is capable to impair ligand-induced Wnt signaling. While gene expression analyses suggested an augmented and active canonical Wnt pathway, the respective signaling was inhibited due to the endogenous expression of the antagonist DKK1. Subsequent TMA stainings indicated Dkk1 as linked with HPV-positivity and metastatic disease progression in PeCa suggesting potential as a prognostic marker.

miRNA Expression Characterizes Histological Subtypes and Metastasis in Penile Squamous Cell Carcinoma.

Although microRNAs are described as promising biomarkers in many tumor types, little is known about their role in PSCC. Thus, we attempted to identify miRNAs involved in tumor development and metastasis in distinct histological subtypes considering the impact of HPV infection. In a first step, microarray analyses were performed on RNA from formalin-fixed, paraffin-embedded tumor (22), and normal (8) tissue samples. Microarray data were validated for selected miRNAs by qRT-PCR on an enlarged cohort, including 27 tumor and 18 normal tissues. We found 876 significantly differentially expressed miRNAs (p ≤ 0.01) between HPV-positive and HPV-negative tumor samples by microarray analysis. Although no significant differences were detected between normal and tumor tissue in the whole cohort, specific expression patterns occurred in distinct histological subtypes, such as HPV-negative usual PSCC (95 differentially expressed miRNAs, p ≤ 0.05) and HPV-positive basaloid/warty subtypes (247 differentially expressed miRNAs, p ≤ 0.05). Selected miRNAs were confirmed by qRT-PCR. Furthermore, microarray data revealed 118 miRNAs (p ≤ 0.01) that were significantly differentially expressed in metastatic versus non-metastatic usual PSCC. The lower expression levels for miR-137 and miR-328-3p in metastatic usual PSCC were validated by qRT-PCR. The results of this study confirmed that specific miRNAs could serve as potential diagnostic and prognostic markers in single PSCC subtypes and are associated with HPV-dependent pathways.

The HPV and p63 Status in Penile Cancer Are Linked with the Infiltration and Therapeutic Availability of Neutrophils.

Squamous penile cancer displays a rare human papillomavirus (HPV)-associated tumor entity. Investigations on the molecular pathogenesis of HPV-driven penile cancer are impaired by the rareness of clinical specimens and, in particular, are missing relevant cell culture models. Here, we identified in HPV-positive penile cancer cell lines that HPV16 oncoproteins control TP63 expression by modulating critical regulators, while integration into the TP63 open reading frame facilitates oncogene expression. The resulting feed-forward loop leads to elevated p63 levels that in turn enhance the release of the neutrophil-recruiting chemokine CXCL8. Remarkably, elevated CXCL8 amounts lead to the increased surface exposition of the Fc receptor of human IgA antibodies, FcαRI, on neutrophils and correlated with a higher susceptibility to antibody-dependent neutrophil-mediated cytotoxicity (ADCC) using an EGFR-specific IgA2 antibody. IHC staining of tissue microarrays proved that elevated expression of p63 together with neutrophil infiltration were significantly more frequent in HPV-positive penile cancer displaying a higher tumor grade. In summary, we identified a promising marker profile of patients with penile cancer at higher risk for worse prognosis. However, these patients may benefit from immunotherapeutic approaches efficiently engaging neutrophils for tumor cell killing.

Challenging the prognostic impact of the new WHO and TNM classifications with special emphasis on HPV status in penile carcinoma.

The evidence concerning prognostic parameters for clinical decision-making in penile cancer is either weak or missing. We therefore analysed the prognostic value of the revised TNM and WHO classification systems on relapse and survival with special emphasis on HPV status. We collected clinical data and tissue samples of 121 patients from centres in Germany and Russia. HPV genotyping and p16INK4a immunostaining were performed. The histological subtype and TNM were reclassified by two experienced uropathologists. Survival analyses were performed by Kaplan-Meier estimator and log-rank test. Uni- and multivariable analyses were performed by Cox proportional hazard model and Fisher's exact test for contingency analysis. HPV status was not found to be an independent prognostic factor. Histological subtypes differ in prognosis with the best outcome found in warty and the worst in basaloid carcinomas. Patients with pT1b defined by poor differentiation or lymphovascular invasion (LVI) had the shortest metastasis-free survival compared with pT1a (log-rank, p = 0.02). Lymph node metastasis and LVI were significantly associated with poor metastasis-free, cancer-specific and overall survival and could be identified as the only independent prognostic parameters. Prognostic value of TNM could not be improved using the 8th versus the 7th edition. In contrast to HPV status, histological subtypes are of prognostic value and should be an essential part of pathologic reports. The impact of the HPV status needs to be analysed in a subtype-specific manner. Parameters describing lymphatic dissemination have the highest impact on prognosis. Inclusion of tumour grade and LVI into a single T-category (pT1b) seems questionable.