Molecular prognostic factors in penile cancer

High tumour mutational burden is associated with strong PD-L1 expression, HPV negativity, and worse survival in penile squamous cell carcinoma: an analysis of 165 cases

Penile squamous cell carcinoma (pSCC) is a rare tumour with a variable prognosis. More prognostic markers linked to mutational signatures and the tumour immune microenvironment are needed. A cohort made up of 165 invasive pSCC was retrospectively analysed using formalin-fixed, paraffin-embedded tumour tissue, focusing on tumour mutational burden (TMB), programmed death ligand 1 (PD-L1) expression, microsatellite instability (MSI), the number of tumour infiltrating lymphocytes (TILs) expressing cytotoxic T-lymphocyte-associated protein 4 (CTLA4), HPV status determined by p16 immunohistochemistry, and several traditional histopathological variables. High TMB (>10 mut/Mb) was associated with high PD-L1 expression (TPS 50-100%), and HPV-negative status. High PD-L1 expression was linked to HPV negativity, a high number of intratumoural CTLA4+ cells, and brisk lymphocytic infiltrate. High TMB was a significant predictor of shorter overall survival (OS) in both univariate and multivariate analysis when using a median cut-off value of 4.3 mut/Mb, but not when using an arbitrary cut-off of 10 mut/Mb. Low CTLA4+ cell infiltration at the tumour invasion front was a marker of shorter OS and cancer-specific survival in both univariate and multivariate analysis. PD-L1 expression had no significant impact on prognosis. Only two cases were MSI high. The results support the hypothesis of two aetiological pathways in pSCC cancerogenesis: (1) SCC linked to HPV infection characterised by low TMB, less common PD-L1 expression, and a lower number of TILs; and (2) SCC linked to chronic inflammation leading to a high number of acquired mutations (high TMB), HPV negativity, increased neoantigen production (i.e., PD-L1), and high immune cell infiltration.

Immune cell infiltration, tumour budding, and the p53 expression pattern are important predictors in penile squamous cell carcinoma: a retrospective study of 152 cases

Penile squamous cell carcinoma (pSCC) is a rare malignancy with a slowly increasing incidence and variable prognosis. Regional lymph node involvement signifies poor prognosis but represents a late sign, and more prognostic markers for effective patient risk stratification are urgently needed. In this retrospective study, 152 tumour samples with formalin-fixed, paraffin-embedded tissue were analysed for traditional pathological variables, tumour budding, p53, p16, and mismatch repair proteins (MMR) immunohistochemistry. The density of tumour lymphocytic infiltrate was also determined, using subjective evaluation by two pathologists (brisk/non-brisk/absent) and also using the immunoscore method, which categorised the cohort into five immunoscore groups according to the number of CD3+ and CD8+ T-cells in both the tumour centre and tumour invasion front. Only one case (0.6%) was MMR-deficient. Tumour budding count ≥5 tumour buds/20× power field and non-brisk/absent lymphocytic infiltrate were significant negative predictors of both the overall survival (OS) and cancer-specific survival (CSS), whereas a low immunoscore was a significant marker of shorter OS but not CSS. Advanced pT stage (3+4) was a significant marker of shorter CSS but not OS. In the multivariate analysis, high-grade budding was a significant parameter if adjusted for the patient's age and associated variables, except for the pN stage. The lymphocytic infiltrate retained its prognostic significance if adjusted for age and associated variables. The negative prognostic significance of the previously described parameters (lymphatic, venous, and perineural invasion, regional lymph node metastasis, and p53 mutated profile) were confirmed in our study. Grade, histological subtype, and HPV status (as determined by p16 immunohistochemistry) showed, surprisingly, little or no prognostic significance.

Clinical significance of p16INK4a and p53 and their involvement in penile cancer development. A literature review

"Background: Human papillomavirus (HPV) E6 and E7 oncoproteins are vital for developing HPV induced penile carcinoma. The viral oncoproteins play a central role in oncogenesis by interacting with several cellular regulatory proteins, such as p16INK4a and p53. Many studies suggest that these proteins showed clinical utility in predicting nodal disease, cancer specific survival, overall survival and even tumor grade. Understanding the molecular mechanism involved in the carcinogenesis of penile cancer could offer biomarkers for disease progression, treatment response and potential targeted therapies; (2) Methods: This paper is a prospective study on a group of 100 patients who underwent prostate surgery during 2013 and 2014 in the Urology Clinic of “Carol Davila” Central Military Emergency University Hospital Bucharest. They were tested for HPV by PCR and IHC (p16) methods; (3) Results: 11 cases (22%) of HPV were found in the cluster of patients tested. PCR and P16 were the HPV diagnostic tests used. In order to determine the consistency of the 2 tests, the Cohen’s kappa coefficient was used at a p level < 0.05. The PCR method had a sensitivity of 81.8% and a specificity of 94.9%. The P16 method had a sensitivity of 63.6% and a specificity of 89.7%."

The Development and Validation of a Nomogram Incorporating Clinical, Pathological, and Therapeutic Features to Predict Overall Survival in Patients With Penile Cancer: A SEER-Based Study

Objective

This study aimed to investigate the prognostic factors of penile cancer and establish a comprehensive predictive model for clinical application.

Methods

A total of 581 patients from the Surveillance, Epidemiology, and End Results (SEER) program (2000-2018) were used to develop the prognostic model. The multivariate Cox proportional hazards regression was performed to identify independent prognostic factors to develop the nomogram. The performance of this model was validated internally by a cohort with 143 patients from the SEER database and validated externally by a cohort with 70 patients from the West China Hospital, Sichuan University (2010-2020).

Results

Age, marital status, size of the primary lesion, primary tumor (T), regional lymph nodes status, distant metastasis (M), and the surgery of regional lymph node (LND) were the independent prognostic factors for overall survival (OS) and were incorporated in the prognostic model. The prognostic nomogram showed a good risk stratification ability for OS in the development cohort, internal validation cohort, and external validation cohort.

Conclusion

This study incorporates the clinical, pathological, and therapeutic features comprehensively to develop a novel and clinically effective prognostic model for patients with penile cancer.

The International Penile Advanced Cancer Trial (InPACT): Rationale and Current Status

The historic international penile cancer trial InPACT is now open and accruing patients in the UK and USA. The trial is geared to answer important questions for patients with evidence of inguinal lymph node disease at presentation. This clinical trial update provides an overview of the study and progress to date.

The Prognostic Value of PIK3CA Copy Number Gain in Penile Cancer

OBJECTIVE

To determine whether phosphatidylinositol-4,5-bisphosphate 3- kinase, catalytic subunit alpha (PIK3CA) copy number gain in penile cancer has prognostic value and association with histopathological parameters, human papillomavirus (HPV), and clinical outcome.

METHODS

PIK3CA copy number status was assessed with fluorescence in situ hybridization in tissue microarrays generated from archival paraffin embedded blocks of 199 patients with primary penile squamous cell carcinoma (PSCC). HPV DNA was detected with INNO-LiPA assay. Follow-up data were available for 174 patients. PIK3CA copy number status was correlated with histopathological parameters, high-risk HPV, cancer-specific survival and time to recurrence.

RESULTS

PIK3CA copy number gain was found in 84/199 (42%) of penile cancer cases. PIK3CA copy number gain was associated with tumor subtype, grade, and stage (P = .0028, P < .0001, and P = .0397, respectively), but not with lymph node status (P = .2902). PIK3CA copy number gain showed a tendency to associate with cancer-specific survival (HR = 1.76, 95% CI; 0.94-3.3; P = .0753). In multivariate analysis, PIK3CA copy number gain was found to have no prognostic value for cancer-specific survival (P = .677). Only lymph node metastasis, high tumor grade and stage were found to be independent prognostic factors for cancer-specific survival.

CONCLUSION

PIK3CA copy number gain could be used as a marker of high-risk disease as it correlates with more aggressive PSCC histological subtypes and higher tumor grade and stage. However, it shows no significant association with lymph node metastasis or prognostic value for cancer-specific survival in PSCC.

Surveillance strategies in the management of penile cancer

Penile cancer is a rare disease and can be associated with a high risk of recurrence in regional lymph nodes and distant sites. Surveillance strategies geared towards early detection and treatment are recommended given the significant morbidity and mortality associated with recurrences. Although physical examination is the single most important surveillance strategy, imaging is an important adjunct in high-risk disease and certain clinical scenarios.

Preoperative peripheral plasma fibrinogen level is an independent prognostic marker in penile cancer

BACKGROUND AND AIM

High levels of peripheral plasma fibrinogen have recently been revealed that related to poor clinical prognosis in various types of malignant tumors. The purpose of this research was to identify the prognostic significance of the preoperative peripheral serum fibrinogen level in patients with penile cell carcinoma.

METHODS

This retrospective research included 72 penile cancer patients with date about their serum fibrinogen value before surgery who undergone either partial or radical penectomy at The 2nd Hospital of Tianjin Medical University between January 2002 to January 2012. They had a mean follow-up of 30.8 months. To determine the factors that were significant in predicting a patient's prognosis, univariate and multivariate analyses were performed according to the Cox proportional hazards regression model.

RESULTS

The 5-year cancer specific survival (CSS) rate was 62.4% of patients with preoperative fibrinogen levels below 340 mg/dl and 41.9% for those with higher levels (p = 0.001). Multivariate analysis revealed that the pathological T stage (p < 0.001), tumor grade (p = 0.036), postoperative chemotherapy (p = 0.041), nodal metastasis(p < 0.001), pathological type (p < 0.001) and fibrinogen (p = 0.023) were independent prognostic factors for survival. Patients with low fibrinogen level (<340mg/dl) had significantly longer CSS and the different survival rate were defined using the log-rank test.

CONCLUSIONS

The high preoperative peripheral serum fibrinogen level was related to poor survival in penile cancer patients. Fibrinogen may serve as a powerful predictor of CSS in penile cancer patients.

More precise prediction in Chinese patients with penile squamous cell carcinoma: protein kinase CK2α catalytic subunit (CK2α) as a poor prognosticator

Purpose

In this study, we assess the CK2α expression in human penile squamous cell carcinoma (SCC) and its clinical significance.

Methods

A total of 157 human penile SCC tissue samples were immunohistochemically analyzed. In addition, 12 human penile SCC and adjacent normal tissues were examined for CK2α protein and mRNA expression by Western blotting and real-time quantitative PCR, respectively. Survival was analyzed using the Kaplan-Meier test and the log-rank test. Multivariate Cox proportional hazard regression analysis was performed to determine the impacts of CK2α expression and the clinicopathological features on patient disease-specific survival (DSS). Likelihood ratios (LRs), Akaike information criterion (AIC) values, and concordance indexes (C-indexes) were investigated to evaluate the accuracies of the factors. Bootstrap-corrected C-indexes were used for internal validation (with sampling 1000 times).

Results

A significant difference in the distribution of CK2α was observed between the normal and penile carcinoma tissues (P<0.001). CK2α expression was associated with the pathological T and N stages in the penile cancer tissues (P<0.001). High CK2α expression was with significantly poorer DSS compared with low expression one (P<0.001). Western blotting and real-time quantitative PCR also confirmed that CK2α expression was increased in the penile cancer tissues. In multivariate Cox regression analysis, CK2α overexpression still was one of independent prognostic factors for penile SCC (P=0.005). The predictive accuracy of CK2α was verified by analysis of the C-indexes.

Conclusion

High protein kinase CK2α expression is associated with several prognostic factors and is thus a significant indicator of poor prognosis for penile cancer.

Establishment and characterization of a penile cancer cell line, penl1, with a deleterious TP53 mutation as a paradigm of HPV-negative penile carcinogenesis

PURPOSE

To establish penile cancer (PeCa) cell lines for the study of molecular mechanisms of carcinogenesis and testing therapeutic reagents.

MATERIALS AND METHODS

We successfully established two PeCa cell lines from fresh tumor tissues from 21 cases. One cell line named Penl1 was isolated from a lymph node metastasis (LNM) of penile squamous cell carcinoma (PeSCC), usual type and comprehensively characterized here. Our in-depth characterization analysis of the Penl1 cell line included morphology, tumorigenicity, genetic characteristics, protein expression, biology, and chemosensitivity. Penl1 was authenticated by single tandem repeat (STR) DNA typing.

RESULTS

Comparative histomorphology, genetic characteristics, and protein expression patterns revealed essential similarities between the cell line and its corresponding LNM. In-depth characterization analysis of Penl1 cell line revealed tumorigenicity in immunodeficient mice, negative human papilloma virus (HPV) and mycoplasma infection, TP53 mutations and sensitivity to cisplatin and epirubicin. STR DNA typing did not match any cell lines within three international cell banks. The limitation of this study is that one patient cannot represent the complete heterogeneity of PeCa, especially primary tumor.

CONCLUSIONS

We established and characterized an HPV-negative and moderately differentiated PeCa cell model with a TP53 missense mutation from a PeSCC, usual type patient. A preliminarily study of carcinogenesis and chemosensitivity suggests that this cell model carries a tumor suppressor gene mutation and is sensitive to chemotherapy drugs.

The Emerging Role and Promise of Biomarkers in Penile Cancer

Penile cancer is a rare malignancy, which can be a source of devastating psychosexual distress because of its implication on sexual function and self-image. Current penile staging relies on invasive techniques and is often inaccurate. The authors review the promising biomarkers currently under investigation and their application to the staging and prognosis of penile cancer. Further development of such biomarkers provides the potential of improved clinical management of this disease.

Overexpression of Insulin-like Growth Factor-1 Receptor Is Associated With Penile Cancer Progression

OBJECTIVE

To evaluate insulin-like growth factor-1 receptor (IGF1R) expression in penile cancer and its association with oncologic outcomes.

METHODS

Tissue microarrays were constructed from 53 patients treated at our institution. Expression of IGF1R was evaluated using a Her2-like scoring system. Overexpression was defined as 1+ or greater membranous staining. Association of IGF1R expression with pathologic features was assessed with comparative statistics, and association with local recurrence, progression to nodal or distance metastases, or death was assessed with Kaplan-Meier survival analysis and Cox proportional hazard regression models.

RESULTS

Overall, IGF1R overexpression was seen in 33 (62%) cases. With a median follow-up of 27.8 months, IGF1R overexpression was associated with inferior progression-free survival (PFS) (P  =  .003). In a multivariable model controlling for grade, T stage, perineural invasion, and lymphovascular invasion, IGF1R expression was independently associated with disease progression (hazard ratio 2.3, 95% confidence interval 1.1-5.1, P  =  .03. Comparing patients without IGF1R overexpression to those with overexpression, 5-year PFS was 94.1% vs 45.8%.

CONCLUSION

IGF1R overexpression was associated with inferior PFS in penile cancer. Drugs that target IGF1R and downstream messengers may have a therapeutic benefit in patients that exhibit IGF1R overexpression.

Expression of p53, Ki67, EcPV2- and EcPV3 DNA, and viral genes in relation to metastasis and outcome in equine penile and preputial squamous cell carcinoma

REASONS FOR PERFORMING STUDY

Equine penile and preputial squamous cell carcinoma (SCC) is a potentially lethal disease of which little is known regarding the relationship between tumour characteristics and prognosis.

OBJECTIVES

To assess the relationship between tumour differentiation grade (tumour subtype), presence of papillomaviruses, expression of viral genes (E2, E6, L1), nuclear proteins p53 and Ki67 and metastasis in equine penile and preputial SCC and to assess the relationship of tumour subtype, presence of papillomavirus type 2, p53 and Ki67 with survival.

STUDY DESIGN

Retrospective case-control study using archived material.

METHODS

Samples (n = 103) from 87 horses with penile and/or preputial intraepithelial neoplasia (PIN), papilloma or SCC and corresponding case files were evaluated. Tumours were graded microscopically and p53 and Ki67 expression evaluated immunohistochemically. Equine papillomavirus (EcPV) types 2 and 3 DNA was detected by conventional PCR. Real-time PCR was used for quantification of E2, E6 and L1 mRNA.

RESULTS

Equine papillomavirus type 2 DNA was detected in 89.4% and EcPV3 in 1.5% of horses. No differences in quantitative expression of E2, E6 and L1 oncogenes between subtypes were found. Expression of p53 and occurrence of metastasis were positively correlated to a less differentiated subtype (r = 0.429, P<0.001 and r = 0.769, P = 0.001, respectively). Differences in survival between subtypes were significant (log Rank P<0.001); horses with less differentiated tumours were more likely to die of the disease (papilloma 8.3%; G1 26.1%; G2 26.3%; G3 63.3%).

CONCLUSIONS

In equine penile and preputial SCC, tumour grading is an important prognosticator for survival and a predictor for presence of metastases. Expression of p53 and Ki67 and presence or expression of EcPV2 and EcPV3 do not appear to be important prognosticators.

Prognostic value of carbonic anhydrase IX expression in penile squamous cell carcinoma: a pilot study

OBJECTIVES

To determine whether carbonic anhydrase IX (CA IX) has prognostic value of lymph node metastases and cancer-specific survival in penile squamous cell carcinoma treated with surgery.

MATERIALS AND METHODS

CA IX expression was detected in the primary disease of 73 penile cancer patients using the method of immunohistochemistry. The expression levels of CA IX were categorized into 2 groups according to the cutoff of 10% of positively stained tumor cells. Associations between CA IX expression and clinicopathologic characteristics, immunoreactivity of p53 and Ki-67, and outcomes were analyzed.

RESULTS

High CA IX expression was observed in 31 (42.5%) of cases. CA IX expression was not associated with patient age, T stage, grade, lymphovascular invasion, and Ki-67 expression, but was associated with p53 expression (P = 0.015). Both univariate and multivariate analysis failed to show CA IX expression was a statistically significant predictor of lymph node metastases and cancer-specific survival.

CONCLUSIONS

Immunohistochemical expression of CA IX did not associate with lymph node metastases and cancer-specific survival in penile squamous cell carcinoma. A panel of prognostic markers that reflect the characteristic of tumor cell and organ microenvironment may be more suitable for prognostication in penile cancer.

Human papillomavirus prevalence, distribution and correlation to histopathological parameters in a large Swedish cohort of men with penile carcinoma

OBJECTIVE

• To analyse the overall and type-specific human papillomavirus (HPV) prevalence and distribution in penile carcinoma and determine the correlation to histopathological parameters.

PATIENTS AND METHODS

• In this retrospective study, we analysed HPV status in 241 patients with penile carcinoma, treated at Örebro University Hospital, Örebro, Sweden, between 1984 and 2008. Age and date at diagnosis was recorded. • The tumour specimens were categorized according to the UICC 2002 TNM classification. A subset of patients was operatively staged with regard to lymph node status. • A commercially available Real Time PCR was used to detect 13 different types of HPV (6,11,16,18,31,33,35,45,51,52,56,58 and 59).

RESULTS

• We excluded 25 patients due to low DNA quality. Of the remaining 216, 179 (82.9%) tumour specimens were HPV infected. The majority of cases positive for HPV (70.4%) were infected by a single-type. The most frequent type was HPV 16 followed by HPV 18. • No significant association between HPV status and pathological tumour stage, grade or lymph node status was found.

CONCLUSION

• The HPV prevalence found is higher than in most other studies, further strengthening HPV as an etiological agent in penile carcinoma. Furthermore, the high prevalence of HPV 16 and 18 raises the question of what potential impact current HPV vaccines that target these specific HPV types might have on penile carcinoma. No significant association between HPV status and histopathological parameters was found in the present study. Additional investigations are needed to draw final conclusions on the prognostic value of HPV status in penile carcinoma.

Controversies in ilioinguinal lymphadenectomy

Patients with penile cancer who are proven to have negative inguinal lymph nodes have an excellent prognosis. Furthermore, patients with small-volume inguinal node involvement can often be cured by surgery alone. Lymphadenectomy has clear survival benefits for patients when applied to those with lymph node metastasis. However, the current morbidity of the standard technique of lymphadenectomy is an impediment to its universal application, and innovative strategies to reduce the morbidity of staging/treatment that do not compromise oncologic control must be developed and standardized. The optimal integration of multimodality therapy to improve survival in advanced disease will occur only through collaborative studies between centers with significant patient volume, which would be facilitated through the development of regional referral centers.

The role of annexins I, II and IV in tumor development, progression and metastasis of human penile squamous cell carcinomas

PURPOSE

The outcome of patients with penile squamous cell carcinomas (PSCC) largely depends on occurrence of metastasis. Therefore, prognostic markers indicating the risk for tumor cell spreading would be useful. Since Annexins are potential prognostic markers in a variety of tumors, we immunohistochemically examined the expression of Annexins I, II and IV (ANX AI, ANX AII and ANX AIV) in PSCC.

METHODS

Samples originated from 29 patients subjected to surgical resection of invasive PSCC. Immunohistochemistry was done on paraffin-embedded sections using monoclonal antibodies against ANX AI, ANX AII and ANX AIV. Expression of ANXs was compared with clinical data.

RESULTS

ANX AI expression was found in conventional PSCC and was absent in basaloid and sarcomatoid subtypes. High ANX AI score was significantly associated with higher T stages (P = 0.006). Strong expression in the invasion front of carcinomas was significantly associated with the occurrence of lymph node metastasis (P = 0.001). ANX AIV expression was weak in conventional PSCC, while it was strong in basaloid and sarcomatoid subtypes. Strong expression of Annnexin IV in the invasion front also showed a significant association with metastasis (P = 0.019).

CONCLUSION

Expression of ANXs was different in histologic subtypes of penile carcinomas. Strong expression of ANX AI and ANX AIV in the invasion front seems to indicate a higher risk of lymph node metastasis.