Human papillomavirus-associated increase in p16INK4A expression in penile lichen sclerosus and squamous cell carcinoma

Immunologic and nonimmunologic sclerodermal skin conditions - review

Scleroderma-like cutaneous lesions have been found in many pathological conditions and they have the clinical appearance of sclerotic or scleroatrophic lesions. Affected skin biopsies described histopathological changes similar to those of scleroderma located strictly on the skin or those of systemic sclerosis. These skin lesions can be found in inflammatory diseases with autoimmune substrate (generalized morphea, chronic graft versus host disease, eosinophilic fasciitis), tissue storage diseases (scleredema, scleromyxedema, nephrogenyc systemic fibrosis, systemic amyloidosis), metabolic diseases (porphyrya cutanea tarda, phenylketonuria, hypothyroidism, scleredema diabeticorum), progeroid syndromes. Given the multiple etiologies of sclerodermal lesions, a correct differential diagnosis is necessary to establish the appropriate treatment.

Lichen sclerosus: The 2023 update

Lichen sclerosus (LS) is an underdiagnosed inflammatory mucocutaneous condition affecting the anogenital areas. Postmenopausal women are predominantly affected and, to a lesser extent, men, prepubertal children, and adolescents. The etiology of LS is still unknown. Hormonal status, frequent trauma and autoimmune diseases are well-known associations for LS, yet infections do not seem to be clear risk factors. LS pathogenesis involves factors such as a genetic predisposition and an immune-mediated Th1-specific IFNγ-induced phenotype. Furthermore, there is a distinct expression of tissue remodeling associated genes as well as microRNAs. Oxidative stress with lipid and DNA peroxidation provides an enabling microenvironment to autoimmunity and carcinogenesis. Circulating IgG autoantibodies against the extracellular matrix protein 1 and hemidesmosome may contribute to the progression of LS or simply represent an epiphenomenon. The typical clinical picture includes chronic whitish atrophic patches along with itching and soreness in the vulvar, perianal and penile regions. In addition to genital scarring, and sexual and urinary dysfunction, LS may also lead to squamous cell carcinoma. Disseminated extragenital LS and oral LS are also reported. The diagnosis is usually clinical; however, a skin biopsy should be performed in case of an unclear clinical picture, treatment failure or suspicion of a neoplasm. The gold-standard therapy is the long-term application of ultrapotent or potent topical corticosteroids and, alternatively, topical calcineurin inhibitors such as pimecrolimus or tacrolimus. Collectively, LS is a common dermatological disease with a so far incompletely understood pathogenesis and only limited treatment options. To foster translational research in LS, we provide here an update on its clinical features, pathogenesis, diagnosis and (emerging) treatment options.

Penile Lichen Sclerosis: A Surgical Perspective of its Aetiology and Treatment

Penile lichen sclerosis is a longstanding inflammatory disease of the skin with a controversial aetiology. Penile lichen sclerosis (PLS) is a growing, inflammatory dermatitis of the anogenital region, which involves the meatus, prepuce, penile shaft, and glans penis. Although the accurate aetiology of PLS is contentious, multiple factors including genetics, autoimmunity, infections of human papillomavirus, hepatitis C, Epstein-Barr virus, risk factors (hormonal and trauma), etc., can be considered to be a part of the etiopathogenesis of PLS. The initial clinical presentations of penile lichen sclerosis are white plaques, atrophied skin, erythema, erosions, and sclerosis in the anogenital region. When the disease advances, the following can occur, including meatal constraints, telangiectasia, petechiae, soreness, papular lesions, tightness of the foreskin, difficulties in passing urine, itching, tenderness on erections, pain, cracking, bleeding, redness, rashes, tightness at frenulum, and dysuria. This disease has a dangerous course of action and if untreated it may be linked with severe urologic and sexual morbidities. PLS is usually treated with medical and surgical interventions like topical or intralesional steroids and circumcision. The role of circumcision is very critical in the course of action and prognosis of PLS, and its treatment is dependent on the stage of the disease. This review brings up the knowledge regarding epidemiology, etiopathology, clinical presentation, and management of PLS with an emphasis on the role of circumcision.

Immunogenetics and human papillomavirus (HPV) in male genital lichen sclerosus (MGLSc)

BackgroundThe pathogenesis of male genital lichen sclerosus (MGLSc) is controversial. Incriminated factors include infection with human papillomavirus (HPV) and autoimmunity (e.g. Human Leukocyte Antigen [HLA]). To address the roles of HLA and HPV in MGLSc we studied adult Caucasian males with a clinical and histological diagnosis of MGLSc. The men in the study attended two specialised Male Genital Dermatoses Clinics between July 2011 and September 2012 and were selected and phenotyped from the clinical records. DNA was extracted from blood and paraffin-embedded biopsy sections, for HLA and HPV typing, respectively. HLA allele frequencies were compared with those derived from the UK-based Caucasian population. Eighty-eight cases of MGLSc were identified. HPV DNA was detected in 33/88 (37.5%) cases of MGLSc. HPV16 was the most prevalent type found: 11/88 (12.5%) MGLSc. No statistically significant HLA associations were established but HLA-B*35, -B*51, -C*15, -DRB1*04, -DRB1*10 (predisposition) and -DQA1*01 (protection) were revealed as alleles of interest. HPV16-associated MGLSc cases showed no statistically significant association with HLA genotype. The relationship between HPV and MGLSc suggests a passenger effect rather than a pathogenic role. HLA is not associated with MGLSc nor co-existent HPV16.

Risk factors and molecular characterization of penile cancer: impact on prognosis and potential targets for systemic therapy

PURPOSE OF REVIEW

To provide a comprehensive summary of risk factors, molecular machinery as well as potential therapeutic targets with a particular focus on literature published in the last 2 years on prognosis and treatment of penile cancer (PeCa).

RECENT FINDINGS

E2F, LAMC2, MAML2, ID1 and IGFBP2 proteins were demonstrated to play a critical role for aggressive tumor behavior and might predict poor survival in PeCa. PD-L1 axis was confirmed as a promising pathway to serve as a therapeutic target. A number of genetic alterations were illuminated. In clinical testing, pan-HER tyrosine kinase inhibitor dacomitinib provided promising results in chemo-naïve and EGFR monoantibody nimotuzumab in chemotherapy-failed PeCa patients.

SUMMARY

Knowledge of prognosis-relevant altered molecular pathways in PeCa is expanding paving the way for identification of potential therapeutic targets. Multicenter clinical trials in the setting of centralized PeCa care are warranted to foster effective marker-based individualized treatment strategies.

The relationship between human papillomavirus and penile cancer over the past decade: a systematic review and meta-analysis

Human papillomavirus (HPV) infection appears to play an important role in the development of penile cancer (PeCa), but their relationship remains unclear. Therefore, we performed a systematic review and meta-analysis to elucidate their relationship. We systematically searched Embase, PubMed, Cochrane Library, and Web of Science for case-control studies and cross-sectional studies using polymerase chain reaction (PCR) technology on formalin-fixed paraffin-embedded (FFPE) or paraffin-embedded (PE) PeCa tissues to detect HPV (published between January 1, 2007, and December 29, 2017; no language restrictions). Twenty-two studies were identified, and 1664 cases were available for analysis. The combined HPV infectious risk of PeCa is 51.0% (95% confidence interval [CI]: 43.0%–60.0%). The three most common subtypes of HPV were HPV16 (28.5%), HPV18 (2.3%), and HPV6 (2.3%). The virus was relevantly associated with basaloid (85.5%, 95% CI: 77.2%–93.8%) and warty (50.0%, 95% CI: 35.2%–64.8%) carcinomas. The invasiveness of PeCa was not associated with HPV (χ² = 0.181, df = 1, P < 0.671). HPV infection in PeCa tended to be moderately differentiated (54.4%, 95% CI: 47.7%–61.1%). This study found that almost half of PeCa patients are associated with HPV. The most commonly associated genotype is HPV16, but several other genotypes were also detected. In addition to types 6 and 11, other single low-risk HPV infections have been found to contribute to PeCa to a lesser degree. HPV-positive tumors tend to exhibit warty and/or basaloid features, corresponding to a moderate histological grade. The role of HPV in PeCa should be revisited to provide evidence for the development of PeCa in the presence of HPV infection.

Prevalence of human papillomavirus DNA and p16INK4a in penile cancer and penile intraepithelial neoplasia: a systematic review and meta-analysis

BACKGROUND

Although previous meta-analyses have examined human papillomavirus (HPV) DNA prevalence in penile cancer, none, to our knowledge, have assessed pooled HPV DNA prevalence in penile intraepithelial neoplasia or p16^INK4a percent positivity in penile cancer and penile intraepithelial neoplasia. Therefore, we aimed to examine the prevalence of HPV DNA and p16^INK4a positivity in penile cancer and penile intraepithelial neoplasia worldwide.

METHODS

In this systematic review and meta-analysis, we searched PubMed, Embase, and the Cochrane Library until July 24, 2017, for English-language articles published from Jan 1, 1986, onwards reporting the prevalence of HPV DNA and p16^INK4a positivity, either alone or in combination, in at least five cases of penile cancer or penile intraepithelial neoplasia. Only studies that used PCR or hybrid capture for the detection of HPV DNA and immunohistochemical staining or methylation for the detection of p16^INK4a were included. Data were extracted and subsequently crosschecked, and inconsistencies were discussed to reach consensus. Using random-effects models, we estimated the pooled prevalence and 95% CI of HPV DNA and p16^INK4a positivity in penile cancer and penile intraepithelial neoplasia, stratifying by histological subtype and HPV DNA or p16^INK4a detection method. Type-specific prevalence of HPV6, HPV11, HPV16, HPV18, HPV31, HPV33, and HPV45 in penile cancer was estimated.

FINDINGS

Our searches identified 1836 non-duplicate records, of which 73 relevant papers (71 studies) were found to be eligible. The pooled HPV DNA prevalence in penile cancer (52 studies; n=4199) was 50·8% (95% CI 44·8-56·7; I²=92·6%, p_{heterogeneity}<0·0001). A high pooled HPV DNA prevalence was seen in basaloid squamous cell carcinomas (84·0%, 95% CI 71·0-93·6; I²=48·0%, p_{heterogeneity}=0·0197) and in warty-basaloid carcinoma (75·7%, 70·1-81·0; I²=0%, p_{heterogeneity}=0·52). The predominant oncogenic HPV type in penile cancer was HPV16 (68·3%, 95% CI 58·9-77·1), followed by HPV6 (8·1%, 4·0-13·7) and HPV18 (6·9%, 2·9-12·4). The pooled HPV DNA prevalence in penile intraepithelial neoplasia (19 studies; n=445) was 79·8% (95% CI 69·3-88·6; I²=83·2%, p_{heterogeneity}<0·0001). The pooled p16^INK4a percent positivity in penile cancer (24 studies; n=2295) was 41·6% (95% CI 36·2-47·0; I²=80·6%, p_{heterogeneity}<0·0001), with a high pooled p16^INK4a percent positivity in HPV-related squamous cell carcinoma (85·8%, 95% CI 72·1-95·4; I²=56·4%, p_{heterogeneity}=0·0011) as compared with non-HPV-related squamous cell carcinoma (17·1%, 7·9-29·1; I²=78·3%, p_{heterogeneity}<0·0001). Moreover, among HPV-positive cases of penile cancer, the p16^INK4a percent positivity was 79·6% (95% CI 65·7-90·7; I²=89·9%, p_{heterogeneity}<0·0001), compared with 18·5% (9·6-29·6; I²=89·3%, p_{heterogeneity}<0·0001) in HPV-negative penile cancers. The pooled p16^INK4a percent positivity in penile intraepithelial neoplasia (six studies; n=167) was 49·5% (95% CI 18·6-80·7).

INTERPRETATION

A large proportion of penile cancers and penile intraepithelial neoplasias are associated with infection with HPV DNA (predominantly HPV16), emphasising the possible benefits of HPV vaccination in men and boys.

FUNDING

None.

Treatment of penile lichen sclerosus with topical corticosteroids for over 25 years' duration: A case report

Topical corticosteroids are currently recommended only for short-term management of flares of lichen sclerosus, with efficacy in halting disease progression. Given the chronic nature of this condition, there is a lack of literature surrounding the chronic effects of topical corticosteroids on the male genitalia with many dermatologists avoiding prescribing long term. This case report aims to provide anecdotal observation for the long-term use of topical corticosteroids and details the long-term follow-up of an individual who used potent and superpotent topical corticosteroids for over 25 years without significant demonstrable side effects. A short review on relevant literature is provided.

Uncommon oral manifestation of lichen sclerosus: critical analysis of cases reported from 1957 to 2016

Background

Lichen sclerosus is a mucocutaneous autoimmune disease which might be initiated by infectious pathogens as Borrelia Bugrdorferi and HPV. This disease shows destructive potential and is rarely diagnosed in oral mucosa. The purpose of this paper is to evaluate the characteristics of cases described in literature from 1957 to 2016, looking to provide valuable evidence about clinicopathologic features of this disease.

Material and Methods

A MedLine search was performed aiming to find oral lichen sclerosus cases in literature and discuss its demographical and pathological characteristics as well as treatment methods performed for these cases.

Results

34 oral lichen sclerosus cases with histological confirmation and one clinicopathologic study linked with this disease were found in literature. Oral lichen sclerosus affected most commonly female patients, were asymptomatic and not associated to skin or genital lesions. Furthermore, affected patients in a range of 7 – 70-years old (Average age = 31.81).

Conclusions

Oral lichen sclerosus is a rare pathologic process with slight predilection for prepubertal girls, for which topical corticosterois have demonstrated satisfactory therapeutic value.

Key words:Lichen sclerosus et atrophicous, skin diseases, mouth disease, autoimmune diseases, mouth.

Vulvar Lichen Sclerosus et Atrophicus

Vulvar lichen sclerosus (VLS) is a chronic inflammatory dermatosis characterized by ivory-white plaques or patches with glistening surface commonly affecting the vulva and anus. Common symptoms are irritation, soreness, dyspareunia, dysuria, and urinary or fecal incontinence. Anogenital lichen sclerosus (LS) is characterized by porcelain-white atrophic plaques, which may become confluent extending around the vulval and perianal skin in a figure of eight configuration. Thinning and shrinkage of the genital area make coitus, urination, and defecation painful. LS is not uncommon in India and present as an itchy vulvar dermatosis which a gynecologist may mistake for candidal vulvovaginitis. There is often a delay in diagnosis of VLS due to its asymptomatic nature and lack of awareness in patients as well as physicians. Embarrassment of patients due to private nature of the disease and failure to examine the genital skin properly are the other reasons for delay in diagnosis. There is no curative treatment for LS. Various medications available only relieve the symptoms. Chronic nature of the disease affects the quality of life. Proper and regular follow-up is required as there are chances of the development of squamous cell carcinoma.

Expression of Ki-67 and P16 INK4a in chemically-induced perioral squamous cell carcinomas in mice

OBJECTIVE

to evaluate the influence of Ki-67 and P16INK4a proteins immunohistochemical expressions on the clinical and morphological parameters of perioral squamous cell carcinoma induced with 9,10-dimethyl-1,2-benzanthracene (DMBA) in mice.

METHODS

we topically induced the lesions in the oral commissure of ten Swiss mice for 20 weeks, determining the time to tumors onset and the average tumor volume up to 26 weeks. In histopathological analysis, the variables studied were histological malignancy grade and the immunohistochemical expression of Ki-67 and P16INK4a proteins. The correlation between variables was determined by application of the Spearman correlation test.

RESULTS

the mean time to onset of perioral lesions was 21.1 ± 2.13 weeks; mean tumor volume was 555.91 ± 205.52 mm3. Of the induced tumors, 80% were classified as low score and 20% high score. There was diffuse positivity for Ki-67 in 100% of lesions - Proliferation Index (PI) of 50.1 ± 18.0. There was a strong direct correlation between Ki-67 immunoreactivity and tumor volume (R = 0.702) and a low correlation with the malignancy score (R = 0.486). The P16INK4a protein expression was heterogeneous, showing a weak correlation with tumor volume (R = 0.334). There was no correlation between the immunohistochemical expression of the two proteins studied.

CONCLUSION

in an experimental model of DMBA-induced perioral carcinogenesis, tumor progression was associated with the tumor proliferative fraction (Ki-67 positive cells) and with tumor histological grading, but not with P16INK4a expression.

OBJETIVO

avaliar a influência da expressão imuno-histoquímica das proteínas Ki-67 e p16INK4a sobre parâmetros clínico-morfológicos em carcinomas espinocelulares periorais quimicamente induzidos com 9,10-dimetil-1,2-benzantraceno (DMBA) em modelo murino.

MÉTODOS

as lesões foram induzidas topicamente na comissura labial de dez camundongos Swiss durante 20 semanas, sendo determinado o momento de surgimento dos tumores e volume tumoral médio até 26 semanas. Na análise histopatológica, as variáveis estudadas foram gradação histológica de malignidade tumoral e expressão imuno-histoquímica das proteínas Ki-67 e p16INK4a. A correlação entre as variáveis estudadas foi determinada pela aplicação do teste de correlação de Spearman.

RESULTADOS

o tempo médio de surgimento das lesões periorais foi 21,1±2,13 semanas. Volume tumoral médio foi de 555,91±205,52mm3. Dos tumores produzidos, 80% foram classificados como de baixo escore e 20%, alto escore. Evidenciou-se positividade difusa para Ki-67 em 100% das lesões - índice de marcação (PI) de 50,1±18,0. Verificou-se correlação direta forte entre a imunoexpressão do Ki-67 e o volume tumoral (R=0,702) e fraca correlação com o escore de malignidade (R=0,486). A expressão da proteína p16INK4a foi heterogênea, mostrando fraca correlação com o volume tumoral (R=0,334). Não houve correlação entre a expressão imuno-histoquímica das duas proteínas estudadas.

CONCLUSÃO

Em modelo experimental de carcinogênese perioral DMBA-induzida, a progressão tumoral está associada à fração proliferativa do tumor (células ki-67 positivas) e com a gradação histológica tumoral, porém não com a expressão da p16INK4a.

Male genital lichen sclerosus

Male genital lichen sclerosus (MGLSc) is a chronic inflammatory skin disease responsible for male sexual dyspareunia and urological morbidity. An afeared complication is squamous cell carcinoma (SCC) of the penis. The precise etiopathogenesis of MGLSc remains controversial although genetic, autoimmune and infective (such as human papillomavirus (HPV) hepatitis C (HCV), Epstein-Barr virus (EBV) and Borrelia) factors have been implicated: Consideration of all the evidence suggests that chronic exposure of susceptible epithelium to urinary occlusion by the foreskin seems the most likely pathomechanism. The mainstay of treatment is topical ultrapotent corticosteroid therapy. Surgery is indicated for cases unresponsive to topical corticosteroid therapy, phimosis, meatal stenosis, urethral stricture, carcinoma in situ (CIS) and squamous cell carcinoma.

Molecular research in penile cancer-lessons learned from the past and bright horizons of the future?

Penile cancer is a rare tumor. There is a limited understanding of the biological mediators of prognostic and therapeutic importance in penile cancer. However, there exists some fundamental understanding of the major pathways involved in the development of penile pre-neoplastic lesions and neoplasms. The aim of the present review is to highlight our current state of molecular knowledge in penile cancer to foster the necessary tools for researchers to pave major advancements in our current treatment paradigms and cancer specific outcomes.

Differential gene hypermethylation in genital lichen sclerosus and cancer: a comparative study

AIMS

Lichen sclerosus (LS) is a chronic inflammatory disease of the genital skin of unknown aetiology. The role of LS in penile squamous cell carcinogenesis is not well characterized. HPV has been implicated in both, as have epigenetic changes. The presence of HPV and hypermethylation of the MGMT, p16, RASSF1, RASSF2, TSLC1 and TSP1 genes were studied in penile LS; MGMT, RASSF2 and TSLC1 hypermethylation in penile cancer and TSLC1 hypermethylation in vulvar LS and cancer extends previous results reported by our group.

METHODS AND RESULTS

Thirty-seven HPV genotypes and hypermethylation were evaluated by PCR/reverse-line-blot and methylation-specific PCR respectively, in 27 preputial LS, 24 penile SCC, 30 vulvar SCC, 21 vulvar LS and 22 normal skin cases. HPV66 was present in 3.7% of penile LS cases, and p16 and RASSF2 hypermethylation were more frequent in penile cancer than in penile LS. p16, RASSF1, RASSF2 and TSP1 hypermethylation were similar in penile and vulvar LS.

CONCLUSIONS

Gene hypermethylation is a common event in penile LS, and occurs approximately as frequently as in vulvar LS. Certain genes can be hypermethylated as an early or late event in LS or cancer, respectively. This suggests a possible sequential role for these alterations in the transition from benign to malignant lesions.

Genital lichen sclerosus/balanitis xerotica obliterans in men with penile carcinoma: a critical analysis

WHAT'S KNOWN ON THE SUBJECT? AND WHAT DOES THE STUDY ADD?: The European Association of Urology guidelines identify lichen sclerosus (LS) as a strong risk factor for penile squamous cell carcinoma (pSCC). However, this statement is based on the findings of case-control studies (Level of Evidence 2a) and a direct causal relationship between LS/balanitis xerotica obliterans (BXO) and pSCC remains to be established. Firm guidelines with respect to the appropriate follow-up policy for LS/BXO are lacking, whereas the impact of synchronous LS/BXO on the prognosis of pSCC remains to be determined. The presence of histologically-confirmed synchronous LS/BXO in patients diagnosed with pSCC is relatively high, although it is not associated with an increased risk of adverse histopathological features. LS/BXO can develop in extragenital skin grafts used for reconstruction after organ-sparing surgery for pSCC.

OBJECTIVES

To determine the rate of lichen sclerosus/balanitis xerotica obliterans (LS/BXO) in patients with penile squamous cell carcinoma (pSCC) and establish whether the presence of LS/BXO is associated with adverse histopathological features of pSCC. To report the phenomenon of LS involving non-genital skin grafts in patients who underwent organ-sparing surgery and split-skin graft (SSG) reconstruction

PATIENTS AND METHODS

Between January 2002 and January 2010, 223 men underwent surgical treatment for pSCC. A group of 52 patients with histologically-confirmed synchronous LS was identified (group A; overall rate of LS/BXO = 23.3%) and compared with a group of patients without synchronous LS (group B; n = 171; 76.7%). A subgroup of patients who underwent surgical excision and SSG reconstruction was also identified The histology reports of graft biopsies obtained during follow-up were reviewed and the rate of LS involving the graft was also recorded.

RESULTS

Mean (range) age at diagnosis was 60.9 (34-81) years and 60.7 (28-89) years for groups A and B, respectively (P = 0.958). The mean (range) duration of follow-up was 38.3 (4-92) months for group A and 45.5 (4-107) months for group B (P = 0.162) No statistically significant differences were noted between groups A and B in terms of tumour grade (P = 0.091), stage (P = 0.697), presence of lymphovascular invasion (P = 0.333), histological subtype (P = 0.107), associated carcinoma in situ (P = 0.246) or nodal status at initial diagnosis (P = 0.555). In the subgroup of 188 patients who underwent SSG reconstruction, 41 (21.8%) patients had histologically-confirmed synchronous LS; in this subgroup, 26 (13.8%) patients underwent graft biopsy during follow-up. Genital LS involving the graft was identified in seven specimens, although none of these seven cases had associated recurrent pSCC.

CONCLUSIONS

The presence of histologically-confirmed synchronous LS in patients with pSCC is relatively high but is not associated with increased rates of adverse histopathological features, including carcinoma in situ. LS can develop in extragenital skin grafts, although its association with the long-term risk for recurrent pSCC is not apparent in the present study.

Overexpression of ANXA1 in penile carcinomas positive for high-risk HPVs

The incidence of penile cancer varies between populations but is rare in developed nations. Penile cancer is associated with a number of established risk factors and associated diseases including phimosis with chronic inflammation, human papillomavirus (HPV) infection, poor hygiene and smoking. The objective of this study was to identify genes related to this type of cancer. The detection of HPV was analyzed in 47 penile squamous cell carcinoma samples. HPV DNA was detected in 48.9% of penile squamous cell carcinoma cases. High-risk HPV were present in 42.5% of cases and low-risk HPV were detected in 10.6% of penile squamous cell carcinomas. The RaSH approach identified differential expression of Annexin A1 (ANXA1), p16, RPL6, PBEF1 and KIAA1033 in high-risk HPV positive penile carcinoma; ANXA1 and p16 were overexpressed in penile squamous cells positive for high-risk HPVs compared to normal penile samples by qPCR. ANXA1 and p16 proteins were significantly more expressed in the cells from high-risk HPV-positive penile carcinoma as compared to HPV-negative tumors (p<0.0001) independently of the subtype of the carcinoma. Overexpression of ANXA1 might be mediated by HPV E6 in penile squamous cell carcinoma of patients with high-risk HPVs, suggesting that this gene plays an important role in penile cancer.

Gene expression profiling in male genital lichen sclerosus

Male genital lichen sclerosus (MGLSc) has a bimodal distribution in boys and men. It is associated with squamous cell carcinoma (SCC). The pathogenesis of MGLSc is unknown. HPV and autoimmune mechanisms have been mooted. Anti extracellular matrix protein (ECM)1 antibodies have been identified in women with GLSc. The gene expression pattern of LSc is unknown. Using DNA microarrays we studied differences in gene expression in healthy and diseased prepuces obtained at circumcision in adult males with MGLSc (n = 4), paediatric LSc (n = 2) and normal healthy paediatric foreskin (n = 4). In adult samples 51 genes with significantly increased expression and 87 genes with significantly reduced expression were identified; paediatric samples revealed 190 genes with significantly increased expression and 148 genes with significantly reduced expression. Concordance of expression profiles between adult and paediatric samples indicates the same disease process. Functional analysis revealed increased expression in the adult and child MGSLc samples in the immune response/cellular defence gene ontology (GO) category and reduced expression in other categories including genes related to squamous cancer. No specific HPV, autoimmune or squamous carcinogenesis-associated gene expression patterns were found. ECM1 and CABLES1 expression were significantly reduced in paediatric and adult samples respectively.

Clinical parameters in male genital lichen sclerosus: a case series of 329 patients

BACKGROUND

  The dermatological aspects of male genital lichen sclerosus (MGLSc) have not received much prominence in the literature. Sexual morbidity appears under-appreciated, the role of histology is unclear, the relative places of topical medical treatment and circumcision are not established, the prognosis for sexual function, urinary function and penis cancer is uncertain and the pathogenesis has not been specifically studied although autoimmunity (as in women) and HPV infection have been mooted.

OBJECTIVE

  To illuminate the above by analysing the clinical parameters of a large series of patients with MGLSc.

METHODS

  A total of 329 patients with a clinical diagnosis of MGLSc were identified retrospectively from a dermatology-centred multidisciplinary setting. Their clinical and histopathological features and outcomes have been abstracted from the records and analysed by simple descriptive statistics.

RESULTS

  The collation and analysis of clinical data derived from the largest series of men with MGLSc ever studied from a dermatological perspective has been achieved. These data allow the conclusions below to be drawn.

CONCLUSIONS

  MGLSc is unequivocally a disease of the uncircumcised male; the adult peak is late in the fourth decade; dyspareunia is a common presenting complaint; non-specific histology requires careful interpretation; most men are either cured by topical treatment with ultrapotent steroid (50-60%) or by circumcision (>75%); effective and definitive management appears to abrogate the risk of developing penile squamous cell carcinoma; urinary contact is implicated in the pathogenesis of MGLSc; HPV infection and autoimmunity seem unimportant.

Alternative HER/PTEN/Akt pathway activation in HPV positive and negative penile carcinomas

Background

The pathogenesis of penile squamous cell carcinoma (PSCC) is not well understood, though risk factors include human papillomavirus (HPV). Disruption of HER/PTEN/Akt pathway is present in many cancers; however there is little information on its function in PSCC. We investigated HER family receptors and phosphatase and tension homolog (PTEN) in HPV-positive and negative PSCC and its impact on Akt activation using immunohistochemistry and fluorescent in situ hybridisation (FISH).

Methodology/Principal Findings

148 PSCCs were microarrayed and immunostained for phosphorylated EGFR (pEGFR), HER2, HER3, HER4, phosphorylated Akt (pAkt), Akt1 and PTEN proteins. EGFR and PTEN gene status were also evaluated using FISH. HPV presence was assessed by PCR. pEGFR expression was detected significantly less frequently in HPV-positive than HPV-negative tumours (p = 0.0143). Conversely, HER3 expression was significantly more common in HPV-positive cases (p = 0.0128). HER4, pAkt, Akt and PTEN protein expression were not related to HPV. HER3 (p = 0.0054) and HER4 (p = 0.0002) receptors significantly correlated with cytoplasmic Akt1 immunostaining. All three proteins positively correlated with tumour grade (HER3, p = 0.0029; HER4, p = 0.0118; Akt1, p = 0.0001). pEGFR expression correlated with pAkt but not with tumour grade or stage. There was no EGFR gene amplification. HER2 was not detected. PTEN protein expression was reduced or absent in 62% of tumours but PTEN gene copy loss was present only in 4% of PSCCs.

Conclusions/Significance

EGFR, HER3 and HER4 but not HER2 are associated with penile carcinogenesis. HPV-negative tumours tend to express significantly more pEGFR than HPV-positive cancers and this expression correlates with pAkt protein, indicating EGFR as an upstream regulator of Akt signalling in PSCC. Conversely, HER3 expression is significantly more common in HPV-positive cases and positively correlates with cytoplasmic Akt1 expression. HER4 and PTEN protein expression are not related to HPV infection. Our results suggest that PSCC patients could benefit from therapies developed to target HER receptors.

Lichen sclerosus in boys

BACKGROUND

Lichen sclerosus (LS) is a sclerosing skin disease. When it appears in boys, it nearly always affects the penis and usually causes phimosis requiring surgical treatment. The clinical significance of this disease in boys is inadequately recognized.

METHODS

The etiology, clinical manifestations, diagnosis, and treatment of LS in boys are presented in the light of a review of selected literature. We also present our own experience with this disease in an ambulatory pediatric surgery practice.

RESULTS

LS has long been recognized as a disease of the prepubertal male genitalia (in such cases, the condition is also called "balanitis xerotica obliterans"). It is thought to be the main cause of acquired phimosis, and it can also involve the meatus and urethra as it progresses. Its possible association with squamous cell carcinoma of the penis remains unclear. Its etiology is unknown; its pathophysiological mechanism involves T-lymphocyte-mediated inflammation. The treatment of choice is complete circumcision. There is still controversy regarding the conservative treatment of LS with topical steroids.

CONCLUSION

LS is much more common in boys than is generally assumed. Lichen sclerosus should be suspected in any case of acquired phimosis. Treatment with complete circumcision does not necessarily bring about a definitive cure. Further research on the pathogenesis of this disease is needed.

Penile cancer--prevention and premalignant conditions

OBJECTIVES

Relatively little evidence is available in the published studies on the prevention of penile cancer and premalignant conditions of the penis. The present review examined the current evidence available in preventing penile cancer and pathologic subtypes of premalignant conditions and their treatment. The recommendations made in the present review formulate the basis of the recent 2009 International Consultation on Urologic Disease Consensus Publishing Group.

METHODS

The association of human papillomavirus subtypes and penile cancer is well-established, although the etiology, natural history, and treatment of premalignant lesions have mainly been reported in retrospective case series with short-term follow-up. The exact pathologic role of chronic inflammatory conditions, such as balanitis xerotica obliterans in the etiology of penile cancer remains largely unknown.

RESULTS

Some of the potential strategies for the prevention of penile cancer could include circumcision, reducing the risk of transmission of penile human papillomavirus infection with male vaccination, early treatment of phimosis, smoking cessation, and hygienic measures. Implementing some of these measures would require extensive cost/benefit analysis, with significant changes in the global health policy.

CONCLUSIONS

Owing to the current levels of evidence from published studies, firm guidelines cannot be formulated for the treatment of premalignant conditions, although preventative measures, such as reducing human papillomavirus transmission, could become strategic health targets.

Relationship among human papillomavirus infection, p16(INK4a), p53 and NF-κB activation in penile cancer from northern Thailand

Human papillomavirus (HPV) E6 and E7 oncoproteins are essential factors for HPV oncogenesis. These E6 and E7 gene products play a central role in the induction of malignant transformation by interacting with several cellular regulatory proteins such as p16(INK4a), p53 and nuclear factor κB (NF-κB). In the present study, conducted in northern Thailand, HPV-DNA was detected in penile cancer cases using an in situ hybridization procedure and p16(INK4a), p53 and NF-κB were detected by immunohistochemistry. Using the cell cycle regulatory proteins p16(INK4a) (61.5%) and p53 (71.8%), it was found that of the 51 cases, 39 (76.5%) were HPV-DNA-positive in penile cancer. On the other hand, 25% p16(INK4a) and 75% p53, respectively, were found in HPV-negative cases. Prevalence of HPV infection (76.5%) was shown in penile cancer cases in northern Thailand. No difference was found between HPV-positive and HPV-negative cases with respect to the presence of the cell cycle regulatory protein p53. On the other hand, p16(INK4a) was found to be different between HPV-positive and HPV-negative cases. Inactivation of tumor suppressor genes, such as p16(INK4a) and p53, to genetic instability, cell immortalization, accumulation of mutations and cancer formation, with or without HPV and irrespective of HPV infection, is therefore suggested. Of the 39 HPV-positive cases, 35 (89.7%) were NF-κB-positive in the nucleus, 29 (74.4%) in the cytoplasm and 37 (94.9%) in the nucleus and/or cytoplasm. NF-κB was detected in 4 (33.3%) of the 12 HPV-negative cases. Therefore, we propose that penile cancer cases with HPV infection are more likely to activate NF-κB than those without HPV infection.

HPV infection and immunochemical detection of cell-cycle markers in verrucous carcinoma of the penis

Penile verrucous carcinoma is a rare disease and little is known of its aetiology or pathogenesis. In this study we examined cell-cycle proteins expression and correlation with human papillomavirus infection in a series of 15 pure penile verrucous carcinomas from a single centre. Of 148 penile tumours, 15 (10%) were diagnosed as pure verrucous carcinomas. The expression of the cell-cycle-associated proteins p53, p21, RB, p16(INK4A) and Ki67 were examined by immunohistochemistry. Human papillomavirus infection was determined by polymerase chain reaction to identify a wide range of virus types. The expression of p16(INK4A) and Ki67 was significantly lower in verrucous carcinoma than in usual type squamous cell carcinoma, whereas the expression of p53, p21 and RB was not significantly different. p53 showed basal expression in contrast to usual type squamous cell carcinoma. Human papillomavirus infection was present in only 3 out of 13 verrucous carcinomas. Unique low-risk, high-risk and mixed viral infections were observed in each of the three cases. In conclusion, lower levels of p16(INK4A) and Ki67 expressions differentiate penile verrucous carcinoma from usual type squamous cell carcinoma. The low Ki67 index reflects the slow-growing nature of verrucous tumours. The low level of p16(INK4A) expression and human papillomavirus detection suggests that penile verrucous carcinoma pathogenesis is unrelated to human papillomavirus infection and the oncogenes and tumour suppressor genes classically altered by virus infection.

Human papillomavirus prevalence and type distribution in penile carcinoma

BACKGROUND

Penile carcinoma is an uncommon and potentially mutilating disease with a heterogeneous aetiology. Several risk factors have been established for its development. Human papillomavirus (HPV) infection seems to play an important role in the development of a subset of these carcinomas and its presence is thought to be related to the histological type. HPV prevalence in penile tumours is reported to be associated to a variety of morphological changes. Its determination will provide a better estimate for HPV related cancer burden and its preventable fraction.

METHODS

A systematic and comprehensive literature review of the major penile cancer studies published from 1986 until June 2008 evaluating the HPV prevalence among the different histological types was carried out.

RESULTS

31 studies including 1466 penile carcinomas were reviewed. Global HPV prevalence was 46.9%. Relative contribution was: HPV-16 (60.23%), HPV-18 (13.35%), HPV-6/11 (8.13%), HPV-31 (1.16%), HPV-45 (1.16%), HPV-33 (0.97%), HPV-52 (0.58%), other types (2.47%). Assessment of multiple infections contribution is limited due to study design. Basaloid and warty squamous cell carcinomas were the most frequent HPV-related histological types, but keratinising and non-keratinising subtypes also showed prevalence rates of around 50%.

CONCLUSIONS

About half of the penile tumours were associated with HPV 16-18 with little presence of other genotypes. Research on the mechanisms behind penile carcinogenesis is warranted. Available HPV vaccines are likely to be effective in penile tumours.

[Organ-sparing surgery for penile cancer]

In patients with penile cancer health-related quality of life is closely related to organ-sparing surgery. To achieve an ideally suited treatment modality for this rare but aggressive tumor entity different operating techniques like micrographic surgery, laser treatment, and glansectomy were developed. These should offer optimal oncological treatment while preserving sexual function. This article gives an overview of indications and limits of organ-sparing treatment in penile cancer.

Molecular prognostic factors in penile cancer

OBJECTIVES

Penile cancer is a rare tumour in developed countries but more common in South America and East Africa. Although pathological prognostic factors have been established, there is great interest in evaluating molecular markers which correlate with prognosis and outcome.

METHODS

We have reviewed the current status of our understanding of the molecular biology of penile cancer in order to identify established and potential prognostic factors in penile cancer. We have conducted an extensive literature search to review the current understanding of the role of prognostic markers in penile cancer.

RESULTS

Although several markers have been evaluated, currently the clinical application of these markers is limited. HPV positive tumours show a variable prognostic outcome. P53 status may correlate with survival in T1 disease but further studies are required to establish the link to lymph node spread.

CONCLUSIONS

Pathological variables are well-established but further work is required to investigate the role of molecular markers. The development of molecular prognostic markers is important for the surveillance of patients and prediction of lymph node involvement as well as a prognostic marker for survival.