Development Of Vulvar Squamous Cell Carcinoma Research Articles

Exploring Differentially Methylated Genes in Vulvar Squamous Cell Carcinoma.

Simple SummaryVulvar squamous cell carcinoma (VSCC) is the most common form of vulvar malignancy, and its incidence has increased in recent years. For better diagnosis and prognostication, and to expand available treatment options, molecular characterization of VSCC is crucial. We sought to identify aberrations in DNA methylation in VSCC, as this has been implicated in the development of several cancers. To this end, we performed genome-wide methylation sequencing on a set of VSCC and normal vulvar tissue using the Infinium MethylationEPIC BeadChip array. We detected 199 genes to be differentially methylated in VSCC compared to normal vulvar tissue. Of these, 194 genes were hyper-methylated, which leads to a loss of function of the genes. As most of these genes are involved in transcription regulator activity, our results suggest that disruption of this process plays an important role in VSCC development.DNA methylation is the most widely studied mechanism of epigenetic modification, which can influence gene expression without alterations in DNA sequences. Aberrations in DNA methylation are known to play a role in carcinogenesis, and methylation profiling has enabled the identification of biomarkers of potential clinical interest for several cancers. For vulvar squamous cell carcinoma (VSCC), however, methylation profiling remains an under-studied area. We sought to identify differentially methylated genes (DMGs) in VSCC, by performing Infinium MethylationEPIC BeadChip (Illumina) array sequencing, on a set of primary VSCC (n = 18), and normal vulvar tissue from women with no history of vulvar (pre)malignancies (n = 6). Using a false-discovery rate of 0.05, beta-difference (Δβ) of ±0.5, and CpG-island probes as cut-offs, 199 DMGs (195 hyper-methylated, 4 hypo-methylated) were identified for VSCC. Most of the hyper-methylated genes were found to be involved in transcription regulator activity, indicating that disruption of this process plays a vital role in VSCC development. The majority of VSCCs harbored amplifications of chromosomes 3, 8, and 9. We identified a set of DMGs in this exploratory, hypothesis-generating study, which we hope will facilitate epigenetic profiling of VSCCs. Prognostic relevance of these DMGs deserves further exploration in larger cohorts of VSCC and its precursor lesions.

Prevalence and type distribution of human papillomavirus infections in Danish patients diagnosed with vulvar squamous cell tumors and precursors

ObjectiveTo study the prevalence and type distribution of human papillomavirus (HPV) in patients with vulvar high-grade precancerous lesions and vulvar squamous cell carcinoma (VSCC). MethodsFormalin-fixed and paraffin-embedded (FFPE) tissue samples from Danish patients diagnosed with vulvar precancerous lesions or VSCC in the period from 2010 to 2012 were obtained. HPV-DNA detection was carried out by the use of polymerase chain reaction (PCR) using GP5+/GP6+ primers and genotyped by sequencing. A systematic literature search on the PubMed database was performed to investigate the prevalence and genotype distribution worldwide. ResultsIn the present study population (n = 149) 52 vulvar high-grade squamous intraepithelial lesions (HSIL), 2 differentiated vulvar intraepithelial neoplasia (dVIN), and 95 VSCC cases were identified. HPV was detected in 85 patients (57.0%). Overall, a higher proportion of the vulvar high-grade precancerous lesions were HPV positive compared to VSCC (83.6% vs. 42.1%, p < 0.001). Additionally, HSIL had a significantly higher HPV-positive rate compared to keratinizing VSCC (84.6% vs. 33.3%, p < 0.001). However, the HPV positivity was comparable between HSIL and non-keratinizing VSCC (84.6% vs. 82.4%, p = 0.825). One dVIN was HPV positive whereas the other was HPV negative. HPV-16 was the most common HPV type (68.2%), followed by HPV-33 (18.8%) and HPV-18 (8.2%). ConclusionsMost vulvar HSIL and non-keratinizing VSCCs appear to be HPV associated. However, we find a high HPV association in keratinizing VSCC, which needs to be further studied. HPV-16 remains the predominant genotype, but HPV-33 also seems to play a role in the development of VSCC.

Somatic Mutation Profiling in Premalignant Lesions of Vulvar Squamous Cell Carcinoma.

Vulvar squamous cell carcinoma (VSCC) originates from the progression of either a high-grade squamous intraepithelial lesion (HSIL) or differentiated-type vulvar intraepithelial neoplasia (dVIN), often in a background of lichen sclerosus (LS). The mechanisms leading to the progression of these premalignant lesions to VSCC are elusive. This study aims to identify pathogenic mutations implicated in VSCC development. Using next-generation sequencing, 38 HSIL, 19 dVIN, 20 LS, of which 10 were solitary lesions and 10 with adjacent VSCC, and 10 VSCC adjacent to LS, were screened for hotspot mutations in 50 genes covered by the Ion AmpliSeq Cancer Hotspot Panel v2 Kit (Thermo Fisher Scientific). Pathogenic mutations of TP53 were the most common genetic alterations identified in 53% and 24% of dVIN and HSIL cases, respectively, followed by CDKN2A (p16) mutated in 42% and 0% of dVIN and HSIL, respectively. Seven (70%) and three (30%) of 10 cases of VSCC associated with LS carried TP53 and CDKN2A mutations, respectively, whereas neither solitary LS nor LS associated with VSCC cases harbored mutations in these genes. It appears that TP53 mutations are early events during VSCC carcinogenesis, being present in both HSIL and dVIN lesions. Our preliminary data do not support a genetic background for the notion of LS as the VSCC premalignant lesion.

Hypermethylation-Induced Inactivation of the IRF6 Gene as a Possible Early Event in Progression of Vulvar Squamous Cell Carcinoma Associated With Lichen Sclerosus.

The molecular mechanism leading to the development of vulvar squamous cell carcinoma (VSCC) from vulvar lichen sclerosus (VLS) is unknown. To assess the possible involvement of the IRF6 tumor-suppressor gene in the development of VSCC from VLS. In laboratories at the University of Ferrara, Ferrara, Italy, IRF6 gene expression and promoter methylation were investigated in paraffin-embedded VSCC and adjacent vulvar intraepithelial neoplasia (VIN) and VLS specimens, in cancer-free VLS (cfVLS) specimens, and in healthy skin specimens by reverse transcriptase-quantitative polymerase chain reaction (RT-qPCR) analysis and by sequencing of PCR-amplified bisulfite-treated DNA. Methylation-induced dysregulation was assessed by expression of p63, the IRF6-transactivator gene. IRF6 expression, correlation with promoter methylation and p63 expression, and association with development of VSCC from VLS. Specimens from 60 participating women (1 specimen from each) were analyzed for the study (mean [SD] age, 66.3 [12.1] years): 20 paraffin-embedded specimens of VSCC (patient age, 75.3 [8.3] years) with adjacent VLS lesions, in 5 of which VIN preneoplastic tissue was also present (patient age, 64.3 [15.3] years); 20 cfVLS specimens (patient age, 62.1 [11.4] years) obtained from diagnostic biopsies; and 20 normal skin specimens from noncancer surgical patients (patient age, 61.4 [9.1] years). IRF6 messenger RNA was found to be reduced 4.5-, 2.9-, 6.6-, and 2.2-fold in VLS, VIN, VSCC, and cfVLS specimens, respectively, compared with controls, although p63 was still expressed in all specimens. IRF6 promoter was hypermethylated in 9 (45%) of 20 VLS specimens, 1 (20%) of 5 VIN specimens, 16 (80%) of 20 VSCC specimens, 2 (10%) of 20 cfVLS specimens, and 0 normal skin specimens. IRF6 dysregulation may be involved in the development of VSCC from VLS. Methylation of the IRF6 promoter may be a marker of cancer risk in patients with VLS.

Increased osteopontin expression is associated with progression from vulvar precancerous lesions to vulvar squamous cell carcinoma

Vulvar squamous cell carcinoma (VSCC) contributes to about 3-5% of all gynecological cancers. Vulvar intraepithelial neoplasia (VIN) and vulvar lichen sclerosus (VLS) are regarded as precancerous lesions. Early detection and treatment of precancerous lesions may prevent development of VSCC. Osteopontin (OPN) has been shown to be involved in many physiological and pathological processes, such as tumor progression, by promoting cancer cell invasion and metastasis. As a result of these findings, OPN has been described as a potential marker for tumor progression in some malignancies. In this study, we investigated the expression of OPN in vulvar tissue specimens and compared its expression between different histopathological grades. In the present study, the expression patterns of OPN in 80 paraffin-embedded tissue specimens, including 25 VSCC samples, 21 VIN lesions and 21 VLS, in addition to 13 normal vulvar samples, were examined by the immunohistochemical method and chromogenic in situ hybridization. The intensity of OPN expression steadily increased according to the pathological grades. In addition, OPN staining was found in the extracellular matrix in VSCC. Expression levels of OPN increased from VLS and VIN to VSCC, and steadily increased with the pathological stage of VSCC. Our results suggest that OPN may be associated with the progression of VSCC.

Specific intraepithelial localization of mast cells in differentiated vulvar intraepithelial neoplasia and its possible contribution to vulvar squamous cell carcinoma development

The aetiology of vulvar squamous cell carcinomas (SCC) that are not causally associated with high-risk human papillomavirus remains largely elusive. The aim of this study was to analyse the inflammatory response in its presumed precursor lesions, lichen sclerosus (LS) and differentiated vulvar intraepithelial neoplasia (dVIN), and provide evidence that dVIN is a likely precursor of vulvar SCC. Immunohistochemical analyses for CD4+, CD8+, CD20+, CD68+, S100+ and tryptase-positive immune cells were performed and quantified in LS (n = 7), dVIN (n = 19), SCC (n = 11), and normal vulvar tissue (n = 8). The subepithelial inflammatory response in dVIN and SCC was comparable, but absent in LS. Abundant intraepithelial mast cells were observed in dVIN only, and confirmed by electron microscopy, toluidine blue staining and cKIT expression. Adjacent keratinocytes displayed increased proliferation as determined by MIB-1 positivity. Electron microscopy revealed intraepithelial mast cell degranulation. Intraepithelial mast cells were not or infrequently observed in vulvar hyperplasia (n = 13), condylomata acuminata (n = 5), keratinocytic intraepidermal neoplasia of sun-exposed skin (n = 15), epidermal hyperplasia of head and neck (n = 12), and psoriasis (n = 3). These data indicate that dVIN can be recognized by intraepithelial mast cells and that they might promote the progression of dVIN to SCC.

The Etiologic Role of HPV in Vulvar Squamous Cell Carcinoma Fine Tuned

High-risk human papilloma virus (HPV) plays a role in the development of a subset of vulvar squamous cell carcinomas. Uncertainty exists about the true impact of HPV in this tumor type because conflicting reports have been published with diverging prevalence rates. This study was done to fine tune the role of high-risk HPV infection in vulvar squamous cell carcinoma development in relation to clinical prognosis. 130 vulvar squamous cell carcinomas of patients with known survival data were analyzed for histology of the adjacent lesion (differentiated or HPV-associated usual vulvar intraepithelial neoplasia), in relation to p16(INK4A) expression as marker of HPV activity, and presence and integration of high-risk HPV DNA. Usual vulvar intraepithelial neoplasia was present adjacent to vulvar squamous cell carcinoma in 25 of 130 cases. Usual vulvar intraepithelial neoplasia-associated squamous cell carcinomas had high p16(INK4A) expression, and 24 of 25 squamous cell carcinomas contained integrated high-risk HPV DNA. Differentiated vulvar intraepithelial neoplasia was found adjacent to 105 of 130 vulvar squamous cell carcinomas. High-risk HPV was detected in 11 (10.5%) differentiated vulvar intraepithelial neoplasia-associated vulvar squamous cell carcinoma but correlated with high p16(INK4A) expression in only one case. Integration of viral DNA was never observed in differentiated vulvar intraepithelial neoplasia-associated squamous cell carcinomas, which suggests that a causal relationship of high-risk HPV in differentiated vulvar intraepithelial neoplasia-associated tumors is highly unlikely. The disease-specific survival of the differentiated vulvar intraepithelial neoplasia-associated vulvar squamous cell carcinoma patients was significantly worse compared with patients with a usual vulvar intraepithelial neoplasia-associated tumor. High-risk HPV is causally associated with the development of usual vulvar intraepithelial neoplasia associated squamous cell carcinomas, which comprise 19% of all vulvar squamous cell carcinomas, but not with differentiated vulvar intraepithelial neoplasia-associated vulvar squamous cell carcinomas. Differentiated vulvar intraepithelial neoplasia-associated vulvar squamous cell carcinomas have a significantly worse prognosis.

Vulvar squamous cell carcinoma development after diagnosis of VIN increases with age

Objective The purpose of the present study is to investigate the trends in incidence of both usual (u) and differentiated (d) vulvar intraepithelial neoplasia (VIN) separately, their malignant potential and the relation with other HPV related anogenital lesions in the Netherlands during a 14-year-period. Methods The incidences of both types of VIN and vulvar SCC were retrieved from the Nationwide Netherlands Database of Histo- and Cytopathology. Population data were retrieved from the Database of Statistics Netherlands. Results In the study period, the incidence of uVIN and dVIN increased, while the incidence of vulvar SCC remained stable. The overall percentage of uVIN patients that were later diagnosed with vulvar SCC was 5.7%, which was significantly lower than the percentage for dVIN patients (32.8%). In addition to this 5.6-fold increased conversion rate, the time of progression from dVIN to SCC development was significantly shorter than that of uVIN ( p = 0.005). Percentage of uVIN patients that were later diagnosed with SCC significantly increased with age ( p = 0.005), whereas the time to SCC significantly shortened with age ( p = 0.05). Forty-one percent of uVIN patients had a past, concomitant or future HPV-associated lesion of the lower genital tract, which is in contrast to the 3% for dVIN patients. Conclusions An increase in diagnoses of both uVIN and dVIN has not led to an increase in vulvar SCC incidence. The malignant potential of dVIN is higher than that for uVIN. For uVIN the malignant potential increases with age.