Pathways of vulvar intraepithelial neoplasia and squamous cell carcinoma

Vulvar squamous cell carcinoma (VSCC) accounts for >90% of the malignant tumours of the vulva. Most VSCCs originate in intraepithelial lesions, named vulvar intraepithelial neoplasia (VIN), that precede the development of VSCC by a variable period of time. Strong evidence has accumulated showing that there are two different aetiopathogenic pathways for the development of VSCC and VIN, one associated with infection by human papillomavirus (HPV), and a second independent of HPV infection. These two different types of VSCC have different epidemiological, pathological and clinical characteristics, and should therefore be considered as two separate entities. Histologically, HPV‐associated VSCCs are of the basaloid or warty type, and arise from VIN of the usual type. Inactivation of p53 and the retinoblastoma tumour suppressor gene product by the viral gene products E6 and E7 is involved in the process of malignant transformation. HPV‐independent VSCCs are histologically keratinizing, are associated with differentiated VIN and lichen sclerosus, and frequently show mutations of p53. p16^INK4a and p53 immunostaining can be useful for classifying VSCC into HPV‐associated or HPV‐independent. Although large, multicentre studies are needed to definitively assess the involvement of HPV in the prognosis of VSCC, most studies have not found clear differences in survival between HPV‐associated and HPV‐independent tumours.     

Premalignant and malignant squamous lesions of the vulva

Vulvar premalignant squamous lesions include low- and high-grade intraepithelial neoplasias. High-grade lesions include usual (classic) and differentiated (simplex) vulvar intraepithelial neoplasia (VIN). Usual VIN (uVIN), the most common, is related to human papilloma virus (HPV), occurs in younger patients, and is frequently multifocal. Differentiated VIN (dVIN), less common, is related to lichen sclerosus and other chronic vulvar dermatoses, occurs in older women, and is usually unifocal. Terminology schemes for premalignant lesions are reviewed. Invasive squamous cell carcinoma also occurs in two distinct clinicopathologic settings. Most conventional keratinizing squamous cell carcinomas arise from a background of dVIN and comprise the majority of invasive squamous tumours. Warty and basaloid invasive squamous cell carcinomas likely develop from uVIN and comprise a minority of invasive tumours. Clinical features, microscopic findings, differential diagnoses, immunoprofiles, prognosis and treatment of premalignant and malignant lesions are addressed.     

Premalignant and malignant squamous lesions of the vulva

Vulvar premalignant squamous lesions include low- and high-grade intraepithelial neoplasias. High-grade lesions include classic (usual) and differentiated (simplex) vulvar intraepithelial neoplasia (VIN). Classic VIN (cVIN), the most common, is related to human papilloma virus (HPV), occurs in younger patients, and is frequently multifocal. Differentiated VIN (dVIN), less common, is related to lichen sclerosus and other chronic vulvar dermatoses, occurs in older women, and is usually unifocal. Terminology schemes for premalignant lesions are reviewed. Invasive squamous cell carcinoma also occurs in two distinct clinicopathologic settings. Most conventional keratinizing squamous cell carcinomas arise from a background of dVIN and comprise the majority of invasive squamous tumours. Warty and basaloid invasive squamous cell carcinomas likely develop from cVIN and comprise a minority of invasive tumours. Clinical features, microscopic findings, differential diagnoses, immunoprofile, prognosis and treatment of premalignant and malignant lesions are addressed.     

Small vulvar squamous cell carcinomas and adjacent tissues. A morphologic study

Vulvar squamous cell carcinomas are of different subtypes and degrees of differentiation, and may be associated with adjacent lichen sclerosus and/or varying degrees of dysplasia. The aim of this investigation was to study small carcinomas with a diameter of less than 2 cm in order to find a possible relation between subtypes of carcinomas and adjacent epithelial changes. Fourteen cases of small vulvar squamous cell carcinomas were totally embedded in paraffin. Serial sectioning made a detailed mapping of all different lesions possible, and a two- and three-dimensional imaging was obtained in each case. Seven patients with keratinizing squamous cell carcinomas (median age 65) had adjacent lichen sclerosus. All carcinomas were completely surrounded by areas of VIN1. VIN2 and VIN3 were not found. Seven patients without lichen sclerosus (median age 58) showed squamous cell carcinomas of the keratinizing type (n=2) or the basaloid type (n=5). Five of these cases were incompletely surrounded by varying degrees of dysplasia, mainly VIN2 and VIN3. Two different pathogenetic pathways for the development of vulvar squamous cell carcinoma are likely.     

Analysis of clonality and HPV infection in benign, hyperplastic, premalignant, and malignant lesions of the vulvar mucosa

To elucidate the pathogenesis of vulvar carcinomas, we studied clonality and human papillomavirus (HPV) infection in vulvar epithelial diseases. Monoclonal composition was demonstrated in all 9 invasive tumors (squamous cell carcinoma [SCC], 6; basal cell carcinoma, 1; malignant melanoma, 2), 15 of 20 cases of vulvar intraepithelial neoplasia (VIN), 7 of 9 cases of Paget disease, 2 of 6 cases of lichen sclerosus (LS), and 2 of 3 cases of squamous cell hyperplasia (SCH); high-risk type HPV was revealed in 5 of 6 SCCs and 17 of 20 VINs. These observations might imply that a subset of cases of LS and SCH result from a neoplastic proliferation, similar to VINs but not related to infection with high-risk type HPV. In 1 case of SCC with concurrent VIN 3 in an adjacent lesion, both lesions showed the same pattern of X chromosome inactivation and the presence of HPV-16 in episomal and integrated forms, suggesting that monoclonal expansion triggered by high-risk type HPV integration is an early event for carcinogenesis of HPV-associated SCC.     

Presence and type of oncogenic human papillomavirus in classic and in differentiated vulvar intraepithelial neoplasia and keratinizing vulvar squamous cell carcinoma

The presence and type of oncogenic papillomavirus (HPV) in classic warty/basaloid vulvar intraepithelial neoplasia and in differentiated vulvar intraepithelial neoplasia and keratinizing vulvar squamous cell carcinoma was investigated using three techniques, that is, histology, in situ hybridization, and PCR-ELISA. HPV typing was performed using in situ hybridization and PCR-ELISA. Differentiated vulvar intraepithelial neoplasia and invasive keratinizing vulvar squamous cell carcinoma proved completely negative for HPV by PCR-ELISA, in situ hybridization, and histologic examination, while in classic vulvar intraepithelial neoplasia, a HPV positivity of 66.1% was found. HPV 16 was the predominant type, with HPV 35, 33, and 52 types found rarely and sometimes together with HPV 16. PCR-ELISA proved to be the most suitable method to detect and type mucosal oncogenic HPVs. The absolute absence of HPV DNA in differentiated vulvar intraepithelial neoplasias and in keratinizing vulvar squamous cell carcinoma suggests a strong HPV-independent pathway of malignant progression to invasive carcinoma.     

Characteristics of vulvar squamous cell carcinoma in Japanese women

Although the presence of racial differences in vulvar squamous cell carcinomas has been suggested, fully analyzed data concerning such tumors in Japanese women have not been reported. A total of 21 vulvar squamous cell carcinomas of Japanese women who lived in north-east Japan, were studied with respect to histological subtype, HPV, p53 and p16(INK4a). The majority of tumors consisted of keratinizing and non-keratinizing types (16/21, 76%), all of which were negative for HPV. The remaining five tumors of basaloid, warty or verrucous types were positive for HPV. HPV-negative tumors showed a trend of greater accumulation of gene abnormalities, including p53 gene mutation, than HPV-positive ones. p16(INK4a) overexpression was shown to not always be a marker for vulvar squamous cell carcinoma in Japanese women with activated high-risk HPV.     

Prevalence of mucosal and cutaneous human papillomaviruses in different histologic subtypes of vulvar carcinoma.

Two independent pathways of vulvar carcinogenesis have currently been identified, one related to infection with mucosal human papillomaviruses (HPVs) and a second related to chronic inflammatory or autoimmune processes. The goal of the study was to examine a possible role of cutaneous HPVs from the beta genus in vulvar carcinogenesis and to evaluate the distribution of intratypic variants of HPV 16 in HPV 16-positive vulvar cancer. Consecutive cases of vulvar carcinoma were retrieved from the files and included the following histologic subtypes: keratinizing (n=21), basaloid (n=7), warty (n=1), mixed basaloid-warty (n=4), verrucous (n=4), keratoacanthoma (n=1), basal cell carcinoma (n=1). All tumors were microdissected and tested for 25 beta HPV types and 25 mucosal HPV types. Cases identified as positive for HPV 16 were further tested for intratypic variants. All cases were immunostained for p16INK4a. Beta HPVs were not detected in any of the tumor cases. Mucosal HPVs were detected in all but one basaloid/warty carcinomas; of these, nine cases (82%) were positive for HPV 16, including five European subtypes, one African subtype, one North American subtype and two indeterminate subtypes. Two of four verrucous carcinomas were positive for HPV 6. Mucosal HPVs were not detected in keratinizing carcinomas, keratoacanthoma and basal cell carcinoma. All cases of basaloid/warty carcinomas, but none of the remaining tumors, overexpressed p16INK4a protein. Our data do not support a role of beta HPVs in the pathogenesis of vulvar carcinoma. The study reaffirms the role of mucosal HPVs, in particular that of HPV 16, in the pathogenesis of basaloid and warty tumor subtypes. The HPV 16 intratypic variation showed correlation with patients' ethnic background. P16INK4a immunostaining seems to be a sensitive and specific marker of vulvar carcinomas positive for oncogenic mucosal HPVs.     

Chromosome 17 aneusomy detected by fluorescence in situ hybridization in vulvar squamous cell carcinomas and synchronous vulvar skin

Vulvar squamous cell carcinoma (SCC) affects a spectrum of women with granulomatous vulvar diseases, human papillomavirus (HPV) infections, and chronic inflammatory vulvar dermatoses. To determine whether there is evidence of chromosomal instability occurring in synchronous skin surrounding vulvar SCCs, we investigated abnormalities in chromosome 17 copy number. Samples of SCC, vulvar intraepithelial neoplasia (VIN), and surrounding vulvar skin were obtained from all vulvar excisions performed for squamous neoplasia at Albany Medical College from 1996 to 1997. Histological categorization, fluorescent in situ hybridization (FISH) for the alpha satellite region of chromosome 17, DNA content by image analysis, and Ki-67 labeling were evaluated. Controls of normal vulvar skin not associated with cancer were used for comparison. One hundred ten specimens were obtained from 33 patients with either SCC or VIN 3 and consisted of 49 neoplastic, 52 nonneoplastic, and 9 histologically normal vulvar skin samples. The majority of SCCs (88%) and a minority (18%) of VIN 3 excisions were associated with lichen sclerosus. Normal vulvar skin controls did not exhibit chromosome 17 polysomy (cells with more than four FISH signals), whereas 56% of normal vulvar skin associated with cancer did. Moreover, the frequency of polysomy significantly increased as the histological classification progressed from normal to inflammatory to neoplastic lesions. The largest mean value and variance for chromosome 17 copy number was identified in SCCs (2.4 +/- 1.0) with intermediate values identified, in decreasing order, for SCC in situ (2.1 +/- 1.0), VIN 2 (2.1 +/- 0.8), lichen sclerosus (2.0 +/- 0.5), lichen simplex chronicus (1.9 +/- 0.4), and normal skin associated with SCC (1.8 +/- 0.4) compared with control vulvar skin (1.5 +/- 0. 05). Concordance of chromosome 17 aneusomy between cancers and synchronous skin lesions was found in 48% of patients. Loss of chromosome 17 was identified 5% of all samples and was significantly associated with women with SCC in situ (HPV-related). Both DNA content and Ki-67 labeling positively and significantly correlated with mean chromosome 17 copy number (r = 0.1, P: = 0.007). A high degree of genetic instability (aneuploidy) occurs in the skin surrounding vulvar carcinomas. As these events could be detected in histologically normal skin and inflammatory lesions (lichen sclerosus), chromosomal abnormalities may be a driving force in the early stages of carcinogenesis. Differences in chromosomal patterns (loss or gain) support the concept of at least two pathways in vulvar carcinogenesis.     

Human papillomavirus genotyping by oligonucleotide microarray and p16 expression in uterine cervical intraepithelial neoplasm and in invasive carcinoma in Korean women

For evaluating the diagnostic significance of p16(INK4A) over-expression in the uterine cervical intraepithelial neoplasm and in invasive carcinoma, human papillomavirus (HPV) was detected and genotyped by oligonucleotide microarray in archival tissues of 117 cervical specimens, including 47 invasive squamous cell carcinomas (SCC), 30 cases of cervical intraepithelial neoplasia (CIN), 20 adenocarcinomas, and 20 cases of non-neoplastic cervix. The expression of p16(INK4A) protein was immunohistochemically studied in these cases and in five HPV-positive and one HPV-negative cervical cancer cell lines. HPV was detected in 50% of CIN, 61.7% of SCC, and 45.5% of adenocarcinomas. p16(INK4A) expression was seen in all 20 cases of adenocarcinoma, 78.7% (37/47) of SCC, and 96.7% (29/30) of CIN, but not in any cases of the non-neoplastic cervix. There was no difference in p16(INK4A) expression between the HPV-positive and HPV-negative cervical lesions. All HPV-positive and -negative cervical cancer cell lines expressed p16(INK4A) protein. In conclusion, the presence of p16(INK4A) expression in cervical squamous and glandular epithelium indicates the existence of dysplasia or malignancy in the uterine cervix, regardless of HPV infection.     

子宫颈病变中HPV L1蛋白和p16的表达

目的 研究HPV L1蛋白和p16在子宫颈各种病变中的表达情况,探讨它们在子宫颈病变进展中的预测价值.方法 应用免疫组化方法检测41例各种子宫颈病变(CIN1级18例、CIN2级9例、CIN3级8例和浸润性鳞状细胞癌6例)中HPV L1蛋白和p16的表达.结果 HPV L1蛋白在各种子宫颈病变中的阳性率为26.8%.其中HPV L1在CIN1中的阳性表达率为38.9%,CIN2为44.4%,CIN3和浸润性鳞状细胞癌均无表达.p16在各种子宫颈病变中的阳性率为68.3%,其在CIN1中的阳性表达率为38.9%,CIN2为77.8%,CIN3和浸润性鳞状细胞癌均表达阳性.100%CIN3和浸润性鳞状细胞癌为p16+/HPV L1-,而61.1% CIN1中为p16-/HPV L1+或p16-/HPV L1-.结论 随着子宫颈病变的进展,HPV L1阳性表达率降低而p16阳性表达率增高.p16+/HPV L1-提示子宫颈鳞状上皮内瘤变有进展的可能,而p16-/HPV L1+和p16-/HPV L1-可能为无进展的或潜在消退的子宫颈病变.     

Expression of cell-cycle-associated proteins pRB2/p130 and p27kip in vulvar squamous cell carcinomas

Squamous cell vulvar carcinoma accounts for 4% of all gynecologic malignancies. The cause of vulvar cancer is still unclear. Identification of new biologic factors involved in vulvar carcinogenesis may be useful in clarifying the natural history of this malignancy. We investigated the immunohistochemical expression of the retinoblastoma-related proteins pRB2/p130 and CKI p27kip1 in a series of 51 invasive squamous cell carcinomas of the vulva (ISCCs) and in synchronous normal vulvar skin, non-neoplastic epithelial disorders (NNED) and vulvar intraepithelial neoplasia (VIN). Normal vulvar skin staining showed positivity for both pRB2/p130 and p27kip1. Loss of pRB2/p130 occurred in 29 (57%) of 51 specimens of ISCCs, and in 1 of 7 specimens with VIN (14%; P = .04). We also observed a significant decrease of pRB2/p130 expression from NNED to neoplastic tissues (VIN and ISCCs) (P = .004). Loss of p27kip1 expression was found in 16 of 51 specimens (31%) of invasive carcinomas, in 1 (14%) of 7 specimens of VIN, and in 2 of 18 specimens of NNED (11%). pRB2/p130 and p27(kip1) did not correlate significantly with any of the clinicopathologic parameters examined. Our data indicate that loss of pRB2/p130 and p27kip1 are frequent events in invasive vulvar carcinomas compared with synchronous premalignant lesions, non-neoplastic epithelial disorders, and normal vulvar skin. The significant progressive decrease of pRB2/p130 expression from non-neoplastic epithelial alterations through intraepithelial neoplasia to invasive vulvar carcinomas suggests a role for this tumor suppressor gene in vulvar carcinogenesis.     

Collagenase-3 (MMP-13) is expressed by tumor cells in invasive vulvar squamous cell carcinomas

Collagenase-3 (MMP-13) is a human matrix metalloproteinase specifically expressed by invading tumor cells in squamous cell carcinomas (SCCs) of the head and neck. Here, we have further elucidated the role of MMP-13 in tumor invasion by examining its expression in invasive malignant tumors of the female genital tract. Using in situ hybridization, expression of MMP-13 mRNA was detected in 9 of 12 vulvar SCCs, primarily in tumor cells, but not in intact vulvar epithelium, in cervical SCCs (n = 12), or in endometrial (n = 11) or ovarian adenocarcinomas (n = 8). MMP-13 expression was especially abundant in vulvar carcinomas showing metastasis to lymph nodes and was associated with expression of membrane type 1 MMP by tumor cells and gelatinase-A (MMP-2) by stromal cells, as detected by immunohistochemistry. MMP-13 mRNAs were detected in 9 of 11 cell lines established from vulvar carcinomas and in 4 of 6 cell lines from cervical carcinomas, whereas endometrial (n = 10) and ovarian (n = 9) carcinoma cell lines were negative for MMP-13 mRNA. No correlation was detected between MMP-13 expression and p53 gene mutations in vulvar SCC cell lines. However, MMP-13 expression was detected in 5 of 6 vulvar and cervical SCC cell lines harboring HPV 16 or 68 DNA. These results show that MMP-13 is specifically expressed by malignantly transformed squamous epithelial cells, including vulvar SCC cells, and appears to serve as a marker for their invasive capacity.     

Histologic classification of penile intraepithelial neoplasia

Penile squamous cell carcinomas (SCCs) and their corresponding precancerous lesions can be classified in 2 major groups: human papillomavirus (HPV) related and HPV unrelated. In the former (warty and basaloid SCC), there is a predominance of undifferentiated basaloid cells. In the latter (eg, usual, papillary, and verrucous SCC), the predominant cell is larger with abundant eosinophilic cytoplasm. Based on these morphologic features, a new term, "penile intraepithelial neoplasia" (PeIN), was proposed. PeIN was further subclassified into differentiated and undifferentiated, with the latter being subdivided into basaloid, warty, and warty-basaloid subtypes. Macroscopically, PeIN subtypes are indistinguishable. Microscopically, differentiated PeIN is characterized by acanthosis, parakeratosis, enlarged keratinocytes with abundant "pink" cytoplasm (abnormal maturation), and hyperchromatic cells in the basal layer. In basaloid PeIN the epithelium is replaced by a monotonous population of uniform, small, round, and basophilic cells. Warty PeIN is characterized by a spiky surface, prominent atypical parakeratosis, and pleomorphic koilocytosis. Warty-basaloid PeIN show features of both warty and basaloid PeIN. There is a significant association of subtypes of PeIN with specific variants of invasive SCCs. This is a simple and reproducible nomenclature for penile precancerous lesions based on cell type and differentiation. It takes into account the similarities between vulvar and penile pathology and the hypothesis of a bimodal pathway of penile cancer progression.     

HPV-assoziierte Ver?nderungen an Vulva und Vagina

Non-neoplastic HPV-induced alterations of the vulva and vagina are frequent. The traditional three-tier grading system of vulvar intraepithelial neoplasia (VIN) will be replaced by the definition of usual and simplex type of VIN. The usual type is characterized by a strong association to high-risk HPV infections, the occurrence at younger age and multifocality, mostly associated with non-keratinizing squamous cell carcinoma. The differentiated (or simplex) type is rare and shows an association to older age and p53 alterations and is typically diagnosed co-incidentally with keratinizing squamous cell carcinoma. Vaginal intraepithelial neoplasia (VAIN) is still graded into VAIN 1-3 where VAIN?1 and 2 are mostly associated with low-risk HPV infections and a high spontaneous regression rate whereas VAIN 3 represents a high-risk HPV-associated lesion with capable progression into (micro-)invasive carcinoma. The differential diagnosis between a non-neoplastic condylomatous lesion and VIN common type and VAIN may be aided by p16 immunohistochemistry. The HPV-associated invasive vulvo-vaginal cancers are verrucous carcinoma (low-risk HPV) and the high-risk HPV-induced (non-keratinizing) squamous cell carcinoma (NOS), the condylomatous (warty) carcinoma and the very rare vaginal squamo-transitional carcinoma.     

In the absence of (early) invasive carcinoma, vulvar intraepithelial neoplasia associated with lichen sclerosus is mainly of undifferentiated type: new insights in histology and aetiology

BACKGROUND: Differentiated vulvar intraepithelial neoplasia (VIN) is presumed to be the precursor of invasive squamous cell carcinoma (SCC) of the vulva. It is commonly assumed that differentiated VIN is related to lichen sclerosus (LS). However, evidence for this is limited to a small number of studies describing epithelial alterations adjacent to vulvar SCC. AIM: To study the histology and human papillomavirus (HPV) status in patients with a history of both LS and VIN without coexistent SCC. METHODS: Original biopsy specimens and surgical specimens of patients retrieved from the pathology files were revised for the presence of LS, VIN and (early) invasive SCC, specifically focused on the two different types of VIN: differentiated and undifferentiated. Thereafter, VIN lesions were tested for the presence of HPV DNA. RESULTS: Twenty-seven patients fulfilled the criteria for LS and VIN without SCC. In all 27 patients, LS was found to be related to undifferentiated VIN. Grading yielded the following results: VIN 1 (n=10), VIN 2 (n=11) and VIN 3 (n=6). Additionally, VIN lesions from 26 patients could be tested for the presence of HPV DNA. HPV DNA, predominantly type 16, was present in 8 (31%) of them. Seven of these eight patients had VIN 2 or 3. During follow-up, three patients progressed to (early) invasive carcinoma. In two of these patients, differentiated VIN was observed overlying early invasive SCC. CONCLUSIONS: VIN related to LS without coexisting SCC is likely to be undifferentiated, in contrast to what was previously thought. HPV DNA was demonstrated in 31% of the lesions, and was strongly related to high-grade VIN.     

Patterns of allelic loss (LOH) in vulvar squamous carcinomas and adjacent noninvasive epithelia.

The pathogenesis of carcinoma of the vulva is diverse and includes both human papilloma virus (HPV)-positive and HPV-negative pathways. The objective of this study was to correlate the morphology with patterns of loss of heterozygosity (LOH) within four vulvar carcinomas and in adjacent vulvar epithelia. Tumors were categorized as HPV positive or negative by polymerase chain reaction (PCR) analysis. Forty-one different sites of normal squamous mucosa, hyperplasia, vulvar intraepithelial neoplasia (VIN), and carcinoma were microdissected in duplicate, and each extracted DNA was analyzed in duplicate for LOH at 10 chromosomal loci by PCR and polyacrylamide gel electrophoresis. Patterns of LOH were compared within different sites of tumors and between the tumor and the noninvasive epithelia. Of three tumors with multiple invasive foci analyzed, divergent patterns of LOH were identified in two, correlating in one with differences in tumor grade. In one HPV-16-positive case, multiple sites of VIN displayed heterogeneity for LOH consistent with divergent clonal or subclonal populations, some of which were not shared by the tumor. In one HPV-negative case, LOH was found in foci of hyperplasia and differentiated VIN (atypical hyperplasia), the latter sharing LOH with the invasive carcinoma at some but not all chromosomal loci. This study suggests that a genetic relationship exists between VIN and carcinoma, irrespective of HPV involvement. It also suggests that in HPV-negative tumors, allelic loss may predate the onset of invasive carcinoma and, in some cases, cellular atypia (VIN). However, the divergent patterns of LOH observed imply that many genetic alterations in the adjacent vulvar epithelium are not directly related to the invasive carcinoma.     

Increased detection of HPV 16 virus in invasive, but not in early cervical cancers.

Human papilloma virus type 16 (HPV 16) DNA is found in about 50% of cervical squamous cell carcinomas (SCCs), and this association has raised the possibility of a causal role for HPV 16 in cervical carcinogenesis. We have tested this hypothesis by assaying a series of biopsies (n = 119) ranging from normal mucosa to infiltrating SCC with the PCR-technique for the presence of HPV 16 DNA. While HPV 16 DNA was detected in 50% of our cases with invasive SCC, the incidence of HPV 16-positive samples was about 10% in all other biopsies ranging from normal mucosa to cases of carcinoma in situ. HPV 16 therefore appears to be involved in late tumor promotion but not in early tumor development.     

Aberrant promoter methylation of SH3GL2 gene in vulvar squamous cell carcinoma correlates with clinicopathological characteristics and HPV infection status

Objective: This study attempted to examine the methylation status of SH3GL2 gene in different types of human vulvar lesions and its correlation with clinicopathological parameters. Methods: Immunohistochemical analysis was used to identify the expression status of SH3GL2 in vulvar squamous cell carcinoma (VSCC), vulvar intraepithelial neoplasia (VIN) and benign vulvar squamous epithelium tissues. Bisulfite genomic sequencing method was used to detect methylation status of the SH3GL2 gene. Clinicopathological correlation of the alterations was analysed by the chi-square tests. Results: Immunohistochemical analysis showed expression of SH3GL2 in VSCC was significantly downregulated than that in VIN and normal vulvar tissues. In accordance with higher frequency of methylation status in SH3GL2, statistical analysis showed methylation status of SH3GL2 was closely related to tumor TNM stage (P=0.003), but not related to age, tumor volume, tumor differentiation, lymph node metastasis and VIN grade. High-methylation status of SH3GL2 showed significant association with HPV infection status. Conclusions: Our results indicated that the methylation status of SH3GL2 gene was associated with the TNM staging and HPV infection status of VSCC, suggesting that it might play a synergistic role in the development of VSCC.