Under expression of the Sonic Hedgehog receptor, Patched1 (PTCH1), is associated with an increased risk of local recurrence in squamous cell carcinoma of the vulva arising on a background of Lichen Sclerosus

Objective

Dysregulation of the Hedgehog (Hh) pathway has been described in a variety of cancers, including cervical cancer, a disease which shares a common aetiology with vulval squamous cell carcinoma (VSCC). Here, we investigate a large number of primary VSCC cases for evidence of Hedgehog pathway activation and examine the implications of pathway activity on clinical outcomes in a cohort of patients with primary VSCC.

Methods

Archival histology blocks containing VSCC and histologically normal adjacent epithelium were retrieved from a cohort of 91 patients who underwent treatment for primary VSCC. Immunohistochemistry staining was undertaken to assess for the expression of key Hh pathway components (SHH, PTCH1, GLI1). A competing risks statistical model was used to evaluate the implications of the levels of key Hh pathway components on clinical outcomes.

Results

We show that 92% of primary VSCC cases over-expressed one or more components of the Hh signalling pathway when compared to the adjacent normal epithelium. While expression of SHH and GLI1 did not correlate with any clinicopathological criteria, over- or under-expression of PTCH1 was associated with a reduced or increased risk of developing a local disease recurrence, respectively. In VSCC arising on a background of Lichen Sclerosus, the risk of local recurrence was potentiated in cases where PTCH1 was under-expressed.

Conclusions

Our findings reveal, for the first time, that the Hh pathway is activated in VSCC and that PTCH1 expression can be used as a biomarker to stratify patients and inform clinicians of the risk of their local recurrence, particularly in cases of VSCC associated with LS.

Intraepidermal nerve fiber density in vulvar lichen sclerosus and normal vulvar tissues

Lichen sclerosus (LS) is a chronic and inflammatory disease causing sensory symptoms such as itch and pain and affecting most frequently genital skin of women. Intraepidermal nerve fiber density (IENFD) was examined immunohistologically in 20 vulvar skin biopsies of patients affected by LS and in 20 control vulvar skin biopsies, in order to determine if these sensory sensations originate in changes in the epidermal innervation. Obtained results show fewer protein gene product 9.5 (PGP 9.5) positive intraepidermal nerve fibers (IENF) in LS tissues compared to controls (P = 0.004), while the number of calcitonin gene-related peptide (CGRP) positive IENF in LS was increased compared to normal vulvar tissue (P = 0.03). No differences in the number of vasoactive intestinal peptide (VIP) expressing IENF could be observed. To our best knowledge, this is the first study to describe intraepidermal nerve fiber density in vulvar LS. Significant differences in IENFD between LS and control skin samples, which have been found, point to the damage to the small nerve fibers in the disease process of LS, which may contribute to pathogenesis of LS sensory symptoms.

Reduction in ERRα is associated with lichen sclerosus and vulvar squamous cell carcinoma

OBJECTIVE

ERRs (estrogen-related receptors) regulate energy metabolism, the cell cycle and inflammatory processes in both normal and cancer cells. Chronic inflammation induced by lichen sclerosus (LS) or human papilloma virus (HPV) precedes vulvar squamous cell carcinoma (vulvar SCC). We investigated the expression of ERRα, ERRβ and ERRγ in normal vulvar skin, LS as well as LS-dependent and LS-independent/HPV-related vulvar SCC.

METHODS

A total of 203 samples were analyzed for ERRα, ERRβ and ERRγ by using immunohistochemistry. These included 37 normal vulvar skin samples, 110 LS samples, 6 vulvar intraepithelial neoplasia (VIN) samples and 50 vulvar SCC samples.

RESULTS

A substantial reduction in or disappearance of ERRα was detected in all vulvar SCC samples. A total of 79% of childhood-onset LS and 51% of adulthood-onset LS lesions showed decreases in ERRα staining. A gradual reduction in ERRα cytoplasmic staining was observed from healthy vulvar skin to precursor lesions and further to SCC. Nuclear ERRα staining was observed in 8/33 (24%) LS-dependent and 10/17 (59%) LS-independent SCC samples.

CONCLUSIONS

ERRα, a key regulator of cell energy metabolism, may play a role in the pathogenesis of both LS and vulvar SCC.

Unusual remodeling of the hyalinization band in vulval lichen sclerosus by type V collagen and ECM 1 protein

OBJECTIVES

The vulva is the primary site affected in lichen sclerosus, a chronic dermatosis in women that is histologically characterized by a zone of collagen remodeling in the superior dermis. The normal physiological properties of the vulva depend on the assembly of collagen types I (COLI), III (COLIII) and V (COLV), which form heterotypic fibers, and extracellular matrix protein interactions. COLV regulates the heterotypic fiber diameter, and the preservation of its properties is important for maintaining normal tissue architecture and function. In the current work, we analyzed the expression of COLV and its relationship with COLI, COLIII, elastic fibers and extracellular matrix protein 1 in vulvar biopsies from patients with lichen sclerosus.

METHODS

Skin biopsies from 21 patients with lichen sclerosus, classified according to Hewitt histological criteria, were studied and compared to clinically normal vulvar tissue (N=21). Morphology, immunohistochemistry, immunofluorescence, 3D reconstruction and morphometric analysis of COLI, COLIII, COLV deposition, elastic fibers and extracellular matrix 1 expression in a zone of collagen remodeling in the superior dermis were performed.

RESULTS

A significant decrease of elastic fibers and extracellular matrix 1 protein was present in the hyalinization zone of lichen sclerosus compared to healthy controls. The non-homogeneous distribution of collagen fibers visualized under immunofluorescence in the hyalinization zone of lichen sclerosus and control skin was confirmed by histomorphometry. Lichen sclerosus dermis shows a significant increase of COLI, COLIII and COLV expression compared to the healthy controls. Significant inverse associations were found between elastic fibers and COLV and between COLV and extracellular matrix 1 expression. A direct association was found between elastic fiber content and extracellular matrix 1 expression. Tridimensional reconstruction of the heterotypic fibers of the lichen sclerosus zone of collagen remodeling confirmed the presence of densely clustered COLV.

CONCLUSIONS

Increased deposition of abnormal COLV and its correlation with extracellular matrix 1 and elastic fibers suggest that COLV may be a trigger in the pathogenesis of lichen sclerosus.

Inactivation of the CDKN2A and the p53 tumour suppressor genes in external genital carcinomas and their precursors

BACKGROUND

p53 has been extensively studied in external genital carcinoma (EGC), and is frequently inactivated, but little is known about the role of the CDKN2A tumour suppressor gene in the oncogenesis of EGC.

OBJECTIVES

To investigate the role of CDKN2A and p53 in the pathogenesis of EGCs and their precursor lesions vulval intraepithelial neoplasia (VIN3), penile intraepithelial neoplasia and lichen sclerosus (LS).

METHODS

By means of CDKN2A and p53 mutation screening (single-strand conformational polymorphism analysis and sequencing), methylation analysis of alternative CDKN2A promoters (methylation-specific polymerase chain reaction) and p53 immununochemistry, we analysed eight invasive EGCs (five from vulva and three from penis) and 25 precancerous lesions (two undifferentiated VIN3 and 23 vulval/penile lesions of LS) from 33 patients.

RESULTS

p53 mutations (mainly transversions) and CDKN2A mutations (including one hot spot) were present in 75% and 50% of invasive tumours, respectively, but were absent in all precancerous lesions. Remarkably, all CDKN2A-mutated tumours also harboured a p53 mutation. CDKN2A or p53 mutations were observed more frequently in LS-derived EGCs than in human papillomavirus-derived EGCs (P = 0.053). A positive anti-p53 staining, but without p53 mutations, was also detected in 30% of LS lesions, suggesting a p53 stabilization in response to inflammation and carcinogenic insult. Methylation of p16(INK4a) and p14(ARF) promoters was not a frequent mechanism of CDKN2A inactivation.

CONCLUSIONS

Our study shows a high prevalence of co-inactivating mutations of p53 and/or CDKN2A genes in EGC, that seem to occur preferentially in LS-derived tumours and late in oncogenesis.

Decorin and chondroitin sulfate distribution in vulvar lichen sclerosus: correlation with distinct histopathologic stages

OBJECTIVE

To characterize decorin and chondroitin sulfate (CS) expression in lichen sclerosus (LS).

STUDY DESIGN

Thirty-one untreated vulvar LS lesions were biopsed, and hematoxylin-eosin-stained cases were graded according to Hewitt's classification. Immunohistochemistry was performed using antibodies directed against human decorin diluted 1:500 and CS diluted 1:200. The control group, made up of cutaneous fragments from vulvoperineal corrective surgeries or nymphoplasties, represented 22 patients.

RESULTS

Decorin and CS were present at the LS hyaline zone in different moments of matrix modulation. In all Hewitt stages CS prevailed at the extracellular matrix in cases with a compact aspect of the hyaline zone, while decorin was seen only in areas of less compactness. Normal vulvar tissue revealed only the presence of CS in juxtaepithelial zones. No decorin immunoexpression was found in normal vulvar skin.

CONCLUSION

Decorin and CS deposition in vulvar LS varies in the distinct histologic stages, which probably reflect the importance of these molecules in matricial remodeling in this disorder. Decorin may play an important role in cases of LS.

[Expression of cyclin D1 and p16 protein in vulvar white lesion]

OBJECTIVE

To investigate the relationship between cell cycle protein (cyclin D1 and p16) expression and vulvar white lesion.

METHODS

Biopsies from 34 cases with vulvar white lesion, including 12 cases with lichen sclerosus (LS), 18 with squamous hyperplasia (SH) and 4 SH accompanied with LS, were examined for protein expression of cyclin D1 and p16 using immunohistochemical techniques. Normal vulvar tissues from 11 patients with other benign gynecologic diseases were used as control.

RESULTS

Fifty-six percent of patients with vulvar white lesion were immunopositive for cyclin D1 protein, which was significantly higher than that of control group (9%, P < 0.05); but there was no significant difference between LS (58%) and SH patients (50%, P > 0.05) in expression of cyclin D1 protein. Immunopositive expression of p16 protein in patients was 6%, with no significant difference from the control group (0, P > 0.05).

CONCLUSIONS

Cyclin D1 and p16 are important factors modulating cell cycle. The interrupt of balance between these two factors derived from abnormal expression of cyclin D1 may be one of the causes of vulvar white lesion.

[Investigation of the relationship between white lesion of vulva and human epidermal growth factor]

The levels of human epidermal growth factor (hEGF) were determined by radioimmunoassay (RIA) in dermal specimens taken from lesion skin and normal vulva skin in 30 patients with white lesions of the vulva as well as their urine specimens, and in another 29 vulva biopsy and 37 urine samples from healthy women without the disease as the control group. The results showed that the mean hEGF levels in lesion vulva skin, normal vulva skin of the patients and normal vulva skin of healthy women were 163.40 +/- 97.89 micrograms/L, 119.00 +/- 53.13 micrograms/L and 67.84 +/- 14.72 micrograms/L respectively. The level of hEGF in lesion skin was higher than that in the normal vulva skin of same patients (P < 0.05) and also higher than that in the normal skin of healthy women (P < 0.01). The hEGF level in normal skin of the patients was higher than that in healthy women (P < 0.01). The hEGF level in lesion skin had no relationship with pathological types. The hEGF levels in urine had no significant difference between the patients and healthy women. The results suggested that high levels of hEGF in local vulva lesions may play an important role in the pathogenesis of white lesions of the vulva.

Histologic criteria for lichen sclerosus of the vulva

Although lichen sclerosus was first described almost a century ago, a grading system was not devised, and the minimal histologic criteria required for diagnosis were not defined. The present study was based on the sequential sectioning of nine vulvectomy specimens removed for invasive carcinoma. Both epidermal and dermal changes were noted, but only the dermal ones were unique to the disease. Early changes included subtle densification of the basement membrane as well as hyalinization of the papillary dermis and superficial capillaries. Based on these findings, a grading system was developed.