Stathmin is a highly sensitive and specific biomarker for vulvar high-grade squamous intraepithelial lesions

STNM1 in human cancers: role, function and potential therapy sensitizer

STMN1 belongs to the stathmin gene family, it encodes a cytoplasmic phosphorylated protein, stathmin1, which is commonly observed in vertebrate cells. STMN1 is a structural microtubule-associated protein (MAP) that binds to microtubule protein dimers rather than microtubules, with each STMN1 binding two microtubule protein dimers and preventing their aggregation, leading to microtubule instability. STMN1 expression is elevated in a number of malignancies, and inhibition of its expression can interfere with tumor cell division. Its expression can change the division of tumor cells, thereby arresting cell growth in the G2/M phase. Moreover, STMN1 expression affects tumor cell sensitivity to anti-microtubule drug analogs, including vincristine and paclitaxel. The research on MAPs is limited, and new insights on the mechanism of STMN1 in different cancers are emerging. The effective application of STMN1 in cancer prognosis and treatment requires further understanding of this protein. Here, we summarize the general characteristics of STMN1 and outline how STMN1 plays a role in cancer development, targeting multiple signaling networks and acting as a downstream target for multiple microRNAs, circRNAs, and lincRNAs. We also summarize recent findings on the function role of STMN1 in tumor resistance and as a therapeutic target for cancer.

Squamous and Glandular Lesions of the Vulva and Vagina: What's New and What Remains Unanswered?

A number of changes have been introduced into the 5th Edition of the World Health Organization (WHO) Classification of squamous and glandular neoplasms of the vulva and vagina. This review highlights the major shifts in tumor classification, new entities that have been introduced, recommendations for p16 immunohistochemical testing, biomarker use, molecular findings and practical points for pathologists which will affect clinical care. It also touches upon several issues that still remain answered in these rare but undeniably important women's cancers.

Transcriptome Analysis in Vulvar Squamous Cell Cancer

Simple Summary

The number of women, especially younger women, diagnosed with vulvar cancer, has been rising mainly due to the infection with human papilloma virus (HPV) over the last years. In contrast to other tumor entities, limited information on the underlying genetic changes is available, and thus treatment advances, especially the development of personalized treatments, are hampered. We aimed to explore the RNA expression profiles in a group of 24 vulvar cancer samples in order to detect potential prognostic markers and therapeutic targets in order to establish to a more profound understanding of vulvar cancer carcinogenesis.

Abstract

To date, therapeutic strategies in vulvar squamous cell carcinoma (VSCC) are lacking molecular pathological information and targeted therapy hasn’t been approved in the treatment of VSCC, yet. Two etiological pathways are widely accepted: HPV induced vs. HPV independent, associated with chronic skin disease, often harboring TP53 mutations (mut). The aim of this analysis was to analyze the RNA expression patterns for subtype stratification on VSCC samples that can be integrated into the previously performed whole exome sequencing data for the detection of prognostic markers and potential therapeutic targets. We performed multiplex gene expression analysis (NanoString) with 770 genes in 24 prior next generation sequenced samples. An integrative data analysis was performed. Here, 98 genes were differentially expressed in TP53mut vs. HPV+ VSCC, in the TP53mut cohort, where 56 genes were upregulated and 42 were downregulated in comparison to the HPV+ tumors. Aberrant expression was primarily observed in cell cycle regulation, especially in HPV+ disease. Within the TP53mut group, a distinct cluster was identified that was correlated to a significantly worse overall survival (p = 0.017). The RNA expression profiles showed distinct patterns with regard to the known VSCC subtypes and could potentially enable further subclassification in the TP53mut groups

HPV-Positive and HPV-Negative Vulvar Squamous Cell Carcinoma Are Biologically, but Not Clinically, Distinct

Vulvar squamous cell carcinoma (VSCC) pathogenesis is traditionally defined by the presence or absence of human papillomavirus (HPV), but the definition of these groups and their molecular characteristics remains ambiguous across studies. Here, we present a retrospective cohort analysis of 36 patients with invasive VSCC where HPV status was determined using RNA in situ hybridization (ISH) and polymerase chain reaction (PCR). Clinical annotation, p16 immunohistochemistry (IHC), programmed death ligand-1 (PD-L1) IHC, HPV16 circular E7 RNA (circE7) detection, and RNA-sequencing (RNA-seq) of the cases was performed. A combination of ISH and PCR identified 20 cases (55.6%) as HPV-positive. HPV-status did not impact overall survival (HR: 1.36, 95% CI: 0.307 to 6.037, p=0.6857) or progression-free survival (HR: 1.12, 95% CI: 0.388 to 3.22, p=0.8367), and no significant clinical differences were found between the groups. PD-L1 expression did not correlate with HPV status, but increased expression of PD-L1 correlated with worse overall survival. Transcriptomic analyses (n=23) revealed distinct groups, defined by HPV status, with multiple differentially expressed genes previously implicated in HPV-induced cancers. HPV-positive tumors showed higher global expression of endogenous circular RNAs (circRNAs), including several circRNAs that have previously been implicated in the pathogenesis of other cancers.

Precursor lesions of vulvar squamous cell carcinoma - histology and biomarkers: A systematic review

The precursor lesion of vulvar squamous cell carcinoma (VSCC), namely vulvar intraepithelial neoplasia (VIN), is classified as: human papillomavirus (HPV)-related high grade squamous intraepithelial lesion (HSIL), and HPV-independent differentiated VIN (dVIN). Traditionally, histology and immunohistochemistry (IHC) have been the basis of diagnosis and classification of VIN. HSIL shows conspicuous histological atypia, and positivity on p16-IHC, whereas dVIN shows less obvious histological atypia, and overexpression or null-pattern on p53-IHC. For both types of VIN, other diagnostic immunohistochemical markers have also been evaluated. Molecular characterization of VIN has been attempted in few recent studies, and novel genotypic subtypes of HPV-independent VSCC and VIN have been identified. This systematic review appraises the VSCC precursors identified so far, focusing on histology and biomarkers (immunohistochemical and molecular). To gain further insights into the carcinogenesis and to identify additional potential biomarkers, gene expression omnibus (GEO) datasets on VSCC were analyzed; the results are presented.

New Directions in Vulvar Cancer Pathology

PURPOSE OF REVIEW

The aim of this article is to provide clinicians and pathologists with an understanding of the aetiopathology, pathogenesis and classification of vulval neoplasia and their molecular correlates.

RECENT FINDINGS

There is an increased understanding of subcellular changes in vulvar malignancies. These provide the direction for further research and aid personalised treatment for patients. The article explores concepts of the aetiology of vulvar cancer and updates the reader with the equivalence of terminology of preneoplastic vulval disease. The differential diagnosis of squamous neoplasia and their clinicopathological correlation is detailed. The salient findings from recent literature into the understanding of the disease of squamous cell neoplasia and rare vulvar malignancies are summarised.

Superficially invasive stage IA vulvar squamous cell carcinoma-therapy and prognosis

OBJECTIVES

Superficially invasive stage IA squamous vulvar cancer (VSCC) is defined as a single lesion measuring ≤2 cm with a depth of invasion of ≤1.0 mm (FIGO stage IA). This article examines the natural course and prognosis of superficially invasive VSCC.

METHODS

This is a retrospective case series of 46 patients (median age 58 years) with superficially invasive stage IA VSCC receiving wide local excision between January 1996 and November 2014 in the University Medical Center Hamburg-Eppendorf.

RESULTS

Median tumor size was 4 mm. In 39/46 (84.8%) patients peri-tumoral high-grade intraepithelial neoplasia (HSIL) and/or lichen sclerosus (LS) of the vulva were histologically detected: 34 (74.0%) usual type high-grade vulvar intraepithelial neoplasia (uVIN, HSIL), 4 (8.7%) LS with simultaneous VIN (3 uVIN, 1 differentiated VIN (dVIN)), 1 (2.2%) with LS only. 37/46 (80.4%) patients had a R0 resection; in 2 (4.3%) a high-grade VIN was detected in the margin and in 7 (15.2%) the resection status was unknown. The mean follow-up was 58 (range 10-185) months. Four patients (8.7%) suffered from an invasive recurrence after 4, 17, 40, and 54 months, three in the vulva and one in the groin. All local recurrences occurred in women with LS in a combination with high-grade VIN (3 uVIN, 1 dVIN). Two were treated surgically again including inguino-femoral lymphadenectomy (ifLAE) (no regional lymph node metastasis histologically) as invasion depth exceeded 1 mm. The third patient refused treatment. Inguinal recurrence was treated with a bilateral ifLAE, revealing one positive lymph node, followed by adjuvant radiotherapy (groins, pelvis). None of these patients had experienced further recurrences at last follow-up.

CONCLUSIONS

Superficially invasive VSCC is characterized by having a very good prognosis. Sole surgical therapy is highly effective. Patients with LS might benefit additionally from intensified surveillance and adequate maintenance therapy in specialized centers.

Genomic Characterization of Vulvar (Pre)cancers Identifies Distinct Molecular Subtypes with Prognostic Significance

Purpose: Vulvar cancer (VC) can be subclassified by human papillomavirus (HPV) status. HPV-negative VCs frequently harbor TP53 mutations; however, in-depth analysis of other potential molecular genetic alterations is lacking. We comprehensively assessed somatic mutations in a large series of vulvar (pre)cancers.Experimental Design: We performed targeted next-generation sequencing (17 genes), p53 immunohistochemistry and HPV testing on 36 VC and 82 precursors (sequencing cohort). Subsequently, the prognostic significance of the three subtypes identified in the sequencing cohort was assessed in a series of 236 VC patients (follow-up cohort).Results: Frequent recurrent mutations were identified in HPV-negative vulvar (pre)cancers in TP53 (42% and 68%), NOTCH1 (28% and 41%), and HRAS (20% and 31%). Mutation frequency in HPV-positive vulvar (pre)cancers was significantly lower (P = 0.001). Furthermore, a substantial subset of the HPV-negative precursors (35/60, 58.3%) and VC (10/29, 34.5%) were TP53 wild-type (wt), suggesting a third, not-previously described, molecular subtype. Clinical outcomes in the three different subtypes (HPV⁺, HPV^-/p53wt, HPV^-/p53abn) were evaluated in a follow-up cohort consisting of 236 VC patients. Local recurrence rate was 5.3% for HPV⁺, 16.3% for HPV^-/p53wt and 22.6% for HPV^-/p53abn tumors (P = 0.044). HPV positivity remained an independent prognostic factor for favorable outcome in the multivariable analysis (P = 0.020).Conclusions: HPV^- and HPV⁺ vulvar (pre)cancers display striking differences in somatic mutation patterns. HPV^-/p53wt VC appear to be a distinct clinicopathologic subgroup with frequent NOTCH1 mutations. HPV⁺ VC have a significantly lower local recurrence rate, independent of clinicopathological variables, opening opportunities for reducing overtreatment in VC. Clin Cancer Res; 23(22); 6781-9. ©2017 AACR.

Role of Human Papillomavirus in Vulvar Cancer

Human papillomavirus (HPV) is involved in one of the at least 2 pathways leading to vulvar squamous cell carcinoma (VSCC). Inactivation of p53 and retinoblastoma by the viral products E6 and E7 is involved in malignant transformation. The percentage of HPV-positive VSCCs ranges from 18% to 75%, depending on the geographical area. HPV-associated tumors affect relatively young women and arise from high-grade intraepithelial lesions, identical to other HPV-associated premalignant lesions of the anogenital tract. HPV-independent tumors tend to affect older women and usually arise in a background of inflammatory skin disorders and a subtle variant of in situ lesion called differentiated vulvar intraepithelial neoplasia. HPV-positive tumors tend to be of basaloid or warty types, whereas HPV-independent tumors tend to be of keratinizing type, but there is frequent overlap between histologic types. There is no conclusive evidence yet on the best strategy in terms of determining HPV attribution. HPV DNA detection is generally considered the gold standard although there is some concern about misclassification when using this technique alone. p16 immunostaining has shown to be an excellent surrogate marker of HPV infection. Positive results for both techniques are considered the best evidence for HPV-association. The prognostic role of HPV in VSCC is still contradictory, but increasing evidence suggests that HPV-associated tumors are less aggressive. Currently, there are no differences in treatment between HPV-associated and HPV-independent VSCC, but novel immunological strategies based on anti-HPV antigens are being evaluated in clinical trials.