p53 protein expression in a population-based series of primary vulval squamous cell carcinoma and immediate adjacent field change

p53 and p16 expression profiles in vulvar cancer: a translational analysis by the Arbeitsgemeinschaft Gynäkologische Onkologie Chemo and Radiotherapy in Epithelial Vulvar Cancer study group

BACKGROUND

There are 2 known pathways for tumorigenesis of vulvar squamous cell carcinoma-a human papillomavirus-dependent pathway characterized by p16 overexpression and a human papillomavirus-independent pathway linked to lichen sclerosus, characterized by TP53 mutation. A correlation of human papillomavirus dependency with a favorable prognosis has been proposed.

OBJECTIVE

The objective of the study was to further understand the role of human papillomavirus and p53 status in vulvar squamous cell carcinoma and characterize its clinical relevance.

STUDY DESIGN

The Arbeitsgemeinschaft Gynaecological Oncology Chemo and Radiotherapy in Epithelial Vulvar Cancer-1 study is a retrospective cohort study of 1618 patients with primary vulvar squamous cell carcinoma Fédération Internationale de Gynécologie et d'Obstétrique stage ≥1B treated at 29 gynecologic cancer centers in Germany between 1998 and 2008. For this translational substudy, formalin-fixed paraffin-embedded tissue was collected. A tissue microarray was constructed (n=652 samples); p16 and p53 expression was determined by immunohistochemistry. Human papillomavirus status and subtype were analyzed by polymerase chain reaction.

RESULTS

p16 immunohistochemistry was positive in 166 of 550 tumors (30.2%); p53 staining in 187 of 597 tumors (31.3%). Only tumors with available information regarding p16 and p53 immunohistochemistry and without p53 silent expression pattern were further analyzed (n=411); 3 groups were defined: p53+ (n=163), p16+/p53- (n=132), and p16-/p53- (n=116). Human papillomavirus DNA was detected in 85.6% of p16+/p53- tumors; human papillomavirus-16 was the most common subtype (86.3%). Patients with p16+ tumors were younger (64 vs 72 years for p53+, respectively, 69 years for p16-/p53- tumors; P<.0001) and showed lower rates of lymph-node involvement (28.0% vs 42.3% for p53+, respectively, 30.2% for p16-/p53- tumors; P=.050). Notably, 2-year-disease-free and overall survival rates were significantly different among the groups: disease-free survival, 47.1% (p53+), 60.2% (p16-/p53-), and 63.9% (p16+/p53-) (P<.001); overall survival, 70.4% (p53+), 75.4% (p16-/p53-), and 82.5% (p16+/p53-) (P=.002). In multivariate analysis, the p16+/p53- phenotype showed a consistently improved prognosis compared with the other groups (hazard ratio, 0.66; 95% confidence interval, 0.44-0.99; P=.042).

CONCLUSION

p16 overexpression is associated with an improved prognosis whereas p53 positivity is linked to an adverse outcome. Our data support the hypothesis of a clinically relevant third subgroup of vulvar squamous cell carcinoma with a p53-/p16- phenotype showing an intermediate prognosis that needs to be further characterized.

The Clinical Relevance of p16 and p53 Status in Patients with Squamous Cell Carcinoma of the Vulva

Objective

To investigate the prognostic significance of HPV status in vulvar squamous cell carcinomas (VSCC) and to determine whether preoperative determination of p16 or p53 status would have clinical relevance.

Methods

Patients treated for VSCC at a tertiary hospital in Sydney, Australia, from 2002 to 2014, were retrospectively evaluated (n = 119). Histological specimens were stained for p53 and p16 expression, and HPV status was determined by PCR detection of HPV DNA.

Results

HPV DNA was detected in 19%, p16 expression in 53%, and p53 expression in 37% of patients. Kaplan-Meier survival estimates indicated that p16/HPV-positive patients had superior five-year disease-free survival (76% versus 42%, resp., p = 0.004) and disease-specific survival (DSS) (89% versus 75% resp., p = 0.05) than p53-positive patients. In univariate analysis, nodal metastases (p < 0.001), tumor size >4 cm (p = 0.03), and perineural invasion (p = 0.05) were associated with an increased risk of disease progression and p16 expression with a decreased risk (p = 0.03). In multivariable analysis, only nodal metastases remained independent for risk of disease progression (p = 0.01). For DSS, lymph node metastases (p < 0.001) and tumor size (p = 0.008) remained independently prognostic.

Conclusion

The p16/HPV and p53 status of VSCC allows separation of patients into two distinct clinicopathological groups, although 10% of patients fall into a third group which is HPV, p16, and p53 negative. p16 status was not independently prognostic in multivariable analysis. Treatment decisions should continue to be based on clinical indicators rather than p16 or p53 status.

The prognostic value of p16 and p53 expression for survival after vulvar cancer: A systematic review and meta-analysis

The tumor suppressor proteins p16 and p53 have been suggested to have prognostic value in some human papillomavirus (HPV)-associated cancers, however, this has been less well established for vulvar cancer. The aim of this review and meta-analysis was to examine the prognostic value of p16 and p53 expression status on survival after vulvar squamous cell carcinoma (VSCC). We conducted a thorough systematic literature search of multiple databases to identify studies examining survival after histolocally verified VSCC that were tested for p16 and/or p53. A total of 18 eligible studies were included. Using a fixed-effects model we calculated study-specific and pooled hazard ratios (HRs) of 5-year overall survival (OS). In the analyses of OS, we included 475 VSCC cases tested for p16 expression of which 38% were p16 positive. The pooled HR_p16 was 0.40 (95% CI: 0.29-0.55). In addition, the majority of results from studies with adjusted analyses on the prognostic value of p16 indicated that p16 expression status could be an independent prognostic marker for OS in women diagnosed with VSCC, and the same pattern was seen for disease specific survival (DSS). We also included 310 VSCC cases tested for p53 expression of which 54% were p53 positive. The pooled HR_p53 was 1.81 (95% CI: 1.22-2.68) indicating that p53 positive VSCC have a significantly lower 5-year OS compared to p53 negative. The results in relation to p53 reported from adjusted analyses OS and on DSS and disease free survival were more equivocal. This meta-analysis and review suggests that p53 and especially p16 expression status are of prognostic importance in women diagnosed with VSCC. This may be clinically important in the future design of targeted therapy and when planning the optimal follow-up strategy. Future studies should include the combined use of biomarkers such as p16, p53 and HPV status.

Assessment of CK17 as a Marker for the Diagnosis of Differentiated Vulvar Intraepithelial Neoplasia

Differentiated vulvar intraepithelial neoplasia (dVIN), precursor of vulvar squamous cell carcinoma, is human papilloma virus independent and often found in a background of lichen sclerosus (LS) and lichen simplex chronicus (LSC). Subtle histologic findings make the diagnosis of dVIN difficult, and, although the use of p53 and Ki-67 has been of some value, there is a need for a better immunohistochemical marker. Cytokeratin 17 (CK17), a cytoskeletal intermediate filament protein, has previously been used in the diagnosis of anogenital lesions. Here we evaluated CK17 in dVIN in comparison with LS, LSC, and usual VIN (uVIN/HSIL). Twenty-nine cases of dVIN, 9 cases of uVIN, 8 cases of LS, and 7 of LSC were evaluated using CK17, Ki-67, and p53. All 29 dVIN cases displayed immunoreactivity for CK17, with 27 (93%) showing intermediate to strong and diffuse reactivity. No cases of uVIN displayed diffuse CK17 expression, whereas 63% of LS and 29% of LSC displayed intermediate to strong diffuse immunoreactivity, confined to the upper half of the epithelium. P53 and Ki-67 expression was present in varying degrees in all types of lesions, displaying limited discriminatory power for dVIN. Our findings suggest that CK17, although not specific for dVIN, when combined with histologic findings, Ki-67, and p53 immunohistochemistry, can be a marker of vulvar dysplasia and serve as an adjunct in the diagnosis of dVIN. Specifically, in small biopsies, the presence of diffuse suprabasal or full thickness expression strongly favors a diagnosis of dVIN over LSC, whereas focal and/or superficial expression supports a diagnosis of LSC.

Biomarkers p16, Human Papillomavirus and p53 Predict Recurrence and Survival in Early Stage Squamous Cell Carcinoma of the Vulva

OBJECTIVE

Vulvar squamous cell carcinoma (VSCC) develops through 2 distinct molecular pathways, one involving high-risk human papillomavirus (HPV) infection and the other through early p53 suppressor gene mutation. We sought to evaluate the influence of p53 mutation, HPV status, and p16 expression on local recurrence and disease-specific mortality in early stage VSCC.

MATERIALS AND METHODS

We performed a retrospective chart review of all patients with stage I VSCC at the Maine Medical Center from 1998 to 2007 (n = 92). Tumor size, depth of invasion, lymphatic/vascular space invasion, and growth pattern were recorded. Paraffin-embedded tissue blocks were stained by immunohistochemistry for p16 and p53; high-risk HPV was detected by polymerase chain reaction assay. Margin distance was determined by a gynecologic pathologist. Survival analyses were conducted to examine predictors of VSCC recurrence and disease-specific mortality.

RESULTS

Age, depth of invasion, lymphatic/vascular space invasion, growth pattern, and margin status were not significant predictors of recurrence or disease-specific mortality. Tumor size of greater than 4.0 cm indicated a 4-fold increase in disease-specific mortality but did not significantly increase recurrence. p16-Positive patients were less likely to recur and had no VSCC-related deaths. Human papillomavirus-positive patients were less likely to recur and had no VSCC-related deaths. p53-positive patients were 3 times more likely to recur and nearly 7 times more likely to die from vulvar cancer.

CONCLUSIONS

Our findings suggest that HPV and the surrogate biomarker p16 indicate a less aggressive type of vulvar cancer. p53 positivity was associated with poor prognosis and significantly increased both recurrence and disease-specific mortality.

Study of biomolecular and clinical prognostic factors in patients with cancer of the vulva undergoing surgical treatment

INTRODUCTION

Cancers of the vulva account for 3% to 5% of all cancers of the female genital. This study was conducted to evaluate clinical, pathological, and molecular prognostic factors in patients with cancer of the vulva.

METHODS

Patients with squamous cell carcinoma of the vulva who had undergone surgical treatment at the Department of Pelvic Surgery and Gynecology Service, Aristides Maltez Hospital, between June 1993 and June 2011 were selected. Clinical, epidemiological, pathological, and molecular characteristics related to the prognosis of these patients were evaluated in relation to the prognosis. In the molecular evaluation, we studied the expression of p53 and matrix metalloproteinase 2 by immunohistochemistry.

RESULTS

Seventy-five patients were eligible for the study. In multivariable analysis, factors related to survival were as follows: tumor size larger than 4 cm (P = 0.014), an invasion depth greater than 2 mm (P = 0.023) and matrix metalloproteinase 2 expression in more than 50% of the tumor cells (P = 0.046). With the use of the relative risks of the factors identified in the multivariable analysis, a point count was developed for a prognostic classification (the score classifies patients into 3 categories).

CONCLUSIONS

A tumor size larger than 4 cm, an invasion depth greater than 2 mm, and metalloproteinase 2 expression in more than 50% of the tumor cells seem to be related to lower overall survival rate in patients with cancer of the vulva undergoing surgical treatment. A classification of the patient's prognosis can be performed using a point count based on these relative risks.

Clinico-pathological and biological prognostic variables in squamous cell carcinoma of the vulva

Several clinical-pathological parameters have been related to survival of patients with invasive squamous cell carcinoma of the vulva, whereas few studies have investigated the ability of biological variables to predict the clinical outcome of these patients. The present paper reviews the literature data on the prognostic relevance of lymph node-related parameters, primary tumor-related parameters, FIGO stage, blood variables, and tissue biological variables. Regarding these latter, the paper takes into account the analysis of DNA content, cell cycle-regulatory proteins, apoptosis-related proteins, epidermal growth factor receptor [EGFR], and proteins that are involved in tumor invasiveness, metastasis and angiogenesis. At present, the lymph node status and FIGO stage according to the new 2009 classification system are the main predictors for vulvar squamous cell carcinoma, whereas biological variables do not have yet a clinical relevance and their role is still investigational.

Vulvo-vaginal cancers: risks, evaluation, prevention and early detection

Vulvar and vaginal cancers are rare and account for approximately 7% of cancers of the female reproductive tract. Vulvar and vaginal neoplasia share similar risk factors: human papillomavirus infection, previous cervical intraepithelial neoplasia or cervical cancer, current smoking, sexual factors, and immunosuppression. Several treatment options are available for patients with documented histologic high-grade intraepithelial vulvar or vaginal neoplasia, including excision, laser vaporization, and 5-fluorouracil. After treatment, lifetime follow-up with cytology and colposcopy is recommended. With the widespread use of the human papillomavirus vaccine, one half to two thirds of vulvar and vaginal cancers may be prevented. Patient education regarding reduction of risk factors for progression and close surveillance of at-risk individuals may prevent the progression to invasive disease.

Vulval cancer: prevention and screening

The incidence of vulval cancer is rising, both in older women and those under 50 years of age. Vulval cancer has at least two types, one arising in association with lichen sclerosus (LS) and the other with vulval intraepithelial neoplasia (VIN). Recent pathological and aetiological descriptions are included, along with the latest description of VIN terminology. Prevention of and screening for vulval cancer will require greater understanding of why some women with LS and VIN are at greater risk: recent studies of molecular change might contribute to this. The use of vulval cytology and toluidine blue staining is described. Patient or vulval awareness may help but clinical features are non-specific. Prophylactic vaccination against HPV and campaigns against smoking may contribute in the future.

Human papillomavirus infection and p53 protein expression in vulvar intraepithelial neoplasia and invasive squamous cell carcinoma

The etiopathogenesis of vulvar intraepithelial neoplasia (VIN III) and invasive squamous cell carcinoma are largely unknown. Since there are few studies on Brazilian patients, our purpose was to determine the frequency of human papillomavirus (HPV) infection and the expression of p53 in these lesions, and associate them with other factors such as age, morphological subtypes, multicentric and multifocal disease. Thirty-eight cases of VIN III, nine of superficially invasive carcinoma, and 55 of invasive vulvar carcinoma were retrospectively evaluated from 1983 to 1995 for the presence of HPV by immunohistochemistry and in situ hybridization, and for p53 protein expression by immunohistochemistry on paraffin sections. All cases for whom material (slides and paraffin blocks) and clinical data were available were included. HPV and p53 were detected in 57.9 and 21.1% of the VIN III lesions, 33.3 and 66.7% of superficially invasive carcinomas, and 7.3 and 58.2% of invasive squamous cell carcinomas, respectively. HPV infection was associated with younger age in the VIN III and invasive carcinoma groups. In the latter, HPV infection was associated with the basaloid variant. p53 expression rate was higher in superficially invasive and invasive lesions and was not related to HPV infection. Our findings are similar to others and support the hypothesis that there are two separate entities of the disease, one associated with HPV and the other unrelated, with p53 inactivation possibly being implicated in some of the cases.

Changes in the management of vulval cancer

Vulval carcinoma is relatively rare. The disease spreads from the vulva through embolization to the locoregional lymphatic station, the inguinofemoral nodes. Prior to this event cure can be achieved, but rarely predicted with certainty. This chapter reviews current therapeutic knowledge and recognizes the increasing importance of individualization of a treatment plan. The adoption of these principles will hopefully evolve a pattern of care that leads to a decrease in morbidity for those women with early tumours and less morbid but more effective strategies for those with advanced disease.

Recent advances in the pathology of the vulva

This review addresses recent and important advances in our knowledge of several uncommon or rare disorders of the vulva including Paget's disease, vulva intraepithelial neoplasia, lichen sclerosus and squamous hyperplasia and their relationship to squamous carcinoma. Emphasis is placed on the two biologically different types of squamous carcinoma related and unrelated to human papillomavirus infection. Finally, the relatively recent concept of the sentinel node as applied to vulva carcinoma is discussed.

Immunohistochemical analysis of p53 in vulval intraepithelial neoplasia and vulval squamous cell carcinoma

Human papillomavirus (HPV) is thought to cause some vulval squamous cell carcinomas (VSCC) by degrading p53 product. Evidence on whether HPV-negative VSCC results from p53 mutation is conflicting. We performed immunohistochemistry for p53 product on 52 cases of lone vulval intraepithelial neoplasia (VIN), 21 cases of VIN with concurrent VSCC and 67 cases of VSCC. We had previously performed HPV detection and loss of heterozygosity (LOH) analyses on these samples. Abnormal p53 immunoreactivity (p53-positive) rates in HPV-positive VSCC and HPV-negative VSCC were 22% (12/54) and 31% (4/13), respectively (P<0.74). p53 immunoreactivity was associated with LOH at the p53 locus (P<0.004), but neither technique differentiated between HPV-positive and HPV-negative VSCC. p53 immunoreactivity was associated with overall LOH rates (p53-positive VSCC vs p53-negative VSCC mean fractional regional allelic loss 0.41 vs 0.24, respectively, P<0.027). LOH at 3p25 was more frequent in p53-positive VSCC cf p53-negative VSCC (70 vs 21%, respectively, P<0.007). There was a trend in p53 disruption associated with invasive disease; HPV-positive VSCC demonstrated more disruption than VIN associated with VSCC, which had more disruption than lone VIN III (22 vs 10 vs 0%, respectively, P<0.005). In all, three out of 73 cases of VIN were p53-positive. All three were associated with concurrent or previous VSCC. Meta-analysis of previous studies revealed significantly more p53 disruption in HPV-negative VSCC cf HPV-positive VSCC (58 vs 33%, respectively; P<0.0001). p53 immunoreactivity/mutation in VIN only appeared in association with VSCC. These data suggest that HPV-independent vulval carcinogenesis does not exclusively require disruption of p53, p53 disruption may work synergistically with LOH at specific loci and p53-positive VIN should be checked carefully for the presence of occult invasion.

Overexpression of wild-type p53 in lichen sclerosus adjacent to human papillomavirus-negative vulvar cancer

Human papillomavirus is a risk factor for vulvar cancer, whereas human papillomavirus-negative late onset vulvar carcinoma is associated with the dermatologic condition, lichen sclerosus. Human papillomavirus E6 protein targets TP53 for degradation and by inference it has been assumed that human papillomavirus-negative vulvar cancer is dependent upon the acquisition of p53 somatic mutations and subsequent allelic loss. To investigate this, TP53 expression, loss of heterozygosity, and p53 genomic sequence were examined in 29 cases of human papillomavirus-negative vulvar carcinoma with adjacent lichen sclerosus. We examined 37 cases of lichen sclerosus without vulvar carcinoma, 10 cases of nongenital lichen sclerosus, and 12 cases of normal vulvar epithelium served as controls. TP53 was evident in 72% of vulvar carcinoma, 48% in epithelium adjacent to vulvar carcinoma, but was minimal in normal samples. When lichen sclerosus cases were selected to exclude samples with absolutely no TP53 expression through probable failed antigen retrieval or homozygous p53 loss the number of epithelial cells expressing TP53 increased progressively from nongenital lichen sclerosus to lichen sclerosus without vulvar carcinoma, then to lichen sclerosus with vulvar carcinoma (p<0.0001). These data suggest elevated TP53 is a feature of vulvar lichen sclerosus. Seventy-four percent of vulvar carcinoma had chromosome 17p-linked loss of heterozygosity, whereas 47% of adjacent lichen sclerosus featured loss of heterozygosity, but only 31% of vulvar carcinoma had p53 mutations, a frequency less than reported previously. Seven percent of adjacent lichen sclerosus had mutations, showing for the first time the presence of an identical mutation to the matched vulvar carcinoma. These data, however, implicate p53 mutations as a later event in vulvar carcinoma and in marked contrast to the original expectation, our loss of heterozygosity data are consistent with loss of another locus (not p53) on 17p operating as a tumor suppressor in lichen sclerosus destined to develop vulvar carcinoma.

High frequency of loss of heterozygosity in vulval intraepithelial neoplasia (VIN) is associated with invasive vulval squamous cell carcinoma (VSCC)

Vulval intraepithelial neoplasia (VIN) is thought to be the premalignant phase of human papillomavirus (HPV)-associated vulval squamous cell carcinoma (VSCC). Various molecular events have been suggested as markers for progression from VIN to VSCC, but loss of heterozygosity (LOH) in vulval neoplasia has rarely been studied in this context. We performed LOH analysis by polymerase chain reaction (PCR) amplification of polymorphic microsatellite markers at 6 chromosomal loci (17p13-p53, 9p21-p16, 3p25, 4q21, 5p14 and 11p15). The presence of HPV was assessed using consensus PCR primers and DNA sequencing. To examine any association between LOH and the presence of invasive disease, we analyzed 43 cases of lone VIN III, 42 cases of lone VSCC and 21 cases of VIN with concurrent VSCC. HPV DNA was detected in 95% of lone VIN III samples and 71% of lone VSCC samples. Fractional regional allelic loss (FRL) in VIN associated with VSCC was higher than in lone VIN (mean FRL 0.43 vs. 0.21, p < 0.005). LOH at 3p25 occurred significantly more frequently in HPV-negative VSCC than in HPV-positive VSCC (58% vs. 22%, p < 0.04). These data suggest that genetic instability in VIN, reflected by LOH, may increase the risk of invasion. In addition, molecular events differ in HPV-positive and -negative VSCC and 3p25 may be the site of a tumor suppressor gene involved in HPV-independent vulval carcinogenesis.