Human papilloma virus (HPV) status, p16INK4a, and p53 overexpression in epithelial malignant and borderline ovarian neoplasms

The frequency and prognostic role of P53 and P16 immunoexpression in primary ovarian mucinous tumors

BACKGROUND

Primary ovarian mucinous tumors are uncommon. Factors leading to invasive progression and metastatic disease have not been fully delineated yet. The aim of this study is to determine the rates of p53 and p16 immunoexpressions in primary ovarian mucinous tumors, to investigate their relationship with clinicopathologic factors and their impact on prognosis and survival.

METHODS

Seventy-eight primary ovarian mucinous tumors (30 mucinous cystadenomas, 30 mucinous borderline tumors (MBOT), 18 mucinous carcinomas (MOC)) were evaluated immunohistochemically with p53 and p16 staining. The demographic, clinicopathological data, and postoperative follow-up findings of the patients were analyzed.

RESULTS

Mutation-type p53 staining was present in 1/30 (3.3 %) cystadenoma, 10/30 (33.3 %) MBOT and 9/18 (50 %) MOC (p = 0.001). p16 overexpression was detected in 3/30 (10.0 %) MBOT and 5/18 (27.8 %) MOC, but not in any cystadenoma (p = 0.04). The frequency of mutation-type p53 staining in MBOTs with microinvasion was higher (71.4 %) than in those without (28.6 %, p = 0.026). The frequencies of p16 or p53 mutations were similar in MBOTs with and without intraepithelial carcinoma, or mural nodule (p > 0.05). In MOCs with ovarian surface involvement, mutation-type p53 staining was detected in 66.7 % (6/9) and p16 overexpression in 55.6 % (5/9) of the cases. A significant difference was found between MOCs with or without ovarian surface involvement regarding the frequency of p16 overexpression (p = 0.029). Any relationship was not detected between survival and p53 and p16 expression in MOCs (p > 0.05).

CONCLUSION

p53 and p16 mutation rates were higher in MOCs compared to mucinous cystadenomas and MBOTs and suggest a relevant role in the development of primary ovarian mucinous carcinoma, however further studies are needed in this regard.

Refined criteria for p53 expression in ovarian mucinous tumours are highly concordant with TP53 mutation status, but p53 expression/TP53 status lack prognostic significance

In gynecological neoplasms, immunohistochemical (IHC) expression of p53 is generally an accurate predictor of TP53 mutation status if correctly interpreted by the pathologist. However, the literature concerning cut-offs, frequency and prognostic significance of p53 staining in ovarian mucinous tumours is limited and heterogeneous. We performed an analysis of 123 primary ovarian mucinous tumours including mucinous borderline tumours (MBT), mucinous carcinomas (MC), and tumours with equivocal features between MBT and MC. We assessed p53 expression for the three recognised patterns of aberrant staining in ovarian carcinoma [overexpression ('all'), null and cytoplasmic] but using a recently suggested cut-off for aberrant overexpression in ovarian mucinous tumours (strong nuclear p53 staining in ≥12 consecutive tumour cells) and correlated the results with next generation sequencing (NGS) in all qualitatively sufficient cases (92/123). Aberrant p53 expression was present in 25/75 (33.3%) MBT, 23/33 (69.7%) MC (75% of MC with expansile invasion and 61.5% with infiltrative invasion), and 10/15 (66.7%) tumours equivocal between MBT and MC. Regarding the 92 tumours with paired IHC and mutation results, 86 showed concordant results and six cases were discordant. Three discordant MBT cases showed aberrant expression but were TP53 wild-type on sequencing. Three cases had normal p53 expression but contained a TP53 mutation. Overall, IHC predicted the TP53 mutation status with high sensitivity (94.1%) and specificity (92.7%). The accuracy of IHC was 93.5% with a positive predictive value of 94.1% and a negative predictive value of 92.7%. When comparing MC cases with wild-type TP53 versus those with TP53 mutation, there were no significant differences concerning disease-free survival, local recurrence-free survival, or metastases-free survival (p>0.05). In the MBT subgroup, there were no events for survival analyses. In conclusion, using an independent large sample set of ovarian mucinous tumours, the results of our study confirm that the suggested refined cut-off of strong nuclear p53 staining in ≥12 consecutive tumour cells reflect high accuracy, sensitivity and specificity for an underlying TP53 mutation but the TP53 mutation status has no prognostic significance in either MC or MBT.

Immunohistochemical Characterization Improves the Reproducibility of the Histological Diagnosis of Ovarian Carcinoma

Background: Ovarian cancer is the leading cause of gynecologic cancer-related death. Histological assessment remains the standard clue for the diagnosis of ovarian carcinoma. Misinterpretation and inconsistent application of histological criteria may lead to significant interobserver variability and poor reproducibility of the diagnosis. In this study, we investigated the discrepancy in histological diagnosis and the significance of a designed panel of immunohistochemical markers for the improvement of the diagnostic reproducibility of ovarian carcinomas. Methods: We performed a retrospective study on 74 ovarian carcinomas. All tumor slides were independently reviewed by two pathologists. The results for seven available immunomarkers as p53, WT-1, p16INK4A, CK7, CK20, and estrogen and progesterone receptors were determined for all cases by immunohistochemistry. Results: The histological diagnosis review performed using standard histology showed a concordance of diagnoses in 86% of cases with Cohen’s kappa of 0.80. Immunohistochemical results increased significantly the diagnosis reproducibility with a concordance of 91% and a Cohen’s kappa of 0.86 (P = 0.001). Conclusion: Although the histological diagnosis remains reliable, the use of a designed panel of immunohistochemical markers improves significantly the interobserver concordance and the classification accuracy of ovarian carcinomas.

Linking common non-coding RNAs of human lung cancer and M. tuberculosis

Lung cancer and pulmonary tuberculosis caused by Mycobacterium are two major causes of deaths worldwide. Tuberculosis linked lung cancer is known. However, the precise molecular mechanism of Mycobacterium associated increased risk of lung cancer is not understood. We report 45 common human miRNAs deregulated in both pulmonary tuberculosis and lung cancer. We show that sRNA_1096 and sRNA_1414 from M. tuberculosis have sequence homology with human mir-21. Hence, the potential role of these three small non-coding RNAs in rifampicin resistance in pulmonary tuberculosis is implied. Further, the linking of sRNA_1096 and sRNA_1414 from M. tuberculosis with the host lung tumorigenesis is inferred. Nonetheless, further analysis and validation is required to associate these three non-coding RNAs with Mycobacterium associated increased risk of lung cancer.

The Putative Role of TP53 Alterations and p53 Expression in Borderline Ovarian Tumors - Correlation with Clinicopathological Features and Prognosis: A Mini-Review

Borderline ovarian tumors (BOTs) represent an independent group among ovarian malignancies, being diagnosed at clinical stage earlier than invasive ovarian carcinomas (OCs) and characterized by a rather favorable outcome after careful surgical management. Data published worldwide showed a substantial discordance of p53 expression in BOTs. The purpose of this work was to present the current status of knowledge on the significance of TP53 gene and p53 protein product alterations in BOTs. In general, higher p53 expression patterns were reported for ovarian malignancies compared to BOTs. Serous, mucinous, and endometrioid BOTs differ substantially in relation to p53 immunostaining, but data concerning the relationship between the protein's immunoreactivity and other clinico-pathological variables are scarce. Finally, reports published to date support the view that TP53 alterations may not be commonly associated with the borderline phenotype of ovarian tumors but they probably occur during the development of invasive OCs. In light of these uncertainties, the impact of TP53 alterations and p53 expression on overall survival in women affected by BOTs requires further multi-institutional studies in large cohorts of patients.

Detection of human papillomavirus-16 e6-oncoprotein in epithelial ovarian tumors samples of iraqi patients

Background:

Human papillomavirus (HPV) is the causal factor for cervical cancer. However, the role of HPV infection in ovarian cancer is unclear.

Objectives:

This study aimed to determine the presence of human papillomavirus-16 (HPV-16) in ovarian tumor tissues.

Patients and Methods:

This was a retrospective study, which included 61 Archived human ovarian tumor tissues embedded in paraffin blocks. The ovarian tumor tissues were divided into four groups. The first group was the malignant ovarian epithelial tumor group; it included 31 cases with invasive surface epithelial ovarian tumors. The second group was the borderline epithelial ovarian tumor group: it included four cases with borderline intermediate malignancy. The third group was the benign epithelial ovarian tumors group: it included 18 cases with benign epithelial ovarian tumors. The fourth group had functional ovarian cystic lesions: it included eight cases with non-neoplastic functional ovarian cysts. Sections were made from each of the paraffin embedded blocks and examined using immunohistochemistry to detect HPV 16-E6-oncoprotein in ovarian tumor tissues.

Results:

Out of the eight cases with functional cysts only one case (12.5%) expressed HPV. No HPV expression was seen in cases with benign and borderline tumors. Out of the 31 cases with one malignant surface epithelial ovarian tumor only three (9.67%) cases expressed HPV. There was no significant statistical difference in HPV expression among neoplastic and non-neoplastic ovarian tumors included in the present study (P= 0.476).

Conclusions:

HPV type 16 was detected in only 9.67% of malignant epithelial tumors. It appears that HPV infection plays a relatively minor role in the pathogenesis of ovarian carcinomas.

Molecular subtypes of serous borderline ovarian tumor show distinct expression patterns of benign tumor and malignant tumor-associated signatures

Borderline ovarian tumors show heterogeneity in clinical behavior. Most have excellent prognosis, although a small percentage show recurrence or progressive disease, usually to low-grade serous carcinoma. The aim of this study was to understand the molecular relationship between these entities and identify potential markers of tumor progression and therapeutic targets. We studied gene expression using Affymetrix HGU133plus2 GeneChip microarrays in 3 low-grade serous carcinomas, 13 serous borderline tumors and 8 serous cystadenomas. An independent data set of 18 serous borderline tumors and 3 low-grade serous carcinomas was used for validation. Unsupervised clustering revealed clear separation of benign and malignant tumors, whereas borderline tumors showed two distinct groups, one clustering with benign and the other with malignant tumors. The segregation into benign- and malignant-like borderline molecular subtypes was reproducible on applying the same analysis to an independent publicly available data set. We identified 50 genes that separate borderline tumors into their subgroups. Functional enrichment analysis of genes that separate borderline tumors to the two subgroups highlights a cell adhesion signature for the malignant-like subset, with Claudins particularly prominent. This is the first report of molecular subtypes of borderline tumors based on gene expression profiling. Our results provide the basis for identification of biomarkers for the malignant potential of borderline ovarian tumor and potential therapeutic targets for low-grade serous carcinoma.

Prevalence of human papillomavirus in epithelial ovarian cancer tissue. A meta-analysis of observational studies

OBJECTIVE

The role of human papillomavirus (HPV) in the pathogenesis of ovarian cancer is controversial, and conflicting results have been published. We conducted a systematic review and meta-analysis to estimate the prevalence of HPV in epithelial ovarian cancer tissue.

MATERIAL AND METHODS

Observational studies published until 4 March 2013 were identified in PubMed and Embase. We adhered to MOOSE guidelines and included 22 studies (case-control, cross-sectional studies). A pooled estimate of the HPV prevalence with corresponding 95% confidence interval (CI) was calculated based on a random effect model. In a meta-regression analysis we examined the contribution of different factors to heterogeneity. Furthermore, publication bias was evaluated.

RESULTS

The pooled HPV prevalence in ovarian cancer tissue was 15.5%, but wide variation was found (0-66.7%). After stratification by geographical region, publication year, tissue type and method of HPV detection, we found that the prevalence of HPV varied most markedly by geographical area, the prevalence being 45.6% (95% CI, 31.0-60.3) in Asia, 18.5% (95% CI, 8.5-28.6) in Eastern Europe, 1.1% (95% CI, -1.6 to 3.8) in Western Europe and zero in North America. A meta-regression analysis revealed that the difference between geographical regions could not be explained by HPV detection method or type of tissue.

CONCLUSIONS

Great geographical variation exists in HPV prevalence in ovarian cancer tissue, which is not explained by different HPV detection methods. The results suggest that HPV is unlikely to play an important role in Western European and American women, but cannot reject a role of HPV in other populations.

Frequency of mutations and polymorphisms in borderline ovarian tumors of known cancer genes

Borderline ovarian tumors represent an understudied subset of ovarian tumors. Most studies investigating aberrations in borderline tumors have focused on KRAS/BRAF mutations. In this study, we conducted an extensive analysis of mutations and single-nucleotide polymorphisms (SNPs) in borderline ovarian tumors. Using the Sequenom MassArray platform, we investigated 160 mutations/polymorphisms in 33 genes involved in cell signaling, apoptosis, angiogenesis, cell cycle regulation and cellular senescence. Of 52 tumors analyzed, 33 were serous, 18 mucinous and 1 endometrioid. KRAS c.35G>A p.Gly12Asp mutations were detected in eight tumors (six serous and two mucinous), BRAF V600E mutations in two serous tumors, and PIK3CA H1047Y and PIK3CA E542K mutations in a serous and an endometrioid BOT, respectively. CTNNB1 mutation was detected in a serous tumor. Potentially functional polymorphisms were found in vascular endothelial growth factor (VEGF), ABCB1, FGFR2 and PHLPP2. VEGF polymorphisms were the most common and detected at four loci. PHLPP2 polymorphisms were more frequent in mucinous as compared with serous tumors (P=0.04), with allelic imbalance in one case. This study represents the largest and most comprehensive analysis of mutations and functional SNPs in borderline ovarian tumors to date. At least 25% of borderline ovarian tumors harbor somatic mutations associated with potential response to targeted therapeutics.

Improved classification of epithelial ovarian cancer: results of 3 danish cohorts

OBJECTIVE

An increasing body of evidence has suggested that epithelial ovarian cancer (EOC) patients can broadly be divided into 2 groups on the basis of histopathologic parameters and molecular profiles. Type 1 tumors are slow-growing tumors with inherent mutations such as KRAS or BRAF mutations, whereas type 2 tumors are more rapidly growing tumors of which many contain TP53 mutations. In the present study, we performed a comprehensive study in a large Danish material to evaluate the clinical importance.

MATERIALS AND METHODS

A total of 512 tissue samples were included (430 EOCs, 34 borderline, 28 benign tumors, and 20 normal ovaries). KRAS mutations (codon 12/13) and BRAF codon 600 mutations were analyzed from formalin-fixed paraffin-embedded tissue by ARMS qPCR. p53 expression was examined by immunohistochemistry.

RESULTS

Of the EOC patients, 25% had histopathologically classified type 1 tumors, and of these, 44% were either KRAS or BRAF mutated. Of patients with histopathologic type 2 tumors, 66% showed p53 protein overexpression, whereas 4 (1.5%) patients contained a KRAS mutation. In a univariate survival analysis, a large difference in survival was seen between patients with type 1 and type 2 tumors. Patients with type histologic 2 tumors had significantly worse survival compared with patients with type 1 tumors (P < 10). International Federation of Gynecology and Obstetrics (FIGO) stage, tumor grade, residual tumor, and KRAS/BRAF mutation were independent predictors of overall survival in the multivariate analysis. Patients with KRAS/BRAF mutated carcinomas showed independent decreased overall survival with a hazard ratio of 2.01 (95% confidence interval, 1.13-3.57; P = 0.018).

CONCLUSIONS

KRAS/BRAF mutations are with very few exceptions constrained to patients with histopathologic type 1 tumors, whereas p53 overexpression is very frequent in type 2 tumors. KRAS/BRAF mutations had independent prognostic importance. The classification presented here should have a major therapeutic implication and serve as a hallmark of future clinical trials.

Ubiquitin becomes ubiquitous in cancer: emerging roles of ubiquitin ligases and deubiquitinases in tumorigenesis and as therapeutic targets

By virtue of its ability to regulate both protein turnover and non-proteolytic signalling functions, ubiquitin protein conjugation has been implicated in the control of multiple cellular processes, including protein localization, cell cycle control, transcription regulation, DNA damage repair, and endocytosis. Ubiquitin metabolism enzymes have been identified as either oncogenes or tumor suppressors in a variety of cancers. Given that ubiquitin metabolism is governed by enzymes--E1, E2, E3, E4, deubiquitinases (DUBs), and the proteasome- the system as a whole is ripe for target and drug discovery in cancer. Of the ubiquitin/proteasome system components, the E3's and DUBs can recognize substrates with the most specificity, and are thus of key interest as drug targets in cancer. This review examines the molecular role in cancer, relevant substrates, and potential for pharmacologic development, of E3's and DUBs that have been associated thus far with human malignancies as oncogenes or tumor suppressors.

Predictive and prognostic protein biomarkers in epithelial ovarian cancer: recommendation for future studies

Epithelial ovarian cancer is the most lethal gynecological malignancy. Due to its lack of symptoms, this disease is diagnosed at an advanced stage when the cancer has already spread to secondary sites. While initial rates of response to first treatment is >80%, the overall survival rate of patients is extremely low, mainly due to development of drug resistance. To date, there are no reliable clinical factors that can properly stratify patients for suitable chemotherapy strategies. Clinical parameters such as disease stage, tumor grade and residual disease, although helpful in the management of patients after their initial surgery to establish the first line of treatment, are not efficient enough. Accordingly, reliable markers that are independent and complementary to clinical parameters are needed for a better management of these patients. For several years, efforts to identify prognostic factors have focused on molecular markers, with a large number having been investigated. This review aims to present a summary of the recent advances in the identification of molecular biomarkers in ovarian cancer patient tissues, as well as an overview of the need and importance of molecular markers for personalized medicine in ovarian cancer.

KLK6 and KLK13 predict tumor recurrence in epithelial ovarian carcinoma

Background:

The human kallikrein-related peptidase family consists of 15 genes. Twelve of these genes are overexpressed in ovarian cancer and may represent potential markers for diagnosis, prognosis, and/or response to treatment. The aim of this study was to determine the prognostic significance of kallikrein-related peptidase 6 (KLK6) and kallikrein-related peptidase 13 (KLK13) in epithelial ovarian cancer by quantifying gene expression levels with tumour pathology and patient survival data.

Methods:

Total RNA was isolated from 106 patients diagnosed with primary ovarian cancer, as well as 8 normal ovary controls. Samples were analysed by quantitative real-time PCR for KLK6 and KLK13 expression. Correlation between kallikrein gene expression and clinical characteristics was evaluated with the χ²-test. Survival analysis was performed using Kaplan–Meier and Cox proportional hazards regression models.

Results:

Expression levels of both KLK6 and KLK13 mRNA were significantly increased in invasive cancers relative to normal ovaries (P=0.002 and 0.039 respectively). High KLK6 and KLK13 expression was an indicator of poor prognosis, with patients having a shorter recurrence-free survival (P=0.002 and 0.027 respectively). High KLK6 expression was also significantly associated with lower overall survival (P=0.011). When subjected to multivariate analysis, patients with either high KLK6 or KLK13 were 3- and 2.2-fold, respectively, more likely to have a recurrence than patients with low kallikrein expression.

Conclusion:

These data show increased mRNA expression of KLK6 and KLK13 in ovarian cancer compared to normal ovarian tissues. High KLK6 or KLK13 expression in primary ovarian tumours can significantly predict prognosis in terms of recurrence-free survival and overall survival. In all, this study shows KLK6 and KLK13 as potential biomarkers and may be therapeutic targets for treatment of ovarian cancer.

Modest effect of p53, EGFR and HER-2/neu on prognosis in epithelial ovarian cancer: a meta-analysis

BACKGROUND

P53, EGFR and HER-2/neu are the most frequently studied molecular biological parameters in epithelial ovarian cancer, but their prognostic impact is still unequivocal. We performed a meta-analysis to more precisely estimate their prognostic significance.

METHODS

Published studies that investigated the association between p53, EGFR and HER-2/neu status and survival were identified. Meta-analysis was performed using a DerSimonian-Laird model. Publication bias was investigated using funnel plots and sources of heterogeneity were identified using meta-regression analysis.

RESULTS

A total of 62 studies were included for p53, 15 for EGFR and 20 for HER-2/neu. P53, EGFR and HER-2/neu status had a modest effect on overall survival (pooled HR 1.47, 95% CI 1.33-1.61 for p53; HR 1.65, 95% CI 1.25-2.19 for EGFR and HR 1.67, 95% CI 1.34-2.08 for HER-2/neu). Meta-regression analysis for p53 showed that FIGO stage distribution influenced study outcome. For EGFR and HER-2/neu, considerable publication bias was present.

CONCLUSIONS

Although p53, EGFR and HER-2/neu status modestly influences survival, these markers are, by themselves, unlikely to be useful as prognostic markers in clinical practice. Our study highlights the need for well-defined, prospective clinical trials and more complete reporting of results of prognostic factor studies.