The molecular and genetic basis of inherited cancer risk in gynaecology

A bespoke target selection tool to guide biomarker discovery in tubo-ovarian cancer

Introduction

Cancers presenting at advanced stages inherently have poor prognosis. High grade serous carcinoma (HGSC) is the most common and aggressive form of tubo-ovarian cancer. Clinical tests to accurately diagnose and monitor this condition are lacking. Hence, development of disease-specific tests are urgently required.

Methods

The molecular profile of HGSC during disease progression was investigated in a unique patient cohort. A bespoke data browser was developed to analyse gene expression and DNA methylation datasets for biomarker discovery. The Ovarian Cancer Data Browser (OCDB) is built in C# with a.NET framework using an integrated development environment of Microsoft Visual Studio and fast access files (.faf). The graphical user interface is easy to navigate between four analytical modes (gene expression; methylation; combined gene expression and methylation data; methylation clusters), with a rapid query response time. A user should first define a disease progression trend for prioritising results. Single or multiomics data are then mined to identify probes, genes and methylation clusters that exhibit the desired trend. A unique scoring system based on the percentage change in expression/methylation between disease stages is used. Results are filtered and ranked using weighting and penalties.

Results

The OCDB’s utility for biomarker discovery is demonstrated with the identified target OSR2. Trends in OSR2 repression and hypermethylation with HGSC disease progression were confirmed in the browser samples and an independent cohort using bioassays. The OSR2 methylation biomarker could discriminate HGSC with high specificity (95%) and sensitivity (93.18%).

Conclusions

The OCDB has been refined and validated to be an integral part of a unique biomarker discovery pipeline. It may also be used independently to aid identification of novel targets. It carries the potential to identify further biomarker assays that can reduce type I and II errors within clinical diagnostics.

Liquid biopsy in ovarian cancer: Catching the silent killer before it strikes

Epithelial ovarian cancer (EOC) is the most lethal gynaecological malignancy in the western world. The majority of women presenting with the disease are asymptomatic and it has been dubbed the "silent killer". To date there is no effective minimally invasive method of stratifying those with the disease or screening for the disease in the general population. Recent molecular and pathological discoveries, along with the advancement of scientific technology, means there is a real possibility of having disease-specific liquid biopsies available within the clinical environment in the near future. In this review we discuss these discoveries, particularly in relation to the most common and aggressive form of EOC, and their role in making this possibility a reality.

Defining the molecular evolution of extrauterine high grade serous carcinoma

OBJECTIVE

High grade serous carcinoma (HGSC) is the most common and most aggressive, subtype of epithelial ovarian cancer. It presents as advanced stage disease with poor prognosis. Recent pathological evidence strongly suggests HGSC arises from the fallopian tube via the precursor lesion; serous tubal intraepithelial carcinoma (STIC). However, further definition of the molecular evolution of HGSC has major implications for both clinical management and research. This study aims to more clearly define the molecular pathogenesis of HGSC.

METHODS

Six cases of HGSC were identified at the Northern Ireland Gynaecological Cancer Centre (NIGCC) that each contained ovarian HGSC (HGSC), omental HGSC (OMT), STIC, normal fallopian tube epithelium (FTE) and normal ovarian surface epithelium (OSE). The relevant formalin-fixed paraffin embedded (FFPE) tissue samples were retrieved from the pathology archive via the Northern Ireland Biobank following attaining ethical approval (NIB11:005). Full microarray-based gene expression profiling was performed on the cohort. The resulting data was analysed bioinformatically and the results were validated in a HGSC-specific in-vitro model.

RESULTS

The carcinogenesis of HGSC was investigated and showed the molecular profile of HGSC to be more closely related to normal FTE than OSE. STIC lesions also clustered closely with HGSC, indicating a common molecular origin.

CONCLUSION

This study provides strong evidence suggesting that extrauterine HGSC arises from the fimbria of the distal fallopian tube. Furthermore, several potential pathways were identified which could be targeted by novel therapies for HGSC. These findings have significant translational relevance for both primary prevention and clinical management of the disease.

Genetic testing in a gynaecological oncology care in developing countries-knowledge, attitudes and perception of Nepalese clinicians

Background

Genetic testing for an inherited susceptibility to cancer is an emerging technology in medical practice. Little information is currently available about physicians’ attitudes towards these tests in developing countries.

Methods

We conducted an email survey of Nepalese physicians practicing in academic and non-academic settings in Nepal, regarding knowledge, attitudes and perception towards genetic testing for gynaecologic cancer.

Results

Responses were received from 251 of 387 practitioners (65%). Only 46% of all respondents felt prepared to answer patients’ questions about genetic testing for gynaecologic cancer, despite 80% reporting that patients had asked questions about genetic testing, and 55% being asked more than 5 times in the past year. 42% reported more than 10 of their patients having had genetic testing for cancer, the majority for BRCA1/2. Access (40%), cost (37%) and lack of physicians’ information (24%) were cited as the main barriers to testing. The most commonly identified concerns regarding genetic testing were the potential for increased patient anxiety, misinterpretation of results by patients, and maintaining confidentiality of results (64%, 47% and 38% of respondents respectively).

Conclusion

This study shows the gap among the health care providers in developing countries and the available modern scientific tools and skills in regard to the benefits of genetic testing for gynaecological cancers in a developing nation. These findings indicate the need for the introduction of further genetic counselling education and support into gynaecological care in Nepal.

Electronic supplementary material

The online version of this article (doi:10.1186/s40661-016-0034-5) contains supplementary material, which is available to authorized users.