RFWD3 modulates response to platinum chemotherapy and promotes cancer associated phenotypes in high grade serous ovarian cancer

Background

DNA damage repair is frequently dysregulated in high grade serous ovarian cancer (HGSOC), which can lead to changes in chemosensitivity and other phenotypic differences in tumours. RFWD3, a key component of multiple DNA repair and maintenance pathways, was investigated to characterise its impact in HGSOC.

Methods

RFWD3 expression and association with clinical features was assessed using in silico analysis in the TCGA HGSOC dataset, and in a further cohort of HGSOC tumours stained for RFWD3 using immunohistochemistry. RFWD3 expression was modulated in cell lines using siRNA and CRISPR/cas9 gene editing, and cells were characterised using cytotoxicity and proliferation assays, flow cytometry, and live cell microscopy.

Results

Expression of RFWD3 RNA and protein varied in HGSOCs. In cell lines, reduction of RFWD3 expression led to increased sensitivity to interstrand crosslinking (ICL) inducing agents mitomycin C and carboplatin. RFWD3 also demonstrated further functionality outside its role in DNA damage repair, with RFWD3 deficient cells displaying cell cycle dysregulation, reduced cellular proliferation and reduced migration. In tumours, low RFWD3 expression was associated with increased tumour mutational burden, and complete response to platinum chemotherapy.

Conclusion

RFWD3 expression varies in HGSOCs, which can lead to functional effects at both the cellular and tumour levels.

High throughput screening identifies dasatinib as synergistic with trametinib in low grade serous ovarian carcinoma

BACKGROUND

Low grade serous ovarian carcinoma (LGSOC) is a distinct histotype of ovarian cancer characterised high levels of intrinsic chemoresistance, highlighting the urgent need for new treatments. High throughput screening in clinically-informative cell-based models represents an attractive strategy for identifying candidate treatment options for prioritisation in clinical studies.

METHODS

We performed a high throughput drug screen of 1610 agents across a panel of 6 LGSOC cell lines (3 RAS/RAF-mutant, 3 RAS/RAF-wildtype) to identify novel candidate therapeutic approaches. Validation comprised dose-response analysis across 9 LGSOC models and 5 high grade serous comparator lines.

RESULTS

16 hits of 1610 screened compounds were prioritised for validation based on >50% reduction in nuclei counts in over half of screened cell lines at 1000 nM concentration. 11 compounds passed validation, and the four agents of greatest interest (dasatinib, tyrosine kinase inhibitor; disulfiram, aldehyde dehydrogenase inhibitor; carfilzomib, proteasome inhibitor; romidepsin, histone deacetylase inhibitor) underwent synergy profiling with the recently approved MEK inhibitor trametinib. Disulfiram demonstrated excellent selectivity for LGSOC versus high grade serous ovarian carcinoma comparator lines (P = 0.003 for IC50 comparison), while the tyrosine kinase inhibitor dasatinib demonstrated favourable synergy with trametinib across multiple LGSOC models (maximum zero interaction potency synergy score 46.9). The novel, highly selective Src family kinase (SFK) inhibitor NXP900 demonstrated a similar trametinib synergy profile to dasatinib, suggesting that SFK inhibition is the likely driver of synergy.

CONCLUSION

Dasatinib and other SFK inhibitors represent novel candidate treatments for LGSOC and demonstrate synergy with trametinib. Disulfiram represents an additional treatment strategy worthy of investigation.

Closing the loop - the role of pathologists in digital and computational pathology research

An increasing number of manuscripts related to digital and computational pathology are being submitted to The Journal of Pathology: Clinical Research as part of the continuous evolution from digital imaging and algorithm-based digital pathology to computational pathology and artificial intelligence. However, despite these technological advances, tissue analysis still relies heavily on pathologists' annotations. There are three crucial elements to the pathologist's role during annotation tasks: granularity, time constraints, and responsibility for the interpretation of computational results. Granularity involves detailed annotations, including case level, regional, and cellular features; and integration of attributions from different sources. Time constraints due to pathologist shortages have led to the development of techniques to expedite annotation tasks from cell-level attributions up to so-called unsupervised learning. The impact of pathologists may seem diminished, but their role is crucial in providing ground truth and connecting pathological knowledge generation with computational advancements. Measures to display results back to pathologists and reflections about correctly applied diagnostic criteria are mandatory to maintain fidelity during human-machine interactions. Collaboration and iterative processes, such as human-in-the-loop machine learning are key for continuous improvement, ensuring the pathologist's involvement in evaluating computational results and closing the loop for clinical applicability. The journal is interested particularly in the clinical diagnostic application of computational pathology and invites submissions that address the issues raised in this editorial.

Compartment-specific multiomic profiling identifies SRC and GNAS as candidate drivers of epithelial-to-mesenchymal transition in ovarian carcinosarcoma

BACKGROUND

Ovarian carcinosarcoma (OCS) is an exceptionally aggressive and understudied ovarian cancer type harbouring distinct carcinomatous and sarcomatous compartments. Here, we seek to identify shared and compartment-specific events that may represent potential therapeutic targets and candidate drivers of sarcomatous compartment formation through epithelial-to-mesenchymal transition (EMT).

METHODS

We performed multiomic profiling (exome sequencing, RNA-sequencing, microRNA profiling) of paired carcinomatous and sarcomatous components in 12 OCS cases.

RESULTS

While paired sarcomatous and carcinomatous compartments demonstrate substantial genomic similarities, multiple loci are recurrently copy number-altered between components; regions containing GNAS and SRC are recurrently gained within the sarcomatous compartment. CCNE1 gain is a common event in OCS, occurring more frequently than in high grade serous ovarian carcinoma (HGSOC). Transcriptomic analysis suggests increased MAPK activity and subtype switching toward poor prognosis HGSOC-derived transcriptomic subtypes within the sarcomatous component. The two compartments show global differences in microRNA profiles, with differentially expressed microRNAs targeting EMT-related genes (SIRT1, ZEB2) and regulators of pro-tumourigenic pathways (TGFβ, NOTCH); chrX is a highly enriched target of these microRNAs and is also frequently deleted across samples. The sarcomatous component harbours significantly fewer CD8-positive cells, suggesting poorer immune engagement.

CONCLUSION

CCNE1 gain and chrX loss are frequent in OCS. SRC gain, increased GNAS expression and microRNA dysregulation represent potential mechanisms driving sarcomatous compartment formation.

Debiased ambient vibrations optical coherence elastography to profile cell, organoid and tissue mechanical properties

The role of the mechanical environment in defining tissue function, development and growth has been shown to be fundamental. Assessment of the changes in stiffness of tissue matrices at multiple scales has relied mostly on invasive and often specialist equipment such as AFM or mechanical testing devices poorly suited to the cell culture workflow.In this paper, we have developed a unbiased passive optical coherence elastography method, exploiting ambient vibrations in the sample that enables real-time noninvasive quantitative profiling of cells and tissues. We demonstrate a robust method that decouples optical scattering and mechanical properties by actively compensating for scattering associated noise bias and reducing variance. The efficiency for the method to retrieve ground truth is validated in silico and in vitro, and exemplified for key applications such as time course mechanical profiling of bone and cartilage spheroids, tissue engineering cancer models, tissue repair models and single cell. Our method is readily implementable with any commercial optical coherence tomography system without any hardware modifications, and thus offers a breakthrough in on-line tissue mechanical assessment of spatial mechanical properties for organoids, soft tissues and tissue engineering.

Whole exome sequencing of low grade serous ovarian carcinoma identifies genomic events associated with clinical outcome

OBJECTIVES

Low-grade serous ovarian carcinoma (LGSOC) is a distinct, rare, ovarian cancer type characterised by younger patient age and intrinsic chemoresistance. Understanding the molecular landscape is crucial for optimising targeted therapy.

METHODS

Genomic data from whole exome sequencing of tumour tissue was analysed in a LGSOC cohort with detailed clinical annotation.

RESULTS

63 cases were analysed and three subgroups identified based on single nucleotide variants: canonical MAPK mutant (cMAPKm: 52%, KRAS/BRAF/NRAS), MAPK-associated gene mutation (MAPK-assoc: 27%) and MAPK wild-type (MAPKwt: 21%). NOTCH pathway disruption occurred across all subgroups. Tumour mutational burden (TMB), mutational signatures and recurrent copy number (CN) changes varied across the cohort with co-occurrence of chromosome 1p loss and 1q gain (CN Chr1pq) a recurrent feature. Low TMB and CN Chr1pq were associated with inferior disease-specific survival (HR 6.43; p < 0.001 and HR 3.29, p = 0.011 respectively). Stepwise genomic classification in relation to outcome resulted in four groups (TMB low; CN Chr1pq; MAPKwt/MAPKassoc; cMAPKm). 5 year disease-specific survival was 46%, 55%, 79% and 100% respectively for these groups. The two most favourable genomic subgroups were enriched for the SBS10b mutational signature, particularly the cMAPKm subgroup.

CONCLUSIONS

LGSOC comprises multiple genomic subgroups with distinct clinical and molecular features. Chr1pq CN arm disruption and TMB represent promising methods to identify individuals with poorer prognosis. Further investigation of the molecular basis for these observations is required. MAPKwt cases represent around a fifth of patients. NOTCH inhibitors represent a candidate therapeutic strategy worthy of exploration across these cases.

Distinct histopathological features are associated with molecular subtypes and outcome in low grade serous ovarian carcinoma

Low grade serous ovarian carcinoma (LGSOC) demonstrates unique clinical and molecular features compared to other ovarian cancer types. The relationship between common histological features of LGSOC and molecular events, such as hormone receptor expression patterns and MAPK gene mutation status, remains poorly understood. Recent data suggest some of these molecular features may be biomarkers of response to recently introduced biologically-targeted therapies, namely endocrine therapy and MEK inhibitors. We utilize a cohort of 63 pathologically-confirmed LGSOC cases with whole exome sequencing and hormone receptor expression data to investigate these relationships. LGSOC cases demonstrated uniformly high oestrogen receptor (ER) expression, but variable progesterone receptor (PR) expression intensity. 60% and 37% of cases demonstrated micropapillary and macropapillary patterns of stromal invasion, respectively. 63% of cases demonstrated desmoplasia, which was significantly associated with advanced disease stage and visible residual disease after cytoreductive surgery. MAPK-mutant cases (KRAS, BRAF, NRAS) more frequently demonstrated macropapillary stromal invasion, while Chr1p loss was associated with desmoplasia and low PR expression. Presence of micropapillary stromal invasion and low PR expression were associated with significantly poorer survival after accounting for stage and residual disease status. Together, these data identify novel relationships between histopathological features and molecularly-defined subgroups in LGSOC.

Abstract 6076: Compartment-specific multiomic characterisation of ovarian carcinosarcoma

Background: Ovarian carcinosarcoma (OCS) is the most aggressive ovarian cancer type. Risk of relapse and death is high across all patient groups, including those diagnosed at early stage. OCS is biphasic, comprising both carcinomatous and sarcomatous populations, leading to its historic consideration alongside true sarcomas. However, we now recognize that OCS in fact represent metaplastic carcinomas, with the sarcomatous component having undergone complete epithelial to mesenchymal transition (EMT) from carcinoma. Detailed understanding of shared and compartment-specific OCS biology has the potential to identify therapeutic opportunities to improve patient survival.

Methods: We recently curated the largest pathologically-confirmed OCS cohort to date. Here, we perform compartment-specific profiling of 12 cases by mRNA sequencing, whole exome sequencing, microRNA (miRNA) profiling and quantification of tumor-infiltrating lymphocytes. These data paint a detailed picture of shared and compartment-specific biology between matched carcinomatous and sarcomatous compartments.

Results: The sarcomatous compartments harbored significantly fewer infiltrating CD8+ cells (P=0.006), with a significantly lower CD8+:CD3+ cell ratio compared to the carcinomatous components (P=0.002). In 11 of 12 cases, identical TP53 mutations were identified in both cell populations; the remaining case was TP53 wild-type in both compartments. Paired analysis of mRNA sequencing identified 1477 significantly differentially expressed transcripts at FDR&lt;0.01. The sarcomatous compartments demonstrated significantly higher MAPK activity, as determined by the MPAS transcriptomic score (P=0.042). Principal component analysis and unsupervised hierarchical clustering of miRNA expression grouped samples by compartment (carcinomatous versus sarcomatous), rather than by patient, suggesting global differences in the miRNA landscape. Paired analysis identified 131 significantly differentially expressed miRNAs between the two populations (FDR&lt;0.01). Significantly enriched miRNA gene targets were identified using The MiRNA Enrichment Analysis and Annotation Tool (miEAA), identifying key EMT-associated gene targets, including SIRT1, PRDM16, ZEB1, ZEB2 and TGFB signaling components, among other biological processes.

Conclusions: Carcinomatous and sarcomatous compartments of OCS demonstrate marked differences in transcriptomic profiles, immune engagement and miRNA expression patterns. Identification of shared TP53 mutations between compartments supports the notion that OCS represent metaplastic carcinomas. Shared biological events represent opportunities for targeted interventions that may be efficacious against both cell populations, while compartment-specific biological events allude to mechanisms by which the carcinomatous population undergoes EMT to form the sarcomatous compartment.

Citation Format: Robert L. Hollis, Ailsa Oswald, Lorna J. Stillie, Ian Croy, Michael Churchman, Charlie Gourley, C. Simon Herrington. Compartment-specific multiomic characterisation of ovarian carcinosarcoma. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 6076.

Multiomic Characterization of High-Grade Serous Ovarian Carcinoma Enables High-Resolution Patient Stratification

PURPOSE

High-grade serous ovarian carcinoma (HGSOC) is the most common ovarian cancer type; most patients experience disease recurrence that accumulates chemoresistance, leading to treatment failure. Genomic and transcriptomic features have been associated with differential outcome and treatment response. However, the relationship between events at the gene sequence, copy number, and gene-expression levels remains poorly defined.

EXPERIMENTAL DESIGN

We perform multiomic characterization of a large HGSOC cohort (n = 362) with detailed clinical annotation to interrogate the relationship between patient subgroups defined by specific molecular events.

RESULTS

BRCA2-mutant (BRCA2m) and EMSY-overexpressing cases demonstrated prolonged survival [multivariable hazard ratios (HR) 0.40 and 0.51] and significantly higher first- and second-line chemotherapy response rate. CCNE1-gained (CCNE1g) cases demonstrated underrepresentation of FIGO stage IV cases, with shorter survival but no significant difference in treatment response. We demonstrate marked overlap between the TCGA- and Tothill-derived subtypes. IMR/C2 cases displayed higher BRCA1/2m frequency (25.5%, 32.5%) and significantly greater immune cell infiltration, whereas PRO/C5 cases had the highest CCNE1g rate (23.9%, 22.2%) and were uniformly low in immune cell infiltration. The survival benefit for cases with aberrations in homologous recombination repair (HRR) genes was apparent across all transcriptomic subtypes (HR range, 0.48-0.68). There was significant co-occurrence of RB loss and HRR gene aberrations; RB loss was further associated with favorable survival within HRR-aberrant cases (multivariable HR, 0.50).

CONCLUSIONS

These data paint a high-resolution picture of the molecular landscape in HGSOC, better defining patients who may benefit most from specific molecular therapeutics and highlighting those for whom novel treatment strategies are needed to improve outcomes.

Clinical research in ovarian cancer: consensus recommendations from the Gynecologic Cancer InterGroup

The Gynecologic Cancer InterGroup (GCIG) sixth Ovarian Cancer Conference on Clinical Research was held virtually in October, 2021, following published consensus guidelines. The goal of the consensus meeting was to achieve harmonisation on the design elements of upcoming trials in ovarian cancer, to select important questions for future study, and to identify unmet needs. All 33 GCIG member groups participated in the development, refinement, and adoption of 20 statements within four topic groups on clinical research in ovarian cancer including first line treatment, recurrent disease, disease subgroups, and future trials. Unanimous consensus was obtained for 14 of 20 statements, with greater than 90% concordance in the remaining six statements. The high acceptance rate following active deliberation among the GCIG groups confirmed that a consensus process could be applied in a virtual setting. Together with detailed categorisation of unmet needs, these consensus statements will promote the harmonisation of international clinical research in ovarian cancer.

Recent Advances in Pathology: the 2022 Annual Review Issue of The Journal of Pathology

The 2022 Annual Review Issue of The Journal of Pathology, Recent Advances in Pathology, contains 15 invited reviews on research areas of growing importance in pathology. This year, the articles include those that focus on digital pathology, employing modern imaging techniques and software to enable improved diagnostic and research applications to study human diseases. This subject area includes the ability to identify specific genetic alterations through the morphological changes they induce, as well as integrating digital and computational pathology with 'omics technologies. Other reviews in this issue include an updated evaluation of mutational patterns (mutation signatures) in cancer, the applications of lineage tracing in human tissues, and single cell sequencing technologies to uncover tumour evolution and tumour heterogeneity. The tissue microenvironment is covered in reviews specifically dealing with proteolytic control of epidermal differentiation, cancer-associated fibroblasts, field cancerisation, and host factors that determine tumour immunity. All of the reviews contained in this issue are the work of invited experts selected to discuss the considerable recent progress in their respective fields and are freely available online (https://onlinelibrary.wiley.com/journal/10969896). © 2022 The Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Ovarian carcinosarcoma is a distinct form of ovarian cancer with poorer survival compared to tubo-ovarian high-grade serous carcinoma

Background

Ovarian carcinosarcoma (OCS) is an uncommon, biphasic and highly aggressive ovarian cancer type, which has received relatively little research attention.

Methods

We curated the largest pathologically confirmed OCS cohort to date, performing detailed histopathological characterisation, analysis of features associated with survival and comparison against high-grade serous ovarian carcinoma (HGSOC).

Results

Eighty-two OCS patients were identified; overall survival was poor (median 12.7 months). In all, 79% demonstrated epithelial components of high-grade serous (HGS) type, while 21% were endometrioid. Heterologous elements were common (chondrosarcoma in 32%, rhabdomyosarcoma in 21%, liposarcoma in 2%); chondrosarcoma was more frequent in OCS with endometrioid carcinomatous components. Earlier stage, complete resection and platinum-containing adjuvant chemotherapy were associated with prolonged survival; however, risk of relapse and mortality was high across all patient groups. Histological subclassification did not identify subgroups with distinct survival. Compared to HGSOC, OCS patients were older (P < 0.0001), more likely to be FIGO stage I (P = 0.025), demonstrated lower chemotherapy response rate (P = 0.001) and had significantly poorer survival (P < 0.0001).

Conclusion

OCS represents a distinct, highly lethal form of ovarian cancer for which new treatment strategies are urgently needed. Histological subclassification does not identify patient subgroups with distinct survival. Aggressive adjuvant chemotherapy should be considered for all cases, including those with early-stage disease.

Improving the Diagnosis of Endometrial Hyperplasia Using Computerized Analysis and Immunohistochemical Biomarkers

Endometrial hyperplasia (EH) is a precursor lesion to endometrial carcinoma (EC). Risks for EC include genetic, hormonal and metabolic factors most notably those associated with obesity: rates are rising and there is concern that cases in pre-menopausal women may remain undetected. Making an accurate distinction between benign and pre-malignant disease is both a challenge for the pathologist and important to the gynecologist who wants to deliver the most appropriate care to meet the needs of the patient. Premalignant change may be recognized by histological changes of endometrial hyperplasia (which may occur with or without atypia) and endometrial intraepithelial neoplasia (EIN). In this study we created a tissue resource of EH samples diagnosed between 2004 and 2009 (n = 125) and used this to address key questions: 1. Are the EIN/WHO2014 diagnostic criteria able to consistently identify premalignant endometrium? 2. Can computer aided image analysis inform identification of EIN? 3. Can we improve diagnosis by incorporating analysis of protein expression using immunohistochemistry. Our findings confirmed the inclusion of EIN in diagnostic criteria resulted in a better agreement between expert pathologists compared with the previous WHO94 criteria used for the original diagnosis of our sample set. A computer model based on assessment of stromal:epithelial ratio appeared most accurate in classification of areas of tissue without EIN. From an extensive panel of putative endometrial protein tissue biomarkers a score based on assessment of HAND2, PTEN, and PAX2 was able to identify four clusters one of which appeared to be more likely to be benign. In summary, our study has highlighted new opportunities to improve diagnosis of pre-malignant disease in endometrium and provide a platform for further research on this important topic.

Trametinib versus standard of care in patients with recurrent low-grade serous ovarian cancer (GOG 281/LOGS): an international, randomised, open-label, multicentre, phase 2/3 trial

BACKGROUND

Low-grade serous carcinoma of the ovary or peritoneum is characterised by MAPK pathway aberrations and its reduced sensitivity to chemotherapy relative to high-grade serous carcinoma. We compared the MEK inhibitor trametinib to physician's choice standard of care in patients with recurrent low-grade serous carcinoma.

METHODS

This international, randomised, open-label, multicentre, phase 2/3 trial was done at 84 hospitals in the USA and UK. Eligible patients were aged 18 years or older with recurrent low-grade serous carcinoma and measurable disease, as defined by Response Evaluation Criteria In Solid Tumors version 1.1, had received at least one platinum-based regimen, but not all five standard-of-care drugs, and had received an unlimited number of previous regimens. Patients with serous borderline tumours or tumours containing low-grade serous and high-grade serous carcinoma were excluded. Eligible patients were randomly assigned (1:1) to receive either oral trametinib 2 mg once daily (trametinib group) or one of five standard-of-care treatment options (standard-of-care group): intravenous paclitaxel 80 mg/m2 by body surface area on days 1, 8, and 15 of every 28-day cycle; intravenous pegylated liposomal doxorubicin 40-50 mg/m2 by body surface area once every 4 weeks; intravenous topotecan 4 mg/m2 by body surface area on days 1, 8, and 15 of every 28-day cycle; oral letrozole 2·5 mg once daily; or oral tamoxifen 20 mg twice daily. Randomisation was stratified by geographical region (USA or UK), number of previous regimens (1, 2, or ≥3), performance status (0 or 1), and planned standard-of-care regimen. The primary endpoint was investigator-assessed progression-free survival while receiving randomised therapy, as assessed by imaging at baseline, once every 8 weeks for 15 months, and then once every 3 months thereafter, in the intention-to-treat population. Safety was assessed in patients who received at least one dose of study therapy. This trial is registered with ClinicalTrials.gov, NCT02101788, and is active but not recruiting.

FINDINGS

Between Feb 27, 2014, and April 10, 2018, 260 patients were enrolled and randomly assigned to the trametinib group (n=130) or the standard-of-care group (n=130). At the primary analysis, there were 217 progression-free survival events (101 [78%] in the trametinib group and 116 [89%] in the standard-of-care group). Median progression-free survival in the trametinib group was 13·0 months (95% CI 9·9-15·0) compared with 7·2 months (5·6-9·9) in the standard-of-care group (hazard ratio 0·48 [95% CI 0·36-0·64]; p<0·0001). The most frequent grade 3 or 4 adverse events in the trametinib group were skin rash (17 [13%] of 128), anaemia (16 [13%]), hypertension (15 [12%]), diarrhoea (13 [10%]), nausea (12 [9%]), and fatigue (ten [8%]). The most frequent grade 3 or 4 adverse events in the standard-of-care group were abdominal pain (22 [17%]), nausea (14 [11%]), anaemia (12 [10%]), and vomiting (ten [8%]). There were no treatment-related deaths.

INTERPRETATION

Trametinib represents a new standard-of-care option for patients with recurrent low-grade serous carcinoma.

FUNDING

NRG Oncology, Cancer Research UK, Target Ovarian Cancer, and Novartis.

Clinicopathological Determinants of Recurrence Risk and Survival in Mucinous Ovarian Carcinoma

Mucinous ovarian carcinoma (MOC) is a unique form of ovarian cancer. MOC typically presents at early stage but demonstrates intrinsic chemoresistance; treatment of advanced-stage and relapsed disease is therefore challenging. We harness a large retrospective MOC cohort to identify factors associated with recurrence risk and survival. A total of 151 MOC patients were included. The 5 year disease-specific survival (DSS) was 84.5%. Risk of subsequent recurrence after a disease-free period of 2 and 5 years was low (8.3% and 5.6% over the next 10 years). The majority of cases were FIGO stage I (35.6% IA, 43.0% IC). Multivariable analysis identified stage and pathological grade as independently associated with DSS (p < 0.001 and p < 0.001). Grade 1 stage I patients represented the majority of cases (53.0%) and demonstrated exceptional survival (10 year DSS 95.3%); survival was comparable between grade I stage IA and stage IC patients, and between grade I stage IC patients who did and did not receive adjuvant chemotherapy. At 5 years following diagnosis, the proportion of grade 1, 2 and 3 patients remaining disease free was 89.5%, 74.9% and 41.7%; the corresponding proportions for FIGO stage I, II and III/IV patients were 91.1%, 76.7% and 19.8%. Median post-relapse survival was 5.0 months. Most MOC patients present with low-grade early-stage disease and are at low risk of recurrence. New treatment options are urgently needed to improve survival following relapse, which is associated with extremely poor prognosis.

A multi-ethnic analysis of immune-related gene expression signatures in patients with ovarian clear cell carcinoma

Little is known about the immune environment of ovarian clear cell carcinoma (OCCC) and its impact on various ethnic backgrounds. The aim of this OCCC immune‐related gene expression signatures (irGES) study was to address the interaction between tumour and immune environment of ethnically‐diverse Asian and Caucasian populations and to identify relevant molecular subsets of biological and clinical importance. Our study included 264 women from three different countries (Singapore, Japan, and the UK) and identified four novel immune subtypes (PD1‐high, CTLA4‐high, antigen‐presentation, and pro‐angiogenic subtype) with differentially expressed pathways, and gene ontologies using the NanoString nCounter PanCancer Immune Profiling Panel. The PD1‐high and CTLA4‐high subtypes demonstrated significantly higher PD1, PDL1, and CTLA4 expression, and were associated with poorer clinical outcomes. Mismatch repair (MMR) protein expression, assessed by immunohistochemistry, revealed that about 5% of OCCCs had deficient MMR expression. The prevalence was similar across the three countries and appeared to cluster in the CTLA4‐high subtype. Our results suggest that OCCC from women of Asian and Caucasian descent shares significant clinical and molecular similarities. To our knowledge, our study is the first study to include both Asian and Caucasian women with OCCC and helps to shine light on the impact of ethnic differences on the immune microenvironment of OCCC. © 2021 The Authors. The Journal of Pathology published by John Wiley & Sons, Ltd. on behalf of The Pathological Society of Great Britain and Ireland.

Recent Advances in Pathology: the 2021 Annual Review Issue of The Journal of Pathology

The 2021 Annual Review Issue of The Journal of Pathology contains 14 invited reviews on current research areas of particular importance in pathology. The subjects included here reflect the broad range of interests covered by the journal, including both basic and applied research fields but always with the aim of improving our understanding of human disease. This year, our reviews encompass the huge impact of the COVID-19 pandemic, the development and application of biomarkers for immune checkpoint inhibitors, recent advances in multiplexing antigen/nucleic acid detection in situ, the use of genomics to aid drug discovery, organoid methodologies in research, the microbiome in cancer, the role of macrophage-stroma interactions in fibrosis, and TGF-β as a driver of fibrosis in multiple pathologies. Other reviews revisit the p53 field and its lack of clinical impact to date, dissect the genetics of mitochondrial diseases, summarise the cells of origin and genetics of sarcomagenesis, provide new data on the role of TRIM28 in tumour predisposition, review our current understanding of cancer stem cell niches, and the function and regulation of p63. The reviews are authored by experts in their field from academia and industry, and provide comprehensive updates of the chosen areas, in which there has been considerable recent progress. © 2021 The Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Structural Variants at the BRCA1/2 Loci are a Common Source of Homologous Repair Deficiency in High-grade Serous Ovarian Carcinoma

PURPOSE

The abundance and effects of structural variation at BRCA1/2 in tumors are not well understood. In particular, the impact of these events on homologous recombination repair deficiency (HRD) has yet to be demonstrated.

EXPERIMENTAL DESIGN

Exploiting a large collection of whole-genome sequencing data from high-grade serous ovarian carcinoma (N = 205) together with matched RNA sequencing for the majority of tumors (N = 150), we have comprehensively characterized mutation and expression at BRCA1/2.

RESULTS

In addition to the known spectrum of short somatic mutations (SSM), we discovered that multi-megabase structural variants (SV) were a frequent, unappreciated source of BRCA1/2 disruption in these tumors, and we found a genome-wide enrichment for large deletions at the BRCA1/2 loci across the cohort. These SVs independently affected a substantial proportion of patients (16%) in addition to those affected by SSMs (24%), conferring HRD and impacting patient survival. We also detail compound deficiencies involving SSMs and SVs at both loci, demonstrating that the strongest risk of HRD emerges from combined SVs at both BRCA1 and BRCA2 in the absence of SSMs. Furthermore, these SVs are abundant and disruptive in other cancer types.

CONCLUSIONS

These results extend our understanding of the mutational landscape underlying HRD, increase the number of patients predicted to benefit from therapies exploiting HRD, and suggest there is currently untapped potential in SV detection for patient stratification.

Could MicroRNAs Be Useful Tools to Improve the Diagnosis and Treatment of Rare Gynecological Cancers? A Brief Overview

Gynecological cancers pose an important public health issue, with a high incidence among women of all ages. Gynecological cancers such as malignant germ-cell tumors, sex-cord-stromal tumors, uterine sarcomas and carcinosarcomas, gestational trophoblastic neoplasia, vulvar carcinoma and melanoma of the female genital tract, are defined as rare with an annual incidence of <6 per 100,000 women. Rare gynecological cancers (RGCs) are associated with poor prognosis, and given the low incidence of each entity, there is the risk of delayed diagnosis due to clinical inexperience and limited therapeutic options. There has been a growing interest in the field of microRNAs (miRNAs), a class of small non-coding RNAs of ∼22 nucleotides in length, because of their potential to regulate diverse biological processes. miRNAs usually induce mRNA degradation and translational repression by interacting with the 3' untranslated region (3'-UTR) of target mRNAs, as well as other regions and gene promoters, as well as activating translation or regulating transcription under certain conditions. Recent research has revealed the enormous promise of miRNAs for improving the diagnosis, therapy and prognosis of all major gynecological cancers. However, to date, only a few studies have been performed on RGCs. In this review, we summarize the data currently available regarding RGCs.

Recent advances in the use of stimulated Raman scattering in histopathology

Stimulated Raman histopathology (SRH) utilises the intrinsic vibrational properties of lipids, proteins and nucleic acids to generate contrast providing rapid image acquisition that allows visualisation of histopathological features. It is currently being trialled in the intraoperative setting, where the ability to image unprocessed samples rapidly and with high resolution offers several potential advantages over the use of conventional haematoxylin and eosin stained images. Here we review recent advances in the field including new updates in instrumentation and computer aided diagnosis. We also discuss how other non-linear modalities can be used to provide additional diagnostic contrast which together pave the way for enhanced histopathology and open up possibilities for in vivo pathology.

GYNOCARE Update: Modern Strategies to Improve Diagnosis and Treatment of Rare Gynecologic Tumors—Current Challenges and Future Directions

Simple Summary

More than 50% of all the tumors affecting the female genital tract can be classified as rare and usually have a poor prognosis owing to delayed diagnosis and treatment. Currently, gynecologic cancer research, due to distinct scientific and technological challenges, is lagging behind. Moreover, the overall efforts for addressing these challenges are fragmented across different countries. The European Network for Gynecological Rare Cancer Research: GYNOCARE aims to address these challenges by creating a unique network between key stakeholders covering distinct domains from basic research to cure. GYNOCARE is part of a European Collaboration in Science and Technology (COST) with the aim to focus on the development of new approaches to improve the diagnosis and treatment of rare gynecological tumors. Here, we provide a brief overview describing the goals of this COST Action and its future challenges with the aim to continue fighting against this rare cancer.

Abstract

More than 50% of all gynecologic tumors can be classified as rare (defined as an incidence of ≤6 per 100,000 women) and usually have a poor prognosis owing to delayed diagnosis and treatment. In contrast to almost all other common solid tumors, the treatment of rare gynecologic tumors (RGT) is often based on expert opinion, retrospective studies, or extrapolation from other tumor sites with similar histology, leading to difficulty in developing guidelines for clinical practice. Currently, gynecologic cancer research, due to distinct scientific and technological challenges, is lagging behind. Moreover, the overall efforts for addressing these challenges are fragmented across different European countries and indeed, worldwide. The GYNOCARE, COST Action CA18117 (European Network for Gynecological Rare Cancer Research) programme aims to address these challenges through the creation of a unique network between key stakeholders covering distinct domains from concept to cure: basic research on RGT, biobanking, bridging with industry, and setting up the legal and regulatory requirements for international innovative clinical trials. On this basis, members of this COST Action, (Working Group 1, “Basic and Translational Research on Rare Gynecological Cancer”) have decided to focus their future efforts on the development of new approaches to improve the diagnosis and treatment of RGT. Here, we provide a brief overview of the current state-of-the-art and describe the goals of this COST Action and its future challenges with the aim to stimulate discussion and promote synergy across scientists engaged in the fight against this rare cancer worldwide.

Molecular stratification of endometrioid ovarian carcinoma predicts clinical outcome

Endometrioid ovarian carcinoma (EnOC) demonstrates substantial clinical and molecular heterogeneity. Here, we report whole exome sequencing of 112 EnOC cases following rigorous pathological assessment. We detect a high frequency of mutation in CTNNB1 (43%), PIK3CA (43%), ARID1A (36%), PTEN (29%), KRAS (26%), TP53 (26%) and SOX8 (19%), a recurrently-mutated gene previously unreported in EnOC. POLE and mismatch repair protein-encoding genes were mutated at lower frequency (6%, 18%) with significant co-occurrence. A molecular taxonomy is constructed, identifying clinically distinct EnOC subtypes: cases with TP53 mutation demonstrate greater genomic complexity, are commonly FIGO stage III/IV at diagnosis (48%), are frequently incompletely debulked (44%) and demonstrate inferior survival; conversely, cases with CTNNB1 mutation, which is mutually exclusive with TP53 mutation, demonstrate low genomic complexity and excellent clinical outcome, and are predominantly stage I/II at diagnosis (89%) and completely resected (87%). Moreover, we identify the WNT, MAPK/RAS and PI3K pathways as good candidate targets for molecular therapeutics in EnOC.

Clear cell carcinoma of the ovary: a clinical and molecular perspective

Clear cell carcinoma of the ovary has distinct biology and clinical behavior. There are significant geographical and racial differences in the incidence of clear cell carcinoma compared with other epithelial ovarian tumors. Patients with clear cell carcinoma are younger, tend to present at an early stage, and their tumors are commonly associated with endometriosis, which is widely accepted as a direct precursor of clear cell carcinoma and has been identified pathologically in approximately 50% of clear cell carcinoma cases. The most frequent and important specific gene alterations in clear cell carcinoma are mutations of AT-rich interaction domain 1A (ARID1A) (~50% of cases) and phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit alpha (PIK3CA) (~50% cases). More broadly, subgroups of clear cell carcinoma have been identified based on C-APOBEC (apolipoprotein B mRNA editing enzyme, catalytic polypeptide-like) and C-AGE (age-related) mutational signatures. Gene expression profiling shows upregulation of hepatocyte nuclear factor 1-beta (HNF1β) and oxidative stress-related genes, and has identified epithelial-like and mesenchymal-like tumor subgroups. Although the benefit of platinum-based chemotherapy is not clearly defined it remains the mainstay of first-line therapy. Patients with early-stage disease have a favorable clinical outcome but the prognosis of patients with advanced-stage or recurrent disease is poor. Alternative treatment strategies are required to improve patient outcome and the development of targeted therapies based on molecular characteristics is a promising approach. Improved specificity of the histological definition of this tumor type is helping these efforts but, due to the rarity of clear cell carcinoma, international collaboration will be essential to design appropriately powered, large-scale clinical trials.

Recent Advances in Pathology: the 2020 Annual Review Issue of The Journal of Pathology

This year's Annual Review Issue of The Journal of Pathology contains 18 invited reviews on current research areas in pathology. The subject areas reflect the broad range of topics covered by the journal and this year encompass the development and application of software in digital histopathology, implementation of biomarkers in pathology practice; genetics and epigenetics, and stromal influences in disease. The reviews are authored by experts in their field and provide comprehensive updates in the chosen areas, in which there has been considerable recent progress in our understanding of disease. © 2020 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Abstract 4161: Integrated analysis of whole exome sequencing and hormone receptor expression data in endometrioid ovarian cancer

Endometrioid ovarian carcinomas (EnOCs) account for 10% of OC diagnoses, representing distinct biological and clinical entities compared to other OC subtypes. We recently reported two molecular subgrouping studies using &gt;100 WT1-negative EnOCs: the first identified molecular subgroups of disease by unsupervised analysis of hormone receptor expression patterns, reporting favorable disease-specific survival (DSS) in the PR-high subgroups (PR+/ER+, PR+/ER- vs PR-/ER+, PR-/ER-). The latter study performed whole exome sequencing, identifying genomic events associated with differential DSS, including TP53 mutation (TP53m) and CTNNB1m. Here, we perform integrated analysis of these data to investigate the overlap between these molecular subgrouping layers.

The PR-high subgroups demonstrated low TP53m rate (5% vs 26%, P=0.035) and frequent CTNNB1m (75% vs 26%, P&lt;0.001), with the highest CTNNB1m rate in the PR+/ER+ subgroup (84%, 21/25). Accordingly, TP53m cases demonstrated significantly lower median histoscore (mHS) for PR (3 vs 203, P=0.028) and a trend for lower ER (mHS 66 vs 160, P=0.056), while cases with CTNNB1m demonstrated significantly higher PR and ER expression (mHS 258 vs 40, P&lt;0.001 and 181 vs 75, P=0.002).

There was no significant difference in tumor mutational burden, microsatellite instability or tumor heterogeneity as defined by Mutant Allele Tumour Heterogeneity (MATH) score between the hormone-receptor-based subgroups. These groups also demonstrated no significant difference in mutation rate of mismatch repair protein-encoding genes.

Multivariable analysis identified only FIGO stage at diagnosis (P=0.002), optimal surgical debulking (P=0.035) and hormone receptor subgroup (P=0.004) as independently associated with DSS. TP53m and CTNNB1m were not independently associated with DSS (P=0.187 and P=0.166), though CTNNB1m demonstrated a trend for association in a corresponding model for relapse-free survival (RFS) (HR=0.26, P=0.064).

Within PR-high cases, specific genomic events were not associated with significantly differential survival. Conversely, TP53m was associated with inferior outcome specifically in PR-low cases (P=0.010 for RFS; P=0.066 for DSS).

Collectively, these data represent the first depiction of the overlay and interplay between recently identified EnOC subgroups defined by WES and hormone receptor expression patterns. They demonstrate that PR-high cases frequently harbor CTNNB1m, while TP53m is rare in this context. Moreover, they suggest that PR-high cases experience favorable outcome irrespective of genomic profile, while TP53m represents an important marker of prognosis in PR-low EnOC. Moreover, given the high expression of ER and PR in the CTNNB1m population, assessment of the potential efficacy of endocrine therapy in this population may now warrant investigation.

Citation Format: Robert L. Hollis, John Thomson, Barbara Stanley, Alison M. Meynert, Michael Churchman, Tzyvia Rye, C. Simon Herrington, Charlie Gourley. Integrated analysis of whole exome sequencing and hormone receptor expression data in endometrioid ovarian cancer [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 4161.

Estrogen Signaling and Its Potential as a Target for Therapy in Ovarian Cancer

The estrogen receptor (ER) has functionality in selected ovarian cancer subtypes and represents a potential target for therapy. The majority (>80%) of high grade serous, low grade serous and endometrioid carcinomas and many granulosa cell tumors express ER-alpha (ERα), and these tumor types have demonstrated responses to endocrine therapy (tamoxifen and aromatase inhibitors) in multiple clinical studies. Biomarkers of responses to these drugs are actively being sought to help identify responsive cancers. Evidence for both pro-proliferative and pro-migratory roles for ERα has been obtained in model systems. ER-beta (ERβ) is generally considered to have a tumor suppressor role in ovarian cancer cells, being associated with the repression of cell growth and invasion. The differential expression of the specific ERβ isoforms may determine functionality within ovarian cancer cells. The more recently identified G protein-coupled receptor (GPER1; GPR30) has been shown to mediate both tumor-suppressive and tumor-promoting action in ovarian cancer cells, suggesting a more complex role. This review will summarize recent findings in this field.

Patterns of clinicopathological features and outcome in epithelial ovarian cancer patients: 35 years of prospectively collected data

OBJECTIVE

Investigate the clinical landscape of ovarian carcinoma (OC) over time.

DESIGN

Register-based prospectively collected data.

SETTING

South East Scotland.

SAMPLE

A total of 2805 OC patients diagnosed in 1981-2015.

METHODS

Survival times were visualised using the Kaplan-Meier method; median survival, 5-year survival probabilities and associated restricted mean survival time analyses were used to quantify survival differences.

MAIN OUTCOME MEASURES

Disease-specific survival.

RESULTS

A significant increase in disease-specific survival (DSS) from 1981-1985 to 2011-2015 was observed (median 1.73 versus 4.23 years, P < 0.0001). Corresponding increase in progression-free survival (PFS) was not statistically significant (median 1.22 versus 1.58 years, P = 0.2568). An increase in the proportion of cases with low residual disease volume (RD) (<2 cm RD) following debulking was observed (54.0% versus 87.7%, P < 0.0001). The proportion of high grade serous (HGS) cases increased (P < 0.0001), whereas endometrioid and mucinous cases decreased (P = 0.0005 and P = 0.0002). Increases in stage IV HGS OC incidence (P = 0.0009) and stage IV HGS OC DSS (P = 0.0122) were observed. Increasing median age at diagnosis correlated with increasing Eastern Cooperative Oncology Group Performance Status (ECOG PS) over time (r = 0.86).

CONCLUSIONS

OC DSS has improved over the last 35 years. PFS has not significantly increased, highlighting that improvement in outcome has been limited to extending post-relapse survival. Distribution of stage at diagnosis, histological subtype and RD following debulking has changed over time, reflecting evolution in tumour classification, staging and optimal debulking definitions (from low RD to minimal or zero RD). Histology, stage, RD and ECOG PS remain reliable outcome predictors. Increasing median age at diagnosis and ECOG PS indicates demographic shifts in the clinical population.

TWEETABLE ABSTRACT

Significant improvement in ovarian carcinoma survival has been seen over time. Most of this improvement is due to an extension of survival following disease relapse.

Recent Advances in Pathology: the 2019 Annual Review Issue of The Journal of Pathology

In this Annual Review Issue of The Journal of Pathology, we present 15 invited reviews on topical aspects of pathology, ranging from the impacts of the microbiome in human disease through mechanisms of cell death and autophagy to recent advances in immunity and the uses of genomics for understanding, classifying and treating human cancers. Each of the reviews is authored by experts in their fields and our intention is to provide comprehensive updates in specific areas of pathology in which there has been considerable recent progress. Copyright © 2019 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Hormone receptor expression patterns define clinically meaningful subgroups of endometrioid ovarian carcinoma

Background

Numerous studies have investigated the association between hormone receptor expression and clinical outcome in ovarian carcinoma (OC); however, these have largely focussed on serous OCs, with few studies reporting specifically on endometrioid OCs (EnOC). Where analyses have been stratified by histotype, expression has been assessed using the percentage of positive tumor cells, without accounting for nuclear expression intensity.

Methods

Here we assess the expression levels of progesterone receptor (PR), estrogen receptor alpha (ER) and androgen receptor (AR) using histoscore – a nuclear scoring method incorporating both proportion of positive cells and the intensity of nuclear staining – across a cohort of 107 WT1 negative EnOCs.

Results

Hierarchical clustering by PR, ER and AR histoscores identified four EnOC subgroups (PR+/ER+, PR+/ER−, PR−/ER+ and PR−/ER−). EnOC patients in the PR+/ER+ and PR+/ER− groups displayed favorable outcome (multivariable HR for disease-specific survival 0.05 [0.01–0.35] and 0.05 [0.00–0.51]) compared to the PR−/ER+ group. Ten-year survival for stage II PR^high and PR^low cases was 94.1% and 42.4%. ER^high EnOC patients (PR+/ER+, PR−/ER+) had higher body mass index compared to ER^low cases (P = 0.015) and high grade serous OC patients (P < 0.001).

Conclusion

These data demonstrate that endometrioid OC cases with high PR expression display markedly favorable outcome. Stage II EnOCs with high PR expression represent potential candidates for de-escalation of first-line therapy. Future work should seek to characterise the sensitivity of PR and ER positive EnOCs to endocrine therapy.

•

We identify four subgroups of endometrioid ovarian carcinoma (EnOC) defined by hormone receptor expression patterns.

•

EnOC patients in the PR^high (PR+/ER+, PR+/ER−) groups demonstrate markedly favorable outcome.

•

Stage II EnOC patients in the PR^high groups display a ten-year survival of approximately 95%.

•

ER^high (PR+/ER+, PR−/ER+) EnOC patients had a higher body mass index vs ER^low cases and high grade serous carcinoma patients.

High EMSY expression defines a BRCA-like subgroup of high-grade serous ovarian carcinoma with prolonged survival and hypersensitivity to platinum

BACKGROUND

Approximately half of high-grade serous ovarian carcinomas (HGSOCs) demonstrate homologous recombination repair (HR) pathway defects, resulting in a distinct clinical phenotype comprising hypersensitivity to platinum, superior clinical outcome, and greater sensitivity to poly(adenosine diphosphate-ribose) polymerase (PARP) inhibitors. EMSY, which is known to be amplified in breast and ovarian cancers, encodes a protein reported to bind and inactivate BRCA2. Thus, EMSY overexpression may mimic BRCA2 mutation, resulting in HR deficiency. However, to our knowledge, the phenotypic consequences of EMSY overexpression in HGSOC patients has not been explored.

METHODS

Here we investigate the impact of EMSY expression on clinical outcome and sensitivity to platinum-based chemotherapy using available data from transcriptomically characterized HGSOC cohorts.

RESULTS

High EMSY expression was associated with better clinical outcome in a cohort of 265 patients with HGSOC from Edinburgh (overall survival multivariable hazard ratio, 0.58 [95% CI, 0.38-0.88; P = .011] and progression-free survival multivariable hazard ratio, 0.62 [95% CI, 0.40-0.96; P = .030]). Superior outcome also was demonstrated in the Medical Research Council ICON7 clinical trial and multiple publicly available data sets. Patients within the Edinburgh cohort who had high EMSY expression were found to demonstrate greater rates of complete response to multiple platinum-containing chemotherapy regimens (radiological complete response rate of 44.4% vs 12.5% at second exposure; P = .035) and corresponding prolonged time to disease progression (median, 151.5 days vs 60.5 days after third platinum exposure; P = .004).

CONCLUSIONS

Patients with HGSOCs demonstrating high EMSY expression appear to experience prolonged survival and greater platinum sensitivity, reminiscent of BRCA-mutant cases. These data are consistent with the notion that EMSY overexpression may render HGSOCs HR deficient.

Abstract 749: Multi-layer molecular characterization of high grade serous ovarian carcinomas

High grade serous ovarian carcinomas (HGSOCs) are molecularly and clinically heterogeneous malignancies. Currently, molecular stratification of patient care is limited to tumors rendered homologous recombination deficient (HRD) by BRCA1/2 mutation (BRCAm). Here we explore the overlap, interplay and clinical impact of molecular subgrouping layers in a cohort of 362 FFPE HGSOCs. We overlay genomic subgrouping and tumor-infiltrating lymphocyte (TIL) burden with the three transcriptionally-defined subtypes (Immune, Angio and AngioImmune) we have previously reported as associated with survival and bevacizumab sensitivity.

The BRCAm group, the Immune subtype and those with high CD8+ TIL burden demonstrated prolonged overall survival (OS) as previously reported. The OS benefit of CD8+ TILs was abrogated in the context of gross residual disease following debulking [multivariable hazard ratio (mHR)=0.51 (0.34-0.78) vs 0.93 (0.76-1.52)]. BRCAwild-type patients demonstrating high expression of EMSY, encoding the BRCA2-binding protein EMSY, demonstrated prolonged OS [mHR=0.48 (0.29-0.79)]. BRCA2m and high-EMSY patients displayed greater chemosensitivity (first-line CA125-CR 94.4% and 81.3% vs 48.2%, P&lt;0.001 and P=0.016; CA125-CR at relapse 58.3% and 50.0% vs 14.3%, P=0.002 and P=0.015).

There was significant enrichment and depletion of BRCAm and CCNE1-gain (CCNE1g) in the Immune subtype (28.9% vs 6.3%, P=0.001 and 9.1% vs 17.4%, P=0.050). The Angio subtype harboured far fewer CD8+ TILs compared to the Immune and AngioImmune subtypes (P&lt;0.0001 for both). The frequency of RB1 loss and nonsense TP53 mutation was significantly higher in BRCAm versus BRCA wild-type cases (33.3% vs 13.5%, P=0.020 and 21.4% vs 10.3%, P=0.019).

The clinical impact of CCNE1g was modulated by transcriptomic subtype: in the Immune group, CCNE1g was associated with poor OS [mHR=3.32 (1.49-7.41)], while in the Angio group CCNE1g cases had favourable outcome [PFS mHR=0.26 (0.10-0.68)]. CD8+ TIL burden was not associated with outcome in CCNE1g cases. Missense TP53 mutation was associated with better outcome versus TP53-null mutations in BRCAm patients [PFS mHR=0.43 (0.14-0.82)], but not in the context of HR proficiency [mHR=0.90 (0.67-1.22)].

Integrated classification using the consensus of favourable and unfavourable HR-centric (HRD favourable, HR-proficient unfavourable) and transcriptomic (Immune favourable, Angio/AngioImmune unfavourable) subgrouping yielded three groups with distinct OS [favourable vs unfavourable mHR=0.49 (0.34-0.74); favourable vs no-consensus mHR=0.64 (0.42-0.98); unfavourable vs no-consensus mHR=1.31 (1.00-1.70)].

Together, these data paint a more granular picture of the clinical impact of HGSOC subgroups and demonstrate novel candidate interactions between subgrouping layers. The poorest outcome groups represent those with most to gain from trials of novel treatment regimens.

Citation Format: Robert L. Hollis, Alison M. Meynert, Michael Churchman, Tzyvia Rye, Patricia Roxburgh, Daniel Stetson, Athena Matakidou, Brian Dougherty, J. Carl Barrett, Ruth E. March, Colin A. Semple, C. Simon Herrington, Charlie Gourley. Multi-layer molecular characterization of high grade serous ovarian carcinomas [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 749.

Molecular stratification of endometrioid ovarian carcinomas

5553

Background: Endometrioid ovarian carcinomas (EC) have been historically under-investigated. We sought to determine the molecular landscape of contemporarily defined EC using whole exome sequencing (WES). Methods: Tumours diagnosed as EC between May 1980 and December 2013 were identified through the Edinburgh Ovarian Cancer Database. Pathology review was performed according to WHO 2014. Other pathologies including WT1 positive HGSOC were excluded. A selected cohort underwent WES and were analysed for single nucleotide and copy number variants across a panel of genes previously reported as mutated in endometrial, ovarian or pan cancer studies. Tissue microarrays were stained for ER, PR and AR. Multivariable analysis for disease specific survival (DSS) was performed. Results: 125 tumours were included. 61 tumours of all grades underwent WES. 5 molecular groups were identified based on the presence of TP53 mutations (45.9%); or an EClike profile (one or more mutations in ARID1A (41.0%); CTNNB1 (31.1%), PTEN (24.6%) or PIK3CA (23.0%)). Tumours with no mutations in EClike genes were termed ECnull. Each group demonstrated differential DSS (table). Some ECnull: TP53mut tumours also displayed mutations in KRAS, APC and mismatch repair genes. Unsupervised clustering analysis based on the top 100 differentially mutated genes across the dataset validated these groups. Somatic copy number alterations were significantly higher in the TP53mu t groups than the TP53wt groups (P<0.0001), and were identified across EClike genes in the ECnull groups. A PR histoscore of >150, but not ER or AR, was more frequent in the TP53wt group compared to the TP53mut groups (P=0.003). TP53mut status (P=0.0182) and PR histoscore ≤150 (P=0.0115) were independently associated with DSS. Conclusions: EC is a heterogeneous disease comprising 5 molecular subgroups each demonstrating differential clinical outcome. TP53 mutations and PR histoscore ≤150 are independently associated with poor prognosis. [Table: see text]

SCOTfluors: Small, Conjugatable, Orthogonal, and Tunable Fluorophores for In Vivo Imaging of Cell Metabolism

The transport and trafficking of metabolites are critical for the correct functioning of live cells. However, in situ metabolic imaging studies are hampered by the lack of fluorescent chemical structures that allow direct monitoring of small metabolites under physiological conditions with high spatial and temporal resolution. Herein, we describe SCOTfluors as novel small-sized multi-colored fluorophores for real-time tracking of essential metabolites in live cells and in vivo and for the acquisition of metabolic profiles from human cancer cells of variable origin.

Wide-field multiphoton imaging through scattering media without correction

Optical approaches to fluorescent, spectroscopic, and morphological imaging have made exceptional advances in the last decade. Super-resolution imaging and wide-field multiphoton imaging are now underpinning major advances across the biomedical sciences. While the advances have been startling, the key unmet challenge to date in all forms of optical imaging is to penetrate deeper. A number of schemes implement aberration correction or the use of complex photonics to address this need. In contrast, we approach this challenge by implementing a scheme that requires no a priori information about the medium nor its properties. Exploiting temporal focusing and single-pixel detection in our innovative scheme, we obtain wide-field two-photon images through various turbid media including a scattering phantom and tissue reaching a depth of up to seven scattering mean free path lengths. Our results show that it competes favorably with standard point-scanning two-photon imaging, with up to a fivefold improvement in signal-to-background ratio while showing significantly lower photobleaching.

Abstract 322: High EMSY expression defines a BRCA-like subgroup of high-grade serous ovarian carcinoma with superior survival and platinum sensitivity

EMSY, encoding a BRCA2-binding protein, is reportedly amplified in 6-18% of high grade serous ovarian carcinomas (HGSOCs). As a negative regulator of BRCA2, HGSOCs with EMSY overexpression may mimic BRCA-mutant patients, who experience superior clinical outcome and hypersensitivity to platinum chemotherapy and PARP inhibition by virtue of homologous recombination deficiency (HRD).

Here we investigate the impact of EMSY expression, extracted from local and publicly available transcriptomic data, on the outcome and platinum sensitivity of HGSOCs. Platinum response data were collected from the Edinburgh Ovarian Cancer Database. Overall survival (OS) and progression-free survival (PFS) differences were assessed using multivariate cox regression accounting for age, stage at diagnosis and debulking status.

Within the Edinburgh cohort, high EMSY expression was associated with superior OS and PFS (table 1). Datasets from the MRC ICON7 trial control arm, Tothill et al, Mateescu et al, Pils et al, and TCGA cohorts demonstrated similar benefit for high-EMSY patients. Within the Edinburgh cohort, high-EMSY patients displayed significantly superior complete response (CR) rate to platinum at second (radio CR 44.4% vs 12.5%, P = 0.035; CA125 CR 88.0% vs 55.0%, P = 0.002) and third exposure (radio CR 50.0% vs 5.9%, P = 0.080; CA125 CR 53.3% vs 21.3%, P = 0.021), with prolonged time to progression (median 127 vs 83.5 days from second platinum, P = 0.084; median 151.5 vs 60.5 days from third platinum, P = 0.004). Within high-risk (advanced stage suboptimally debulked) HGSOCs, more high-EMSY patients remained recurrence-free 5 and 10 years from diagnosis (17.6% vs 2.7%, P = 0.031; 12.5% vs 0.9%, P = 0.041).

Together these data demonstrate a subgroup of HGSOCs defined by high EMSY expression experience superior clinical outcome and platinum sensitivity, consistent with HRD. This subgroup may therefore represent HGSOCs that are also sensitive to PARP inhibition.

DatasetEventMulti HR95% CIPEdinburghOS0.590.39 – 0.900.013PFS0.600.38 – 0.930.022MRC ICON7 control armOS0.210.07 – 0.680.009Tothill (primary tumour masses)OS0.280.09 – 0.900.032MateescuOS0.430.18 – 0.990.048PilsOS0.270.08 – 0.870.028TCGA advanced stage patientsPFS0.690.45 – 1.050.081

Citation Format: Robert L. Hollis, Michael Churchman, Tzyvia Rye, Andrena M. McCavigan, Laura A. Knight, Richard Kennedy, C. Simon Herrington, Charlie Gourley. High EMSY expression defines a BRCA-like subgroup of high-grade serous ovarian carcinoma with superior survival and platinum sensitivity [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 322.

Towards automated cancer screening: Label-free classification of fixed cell samples using wavelength modulated Raman spectroscopy

The ability to provide quantitative, objective and automated pathological analysis would provide enormous benefits for national cancer screening programmes, in terms of both resource reduction and improved patient wellbeing. The move towards molecular pathology through spectroscopic methods shows great promise, but has been restricted by spectral quality, acquisition times and lack of direct clinical application. In this paper, we present the application of wavelength modulated Raman spectroscopy for the automated label- and fluorescence-free classification of fixed squamous epithelial cells in suspension, such as those produced during a cervical smear test. Direct comparison with standard Raman spectroscopy shows marked improvement of sensitivity and specificity when considering both human papillomavirus (sensitivity +12.0%, specificity +5.3%) and transformation status (sensitivity +10.3%, specificity +11.1%). Studies on the impact of intracellular sampling location and storage effects suggest that wavelength modulated Raman spectroscopy is sufficiently robust to be used in fixed cell classification, but requires further investigations of potential sources of molecular variation in order to improve current clinical tools.

Enhanced response rate to pegylated liposomal doxorubicin in high grade serous ovarian carcinomas harbouring BRCA1 and BRCA2 aberrations

BACKGROUND

Approximately 10-15% of ovarian carcinomas (OC) are attributed to inherited susceptibility, the majority of which are due to mutations in BRCA1 or BRCA2 (BRCA1/2). These patients display superior clinical outcome, including enhanced sensitivity to platinum-based chemotherapy. Here, we seek to investigate whether BRCA1/2 status influences the response rate to single-agent pegylated liposomal doxorubicin (PLD) in high grade serous (HGS) OC.

METHODS

One hundred and forty-eight patients treated with single-agent PLD were identified retrospectively from the Edinburgh Ovarian Cancer Database. DNA was extracted from formalin-fixed paraffin-embedded (FFPE) archival tumour material and sequenced using the Ion Ampliseq BRCA1 and BRCA2 panel. A minimum variant allele frequency threshold was applied to correct for sequencing artefacts associated with formalin fixation.

RESULTS

A superior response rate to PLD was observed in patients with HGS OC who harboured variants likely to affect BRCA1 or BRCA2 function compared to the BRCA1/2 wild-type population (36%, 9 of 25 patients versus 12.1%, 7 of 58 patients; p = 0.016). An enhanced response rate was also seen in patients harbouring only the BRCA1 SNP rs1799950, predicted to be detrimental to BRCA1 function (50%, 3 of 6 patients versus 12.1%, 7 of 58 patients; p = 0.044).

CONCLUSIONS

These data demonstrate that HGS OC patients with BRCA1/2 variants predicted damaging to protein function experience superior sensitivity to PLD, consistent with impaired DNA repair. Further characterisation of rs1799950 is now warranted in relation to chemosensitivity and susceptibility to developing ovarian carcinoma.

The terminology of pre-invasive cervical lesions in the UK cervical screening programme

The terminology of non-invasive epithelial abnormalities associated with an elevated risk of having or developing invasive cervical carcinoma (pre-invasive lesions) has been modified frequently over time as understanding of the underlying biology, and approaches to disease management, have changed. The arguments are now converging on the conclusion that the most appropriate terminology for cervical squamous intraepithelial abnormalities should be two-tier rather than three-tier. Given the findings of the Lower Anogenital Squamous Terminology (LAST) project in the USA, which have recently been endorsed by the World Health Organisation classification of tumours of female reproductive organs, the recommended terms are low-grade and high-grade squamous intraepithelial lesion (SIL), with the option of including the relevant cervical intraepithelial neoplasia (CIN) grade in parentheses. Although, at first sight, this appears to represent only a small change, there is a fundamental conceptual difference between the systems. The CIN system requires, first, the identification of a CIN lesion and, second, the determination of its grade on a continuum, with subsequent division into three grades. The SIL system is based on the existence of two different forms of human papillomavirus (HPV) infection, with productive infection leading to low-grade SIL and transforming infection leading to high-grade SIL.

Recommendations for minimum information for publication of experimental pathology data: MINPEPA guidelines

Animal models are essential research tools in modern biomedical research, but there are concerns about their lack of reproducibility and the failure of animal data to translate into advances in human medical therapy. A major factor in improving experimental reproducibility is thorough communication of research methodologies. The recently published ARRIVE guidelines outline basic information that should be provided when reporting animal studies. This paper builds on ARRIVE by providing the minimum information needed in reports to allow proper assessment of pathology data gathered from animal tissues. This guidance covers aspects of experimental design, technical procedures, data gathering, analysis, and presentation that are potential sources of variation when creating morphological, immunohistochemical (IHC) or in situ hybridization (ISH) datasets. This reporting framework will maximize the likelihood that pathology data derived from animal experiments can be reproduced by ensuring that sufficient information is available to allow for replication of the methods and facilitate inter-study comparison by identifying potential interpretative confounders.

Viruses and disease: emerging concepts for prevention, diagnosis and treatment

Viruses cause a wide range of human diseases, ranging from acute self‐resolving conditions to acute fatal diseases. Effects that arise long after the primary infection can also increase the propensity for chronic conditions or lead to the development of cancer. Recent advances in the fields of virology and pathology have been fundamental in improving our understanding of viral pathogenesis, in providing improved vaccination strategies and in developing newer, more effective treatments for patients worldwide. The reviews assembled here focus on the interface between virology and pathology and encompass aspects of both the clinical pathology of viral disease and the underlying disease mechanisms. Articles on emerging diseases caused by Ebola virus, Marburg virus, coronaviruses such as SARS and MERS, Nipah virus and noroviruses are followed by reviews of enteroviruses, HIV infection, measles, mumps, human respiratory syncytial virus (RSV), influenza, cytomegalovirus (CMV) and varicella zoster virus (VZV). The issue concludes with a series of articles reviewing the relationship between viruses and cancer, including the role played by Epstein–Barr virus (EBV) in the pathogenesis of lymphoma and carcinoma; how human papillomaviruses (HPVs) are involved in the development of skin cancer; the involvement of hepatitis B virus infection in hepatocellular carcinoma; and the mechanisms by which Kaposi's sarcoma‐associated herpesvirus (KSHV) leads to Kaposi's sarcoma. We hope that this collection of articles will be of interest to a wide range of scientists and clinicians at a time when there is a renaissance in the appreciation of the power of pathology as virologists dissect the processes of disease. Copyright © 2014 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Multi-modal approach using Raman spectroscopy and optical coherence tomography for the discrimination of colonic adenocarcinoma from normal colon

We report a multimodal optical approach using both Raman spectroscopy and optical coherence tomography (OCT) in tandem to discriminate between colonic adenocarcinoma and normal colon. Although both of these non-invasive techniques are capable of discriminating between normal and tumour tissues, they are unable individually to provide both the high specificity and high sensitivity required for disease diagnosis. We combine the chemical information derived from Raman spectroscopy with the texture parameters extracted from OCT images. The sensitivity obtained using Raman spectroscopy and OCT individually was 89% and 78% respectively and the specificity was 77% and 74% respectively. Combining the information derived using the two techniques increased both sensitivity and specificity to 94% demonstrating that combining complementary optical information enhances diagnostic accuracy. These data demonstrate that multimodal optical analysis has the potential to achieve accurate non-invasive cancer diagnosis.

Optimisation of wavelength modulated Raman spectroscopy: towards high throughput cell screening

In the field of biomedicine, Raman spectroscopy is a powerful technique to discriminate between normal and cancerous cells. However the strong background signal from the sample and the instrumentation affects the efficiency of this discrimination technique. Wavelength Modulated Raman spectroscopy (WMRS) may suppress the background from the Raman spectra. In this study we demonstrate a systematic approach for optimizing the various parameters of WMRS to achieve a reduction in the acquisition time for potential applications such as higher throughput cell screening. The Signal to Noise Ratio (SNR) of the Raman bands depends on the modulation amplitude, time constant and total acquisition time. It was observed that the sampling rate does not influence the signal to noise ratio of the Raman bands if three or more wavelengths are sampled. With these optimised WMRS parameters, we increased the throughput in the binary classification of normal human urothelial cells and bladder cancer cells by reducing the total acquisition time to 6 s which is significantly lower in comparison to previous acquisition times required for the discrimination between similar cell types.

Peritoneal mesothelial hyperplasia associated with gynaecological disease: a potential diagnostic pitfall that is commonly associated with endometriosis

Aims

To describe the clinicopathological features of florid peritoneal mesothelial hyperplasia associated with gynaecological disease.

Methods

Review of a series of 44 cases where there was significant peritoneal mesothelial proliferation, usually on the surface of the ovary, which resulted in diagnostic problems, often including a consideration of malignancy.

Results

Florid mesothelial proliferation was associated with a variety of benign and malignant lesions, most commonly endometriosis. The most characteristic morphological appearance was that of small bland tubules and nests and cords of cells often embedded in fibrous tissue, sometimes with a linear arrangement. In a minority of cases, there were closely packed small glands and papillae resulting in mimicry of a serous proliferation; psammoma bodies were present in one such case. In several cases, the groups of mesothelial cells either exhibited true lymphovascular invasion or were surrounded by spaces closely simulating lymphovascular invasion. Although most cases were appreciated to represent a reactive mesothelial proliferation, several were referred with a presumed or possible diagnosis of mesothelioma, low-grade serous carcinoma, adenocarcinoma, adenomatoid tumour or Sertoli cell tumour. Positive staining with calretinin and negative staining with Ber-EP4 often helped to identify the cells as mesothelial rather than epithelial.

Conclusions

Florid peritoneal mesothelial hyperplasia can occur in association with a variety of gynaecological disorders. Recognition of this phenomenon and appreciation that it can produce worrisome histological patterns, particularly when associated with endometriosis, is key to reaching the correct diagnosis.

Modulated Raman spectroscopy for enhanced identification of bladder tumor cells in urine samples

Standard Raman spectroscopy (SRS) is a noninvasive technique that is used in the biomedical field to discriminate between normal and cancer cells. However, the presence of a strong fluorescence background detracts from the use of SRS in real-time clinical applications. Recently, we have reported a novel modulated Raman spectroscopy (MRS) technique to extract the Raman spectra from the background. In this paper, we present the first application of MRS to the identification of human urothelial cells (SV-HUC-1) and bladder cancer cells (MGH) in urine samples. These results are compared to those obtained by SRS. Classification using the principal component analysis clearly shows that MRS allows discrimination between Raman spectra of SV-HUC-1 and MGH cells with high sensitivity (98%) and specificity (95%). MRS is also used to distinguish between SV-HUC-1 and MGH cells after exposure to urine for up to 6 h. We observe a marked change in the MRS of SV-HUC-1 and MGH cells with time in urine, indicating that the conditions of sample collection will be important for the application of this methodology to clinical urine samples.