Clear cell carcinoma of the ovary: a report from the first Ovarian Clear Cell Symposium, June 24th, 2010

Non-small cell lung carcinoma with clear cell features: a clinicopathologic, immunohistochemical, and molecular study of 31 cases

Non-small cell lung carcinoma with predominantly clear cell features is a rare histologic presentation of lung carcinoma. We have examined 31 cases of lung carcinomas showing extensive clear cell features. The patients were 10 women and 21 men aged 47-92 years (mean: 70 years). The tumors showed a predilection for the right upper and lower lobes and measured from 0.8 to 9.5 cm (mean: 4.2 cm). By immunohistochemistry, 9 cases were typed as adenocarcinoma, 19 cases as squamous cell carcinoma, and 3 showed a "null" phenotype with complete loss of markers for adenocarcinoma or squamous cell carcinoma. Most cases that typed as adenocarcinoma showed a solid growth pattern. A subset of the solid adenocarcinoma cases showed a distinctive "pseudosquamous" morphology. Next-generation sequencing was performed in 20 cases and showed a variety of molecular alterations. The most common abnormalities were found in the TP53 gene (9 cases), FGFR gene family (8 cases), KRAS (5 cases), AKT1 (5 cases), and BRAF (3 cases). Clinical follow-up was available in 21 patients; 16/21 patients died of their tumors from 6 months to 12 years after initial diagnosis (mean: 4.2 years, median: 1.5 years). Four patients were alive and well from 4 to 27 years (mean: 11.5 years, median: 7.5 years); all were pathologic stage 1 or 2. NSCLC with clear cell features can display aggressive behavior and needs to be distinguished from various other tumors of the lung that can show clear cell morphology. The identification of targetable molecular alterations in some of these tumors may be of value for therapeutic management.

Phase II trial of pembrolizumab and epacadostat in recurrent clear cell carcinoma of the ovary: An NRG oncology study GY016

INTRODUCTION

Early reports of PD-1 inhibition in ovarian clear cell carcinomas (OCCC) demonstrate promising response. We evaluated the combination of pembrolizumab and IDO-1 inhibitor epacadostat in patients with recurrent OCCC.

METHODS

This single arm, two-stage, phase 2 trial included those with measurable disease and 1-3 prior regimens. Patients received intravenous pembrolizumab 200 mg every 3 weeks and oral epacadostat 100 mg twice a day. Primary endpoint was overall response rate (ORR), secondary endpoints were toxicity, progression-free survival (PFS) and overall survival (OS). The study was powered to detect an absolute 25% increase in response (15% to 40%).

RESULTS

Between September 28, 2018 and April 10, 2019, 14 patients enrolled at first stage. Rate of accrual was 2.3 patients per month. Median age was 65 years (44-89), 10 (71.4%) had ≥2 prior regimens. ORR was 21% (95% CI 5-51%) within 7 months of study entry with 3 partial responses, and 4 had stable disease (disease control rate 50%). Median PFS was 4.8 months (95% CI: 1.9-9.6), OS 18.9 months (95% CI: 1.9-NR). Most common grade ≥ 3 adverse events were electrolyte abnormalities and gastrointestinal pain, nausea, vomiting, bowel obstruction. In July 2019, the study reached the pre-specified criteria to re-open to second stage; however, the study closed prematurely in February 2021 due to insufficient drug supply.

CONCLUSIONS

Pembrolizumab and epacadostat demonstrated an ORR of 21% in this small cohort of recurrent OCCC. The rapid rate of accrual highlights the enthusiasm and need for therapeutic studies in patients with OCCC.

Genome-wide DNA methylation in relation to ARID1A deficiency in ovarian clear cell carcinoma

BACKGROUND

The poor chemo-response and high DNA methylation of ovarian clear cell carcinoma (OCCC) have attracted extensive attentions. Recently, we revealed the mutational landscape of the human kinome and additional cancer-related genes and found deleterious mutations in ARID1A, a component of the SWI/SNF chromatin-remodeling complex, in 46% of OCCC patients. The present study aims to comprehensively investigate whether ARID1A loss and genome-wide DNA methylation are co-regulated in OCCC and identify putative therapeutic targets epigenetically regulated by ARID1A.

METHODS

DNA methylation of ARID1Amt/ko and ARID1Awt OCCC tumors and cell lines were analyzed by Infinium MethylationEPIC BeadChip. The clustering of OCCC tumors in relation to clinical and mutational status of tumors were analyzed by hierarchical clustering analysis of genome-wide methylation. GEO expression profiles were used to identify differentially methylated (DM) genes and their expression level in ARID1Amt/ko vs ARID1Awt OCCCs. Combining three pre-ranked GSEAs, pathways and leading-edge genes epigenetically regulated by ARID1A were revealed. The leading-edge genes that passed the in-silico validation and showed consistent ARID1A-related methylation change in tumors and cell lines were regarded as candidate genes and finally verified by bisulfite sequencing and RT-qPCR.

RESULTS

Hierarchical clustering analysis of genome-wide methylation showed two clusters of OCCC tumors. Tumor stage, ARID1A/PIK3CA mutations and TP53 mutations were significantly different between the two clusters. ARID1A mutations in OCCC did not cause global DNA methylation changes but were related to DM promoter or gene-body CpG islands of 2004 genes. Three pre-ranked GSEAs collectively revealed the significant enrichment of EZH2- and H3K27me3-related gene-sets by the ARID1A-related DM genes. 13 Leading-edge DM genes extracted from the enriched gene-sets passed the expression-based in-silico validation and showed consistent ARID1A-related methylation change in tumors and cell lines. Bisulfite sequencing and RT-qPCR analysis showed promoter hypermethylation and lower expression of IRX1, TMEM101 and TRIP6 in ARID1Amt compared to ARID1Awt OCCC cells, which was reversed by 5-aza-2'-deoxycytidine treatment.

CONCLUSIONS

Our study shows that ARID1A loss is related to the differential methylation of a number of genes in OCCC. ARID1A-dependent DM genes have been identified as key genes of many cancer-related pathways that may provide new candidates for OCCC targeted treatment.

PURE vs. mixed clear cell ovarian carcinomas: Is there any impact on survival?

OBJECTIVE

Our primary aim in this study is to define the clinical characteristics of patients with clear-cell ovarian carcinoma and evaluate the prognostic factors affecting survival.

STUDY DESIGN

Records of 85 patients, operated between 2000 and 2018, for an adnexal mass and whose final pathology reported clear cell ovarian carcinoma were reviewed. The study considered demographic data, clinical characteristics of the patients, as well as pure and mixed-type clear cell histology. The patients' follow-up time, disease-free and overall survival recorded. The primary outcomes were disease-free survival (DFS) and overall survival (OS).

RESULTS

The median age of the patients at diagnosis was 52. In 64.7 % of the cases, clear cell histology was pure, while the others (35.3 %) were mixed. Patients with ovarian endometriosis constituted 27.1 % of the whole population. The median OS for the entire population was 92 months (95 %CI:72-124). On univariate and multivariate analyses, advanced age was found to have a significant independent impact on OS and DFS (p < 0.05) and, was associated with a worse prognosis. Also, the multivariate analyses showed that the presence of endometriosis has a significant independent impact on OS (p < 0.05). When examining the relationship between the histological origin (mixed vs. pure) and 5-year survival, the mixed type showed longer OS and DFS rates (76.8 % vs. 69.8 %, 61.5 % vs. 53.8 %), the difference was not statistically significant (p > 0.05).

CONCLUSION

This retrospective study showed that although mixed type histological origin was associated with higher OS and DFS rates compared to pure type in patients with CCOC, the difference was not statistically significant. Advanced age and the presence of endometriosis was found to have a significant independent effect on OS and DFS and was associated with a worse prognosis. Overall, this study provides useful insights into the clinical characteristics of patients with CCOC and identifies important prognostic factors affecting survival.

Application of interpretable machine learning algorithms to predict distant metastasis in ovarian clear cell carcinoma

BACKGROUND

Ovarian clear cell carcinoma (OCCC) represents a subtype of ovarian epithelial carcinoma (OEC) known for its limited responsiveness to chemotherapy, and the onset of distant metastasis significantly impacts patient prognoses. This study aimed to identify potential risk factors contributing to the occurrence of distant metastasis in OCCC.

METHODS

Utilizing the Surveillance, Epidemiology, and End Results (SEER) database, we identified patients diagnosed with OCCC between 2004 and 2015. The most influential factors were selected through the application of Gaussian Naive Bayes (GNB) and Adaboost machine learning algorithms, employing a Venn test for further refinement. Subsequently, six machine learning (ML) techniques, namely XGBoost, LightGBM, Random Forest (RF), Adaptive Boosting (Adaboost), Support Vector Machine (SVM), and Multilayer Perceptron (MLP), were employed to construct predictive models for distant metastasis. Shapley Additive Interpretation (SHAP) analysis facilitated a visual interpretation for individual patient. Model validity was assessed using accuracy, sensitivity, specificity, positive predictive value, negative predictive value, F1 score, and the area under the receiver operating characteristic curve (AUC).

RESULTS

In the realm of predicting distant metastasis, the Random Forest (RF) model outperformed the other five machine learning algorithms. The RF model demonstrated accuracy, sensitivity, specificity, positive predictive value, negative predictive value, F1 score, and AUC (95% CI) values of 0.792 (0.762-0.823), 0.904 (0.835-0.973), 0.759 (0.731-0.787), 0.221 (0.186-0.256), 0.974 (0.967-0.982), 0.353 (0.306-0.399), and 0.834 (0.696-0.967), respectively, surpassing the performance of other models. Additionally, the calibration curve's Brier Score (95%) for the RF model reached the minimum value of 0.06256 (0.05753-0.06759). SHAP analysis provided independent explanations, reaffirming the critical clinical factors associated with the risk of metastasis in OCCC patients.

CONCLUSIONS

This study successfully established a precise predictive model for OCCC patient metastasis using machine learning techniques, offering valuable support to clinicians in making informed clinical decisions.

Clear cell carcinoma of the ovary: Clues for radiologists to perform a correct diagnosis

Ovarian clear cell carcinoma (OCCC) is an uncommon high-grade primary epithelial ovarian cancer, covering about 10-12 % of all ovarian malignancies. It has a strong association with endometriosis. OCCC diagnosis, at advanced stages, has an aggressive biological behaviour, and the therapeutic strategies for ovarian OCCC are somehow different from other ovarian carcinomas. Therefore, early diagnosis of these tumours is of extreme importance. As some ovarian tumours subtypes have distinguishing features, it is possible to differentiate them based on their imaging characteristics, which can guide patient management and help the clinicians and pathologists in their diagnosis. A large mass on one side of the ovary that is mostly cystic, with a focal or multifocal irregular eccentric growing solid mural nodules or projections protruding into the cystic space, may suggest clear cell carcinoma of the ovary diagnosis. The solid nodules usually have an intermediate signal on T2-weighted images. The cystic component can be either single or multilocular, and the contents may contain protein or blood. CT scanning is still the preferred method for preoperative staging and postoperative restaging, and radiologists are crucial in identifying this type of tumour. We reviewed the imaging files of patients with surgically proven clear cell carcinoma at the specimens, and our findings agree with previous studies. This paper aims to perform a comprehensive revision of OCCC's radiological and clinic-pathological features and assist radiologists in recognizing OCCC and narrowing down the possibilities of differential diagnosis.

Cell State of Origin Impacts Development of Distinct Endometriosis-Related Ovarian Carcinoma Histotypes

Clear cell ovarian carcinoma (CCOC) and endometrioid ovarian carcinoma (ENOC) are ovarian carcinoma histotypes, which are both thought to arise from ectopic endometrial (or endometrial-like) cells through an endometriosis intermediate. How the same cell type of origin gives rise to two morphologically and biologically different histotypes has been perplexing, particularly given that recurrent genetic mutations are common to both and present in nonmalignant precursors. We used RNA transcription analysis to show that the expression profiles of CCOC and ENOC resemble those of normal endometrium at secretory and proliferative phases of the menstrual cycle, respectively. DNA methylation at the promoter of the estrogen receptor (ER) gene (ESR1) was enriched in CCOC, which could potentially lock the cells in the secretory state. Compared with normal secretory-type endometrium, CCOC was further defined by increased expression of cysteine and glutathione synthesis pathway genes and downregulation of the iron antiporter, suggesting iron addiction and highlighting ferroptosis as a potential therapeutic target. Overall, these findings suggest that while CCOC and ENOC arise from the same cell type, these histotypes likely originate from different cell states. This "cell state of origin" model may help to explain the presence of histologic and molecular cancer subtypes arising in other organs.

SIGNIFICANCE

Two cancer histotypes diverge from a common cell of origin epigenetically locked in different cell states, highlighting the importance of considering cell state to better understand the cell of origin of cancer.

A preoperative nomogram incorporating CT to predict the probability of ovarian clear cell carcinoma

OBJECTIVES

To evaluate clinical, laboratory, and radiological variables from preoperative contrast-enhanced computed tomography (CECT) for their ability to distinguish ovarian clear cell carcinoma (OCCC) from non-OCCC and to develop a nomogram to preoperatively predict the probability of OCCC.

METHODS

This IRB-approved, retrospective study included consecutive patients who underwent surgery for an ovarian tumor from 1/1/2000 to 12/31/2016 and CECT of the abdomen and pelvis ≤90 days before primary debulking surgery. Using a standardized form, two experienced oncologic radiologists independently analyzed imaging features and provided a subjective 5-point impression of the probability of the histological diagnosis. Nomogram models incorporating clinical, laboratory, and radiological features were created to predict histological diagnosis of OCCC over non-OCCC.

RESULTS

The final analysis included 533 patients with surgically confirmed OCCC (n = 61) and non-OCCC (n = 472); history of endometriosis was more often found in patients with OCCC (20% versus 3.6%; p < 0.001), while CA-125 was significantly higher in patients with non-OCCC (351 ng/mL versus 70 ng/mL; p < 0.001). A nomogram model incorporating clinical (age, history of endometriosis and adenomyosis), laboratory (CA-125) and imaging findings (peritoneal implant distribution, morphology, laterality, and diameter of ovarian lesion and of the largest solid component) had an AUC of 0.9 (95% CI: 0.847, 0.949), which was comparable to the AUCs of the experienced radiologists' subjective impressions [0.8 (95% CI: 0.822, 0.891) and 0.9 (95% CI: 0.865, 0.936)].

CONCLUSIONS

A presurgical nomogram model incorporating readily accessible clinical, laboratory, and CECT variables was a powerful predictor of OCCC, a subtype often requiring a distinctive treatment approach.

Genomic landscapes of ovarian clear cell carcinoma from latin countries reveal aberrations linked to survival and progression

BACKGROUND

Ovarian clear cell carcinomas (OCCCs) are rare, aggressive and chemoresistant tumors. Geographical and ethnic differences in the incidence of OCCC have been reported with a higher incidence in Asiatic countries. There is a paucity of information regarding OCCC in Latin America (LA) and other countries.

METHODS

Here, we characterized two cohorts of 33 patients with OCCC from LA (24 from Brazil and 9 from Costa Rica) and a cohort of 27 patients from Spain. Genomic analysis was performed for 26 OCCC using the OncoScan platform. Tumors were classified according to their genomic landscapes into subgroups. Clinical parameters were related to the frequency of genomic aberrations.

RESULTS

The median overall survival (OS) was not significantly different between the cohorts. Genomic landscapes were characterized by different homologous recombination deficiency (HRD) levels. No difference in the distribution of genomic landscapes profiles was detected between patients from the different cohorts. OCCCs with MYC-amplified tumors harboring a concomitant loss of a region in chromosome 13q12-q13 that includes the BRCA2 gene had the longest OS. In contrast, patients carrying a high number (> 30) of total copy number (CN) aberrations with no concomitant alterations in MYC and BRCA2 genes presented the shortest OS. Furthermore, amplification of the ASH1L gene was also associated with a shorter OS. Initial-stage OCCCs with early progression were characterized by gains in the JNK1 and MKL1 genes.

CONCLUSIONS

Our results provide new data from understudied OCCC populations and reveal new potential markers for OCCCs.

Clear cell carcinoma of the ovary and venous thromboembolism: a systematic review and meta-analysis

OBJECTIVES

As the second most common subtype of Epithelial ovarian cancers (EOCs), ovarian clear cell carcinoma (OCCC) is associated with a high rate of cancer-associated thrombosis. Previous studies revealed the wide range prevalence (6-42%) of venous thromboembolism (VTE) among OCCC patients. This study aimed to determine the prevalence of VTE among OCCC patients as well as factors affecting it.

METHODS

PubMed, Scopus, Embase, and Cochrane Library databases were searched up to December 12th, 2022. Studies reporting venous thromboembolic events in women with clear cell carcinoma of the ovary were included. Demographic data, clinical, and paraclinical features of the patients were independently extracted by two reviewers.

RESULTS

Out of the 2254 records, 43 studies were processed for final review. The qualified studies involved 573 VTE cases among 2965 patients with OCCC. The pooled prevalence of VTE among OCCC patients was 21.32% (95%CI=(17.38-25.87)). Most VTE events were reported in Japanese women (26.15%), followed by Americans (24.41%) and UK (21.57%), and Chinese (13.61%) women. VTE was more common in patients with advanced stages (37.79%) compared to those with early stages of the disease (16.54%).

CONCLUSIONS

Ovarian clear cell carcinoma is associated with a high rate of cancer-associated thrombosis. VTE events in OCCC patients were higher in advanced stages and Japanese women.

Liposomal DQ in Combination with Copper Inhibits ARID1A Mutant Ovarian Cancer Growth

Therapeutic strategies for ARID1A-mutant ovarian cancers are limited. Higher basal reactive oxygen species (ROS) and lower basal glutathione (GSH) empower the aggressive proliferation ability and strong metastatic property of OCCCs, indicated by the increased marker of epithelial-mesenchymal transition (EMT) and serving the immunosuppressive microenvironment. However, the aberrant redox homeostasis also empowers the sensitivity of DQ-Lipo/Cu in a mutant cell line. DQ, a carbamodithioic acid derivative, generates dithiocarbamate (DDC) in response to ROS, and the chelation of Cu and DDC further generates ROS and provides a ROS cascade. Besides, quinone methide (QM) released by DQ targets the vulnerability of GSH; this effect, plus the increase of ROS, destroys the redox homeostasis and causes cancer cell death. Also importantly, the formed Cu(DDC)₂ is a potent cytotoxic anti-cancer drug that successfully induces immunogenic cell death (ICD). The synergistic effect of EMT regulation and ICD will contribute to managing cancer metastasis and possible drug resistance. In summary, our DQ-Lipo/Cu shows promising inhibitory effects in cancer proliferation, EMT markers, and "heat" the immune response.

Next-generation sequencing shows the genomic features of ovarian clear cell cancer and compares the genetic architectures of high-grade serous ovarian cancer and clear cell carcinoma in ovarian and endometrial tissues

Ovarian clear cell carcinoma (OCCC) is a special histological type of epithelial ovarian cancer (EOC) that is not derived from epithelial cells of the ovarian or fallopian tube as the most common type of ovarian cancer, high-grade serous ovarian carcinoma (HGSOC), but is closely related to endometriosis and similar to endometrial clear cell carcinoma (ECCC) at morphologic and phenotypic features. However, limited data was shown in OCCC genomic features and compared with that in OCCC, HGSOC and ECCC. Herein, we utilized next-generation sequencing analysis of a panel of 1,021 genes to profile the mutational alterations in 34 OCCC and compared them to those from HGSOC (402 cases) and ECCC (30 cases). In result, the ARID1A and PIK3CA are high-frequency mutations of OCCC. Clonal architectures showed that all the mutations of genes occur in the later stage in the OCCC progress, whereas KRAS mutation is the earlier event compared with mutation of ARID1A or PIK3CA, which usually occurs in a group of ARID1A or PIK3CA mutations. The mutation frequency of main driver genes is similar between OCCC and ECCC, while TP53 is the main mutation in HGSOC and ECCC. Shared mutational signatures between OCCC and ECCC tissues with commonly observed a C>T change indicated a common carcinogens-exposed between these two carcinomas, but HGSOC and ECCC have common and distinct mutational signatures across cohorts respectively. In addition, we identified some novel CNV gains in NF1, ASXL1, TCF7L2, CREBBP and LRP1B and loss in ATM, FANCM, RB1 and FLT in OCCC. Our study offered a new perspective for OCCC tumorigenesis from two organs, the ovary and uterus, at genomic architectures and revealed novel CNV events for helping to provide theoretical support for OCCC treatment.

Review the progression of ovarian clear cell carcinoma from the perspective of genomics and epigenomics

Ovarian clear cell carcinoma (OCCC) is a rare subtype of epithelial ovarian cancer with unique molecular characteristics, specific biological and clinical behavior, poor prognosis and high resistance to chemotherapy. Pushed by the development of genome-wide technologies, our knowledge about the molecular features of OCCC has been considerably advanced. Numerous studies are emerging as groundbreaking, and many of them are promising treatment strategies. In this article, we reviewed studies about the genomics and epigenetics of OCCC, including gene mutation, copy number variations, DNA methylation and histone modifications.

Preoperative serum microRNAs as potential prognostic biomarkers in ovarian clear cell carcinoma

OBJECTIVE

Ovarian clear cell carcinoma (OCCC) is a subtype of epithelial ovarian carcinoma with poor prognosis. However, no effective biomarkers have been established for predicting unfavorable events, including recurrence and poor prognoses. Serum microRNAs (miRNAs) have been increasingly reported to be useful in predicting a patient's condition and have been recognized as a potentially less-invasive source for liquid biopsy in cancer. Therefore, this study aimed to evaluate serum miRNA profiles from patients with OCCC and to establish biomarker for predicting the prognoses.

METHODS

The GSE106817, which included preoperative serum miRNA profiles of patients with ovarian tumors, was used, and clinical information was investigated. In all, 66 patients with OCCC were included, excluding those with other histological subtypes or insufficient prognostic information. Moreover, miRNA profiles of OCCC tissues were also examined.

RESULTS

The median follow-up period was 64.3 (8.0-153.3) months. Based on multivariable Cox regression analyses and the expression of miRNAs in OCCC tissues, miR-150-3p, miR-3195, and miR-7704 were selected as miRNA candidates associated with both progression-free survival (PFS) and overall survival (OS). Then, the prognostic index was calculated based on expression values of 3 serum miRNAs. Kaplan-Meier survival analysis indicated that the prognostic index was significantly predictive of PFS and OS (p=0.004 and p=0.012, respectively).

CONCLUSION

Preoperative serum miRNA profiles of miR-150-3p, miR-3195, and miR-7704 can be used to potentially predict the prognosis of patients with OCCC.

NEXGB: A Network Embedding Framework for Anticancer Drug Combination Prediction

Compared to single-drug therapy, drug combinations have shown great potential in cancer treatment. Most of the current methods employ genomic data and chemical information to construct drug–cancer cell line features, but there is still a need to explore methods to combine topological information in the protein interaction network (PPI). Therefore, we propose a network-embedding-based prediction model, NEXGB, which integrates the corresponding protein modules of drug–cancer cell lines with PPI network information. NEXGB extracts the topological features of each protein node in a PPI network by struc2vec. Then, we combine the topological features with the target protein information of drug–cancer cell lines, to generate drug features and cancer cell line features, and utilize extreme gradient boosting (XGBoost) to predict the synergistic relationship between drug combinations and cancer cell lines. We apply our model on two recently developed datasets, the Oncology-Screen dataset (Oncology-Screen) and the large drug combination dataset (DrugCombDB). The experimental results show that NEXGB outperforms five current methods, and it effectively improves the predictive power in discovering relationships between drug combinations and cancer cell lines. This further demonstrates that the network information is valid for detecting combination therapies for cancer and other complex diseases.

Ovarian Clear Cell Carcinoma with Functioning Stroma and Associated Endometrial Intraepithelial Neoplasia

We report the case of a 79-year-old woman with a large pelvic mass and postmenopausal bleeding, associated with hyperestrogenism. A pelvic MRI shows the presence of a large mass of 12.6 cm originating from the right ovary without signs of metastasis. A total abdominal hysterectomy with unilateral salpingooophorectomy was performed, knowing the patient underwent a left salpingooophorectomy decades ago. The pathological findings showed an ovarian clear cell carcinoma (pT1A) with associated endometrial intraepithelial neoplasia. There is convincing evidence that the production of estrogen is located in the activated ovarian stroma. This supports the view that functioning stroma of ovarian cancer can lead to hyperestrogenism and eventually endometrial cancer.

Exosomal MicroRNA as Biomarkers for Diagnosing or Monitoring the Progression of Ovarian Clear Cell Carcinoma: A Pilot Study

Ovarian cancer is the most common cause of gynecological malignancy-related mortality since early-stage disease is difficult to diagnose. Advanced clear cell carcinoma of the ovary (CCCO) has dismal prognosis, and its incidence has been increasing in Japan, emphasizing the need for highly sensitive diagnostic and prognostic CCCO biomarkers. Exosomal microRNAs (miRNAs) secreted by tumor cells are known to play a role in carcinogenesis; however, their involvement in ovarian cancer is unclear. In this study, we performed expression profiling of miRNAs from exosomes released by five cell lines representing different histological types of ovarian cancer. Exosomes isolated from culture media of cancer and normal cells were compared for miRNA composition using human miRNA microarray. We detected 143 exosomal miRNAs, whose expression was ≥1.5-fold higher in ovarian cancer cells than in the control. Among them, 28 miRNAs were upregulated in cells of all histological ovarian cancer types compared to control, and three were upregulated in CCCO cells compared to other types. Functional analyses indicated that miR-21 overexpressed in CCCO cells targeted tumor suppressor genes PTEN, TPM1, PDCD4, and MASP1. The identified miRNAs could represent novel candidate biomarkers to diagnose or monitor progression of ovarian cancer, particularly CCCO.

Retinol dehydrogenase 10 contributes to cancer stemness and intracellular carbohydrate storage in ovarian clear cell carcinomas

BACKGROUND

Ovarian clear cell carcinomas (OCCCs) have been recurrent and refractory among the present treatments, so novel therapeutics are urgently needed.

OBJECTIVE

The present study accumulates the proof of concept to examine the feasibility of RDH10 as a therapeutic target for treating OCCCs.

METHODS

Immunohistochemically, RDH10 expression was evaluated in 111 primary epithelial ovarian cancers, including 55 OCCCs, 31 ovarian endometrioid carcinomas and 25 ovarian serous carcinomas. The spherogenecity provoked by RDH10 was evaluated in OCCC cells. To analyze whether RDH10 promotes carbohydrate storage via the vitamin A-gluconeogenesis pathway, phosphoenolpyruvate carboxykinase 1 (PCK1) protein levels and intracellular carbohydrate content were measured in response to modified RDH10 expression.

RESULTS

Abundant RDH10 was expressed specifically in OCCCs. RDH10 promoted spherogenecity and intracellular carbohydrate storage via modulation of PCK1 expression in OCCC cells.

CONCLUSIONS

In the present study, abundant RDH10 contributed to cancer cell stemness and intracellular carbohydrate storage in OCCCs. RDH10 is a potentially, new therapeutic candidate for treating OCCC cases.

Treatment of ovarian clear cell carcinoma with immune checkpoint blockade: a case series

BACKGROUND

Although immune checkpoint blockade has demonstrated limited effectiveness against ovarian cancer, subset analyses from completed trials suggest possible superior efficacy in the clear cell carcinoma subtype.

OBJECTIVE

To describe the outcomes of patients with ovarian clear cell carcinoma treated with immune checkpoint blockade.

METHODS

This was a single-institution, retrospective case series of patients with ovarian clear cell carcinoma treated with a programmed cell death protein 1 (PD-1) or programmed death-ligand 1 (PD-L1) inhibitor with or without concomitant cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) inhibition between January 2016 and June 2021. Demographic variables, tumor microenvironment, molecular data, and clinical outcomes were examined. Time to treatment failure was defined as the number of days between start of treatment and next line of treatment or death.

RESULTS

A total of 16 eligible patients were analyzed. The median treatment duration was 56 days (range 14-574); median time to treatment failure was 99 days (range 27-1568). The reason for discontinuation was disease progression in 88% of cases. Four patients (25%) experienced durable clinical benefit (time to treatment failure ≥180 days). One patient was treated twice with combined immune checkpoint blockade and experienced a complete response each time. All 12 patients who underwent clinical tumor-normal molecular profiling had microsatellite-stable disease, and all but one had low tumor mutation burden. Multiplex immunofluorescence analysis available from pre-treatment biopsies of two patients with clinical benefit demonstrated abundant tumor-infiltrating lymphocytes expressing PD-1.

CONCLUSION

Our study suggests a potential role for immune checkpoint blockade in patients with clear cell carcinoma of the ovary. Identification of genetic and microenvironmental biomarkers predictive of response will be key to guide therapy.

Friend or foe? The prognostic role of endometriosis in women with clear cell ovarian carcinoma. A UK population-based cohort study

PURPOSE

The prognostic role of endometriosis amongst women with ovarian clear cell carcinoma (OCCC) remains debatable. The aim of this study was to ascertain the effect of endometriosis on the prognosis of OCCC.

METHODS

A retrospective review of the medical records of 94 women diagnosed and treated for OCCC at a tertiary gynaecological cancer centre in the UK, spanning the period 2010-2019. Women were divided into two groups according to the presence of endometriosis. Clinico-pathological characteristics, progression-free survival (PFS) and overall survival (OS) were collated between the two groups.

RESULTS

Forty-six cases of endometriosis-free OCCC (Ef-OCCC) were collated with 48 cases of endometriosis-related OCCC (Er-OCCC). There was no significant difference between the two groups regarding age (p-value = 0.2), FIGO stage (p-value = 0.8), residual disease (RD) (p-value = 0.07), adjuvant chemotherapy agent (p-value = 0.4) or chemo-resistance (p-value = 0.9). The presence of endometriosis did not significantly affect either OS or PFS. The median OS in the Ef-OCCC and Er-OCCC was 55.00 (95% CI 32.00-189.00) and 71.00 (95% CI 47.00-97.00; log rank = 1.35, p-value = 0.2) months. The median PFS in the Ef-OCCC and Er-OCCC group was 39.00 (95% CI 19.00-143.00) and 39.00 (95% CI 19.00-62.00; log rank = 0.7, p-value = 0.4) months. Survival differences between the two groups were not significant after stratification analysis for independent prognosticators.

CONCLUSION

Endometriosis was not independently associated with the prognosis of OCCC either in crude analysis or after stratification for stage and RD. Further larger, well-designed prospective studies are warranted to draw firmer conclusions on the intrinsic link between endometriosis and OCCC.

Remarkable Response to the Triplet Combination of Olaparib with Pembrolizumab and Bevacizumab in the Third-Line Treatment of an Ovarian Clear Cell Carcinoma Patient with an ARID1A Mutation: A Case Report

Ovarian clear cell carcinoma (OCCC) is a highly aggressive malignancy with a poor prognosis, and most patients experience recurrence after primary treatment. Currently, there is no standard treatment option for recurrent OCCC. Herein, we report the case of a 32-year-old female patient with OCCC. The patient received primary cytoreductive surgery with adjuvant chemotherapy and remained disease-free for four months. She then experienced retroperitoneal lymph node recurrence and was treated with liposomal doxorubicin chemotherapy followed by secondary debulking surgery. The patient experienced a second relapse in the lower left lung 11 months later. Genomic profiling of tumor samples revealed a deleterious AT-rich interactive domain 1A (ARID1A) mutation and homologous recombination deficiency. Thus, the triplet combination of the poly (ADP-ribose) polymerase (PARP) inhibitor, olaparib; the PD-1 inhibitor, pembrolizumab; and the antiangiogenic agent, bevacizumab was administered. The patient achieved partial response, which was sustained for 12 months. Our study provides the first clinical evidence that the combination of olaparib with pembrolizumab and bevacizumab could be an effective treatment for patients with platinum-resistant, recurrent OCCC.

Prognostic and Theranostic Biomarkers in Ovarian Clear Cell Carcinoma

In this study, we aimed to test whether prognostic biomarkers can achieve a clinically relevant stratification of patients with stage I ovarian clear cell carcinoma (OCCC) and to survey the expression of 10 selected actionable targets (theranostic biomarkers) in stage II to IV cases. From the population-based Alberta Ovarian Tumor Type study, 160 samples of OCCC were evaluated by immunohistochemistry and/or silver-enhanced in situ hybridization for the status of 5 prognostic (p53, p16, IGF2BP3, CCNE1, FOLR1) and 10 theranostic biomarkers (ALK, BRAF V600E, ERBB2, ER, MET, MMR, PR, ROS1, NTRK1-3, VEGFR2). Kaplan-Meier survival analyses were performed. Cases with abnormal p53 or combined p16/IFG2BP3 abnormal expression identified a small subset of patients (6/54 cases) with stage I OCCC with an aggressive course (5-yr ovarian cancer-specific survival of 33.3%, compared with 91.5% in the other stage I cases). Among theranostic targets, ERBB2 amplification was present in 11/158 (7%) of OCCC, while MET was ubiquitously expressed in OCCC similar to a variety of normal control tissues. ER/PR showed a low prevalence of expression. No abnormal expression was detected for any of the other targets. We propose a combination of 3 biomarkers (p53, p16, IGF2BP3) to predict prognosis and the potential need for adjuvant therapy for patients with stage I OCCC. This finding requires replication in larger cohorts. In addition, OCCC could be tested for ERBB2 amplification for inclusion in gynecological basket trials targeting this alteration.

Fibrinogen/albumin ratio as a promising predictor of platinum response and survival in ovarian clear cell carcinoma

Background

This study aims to evaluate the role of the fibrinogen/albumin ratio (FAR) in predicting platinum resistance and survival outcomes of patients with ovarian clear cell carcinoma (OCCC).

Methods

Coagulation function and D-dimer, serum albumin, CA125 and HE4 levels were measured before surgery in OCCC patients undergoing initial surgery in our institution. FAR was calculated as fibrinogen/albumin level. The correlation between these indicators and clinicopathological features, platinum response, and survival outcomes was further analyzed. The Kaplan-Meier method and multivariable Cox regression model were used to assess the effects of FAR on progression-free survival (PFS) and overall survival (OS).

Results

Advanced stage patients accounted for 42.1% of the 114 participants. Optimal cytoreductive surgery was achieved in 105 patients, and the complete resection rate was 78.1%. FAR was associated with tumor stage, residual tumor and platinum response. A receiver operating characteristic curve for predicting platinum response showed that the optimal cutoff point of the FAR was 12%. The sensitivity was 73.3% and the specificity was 68.2%. In multivariate analysis, FAR ≥12% (HR = 4.963, P = 0.002) was an independent risk factor for platinum resistance. In addition, FAR and D-dimer proved to be independent negative factors for outcomes including both PFS and OS. The median follow-up time was 52 months. A high FAR (≥ 12%) showed a stronger correlation with poor OS and PFS in the subgroup analysis of advanced and completely resected patients.

Conclusions

The FAR might be a potential preoperative biochemical marker for predicting treatment response and oncological outcomes in OCCC patients.

Endometriosis-associated Ovarian Clear Cell Carcinoma: A Special Entity?

Endometriosis is an estrogen-dependent disease, which serves as a precursor of ovarian cancer, especially clear cell carcinoma (OCCC) and endometrial carcinoma. Although micro-environmental factors such as oxidative stress, immune cell dysfunction, inflammation, steroid hormones, and stem cells required for malignant transformation have been found in endometriosis, the exact carcinogenic mechanism remains unclear. Recent research suggest that many putative driver genes and aberrant pathways including ARID1A mutations, PIK3CA mutations, MET activation, HNF-1β activation, and miRNAs dysfunction, play crucial roles in the malignant transformation of endometriosis to OCCC. The clinical features of OCCC are different from other histological types. Patients usually present with a large, unilateral pelvic mass, and occasionally have thromboembolic vascular complications. OCCC patients are easier to be resistant to chemotherapy, have a worse prognosis, and are usually difficult to treat. To improve the survival of OCCC patients, it is necessary to better understand its specific carcinogenic mechanism and explore new treatment strategy, including molecular target.

Distinct transcriptional programs stratify ovarian cancer cell lines into the five major histological subtypes

BACKGROUND

Epithelial ovarian cancer (OC) is a heterogenous disease consisting of five major histologically distinct subtypes: high-grade serous (HGSOC), low-grade serous (LGSOC), endometrioid (ENOC), clear cell (CCOC) and mucinous (MOC). Although HGSOC is the most prevalent subtype, representing 70-80% of cases, a 2013 landmark study by Domcke et al. found that the most frequently used OC cell lines are not molecularly representative of this subtype. This raises the question, if not HGSOC, from which subtype do these cell lines derive? Indeed, non-HGSOC subtypes often respond poorly to chemotherapy; therefore, representative models are imperative for developing new targeted therapeutics.

METHODS

Non-negative matrix factorisation (NMF) was applied to transcriptomic data from 44 OC cell lines in the Cancer Cell Line Encyclopedia, assessing the quality of clustering into 2-10 groups. Epithelial OC subtypes were assigned to cell lines optimally clustered into five transcriptionally distinct classes, confirmed by integration with subtype-specific mutations. A transcriptional subtype classifier was then developed by trialling three machine learning algorithms using subtype-specific metagenes defined by NMF. The ability of classifiers to predict subtype was tested using RNA sequencing of a living biobank of patient-derived OC models.

RESULTS

Application of NMF optimally clustered the 44 cell lines into five transcriptionally distinct groups. Close inspection of orthogonal datasets revealed this five-cluster delineation corresponds to the five major OC subtypes. This NMF-based classification validates the Domcke et al. analysis, in identifying lines most representative of HGSOC, and additionally identifies models representing the four other subtypes. However, NMF of the cell lines into two clusters did not align with the dualistic model of OC and suggests this classification is an oversimplification. Subtype designation of patient-derived models by a random forest transcriptional classifier aligned with prior diagnosis in 76% of unambiguous cases. In cases where there was disagreement, this often indicated potential alternative diagnosis, supported by a review of histological, molecular and clinical features.

CONCLUSIONS

This robust classification informs the selection of the most appropriate models for all five histotypes. Following further refinement on larger training cohorts, the transcriptional classification may represent a useful tool to support the classification of new model systems of OC subtypes.

LncRNA GAS5 inhibits the proliferation and invasion of ovarian clear cell carcinoma via the miR-31-5p/ARID1A axis

To investigate the role of the lncRNA growth arrest special 5 (GAS5) in ovarian clear cell carcinoma (OCCC), we measured the expression of GAS5 and miR-31-5p in OCCC tissue samples and OCCC cell lines using RT-qPCR. MTT and colony formation assays were used to measure cell viability and colony formation ability. Cell invasion was determined by Transwell assays. The binding between GAS5 and miR-31-5p as well as miR-31-5p and ARID1A was determined by dual-luciferase reporter assays. The ARID1A protein levels were detected using western blotting. Kaplan-Meier curves were used for the analysis of the 5-year survival rate of patients with OCCC. GAS5 and ARID1A levels were significantly decreased, while miR-31-5p levels were strongly elevated in the OCCC tissues and cell lines. Patients with lower GAS5/ARID1A levels had shorter overall survival times. Overexpression of GAS5 or inhibition of miR-31-5p suppressed cell viability and invasion of OCCC cells and upregulated the protein levels of ARID1A. Moreover, overexpression of miR-31-5p reversed the effects of overexpression of GAS5. Cotransfection with pcDNA3.1-GAS5 and miR-31-5p inhibitor led to the lowest cell viability and cell invasion rates. A dual-luciferase reporter assay was performed to confirm the target relationship between GAS5 and miR-31-5p, as well as between miR-31-5p and ARID1A. LncRNA GAS5 inhibited cell viability and invasion of OCCC through activation of ARID1A by sponging miR-31-5p.

A CLEARER VIEW ON OVARIAN CLEAR CELL CARCINOMA

Introduction: Ovarian clear cell carcinoma (OCCC) is a less common subtype accounting for approximately 5% of all epithelial ovarian cancers (EOCs). Clinical experience and research findings confirm the remarkable differences in clinical behavior, molecular alterations and pathogenesis of OCCC. The diagnosis of OCCC is typically set at a younger age, and earlier stage and in a background of endometriosis.Results: Molecularly, OCCCs rarely harbor BRCA1/BRCA2 mutations and have fewer copy number variants (CNVs). The most common molecular changes occur in the SWI/SNF chromatin remodeling complex genes, the PI3K/AKT signaling pathway and the receptor tyrosine kinase (RTK)/Ras signaling pathway.Five-year disease-specific survival of patients with OCCC is worse compared to high grade serous carcinomas (HGSOC). The current treatment options for OCCC are based on studies that included patients with predominantly HGSOC and only a minor proportion of cancers with clear cell histology. In order to improve outcomes for patients with OCCC, research should be specific for this subtype.Discussion: As the available information about the specific characteristics of OCCC is increasing, especially at a molecular level, it should be possible to continuously improve the specific diagnostics and treatment. Since OCCC is so rare, it is essential to collect new evidence at an international level. To avoid extrapolation from EOC trials with possible erroneous conclusions, patients should always be encouraged to participate in specific histological trials and basket trials, while paying extra attention to OCCC-like subtypes.

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.

Endometriosis-associated cancer

Endometriosis will affect about 10% of the female population and not only can it significantly impact adversely on quality of life and result in infertility, but data are accumulating that malignant transformation is an important consideration. Endometriosis can be histologically typical or atypical, ovarian, superficial peritoneal or deep infiltrating. The precursor for malignant transformation appears to be the ovarian atypical endometriosis component. Ovarian cancer is the most important associated cancer, primarily endometrioid and clear cell cancer. These are the only subtypes wherein a direct clonal relationship between endometriosis, as a direct precursor, and cancer has been made. There is no substantive evidence to support an altered association of borderline cancers of the ovary, serous ovarian cancers and breast, endometrial or cervical cancers. This review provides an overview of the prevailing data pertaining to the molecular and genetic aberrations that accompany the transformation of atypical endometriosis to malignancy and the accumulated epidemiologic evidence which supports the association.

Treatment Strategies for ARID1A-Deficient Ovarian Clear Cell Carcinoma

Ovarian clear cell carcinoma (OCCC) is a histological subtype of ovarian cancer that is more frequent in Asian countries (~25% of ovarian cancers) than in US/European countries (less than 10%). OCCC is refractory to conventional platinum-based chemotherapy, which is effective against high-grade serous carcinoma (HGSC), a major histological subtype of ovarian cancer. Notably, deleterious mutations in SWI/SNF chromatin remodeling genes, such as ARID1A, are common in OCCC but rare in HGSC. Because this complex regulates multiple cellular processes, including transcription and DNA repair, molecularly targeted therapies that exploit the consequences of SWI/SNF deficiency may have clinical efficacy against OCCC. Three such strategies have been proposed to date: prioritizing a gemcitabine-based chemotherapeutic regimen, synthetic lethal therapy targeting vulnerabilities conferred by SWI/SNF deficiency, and immune checkpoint blockade therapy that exploits the high mutational burden of ARID1A-deficient tumor. Thus, ARID1A deficiency has potential as a biomarker for precision medicine of ovarian cancer.

Oral recombinant methioninase combined with paclitaxel arrests recalcitrant ovarian clear cell carcinoma growth in a patient-derived orthotopic xenograft (PDOX) nude-mouse model

PURPOSE

Advanced ovarian clear cell carcinoma (OCCC) is a recalcitrant disease, often resistant to the first-line platinum-based therapy. Using a novel patient-derived orthotopic xenograft (PDOX) nude-mouse model of OCCC, we tested whether oral-recombinant methioninase (o-rMETase) could enhance the efficacy of paclitaxel (PTX).

METHODS

The OCCC PDOX model was established and passaged in nude mice. The OCCC PDOX models were randomized into 5 groups. G1: untreated control; G2: paclitaxel (PTX) (20 mg/kg, intraperitoneal (i.p.) injection, weekly); G3: o-rMETase (100 units, oral, daily); G4: PTX (20 mg/kg, i.p. injection, weekly) + carboplatinum (CBDCA) (40 mg/kg, i.p. injection weekly); G5: PTX (20 mg/kg, i.p. injection, weekly) + o-rMETase (100 units, oral, daily). The treatment period was 2 weeks.

RESULTS

The combination of PTX and o-rMETase arrested OCCC tumor growth (relative tumor volume: 1.09 ± 0.63 (mean ± SD)) compared with the untreated control (relative tumor volume: 3.92 ± 1.04 (mean ± SD)) (p < 0.0001). There was no significant difference in relative tumor volume between PTX plus o-rMETase and PTX plus CBDCA (relative tumor volume: 1.39 ± 0.37 (mean ± SD)) (p = 0.93).

CONCLUSION

PTX plus o-rMETase arrested the OCCC tumor growth. o-rMETase is readily administered and can greatly enhance first-line therapy of a recalcitrant cancer. The novel and effective treatment strategy in the present report has future clinical potential for patients with OCCC, especially for patients who cannot well tolerate platinum-based therapy.

Diffuse Intratumoral Stromal Inflammation in Ovarian Clear Cell Carcinoma is Associated With Loss of Mismatch Repair Protein and High PD-L1 Expression

Ovarian clear cell carcinoma (OCCC) is an aggressive chemotherapy-resistant cancer with limited treatment options, and some OCCCs have mismatch repair (MMR) deficiency (MMRD). Emerging evidence has revealed that various cancers with MMRD are susceptible to anti-programmed death-1/programmed death ligand-1 (anti-PD-1/PD-L1) immunotherapy, and certain histologic features are associated with MMRD. However, few studies have addressed this in OCCC. We reviewed 76 OCCCs for tumor-associated inflammation (intratumoral stromal inflammation and peritumoral lymphocytes) and performed immunohistochemistry for 4 MMR proteins and PD-L1. MMR-deficient OCCCs were analyzed for microsatellite instability (MSI), and those with MLH1 loss were tested for MLH1 promoter methylation. No patients fulfilled the Amsterdam II criteria for the diagnosis of Lynch syndrome. Four (5.3%) tumors showed diffuse intratumoral stromal inflammation obliterating the tumor-stroma interfaces, and none had peritumoral lymphoid aggregates. MMRD was found in 2 (2.6%) tumors; one had MLH1/PMS2 loss (MSI-high and MLH1 promoter methylation was detected) and the other had MSH2/MSH6 loss (MSI-low). Twenty (26.3%) tumors showed tumoral PD-L1 expression ≥1%. Both MMR-deficient tumors showed diffuse intratumoral stromal inflammation and tumoral PD-L1 expression ≥50%. Three of the 4 (75%) tumors with diffuse intratumoral stromal inflammation also showed tumoral PD-L1 expression ≥50%. None of the tumors without diffuse intratumoral stromal inflammation showed MMRD (P=0.021) or tumoral PD-L1 expression ≥50% (P=0.0001). We identified a strong correlation among diffuse intratumoral stromal inflammation, MMRD, and high tumoral PD-L1 expression in a small but significant subset of OCCCs. Histologic evaluation can facilitate patient selection for subsequent anti-PD-1/PD-L1 immunotherapy.

Targeting BET Proteins BRD2 and BRD3 in Combination with PI3K-AKT Inhibition as a Therapeutic Strategy for Ovarian Clear Cell Carcinoma

Ovarian clear cell carcinoma (OCCC) is a rare, chemo-resistant subtype of ovarian cancer. To identify novel therapeutic targets and combination therapies for OCCC, we subjected a set of patient-derived ovarian cancer cell lines to arrayed high-throughput siRNA and drug screening. The results indicated OCCC cells are vulnerable to knockdown of epigenetic gene targets such as bromodomain and extra-terminal domain (BET) proteins BRD2 and BRD3. Subsequent RNA interference assays, as well as BET inhibitor treatments, validated these BET proteins as potential therapeutic targets. Because development of resistance to single targeted agents is common, we next performed sensitizer drug screens to identify potential combination therapies with the BET inhibitor CPI0610. Several PI3K or AKT inhibitors were among the top drug combinations identified and subsequent work showed CPI0610 synergized with alpelisib or MK2206 by inducing p53-independent apoptosis. We further verified synergy between CPI0610 and PI3K-AKT pathway inhibitors alpelisib, MK2206, or ipatasertib in tumor organoids obtained directly from patients with OCCC. These findings indicate further preclinical evaluation of BET inhibitors, alone or in combination with PI3K-AKT inhibitors for OCCC, is warranted.

Tissue factor pathway inhibitor‑2 is specifically expressed in ovarian clear cell carcinoma tissues in the nucleus, cytoplasm and extracellular matrix

Tissue factor pathway inhibitor-2 (TFPI-2) is a promising candidate as a serum biomarker of ovarian clear cell carcinoma (OCCC), a lethal histological subtype of epithelial ovarian cancer (EOC). TFPI-2 is a secreted serine protease inhibitor that suppresses cancer progression through the inhibition of matrix protease activities. Previous studies have also identified TFPI-2 in the nucleus, and a possible function of nuclear TFPI-2 as a transcriptional repressor of matrix metalloproteinase-2 (MMP-2) was recently demonstrated. We are currently establishing TFPI-2 as a serum biomarker for OCCC patients; however, TFPI-2 expression in OCCC tissues has not been previously investigated. In the present study, we examined TFPI-2 expression and its localization in 11 OCCC cell lines by western blotting and enzyme-linked immune assay. Four cell lines expressed TFPI-2 in the nucleus, cytoplasm and culture plate–attached extracellular fraction, while four other cell lines expressed TFPI-2 only in the extracellular fraction. In the remaining three cell lines, TFPI-2 was not identified in any fraction. The amount of secreted soluble TFPI-2 showed similar trends to that of the plate-attached fraction. We next investigated the expression levels and distribution of TFPI-2 in surgically resected EOC tissues by immunohistochemistry. In 52 of the 77 (67.5%) OCCC tumors, TFPI-2 expression was detected in at least one of the nuclear, cytoplasmic and extracellular matrix fractions. In contrast, we did not identify TFPI-2 in the other EOC subtypes (n=65). TFPI-2-positive expression distinguished CCC from the other EOC tissues with a sensitivity of 67.5% and specificity of 100%. Although the inherent tumor suppressor function, statistical analyses failed to demonstrate correlations between TFPI-2 expression and clinical parameters, including 5-year overall survival, except for the patient age. In conclusion, we identified TFPI-2 expression in the nucleus, cytoplasm and extracellular matrix in OCCC tissues. The high specificity of TFPI-2 may support its use for diagnosis of OCCC in combination with existing markers.

Expression of the chrXq27.3 miRNA cluster in recurrent ovarian clear cell carcinoma and its impact on cisplatin resistance

Ovarian clear cell carcinoma (OCCC) is a histological subtype of epithelial ovarian cancer and exhibits dismal prognosis due to chemoresistance. Moreover, only few effective therapeutic options exist for patients with recurrent OCCC, and an understanding of its molecular characteristics is essential for the development of novel therapeutic approaches. In the present study, we investigated unique MicroRNAs (miRNA) profiles in recurrent/metastatic OCCC and the role of miRNAs in cisplatin resistance. Comprehensive miRNA sequencing revealed that expression of several miRNAs, including miR-508-3p, miR-509-3p, miR-509-3-5p, and miR-514a-3p was remarkably less in recurrent cancer tissues when compared with that in paired primary cancer tissues. These miRNAs are located in the chrXq27.3 region on the genome. Moreover, its expression was negative in omental metastases in two patients with advanced OCCC. In vitro analyses revealed that overexpression of miR-509-3p and miR-509-3-5p reversed cisplatin resistance and yes-associated protein 1 (YAP1) was partially responsible for the resistance. Immunohistochemistry revealed that YAP1 expression was inversely correlated with the chrXq27.3 miRNA cluster expression. In conclusion, these findings suggest that alteration of the chrXq27.3 miRNA cluster could play a critical role in chemoresistance and miRNAs in the cluster and their target genes can be potential therapeutic targets.

Over-expression of RALYL suppresses the progression of ovarian clear cell carcinoma through inhibiting MAPK and CDH1 signaling pathways

Background: The molecular mechanism in the progression of ovarian clear cell carcinoma (OCCC) remains unclear. Objective: This study aimed to investigate the potential function of RAYLY in OCCC. Methods: To validate RAYLY expression, immunohistochemistry, quantitative real-time PCR and western blotting were performed in OCCC tissues and the cell lines of OCCC and epithelial ovarian carcinoma (EOC). Subsequently, the biological effects of RALYL were evaluated through colony formation, and cell proliferation, migration and invasion assays. Finally, RNA-sequencing and gene set enrichment analysis (GSEA) were conducted to explore potential mechanism of RALYL in OCCC. Results: In our study, RALYL was significantly down-regulated in a majority of OCCC tissues compared to adjacent non-tumorous tissues, and OCCC cells had a lower expression level of RALYL than that of EOC cells. OCCC patients with high RALYL expression had a better pathological stage and prognosis. In vitro, over-expression of RALYL inhibited cell proliferation, migration and invasion in OCCC. GSEA analysis and western blot indicated an enrichment of MAPK and CDH1 signaling pathways in OCCC cells without RALYL over-expression. Conclusions: RALYL played an important role in the progression of OCCC, and might serve as a potential prognostic biomarker and novel therapeutic target for OCCC.

Risk of second malignancy in patients with ovarian clear cell carcinoma

OBJECTIVE

Ovarian clear cell carcinoma has unique clinical and molecular features compared with other epithelial ovarian cancer histologies. Our objective was to describe the incidence of second primary malignancy in patients with ovarian clear cell carcinoma.

METHODS

Retrospective cohort study of patients with ovarian clear cell carcinoma at two tertiary academic centers in Toronto, Canada between May 1995 and June 2017. Demographic, histopathologic, treatment, and survival details were obtained from chart review and a provincial cancer registry. We excluded patients with histologies other than pure ovarian clear cell carcinoma (such as mixed clear cell histology), and those who did not have their post-operative follow-up at these institutions.

RESULTS

Of 209 patients with ovarian clear cell carcinoma, 54 patients developed a second primary malignancy (25.8%), of whom six developed two second primary malignancies. Second primary malignancies included: breast (13), skin (9), gastrointestinal tract (9), other gynecologic malignancies (8), thyroid (6), lymphoma (3), head and neck (4), urologic (4), and lung (4). Eighteen second primary malignancies occurred before the index ovarian clear cell carcinoma, 35 after ovarian clear cell carcinoma, and 7 were diagnosed concurrently. Two patients with second primary malignancies were diagnosed with Lynch syndrome. Smoking and radiation therapy were associated with an increased risk of second primary malignancy on multivariable analysis (OR 3.69, 95% CI 1.54 to 9.07, p=0.004; OR 4.39, 95% CI 1.88 to 10.6, p=0.0008, respectively). However, for patients developing second primary malignancies after ovarian clear cell carcinoma, radiation therapy was not found to be a significant risk factor (p=0.17). There was no significant difference in progression-free survival (p=0.85) or overall survival (p=0.38) between those with second primary malignancy and those without.

CONCLUSION

Patients with ovarian clear cell carcinoma are at increased risk of second primary malignancies, most frequently non-Lynch related. A subset of patients with ovarian clear cell carcinoma may harbor mutations rendering them susceptible to second primary malignancies. Our results may have implications for counseling and consideration for second primary malignancy screening.

Endometriosis-associated ovarian carcinomas: insights into pathogenesis, diagnostics, and therapeutic targets-a narrative review

Endometriosis is a benign gynecologic condition affecting up to one woman out of ten of reproductive age. It is defined by the presence of endometrial-like tissue in localizations outside of the uterine cavity. It often causes symptoms such as chronic pain, most frequently associated with the menstrual cycle, and infertility, but may also be oligo- or asymptomatic. There is evidence that some ovarian carcinoma (OC) histotypes, mainly the ovarian clear cell (OCCC) and endometrioid (EnOC) carcinoma, may arise from endometriosis. The most frequent genomic alterations in these carcinomas are mutations in the AT-rich interacting domain containing protein 1A (ARID1A) gene, a subunit of the SWI/SNF chromatin remodeling complex, and alterations in the phosphatidylinositol 3-kinase (PI3K)/AKT/mTOR pathway, which frequently co-occur. In ARID1A deficient cancers preclinical experimental data suggest different targetable mechanisms including epigenetic regulation, cell cycle, genomic instability, the PI3K/AKT/mTOR pathway, inflammatory pathways, immune modulation, or metabolic alterations as potential precision oncology approaches. Most of these strategies are relying on the concept of synthetic lethality in which tumors deficient in ARID1A are more sensitive to the different compounds. Some of these approaches are currently being or have recently been investigated in early clinical trials. The remarkably frequent occurrence of these mutations in endometriosis-associated ovarian cancer, the occurrence in a relatively young population, and the high proportion of platinum-resistant disease certainly warrants further investigation of precision oncology opportunities in this population. Furthermore, advanced knowledge about oncogenic mutations involved in endometriosis-associated ovarian carcinomas may be potentially useful for early cancer detection. However, this approach may be complicated by the frequent occurrence of somatic mutations in benign endometriotic tissue as recent studies suggest. In this narrative review of the current literature, we will discuss the data available on endometriosis-associated ovarian carcinoma, with special emphasis on epidemiology, diagnosis and molecular changes that could have therapeutic implications and clinical applicability in the future.

Is There a Survival Benefit for Patients with Advanced Ovarian Clear Cell Carcinoma Who Complete More Than 6 Cycles of Postoperative Chemotherapy?

Purpose

To provide a reference for clinicians, whether patients with advanced ovarian clear cell carcinoma (OCCC) require chemotherapy (CT) for more than 6 cycles after tumor debulking.

Patients and Methods

A retrospective review was performed on 85 women diagnosed and treated for advanced OCCC. Outcomes of patients who underwent >6 vs ≤6 cycles of CT were analyzed based on clinicopathological factors.

Results

Among the 85 patients with advanced OCCC, 47 patients underwent ≤6 cycles of CT, and 38 patients underwent CT for over 6 cycles. Out of these, 49 patients had disease recurrence, and 35 died. The 2-year progression-free survival (PFS) for patients in the two groups was 51.5% and 42.2% (P＞0.05), respectively. The 2-year overall survival (OS) was 59.7% and 64.5%, respectively (P＞0.05), and the difference was not statistically significant. Multivariate analysis showed that residual tumor diameter was an independent risk factor for prognosis (PFS and OS). We divided the patients into three groups according to residual tumor diameter as 0 (R0), ≤1cm (R1), and >1cm (R2). The prognosis of R0 was better than R1 and R2. Further studies found that patients who received postoperative adjuvant chemotherapy for over 6 cycles showed no difference in improved prognosis, regardless of residual tumor diameter.

Conclusion

Patients with advanced OCCC who received more than 6 courses of adjuvant chemotherapy after surgery did not show improved prognosis. The residual tumor diameter is an independent indicator of prognosis in patients with advanced OCCC. Complete staging improves the prognosis of patients compared to the ideal or non-ideal cytoreductive surgery.

Early-stage clear cell ovarian cancer compared to high-grade histological subtypes: An outcome exploratory analysis in two oncology centers

OBJECTIVE

advanced stage clear cell ovarian cancer (CCOC) carries a higher risk of relapse and death compared to other histological subtypes. The prognosis of early-stage CCOC is controversial.

METHODS

Early-stage high-grade OC patients from two Italian oncologic centers were included. Patients with early-stage CCOC were compared with those with high-grade endometrioid (HGE) and serous (HGS) OC in terms of relapse-free interval (RFI), cancer-specific survival (CSS) and post relapse cancer-specific survival (prCSS). The Cox proportional hazard model and the restricted mean survival time were used.

RESULTS

Between 1981 and 2012, 134 patients with CC, 152 with HGE and 160 with HGS were treated at two referral centers. Median follow-up was 11.5 years. Ten years RFI rates were 80.6%, 72.1%, 60.6%, and CSS rates were 84.3%, 82.6%, 81.7% respectively. Adjuvant chemotherapy significantly improved RFI (aHR 0.61, 95%CI 0.40 to 0.91, P = 0.015). In the multivariable analysis HGS histotype was associated with a shorter RFI compared to CC, (Hazard Ratio [HR]: 1.81; 95%CI: 1.12-2.93; P = 0.016), whereas CSS was not statistically different. prCSS was longer in HGS compared to CCOC (HR, 0.36; 95% CI, 0.17-0.74; P = 0.006). According to the stage, IA/IB/IC1 HGSOC had a shorter RFI (HR, 2.13; 95% CI, 1.14-3.99; P = 0.018) compared to IA/IB/IC1 CCOC, but similar CSS. For prCSS, CC compared to HGS conferred a worse prognosis regardless of the initial stage.

CONCLUSIONS

Early-stage CCOC is associated with a longer RFI, similar CSS and a shorter prCSS compared to HGSOC. No prognostic differences were observed between CC and HGE OC. The relapse risk was the lowest in IA/IB/IC1 CC compared to HGS, whereas CC displayed poor sensitivity to chemotherapy after relapse.

Simvastatin is a potential candidate drug in ovarian clear cell carcinomas

Ovarian clear cell carcinomas (OCCC) constitute a rare subtype of epithelial ovarian cancer, lacking efficient treatment options. Based on previous studies, we assessed the anti-proliferative effect of simvastatin, a Rho GTPase interfering drug, in three OCCC cell lines: JHOC-5, OVMANA and TOV-21G, and one high-grade serous ovarian cancer (HGSOC) cell line, Caov3. We used the Rho GTPase interfering drug CID-1067700 as a control. All OCCC cell lines were more sensitive to single-agent simvastatin than the HGSOC cells, while all cell lines were less sensitive to CID-1067700 than to simvastatin. Combinations of carboplatin and simvastatin were generally antagonistic. Most treatments inhibited migration, while only simvastatin and CID-1067700 also disrupted actin organization in the OCCC cell lines. All treatments induced a G1 arrest in JHOC-5 and TOV-21G cells. Treatments with simvastatin consistently reduced c-Myc protein expression in all OCCC cell lines and displayed evidence of causing both caspase-mediated apoptotic cell death and autophagic response in a cell line dependent manner. Differences between cell lines in response to the treatments were observed and such differences, including e. g. prior treatment, should be investigated further. Conclusively, simvastatin efficiently controlled OCCC proliferation and migration, thus showing potential as a candidate drug for the treatment of OCCC.

Adjuvant Treatment of Early Ovarian Clear Cell Carcinoma: A Population-Based Study of Whole Abdominal Versus Pelvic Nodal Radiotherapy

BACKGROUND

Adjuvant treatment in early ovarian clear cell carcinoma (OCCC) is not yet standardized. The objective of this population-based study was to compare the outcome of patients with early OCCC treated with adjuvant chemotherapy versus chemoradiotherapy (chemoRT) and evaluate the association of adjuvant radiotherapy regimens (whole abdominal radiotherapy [WART] versus pelvic nodal radiotherapy [PRT]) with outcome.

PATIENTS AND METHODS

Chart review was conducted to identify patients with stage I and II OCCC with complete information on staging. Patients with stage IA, IB, or IC OCCC purely resulting from capsular rupture were excluded because the provincial protocol does not recommend adjuvant treatment.

RESULTS

Overall, 403 patients were identified and 343 received adjuvant treatment, of whom 255 had stage IC or II OCCC and 153 were eligible for final analysis. On Cox multivariable regression, receipt of chemoRT (n=90) was associated with an improvement in failure-free survival (FFS) (hazard ratio [HR], 0.57; 95% CI, 0.34-0.94) compared with chemotherapy alone (n=63). Use of chemoRT also resulted in 54% reduction in the cumulative incidence of cancer-specific mortality (subdistribution HR, 0.46; 95% CI, 0.24-0.89). However, there was no significant difference in the HR for overall survival (OS) between the chemoRT (HR, 0.70; 95% CI, 0.43-1.13) and chemotherapy group. Relative to chemotherapy + WART (chemo-WART), chemotherapy + PRT (chemo-PRT) was not associated with any significant difference in HR for FFS (HR, 1.34; 95% CI, 0.40-4.44) or OS (HR, 1.13; 95% CI, 0.37-3.46).

CONCLUSIONS

Adjuvant chemoRT was associated with a lower risk of failure compared with chemotherapy alone. However, there was no difference in OS between the adjuvant chemotherapy and chemoRT regimens. Additionally, no significant difference in terms of FFS or OS was found between the chemo-WART and chemo-PRT groups.

Serum D-dimer, albumin and systemic inflammatory response markers in ovarian clear cell carcinoma and their prognostic implications

Background

This study attempts to evaluate whether preoperative systemic inflammatory response (SIR) markers or other hematological variables, such as albumin, D-dimer, and carbohydrate antigen 125, play roles in predicting chemotherapy response and survival outcome in patients with ovarian clear cell carcinoma (OCCC).

Methods

Preoperative leukocyte differential counts, as well as platelet, serum albumin, plasma D-dimer and CA-125 levels, were measured in patients with FIGO IC-IV ovarian clear cell cancer. The correlations of these hematological biomarkers with clinicopathological features, chemotherapy response, and survival outcomes were further analyzed. Survival time was estimated using the Kaplan-Meier model, whereas Cox regression was conducted for multivariate analysis.

Results

Among the 84 patients, 28.6% were classified as platinum resistant, and 69.0% were platinum sensitive. Preoperative CA125, albumin, and D-dimer levels; neutrophil to lymphocyte ratios (NLR); and monocyte to lymphocyte ratios were significantly correlated with FIGO stage, residual tumor, and platinum response. Platelet to lymphocyte ratio was not related to platinum response (P = 0.060). The median follow-up time was 28 months (range, 1 to 128 months). Preoperative CA125, albumin, and D-dimer levels were significant prognostic factors for overall survival (OS) and progression-free survival (PFS). In the univariate analysis, only NLR exhibited prognostic significance for PFS (P = 0.007). Multivariate analysis indicated that D-dimer > 3.27 (P = 0.001 for OS; P = 0.040 for PFS) and albumin < 39.6 (P = 0.005 for OS and P = 0.041 for PFS) retained significance.

Conclusions

Preoperative NLR has some predictive value for platinum resistance in patients with IC-IV stage OCCC but has little predictive effect on prognosis. Elevated D-dimer and reduced albumin might be potential biomarkers for worse response to first-line platinum-based chemotherapy and poor clinical outcomes.

The role of 18F-FDG PET/CT-based quantitative metabolic parameters in patients with ovarian clear cell carcinoma

BACKGROUND

Ovarian clear cell carcinoma (CCC) is enriched in genes associated with glucose metabolism.

OBJECTIVE

To evaluate the 18F-FDG PET/CT-based metabolic variables and the correlations with clinicopathologic features in OCCC patients.

METHODS

We measured quantitative parameters including maximum standardized uptake value (SUVmax), metabolic tumor volume (MTV) and total lesion glycolysis (TLG).

RESULTS

A total of 22 patients were included. PET/CT-based metabolic parameters were calculated for 20 patients because two had low glucose-uptake tumor. The median SUVmax was 7.25 (range 2.50-14.80). Spearman's correlation test revealed that the level of pre-operative serum cancer antigen 125 (CA 125) correlated significantly with MTV (P= 0.020) and TLG (P= 0.023). Interestingly, platinum-sensitive patients tended to have higher MTV/TLG though significance not achieved. On univariate analysis, the following four variables (stage, residual disease, platinum sensitivity and MTV50) were significant for both progression-free survival and overall survival. Besides, four metabolic parameters (MTV40, TLG40, TLG50 and TLG60) were significantly associated with patients' overall survival. Out of expectation, ovarian CCC patients with higher level of MTV/TLG tended to have better survival.

CONCLUSIONS

18F-FDG PET/CT-based metabolic volumetric parameters might be predicators for survival in ovarian CCC patients. Cautions should be taken when interpreting the results due to the small sample size.

Modelling Epithelial Ovarian Cancer in Mice: Classical and Emerging Approaches

High-grade serous epithelial ovarian cancer (HGSC) is the most aggressive subtype of epithelial ovarian cancer. The identification of germline and somatic mutations along with genomic information unveiled by The Cancer Genome Atlas (TCGA) and other studies has laid the foundation for establishing preclinical models with high fidelity to the molecular features of HGSC. Notwithstanding such progress, the field of HGSC research still lacks a model that is both robust and widely accessible. In this review, we discuss the recent advancements and utility of HGSC genetically engineered mouse models (GEMMs) to date. Further analysis and critique on alternative approaches to modelling HGSC considers technological advancements in somatic gene editing and modelling prototypic organs, capable of tumorigenesis, on a chip.

Genomic characterization of Chinese ovarian clear cell carcinoma identifies driver genes by whole exome sequencing

Little is known about the genetic alterations characteristic of ovarian clear cell carcinoma (OCCC). Our aim was to identify targetable genomic alterations in this type of cancer. Forty-two OCCC formalin-fixed, paraffin-embedded (FFPE) tissue samples were analyzed by whole-exome sequencing (WES), and 74 FFPE tissue samples underwent targeted sequencing (TS) to confirm the relevant driver mutations. Cell proliferation was assessed by cell counting kit-8 (CCK8) assays. In the 42 samples, ARID1A (64.3%) and PIK3CA (28.5%) were frequently mutated, as were PPP2R1A (11.9%), PTEN (7.1%) and KRAS (4.8%), which have been reported in previous OCCC studies. We also detected mutations in MUC4 (28.6%), MAGEE1 (19%), and ARID3A (16.7%); associations with these genes have not been previously reported. The functional protein-activated pathways were associated with proliferation and survival (including the PI3K/AKT, TP53, and ERBB2 pathways) in 83% of OCCCs and with chromatin remodeling in 71% of OCCCs. Patients with alterations in MAGEE1 (64% in the targeted sequencing cohort) had worse clinical outcomes (log-rank p < 0.05). A functional study revealed that two MAGEE1 mutants, one lacking two MAGE domains and the other containing two MAGE domains, significantly decreased the proliferative capacity of OCCC cells. We successfully identified novel genetic alterations in OCCC using whole-exome sequencing and targeted sequencing of OCCC patient samples and potential therapeutic targets for the treatment of this malignancy.

Prognostic value of neutrophil-to-lymphocyte ratio in early-stage ovarian clear-cell carcinoma

Objectives

There is increasing evidence that systemic inflammatory response (SIR) markers are prognostic factors for various types of cancers. This is the first study to evaluate the usefulness of SIR markers for the prognosis of early-stage ovarian clear-cell carcinoma (OCCC).

Methods

We retrospectively investigated 83 patients diagnosed with stage I–II OCCC who underwent surgery between 2005 and 2017. Initially, receiver operating characteristic curve analysis for overall survival (OS) was used to determine optimal cut-off values for neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR). Patients were stratified into 2 groups by the cut-off values (NLR=3.26, PLR=160). Univariate and multivariate analyses were performed to elucidate the significance of SIR markers as prognostic factors.

Results

In the median follow-up period of 64.1 months, 16 patients experienced recurrence, and nine patients died. The Kaplan-Meier curve showed that OS of the NLR-low group was significantly longer than the NLR-high group (p=0.021). There was no significant difference in progression-free survival between the 2 groups (p=0.668), but the post-recurrence survival of the NLR-low group was significantly longer than the NLR-high group (p=0.019). Furthermore, multivariate analysis showed that increase in NLR is a significant independent prognostic factor for poor prognosis (hazard ratio=7.437, p=0.017). There was no significant difference between PLR-low and PLR-high group.

Conclusion

Results suggest that NLR can be a significant independent prognostic factor for early-stage OCCC.

Differences in the molecular profile of endometrial cancers from British White and British South Asian women

Objectives

To identify differences in the mutational profile of endometrial tumours between British White (BW) and South Asian (BSA) women.

Methods

We analysed primary tumours from matched cohorts of British White (BW) and British South Asian (BSA) women resident in Leicestershire diagnosed with EC. Next Generation Sequencing was performed to investigate mutational differences in a panel of 10 genes previously identified as being commonly mutated in EC. The presence of somatic Mismatch Repair (MMR) gene deficiencies was determined by immunohistochemistry.

Results

In total, 57 tumours (27 BSA and 30 BW) were sequenced. There was no significant difference in the overall mutation frequency of the 10 genes analysed; however, numerous differences were observed between the groups. There was a positive association between PIK3CA and PTEN mutations in the BSA group, with 78% of PIK3CA-mutant tumours harbouring a PTEN mutation, whereas only 11% of PIK3CA wild-type (wt) tumours were PTEN mutant positive (p = 0.0012). In BW women, 90% of ARID1A mutant tumours had co-existent PI3K pathway mutations versus 50% of wild-type (wt) ARID1A patients (p = 0.0485). This trend was not significant in the BSA group (p = 0.66). The age at diagnosis was significantly higher in the BW group with a somatic MMR gene deficiency compared to those with no deficiency (72.8 years versus 59.6 years, p = 0.007), whereas this difference was not seen in the BSA group (64 years versus 60 years, p = 0.37).

Conclusion

We have identified differences in the mutational profile of primary EC tumours from BW and BSA women. Further research is needed to confirm these findings and to explore their potential implications for early detection, treatment response and prognosis.