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.

Outcomes after fertility-sparing surgery of early-stage ovarian cancer: A nationwide population-based study

BACKGROUND

Fertility-sparing surgery (FSS) is an alternative choice of young patients who have not completed their family planning and still have fertility needs. The aims of this study were to compare the outcomes of early-stage epithelial ovarian cancer (EOC) patients undergoing FSS and radical comprehensive staging surgery (RCS), and the suitability of FSS.

METHODS

A total of 1297 patients aged between 20 and 44 years with newly diagnosed early-stage EOC were recruited from the Taiwan Cancer Registry database between 2009 and 2017. Site-specific surgery codes were used to distinguish patients in FSS group or RCS group. Cancer-specific survival (CSS) was evaluated using Kaplan-Meier method with log-rank test and Cox regression model.

RESULTS

There were 401 and 896 patients in FSS and RCS group. Patients in FSS group were with younger age and mostly had Stage I disease. In contrast, patients in RCS group were older. There were more Stage II, high-grade (Grade 3) disease, and adjuvant chemotherapy in RCS group. Stage and tumor grade were two independent factors correlating with CSS and the type of surgery showed no effect on CSS (HR: 1.09, 95% CI: 0.66-1.77, p = 0.73) in multivariable analysis. In multivariable analysis, the clear cell carcinoma group who underwent FSS demonstrated better CSS compared to those in the RCS group (HR: 0.28, 95% CI: 0.06-0.82, p = 0.04). A total of 17 women who underwent FSS developed second malignancies of the uterine corpus or contralateral ovary.

CONCLUSION

FSS can be a safe alternative procedure in selected young patients of Stage I EOC who have fertility desire. Endometrial biopsy before or during FSS and regular surveillance to detect recurrence are mandatory for ovarian cancer patients undergoing FSS.

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.

The impact of lymphadenectomy on the survival outcomes of ovarian clear cell carcinoma: A retrospective study of the SEER database and Chinese registry

BACKGROUND

Ovarian clear cell carcinoma (OCCC) is a rare pathological type of ovarian cancer with a poor prognosis, and lymphadenectomy is controversial in patients with OCCC. The objective of this study was to evaluate the impact of lymphadenectomy on the prognosis of patients with OCCC.

METHODS

In this retrospective study, we collected data from the Surveillance, Epidemiology and End Results (SEER) database and institutional registries in China. The SEER cohort included 1777 women diagnosed with OCCC between 2010 and 2019, while the Chinese cohort included 199 women diagnosed between April 2004 and April 2021. Recurrence-free survival (RFS) and overall survival (OS) were studied using Kaplan-Meier curve and Cox regression analysis. We also employed propensity score matching (PSM) to adjust for baseline imbalances between the lymphadenectomy group and the no-lymphadenectomy group.

RESULTS

Multivariate cox regression analysis showed that lymphadenectomy was not associated with better overall survival (OS) in either early (hazard ratio [HR] 0.84[0.50-1.43], p = 0.528) or advanced (HR 0.78[0.50-1.21], p = 0.270) patients in the SEER cohort after PSM. Additionally, in the Kaplan-Meier curve analysis, lymphadenectomy did not significantly improve OS in both early (p = 0.28) and advanced (p = 0.49) patients in the SEER cohort after PSM. Similarly, in the Chinese cohort, lymphadenectomy had no significant effect on OS (early p = 0.22; advanced p = 0.61) or RFS (early p = 0.18; advanced p = 0.83) in both early and advanced patients.

CONCLUSION

In completely homogeneous groups, lymphadenectomy in women diagnosed with OCCC had no effect on either recurrence-free survival or overall survival compared to patients without lymphadenectomy.

Moesin affects the plasma membrane expression and the immune checkpoint function of CD47 in human ovarian clear cell carcinoma

Among major histological subtypes of epithelial ovarian cancer, a higher incidence of ovarian clear cell carcinoma (OCCC) is observed in East Asian populations, particularly in Japan. Despite recent progress in the immune checkpoint inhibitors for a wide variety of cancer cell types, patients with OCCC exhibit considerably low response rates to these drugs. Hence, urgent efforts are needed to develop a novel immunotherapeutic approach for OCCC. CD47, a transmembrane protein, is overexpressed in almost all cancer cells and disrupts macrophage phagocytic activity in cancer cells. Ezrin-Radixin-Moesin (ERM) family member of proteins serve as scaffold proteins by crosslinking certain transmembrane proteins with the actin cytoskeleton, contributing to their plasma membrane localization. Here, we examined the role of ERM family in the plasma membrane localization and functionality of CD47 in OCCC cell lines derived from Japanese women. Confocal laser scanning microscopy analysis showed colocalization of CD47 with all three ERM in the plasma membrane of OCCC cells. RNA interference-mediated gene silencing of moesin, but not others, decreased the plasma membrane expression and immune checkpoint function of CD47, as determined by flow cytometry and in vitro phagocytosis assay using human macrophage-like cells, respectively. Interestingly, clinical database analysis indicated that moesin expression in OCCC was higher than that in other histological subtypes of ovarian cancers, and the expression of CD47 and moesin increased with the cancer stage. In conclusion, moesin is overexpressed in OCCC and may be the predominant scaffold protein responsible for CD47 plasma membrane localization and function in OCCC.

3'-Hydroxypterostilbene Potently Suppresses Tumor Growth via Inhibiting the Activation of the JAK2/STAT3 Pathway in Ovarian Clear Cell Carcinoma

SCOPE

Ovarian clear cell carcinoma (OCCC) is a subtype of epithelial ovarian cancer (EOC) that is associated with higher interleukin-6 (IL-6) levels, and suppression of the Janus kinase 2/Signal transducer and activator of transription 3 (JAK2/STAT3) pathway may contribute to the suppression of this cancer. This study aims to compare the anti-cancer effect of pterostilbene (PSB) and 2'- and 3'-hydroxypterostilbene (2HPSB and 3HPSB, respectively) on the JAK2/STAT3 pathway.

METHODS AND RESULTS

In vitro experiments with the OCCC cell line TOV21G and a xenograft nude mouse model are used to achieve the study aims. The results showed that 3HPSB has the greatest anti-proliferative and pro-apoptotic effects of the three compounds studied. Activation of the JAK2/STAT3 pathway and the nuclear translocation of STAT3 are effectively inhibited by 3HPSB and PSB. Both 3HPSB and PSB can effectively suppress tumor growth, which is mediated by the inhibition of JAK2/STAT3 phosphorylation.

CONCLUSION

This is the first study to compare the efficacy of PSB, 3HPSB, and the newly identified compound 2HPSB regarding ovarian cancer. Moreover, targeting JAK2/STAT3 is shown to be a potentially effective strategy for OCCC treatment. This study is expected to provide new insights into the potential of the abovementioned phytochemicals for development as adjuvants for cancer treatment in the future.

Malignant Pericardial Tamponade Secondary to Ovarian Clear Cell Carcinoma

Malignant pericardial effusion is an uncommon metastatic manifestation of ovarian carcinoma. Few cases of ovarian serous carcinoma have been previously reported. Ovarian clear cell carcinoma is the second most common histologic subtype in East Asian countries and is a relatively rare in Western countries. Here, we report the case of cardiac tamponade secondary to Ovarian clear cell carcinoma. A 46-year-old woman with recurrent Ovarian clear cell carcinoma presented with worsening cough, palpitations, and shortness of breath during chemotherapy. Chest radiography and computed tomography confirmed a pleural effusion with cardiac tamponade. The patient underwent pericardial fenestration and drainage for cardiac tamponade. Pericardial fluid cytology showed malignant cells forming papillary and ball-like clusters with irregular stacking. The cells had a mirror ball-like appearance and collagenous stroma, in which a homogenous hyaline core was observed in the center of most tumor cell clusters. Based on these findings, a diagnosis of Ovarian clear cell carcinoma metastasis was made. She received palliative care and died 5 months after the operation without recurrent cardiac tamponade. This case suggests that cytological findings from pericardial effusion are useful in diagnosing Ovarian clear cell carcinoma metastasis.

Interaction between membranous EBP50 and myosin 9 as a favorable prognostic factor in ovarian clear cell carcinoma

Ezrin-radixin-moesin-binding phosphoprotein 50 (EBP50) is a scaffold protein that is required for epithelial polarity. Knockout (KO) of membranous EBP50 (Me-EBP50) in ovarian clear cell carcinoma (OCCC) cells induced an epithelial-mesenchymal transition (EMT)-like phenotype, along with decreased proliferation, accelerated migration capability, and induction of cancer stem cell (CSC)-like properties. Shotgun proteomics analysis of proteins that co-immunoprecipitated with EBP50 revealed that Me-EBP50 strongly interacts with myosin 9 (MYH9). Specific inhibition of MYH9 with blebbistatin phenocopied Me-EBP50 KO, and blebbistatin treatment potentiated the effects of Me-EBP50 KO. In OCCC cells from clinical samples, Me-EBP50 and MYH9 were co-localized at the apical plasma membrane. Patients with a combination of Me-EBP50-high and MYH9-high scores had the best prognosis for overall and progression-free survival. Our data suggest that Me-EBP50 has tumor-suppressive effects through the establishment and maintenance of epithelial polarization. By contrast, loss of Me-EBP50 expression induces EMT-like phenotypes, probably due to MYH9 dysfunction; this results in increased cell mobility and enhanced CSC-like properties, which in turn promote OCCC progression.

Lymphatic vasculature in ovarian cancer

Ovarian cancer (OVCA) is the second most common gynecological cancer and one of the leading causes of cancer related mortality among women. Recent studies suggest that among ovarian cancer patients at least 70% of the cases experience the involvement of lymph nodes and metastases through lymphatic vascular network. However, the impact of lymphatic system in the growth, spread and the evolution of ovarian cancer, its contribution towards the landscape of ovarian tissue resident immune cells and their metabolic responses is still a major knowledge gap. In this review first we present the epidemiological aspect of the OVCA, the lymphatic architecture of the ovary, we discuss the role of lymphatic circulation in regulation of ovarian tumor microenvironment, metabolic basis of the upregulation of lymphangiogenesis which is often observed during progression of ovarian metastasis and ascites development. Further we describe the implication of several mediators which influence both lymphatic vasculature as well as ovarian tumor microenvironment and conclude with several therapeutic strategies for targeting lymphatic vasculature in ovarian cancer progression in present day.

Genetic characteristics of platinum-sensitive ovarian clear cell carcinoma

OBJECTIVE

Most ovarian clear cell carcinomas are resistant to platinum-based chemotherapy, while a small subset shows a positive response. The aim of this study was to clarify the clinical, pathological and genetic characteristics of platinum-sensitive ovarian clear cell carcinomas.

METHODS

The study included 53 patients with stage III-IV ovarian clear cell carcinoma who had residual tumours after primary surgery and received platinum-based therapy between 2009 and 2018. A retrospective examination of platinum sensitivity was performed using the criterion of ≥6 months from the last day of first-line platinum therapy until recurrence/progression. Cases determined to be platinum-sensitive were subjected to immunohistochemical staining, genomic analyses using target sequencing (i.e. NCC Oncopanel) and homologous recombination deficiency (myChoice® HRD Plus) assays.

RESULTS

Of the 53 stage III-IV ovarian clear cell carcinoma cases, 11 (21%) were platinum-sensitive. These cases showed better progression-free and overall survival than platinum-resistant cases (hazard ratio = 0.16, P < 0.001). Among the seven sensitive cases whose tumour tissues were available for molecular profiling, five were pure ovarian clear cell carcinoma based on pathological and genetic features, whereas the remaining two cases were re-diagnosed as high-grade serous ovarian carcinoma. The pure ovarian clear cell carcinomas lacked BRCA1 and BRCA2 mutations, consistent with the absence of the homologous recombination deficiency phenotype, whereas two cases (40%) had ATM mutations. By contrast, the two high-grade serous ovarian carcinoma cases had BRCA1 or BRCA2 mutations associated with the homologous recombination deficiency phenotype.

CONCLUSION

The subset of platinum-sensitive ovarian clear cell carcinomas includes a majority with pure ovarian clear cell carcinoma features that lack the homologous recombination deficiency phenotype.

Ovarian clear cell carcinoma with or without endometriosis origin in a single institution cohort

BACKGROUND

As ovarian clear cell carcinoma (OCCC) has distinct clinical features, biology, genetic characteristics and mechanisms of pathogenesis, and whether the origin of endometriosis or not affects the prognosis of OCCC remains controversial.

METHODS

We retrospectively collected medical records and follow-up data of patients with OCCC treated at the Obstetrics and Gynecology Hospital of Fudan University from January 2009 to December 2019. Further, we divided patients into 2 groups. Group 1: non-endometriosis origin; Group 2: endometriosis origin. Clinicopathological characteristics and survival outcomes were compared between the 2 groups.

RESULTS

A total of one hundred and twenty-five patients with ovarian clear cell carcinoma were identified and included. In the overall patients' population, the 5 year overall survival was 84.8%, the mean overall survival was 85.9 months. The results of the stratified analysis showed that early stage (FIGO stage I/II) OCCC had a good prognosis. The results of univariate analyses indicated that a statistically significant relationship between overall survival (OS) and FIGO stage, lymph node metastasis, peritoneum metastasis, chemotherapy administration methods, Chinese herbal treatment, molecular target therapy. As for progression-free survival (PFS), a significant relationship between PFS and child-bearing history, largest residual tumor size, FIGO stage, tumor maximum diameter, lymph node metastasis was found, respectively. FIGO stage and lymph node metastasis are common poor prognostic factors affecting OS and PFS. The multivariate regression analysis revealed that FIGO stage (p = 0.028; HR, 1.944; 95% CI 1.073-3.52) and treatment by Chinese herbs (p = 0.018; HR, 0.141; 95% CI 0.028-0.716) were identified as influencing factors with regard to survival. The presence or absence of lymphadenectomy did not affect OS of 125 OCCC patients (p = 0.851; HR, 0.825; 95% CI 0.111-6.153). There was a trend towards a better prognosis for patients with OCCC of endometriosis origin than those with OCCC of non-endometriosis origin (p = 0.062; HR, 0.432; 95% CI 0.179-1.045). The two groups differed with respect to several clinicopathological factors. And the proportion of patients with disease relapse was higher in Group 1 (46.9%) than in Group 2 (25.0%), with a statistically significant difference (p = 0.048).

CONCLUSIONS

Surgical staging and treatment by Chinese herbs postoperatively are two independent prognostic factors affecting the OS of OCCC, early detection and Chinese herbal medicine combined with chemotherapy postoperatively may be a good choice. Tumor with endometriosis-origin was found less likely to relapse. While the non-necessity of lymphadenectomy in advanced ovarian cancer has been proven, the need for lymphadenectomy in the early stage ovarian cancer, including early stage OCCC, still deserved to be explored.

Advanced ovarian clear cell carcinoma with RAD50 mutation treated by PARP inhibitor pamiparib combined with anti-angiogenesis therapy: a case report

Ovarian clear cell carcinoma (OCCC) is a relatively uncommon epithelial ovarian malignancy with unique clinical, histopathologic and genetic characteristics. Patients with advanced OCCC have poor outcomes and are resistant to standard chemotherapy. Targeted therapy offers a novel approach for treating OCCC. We report the case of a 45-year-old female patient with advanced OCCC who experienced relapse after standard treatment. Further, a frameshift mutation in the homologous recombination repair-related gene RAD50 (RAD50-p.I371Ffs*8) was identified by genetic testing. Next, the patient had received targeted combination therapy with poly (ADP-ribose) polymerase (PARP) inhibitor pamiparib and bevacizumab, achieving partial remission. Patient's symptoms improved significantly compared to before. To date, the patient has been followed up for more than half a year with favorable survival and high quality of life. The case report suggested that parmiparib-targeted therapy is a viable treatment option for advanced OCCC patients with RAD50 mutation.

Neoadjuvant chemotherapy in advanced epithelial ovarian cancer by histology: A SEER based survival analysis

To evaluate the prognostic effect of neoadjuvant chemotherapy (NACT) in advanced epithelial ovarian cancer (EOC) patients with different histological subtype. Stage III/IV EOC patients diagnosed between 2010 and 2018 were identified from the surveillance, epidemiology, and end results database (SEER) database and stratified by histological subtype. Kaplan-Meier analysis was used for the assessment of overall survival (OS) cause-specific survival (CSS) before and after matching for baseline characteristics between NACT and primary debulking surgery (PDS) groups. Cox proportional risk model was conducted to identify independent prognostic factors. A total of 13,582 patients were included in the analysis. Of them, 9505 (74.50%) received PDS and 3253 (25.50%) received NACT. Overall, an inferior OS and CSS was observed among patients with high-grade serous carcinoma (HGSC) receiving NACT, while NACT served as a protective factor in clear cell carcinoma and carcinosarcoma in both original cohorts and adjusted cohorts. For other histo-subtypes, PDS showed survival benefit over NACT in certain cohorts of models. Prognostic effect of NACT in advanced EOC differed from pathological subtypes. Although it served as a risk factor for HGSC, patients with less common subtypes may benefit from NACT.

Immunohistochemical expression of PD-L1 and its correlation with microsatellite status in endometrial and ovarian clear cell carcinomas: a cross-sectional study

BACKGROUND

Clear cell carcinoma is an uncommon histologic subtype of ovarian and endometrial carcinoma with poor response to Platinium-based chemotherapy agents at high stages. Blockage of Programmed cell Death Ligand-1 (PD-L1), can be used in targeted immunotherapy. This study investigated Mismatch Repair Deficiency (MMR-D) status, PD-L1 expression, and the correlation between PD-L1 expression and microsatellite instability (MSI) status in ovarian and endometrial clear cell carcinomas.

METHODS

Ovarian clear cell carcinoma (OCCC) (n = 28) and endometrial clear cell carcinoma (ECCC) (n = 28) samples were evaluated for PD-L1 (in tumoral and peri-tumoral inflammatory cells), MSH6 and PMS2 expression by immunohistochemistry (IHC) study. PD-L1 expression > 1% in tumor cells and > 5% in peritumoral inflammatory cells were considered positive.

RESULTS

The prevalence of PD-L1 expression was higher in ECCC (20/28, 71.43%) compared to OCCC tumor cells (16/28, 57.15%) (p > 0.05), while expression in peritumoral inflammatory cells was significantly higher in ECCC (25/28, 89.29%) compared to OCCC (11/28, 39.28%) (p < 0.05). MMR-D was observed in 5 cases, four OCCCs and one ECCC, among which, four (80%) showed PD-L1 expression in peritumoral inflammatory and tumor cells. The only OCCC case with extensive PD-L1 expression in tumor cells (> 50%) exhibited MSH6/MSH2 loss. No significant correlation was noted between PD-L1 expression and the pathologic stage or survival.

CONCLUSION

PD-L1 expression was significantly associated with clear cell morphology, especially in the endometrium, independent of MMR protein status.

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.

The worsening impact of programmed cell death ligand 1 in ovarian clear cell carcinomas

PURPOSE

To investigate the clinical significance of programmed cell death ligand 1 (PD-L1) expression in ovarian clear cell carcinoma (CCC).

MATERIALS AND METHODS

Patients with CCC who underwent primary surgery at our hospital between 1984 and 2014 were enrolled in this study. PD-L1 and mismatch repair (MMR) protein expression in tumor cells, tumor-infiltrating lymphocytes (TILs), including cluster of differentiation (CD) 8, CD4, forkhead box P3 (FOXP3), programmed cell death 1 (PD-1), and BAF250a, were evaluated using immunohistochemistry. The association between PD-L1 expression, clinicopathological features, prognosis, and expression of several proteins was investigated.

RESULTS

Of the 125 patients with CCC, 17 had negative PD-L1 and 108 had positive PD-L1. Patients with positive PD-L1 expression showed a lower response to chemotherapy (p = 0.01). In addition, patients with positive PD-L1 showed worse progression-free survival (PFS, p = 0.01) and overall survival (OS, p = 0.01) than that in patients with negative PD-L1 expression. Multivariate analyses for PFS and OS showed that PD-L1 expression was an independent prognostic factor for PFS (hazard ratio [HR] 7.81, p < 0.01) and OS (HR 12.90, p < 0.01). PD-L1 expression was not associated with the expression of several TILs or proteins.

CONCLUSION

The expression of PD-L1 was related to a lower response to chemotherapy and worse prognosis in CCC. These results may be useful for the development of new treatments.

Therapeutic Strategies Focused on Cancer-Associated Hypercoagulation for Ovarian Clear Cell Carcinoma

Ovarian clear cell carcinoma (OCCC) is associated with chemotherapy resistance and poor prognosis, especially in advanced cases. Although comprehensive genomic analyses have clarified the significance of genomic alterations such as ARID1A and PIK3CA mutations in OCCC, therapeutic strategies based on genomic alterations have not been confirmed. On the other hand, OCCC is clinically characterized by a high incidence of thromboembolism. Moreover, OCCC specifically shows high expression of tissue factor and interleukin-6, which play a critical role in cancer-associated hypercoagulation and may be induced by OCCC-specific genetic alterations or the endometriosis-related tumor microenvironment. In this review, we focused on the association between cancer-associated hypercoagulation and molecular biology in OCCC. Moreover, we reviewed the effectiveness of candidate drugs targeting hypercoagulation, such as tissue factor- or interleukin-6-targeting drugs, anti-inflammatory drugs, anti-hypoxia signaling drugs, anticoagulants, and combined immunotherapy with these drugs for OCCC. This review is expected to contribute to novel basic research and clinical trials for the prevention, early detection, and treatment of OCCC focused on hypercoagulation.

Next-Generation Sequencing Reveals a Very Low Prevalence of Deleterious Mutations of Homologous Recombination Repair Genes and Homologous Recombination Deficiency in Ovarian Clear Cell Carcinoma

Ovarian clear cell carcinoma (OCCC) is aggressive and drug-resistant. The prevalence of homologous recombination repair (HRR) gene mutations and homologous recombination deficiency (HRD) remains largely unknown. It is also not clear whether the commonly used molecular-based classification for endometrial carcinoma (EC) is potentially applicable in OCCC. In this study, surgically resected samples were collected from 44 patients with OCCC. Genomic alterations were determined using next-generation sequencing. HRD was estimated by genomic instability. Of 44 patients with OCCC, two (4.5%) harbored likely pathogenic mutations in HRR genes. Notably, no pathogenic or likely pathogenic mutations were found in BRCA1/2. A total of 24 variants of uncertain significance (VUS) in HRR-related genes occurred in 18 (40.9%) patients. HRD was observed in only one case (2.3%). In addition, TP53 mutation and microsatellite instability-high (MSI-H) were identified in three patients (6.8%) and in one patient (2.3%), respectively. TP53 mutation was significantly associated with disease-free survival and overall survival. No POLE mutations were found. In conclusion, our results revealed a very low prevalence of HRR gene mutations and HRD in OCCC. Moreover, TP53 mutations and MSI-H are uncommon, while POLE mutations are extremely rare in OCCC. Our findings indicate that the evaluation of HRR gene mutations, HRD status, POLE mutations, and MSI-H may have limited clinical significance for OCCC treatment and prognostic stratification.

Acute Presentation of Large Size Clear Cell Ovarian Carcinoma as Double Torsed Ovarian Tumor

We report a 46-year-old patient who presented to the emergency department with complaints of acute abdominal pain, nausea, and vomiting. An abdominal CT scan revealed a large (207 × 155 × 182 mm) thin-walled inhomogeneous tumor connected to the uterus and right ovary. Emergency surgery laparotomy was performed. Inside the abdominal cavity, a 30 × 30 cm heterogenous, dark blue tumor in the right adnexa area, torsed two times, weighing 3700 g was found. Histological examination revealed right ovary clear cell carcinoma. We emphasize the rare nature of the histology and presentation of this case report. Ovarian clear cell carcinomas are relatively rare malignancies, presenting in 5 to 10% of ovarian malignant tumors in the west.

Diagnosis of lung adenocarcinoma with clear cell features in pleural effusion: Cytomorphologic features, immunocytochemical studies, and differential diagnosis

Clear cell adenocarcinoma (CCA) of the lungs is no longer referred to as a subtype in recent classifications of lung adenocarcinoma. Like signet ring features, clear cell features are regarded as cytological features rather than histological subtypes. Additionally, in serous fluids, adenocarcinoma metastasis with clear cell features is a diagnostic challenging entity due to other tumors that come to mindfirst during the differential diagnosis. Here we report a case, diagnosed as CCA of lung metastasis in pleural fluid and evaluated its differential diagnosis.

Hypoxia-induced Maspin Expression Affects the Prognosis of Ovarian Clear Cell Carcinoma

BACKGROUND/AIM

To investigate the role of the expression of hypoxia-related genes on the prognosis of ovarian clear cell carcinoma (OCCC).

MATERIALS AND METHODS

Basal mRNA levels of eight hypoxia-related genes were compared. Cell viability was assayed after treating ES-2 cells under hypoxic conditions. The mRNA and protein levels were evaluated after the induction of hypoxia and administration of increased doses of N-acetylcysteine (NAC). Finally, the prognostic role of their expression levels was evaluated in 61 patients with OCCC.

RESULTS

The mRNA and protein levels of maspin increased gradually with the induction of hypoxia. Maspin protein expression decreased after treatment with paclitaxel and NAC. High expression of maspin was related to poor progression-free and overall survival in patients with OCCC (adjusted hazard ratios, 3.97 and 7.47; 95% confidence intervals=1.34-11.81, and 1.98-28.13).

CONCLUSION

High expression of maspin induced by hypoxia might be associated with poor prognosis of OCCC.

Adjuvant taxane plus platinum chemotherapy for stage I ovarian clear cell carcinoma with complete surgical staging: are more than three cycles necessary?

BACKGROUND

Previous studies on adjuvant chemotherapy for patients with ovarian clear cell carcinoma (OCCC) have included a limited number of Asian patients with surgical stage I OCCC, despite differences in OCCC survival by race and stage. The aim of this study was to estimate the survival effect of the number of cycles of adjuvant taxane plus carboplatin chemotherapy in Asian patients with surgical stage I OCCC.

METHODS

We retrospectively identified 227 patients with surgical stage I OCCC at 14 institutions from 1995 to 2017. Kaplan-Meier analysis and Cox proportional hazard regression with inverse probability of treatment weighting (IPTW) adjustment were performed to evaluate overall survival (OS) and recurrence-free survival (RFS) in patients receiving ≤ 3 and 4-6 cycles of taxane plus platinum adjuvant chemotherapy.

RESULTS

Eighty-nine and 138 patients received ≤ 3 and 4-6 cycles of adjuvant chemotherapy, respectively. There was no between-group difference in OS or RFS with or without IPTW adjustment. In Cox proportional hazards analysis, 4-6 cycles of adjuvant chemotherapy were not associated with improved OS (HR 1.090; 95% CI 0.518-2.291; p = 0.821) or RFS (HR 1.144; 95% CI 0.619-2.114; p = 0.669) compared to ≤ 3 cycles, even with IPTW adjustment. Subgroup analysis in different substages of stage I OCCC showed that the number of cycles of adjuvant chemotherapy had no impact on OS or RFS.

CONCLUSION

Three or fewer cycles of taxane plus carboplatin chemotherapy may be a reasonable treatment regime for patients with surgical staging I OCCC.

Frequent PIK3CA mutations in eutopic endometrium of patients with ovarian clear cell carcinoma

Recent studies have reported cancer-associated mutations in normal endometrium. Mutations in eutopic endometrium may lead to endometriosis and endometriosis-associated ovarian cancer. We investigated PIK3CA mutations (PIK3CAm) for three hotspots (E542K, E545K, H1047R) in eutopic endometrium in patients with ovarian cancer and endometriosis from formalin-fixed paraffin-embedded specimens by laser-capture microdissection and droplet digital PCR. The presence of PIK3CAm in eutopic endometrial glands with mutant allele frequency ≥ 15% were as follows: ovarian clear cell carcinoma (OCCC) with PIK3CAm in tumors, 20/300 hotspots in 11/14 cases; OCCC without PIK3CAm, 42/78 hotspots in 11/12 cases; high-grade serous ovarian carcinoma, 8/45 hotspots in 3/5 cases; and endometriotic cysts, 5/63 hotspots in 5/6 cases. These rates were more frequent than in noncancer nonendometriosis controls (7/309 hotspots in 5/17 cases). In OCCC without PIK3CAm, 7/12 (58%) cases showed multiple hotspot mutations in the same eutopic endometrial glands. In 3/54 (5.6%) cases, PIK3CAm was found in eutopic endometrial stroma. Multisampling of the OCCC tumors with PIK3CAm showed intratumor heterogeneity in three of eight cases. In two cases, PIK3CAm was detected in the stromal component of the tumor. Homogenous PIK3CAm in the epithelial component of the tumor matched the mutation in eutopic endometrial glands in only one case. Eutopic endometrial glands in ovarian cancer and endometriosis show high frequency of PIK3CAm that is not consistent with tumors, and multiple hotspot mutations are often found in the same glands. While the mutations identified in eutopic endometrium may not be driver mutations in the patient's cancer, these are still driver mutations but this specific clone has not undergone the requisite steps for the development of cancer.

Clear Cell Carcinoma Arising in an Abdominal Wall Cesarean Section Scar: A Case Report With Description of Pathological and Molecular Features

Clear cell carcinoma is a clinically and biologically distinct type of carcinoma predominantly encountered in the ovary and endometrium. In the ovary, it is frequently associated with endometriosis, which is a well-known risk factor. Endometriosis has often been described in the abdominal wall of women who had a cesarean section; however, malignant transformation is a very rare event, occurring in <1% of cases. The authors report a case involving a 52-year-old woman with an abdominal wall nodule at a cesarean section scar. Radiology revealed a mass, measuring 8 cm in size, in the abdominal wall suggestive of a soft tissue tumor. After resection, histology revealed the presence of clear, eosinophilic, and hobnail cells, which, together with immunohistochemical and molecular findings, enabled the diagnosis of clear cell carcinoma of the abdominal wall. The present report describes the clinical, radiological, pathological, and molecular features of an unusual abdominal lesion that represents a rare but challenging diagnosis.

Ovarian Cancer and Cancer Stem Cells-Cellular and Molecular Characteristics, Signaling Pathways, and Usefulness as a Diagnostic Tool in Medicine and Oncology

Simple Summary

Ovarian cancer is still a high-risk, metastatic disease, often diagnosed at a late stage. Difficulties in its treatment are associated with high resistance to chemotherapy and recurrence. Responsible for the malignant features of cancer are considered to be cancer stem cells (CSCs), which generate new cells by modifying various signaling pathways. Signaling pathways are crucial for the regulation of epithelial-mesenchymal transition, metastasis, and self-renewal of CSCs. New therapies based on the use of inhibitors that block CSC growth and proliferation signals are being investigated. The current histological classification of ovarian tumors, their epidemiology, and the recent knowledge of ovarian CSCs, with particular emphasis on their molecular basis, are important considerations.

Abstract

Despite the increasing development of medicine, ovarian cancer is still a high-risk, metastatic disease that is often diagnosed at a late stage. In addition, difficulties in its treatment are associated with high resistance to chemotherapy and frequent relapse. Cancer stem cells (CSCs), recently attracting significant scientific interest, are considered to be responsible for the malignant features of tumors. CSCs, as the driving force behind tumor development, generate new cells by modifying different signaling pathways. Moreover, investigations on different types of tumors have shown that signaling pathways are key to epithelial-mesenchymal transition (EMT) regulation, metastasis, and self-renewal of CSCs. Based on these established issues, new therapies are being investigated based on the use of inhibitors to block CSC growth and proliferation signals. Many reports indicate that CSC markers play a key role in cancer metastasis, with hopes placed in their targeting to block this process and eliminate relapses. Current histological classification of ovarian tumors, their epidemiology, and the most recent knowledge of ovarian CSCs, with particular emphasis on their molecular background, are important aspects for consideration. Furthermore, the importance of signaling pathways involved in tumor growth, development, and metastasis, is also presented.

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.

Kinetics of HE4 and CA125 as prognosis biomarkers during neoadjuvant chemotherapy in advanced epithelial ovarian cancer

BACKGROUND

Ovarian cancer (OC) is considered the most lethal gynecological cancer, of which more than 65% cases are diagnosed in advanced stages, requiring platinum-based neoadjuvant chemotherapy (NACT).

METHODS

A prospective-longitudinal study was conducted among women with advanced epithelial ovarian cancer (AEOC), III and IV stages, and treated with NACT, at the National Cancer Institute - Mexico, from July 2017 to July 2018. Serum samples were obtained for quantification of CA125 and HE4 using ELISA at the first and in each of the three NACT cycles. The therapeutic response was evaluated through standard tomography. We determined whether CA125 and HE4, alone or in combination, were associated with TR to NACT during follow up.

RESULTS

53 patients aged 38 to 79 years were included, 92.4% presented papillary serous subtype OC. Higher serum HE4 levels were observed in patients with non-tomographic response (6.89 vs 5.19 pmol/mL; p = 0.031), specially during the second (p = 0.039) and third cycle of NACT (p = 0.031). Multivariate-adjusted models showed an association between HE4 levels and TR, from the second treatment cycle (p = 0.042) to the third cycle (p = 0.033). Changes from baseline HE4 levels during the first cycle was negative associated with TR. No associations were found between CA125 and TR.

CONCLUSIONS

Serum HE4 levels were independently associated with TR among patients with AOEC treated with NACT, also a reduction between baseline HE4 and first chemotherapy levels was also independently associated with the TR. These findings might be relevant for predicting a lack of response to treatment.

Kaempferia parviflora extract inhibits TNF-α-induced release of MCP-1 in ovarian cancer cells through the suppression of NF-κB signaling

Ovarian clear cell carcinoma (OCCC) is an uncommon subtype of epithelial cell ovarian cancers (EOCs) that has poor response to conventional platinum-based therapy. Therefore, finding new potential therapeutic agents is required. Since inflammatory cytokine, tumor necrosis factor alpha (TNF-α), is strongly expressed in EOCs and associated with the level of tumor grade, disruption of this inflammation pathway may provide another potential target for OCCC treatment. We previously reported that Kaempferia parviflora (KP) extract decreased cell proliferation and induced apoptosis. However, the effects of KP on OCCC, especially the aspects related to inflammatory cytokines, have not been elucidated. Our current study demonstrated the effects of KP extract on cytokine production in TNF-α-induced OCCC TOV-21G cell line. This study showed that KP extract inhibited interleukin 6 (IL-6) and monocyte chemoattractant protein-1 (MCP-1) production at both transcription and translation levels via the suppression of nuclear factor-kappa B (NF-κB) signal transduction. In contrast, KP extract increased the expression of inhibitor kappa B (IκB) protein which may delay NF-κB translocation into the nucleus upon TNF-α activation. Moreover, the suppression of cytokines released from KP treated-TOV-21G reduced the migration of monocyte cell (THP-1). KP extract also exhibited the inhibition of IL-6 and MCP-1 production from THP-1 activated by lipopolysaccharides (LPS). Cells treated with KP extract exhibited a decrease in extracellular signal-regulated kinases (ERK1/2) and protein kinase B (AKT) phosphorylation and induced myeloid leukemia cell differentiation protein Mcl-1 (MCL-1) expression. Suppression of inflammatory cytokine and chemokine production and inhibition of tumor-associated macrophage (TAM) migration support the possibility of using KP for OCCC treatment.

An integrated microfluidic platform for detection of ovarian clear cell carcinoma mRNA biomarker FXYD2

In this work we developed an integrated microfluidic system for automatically detecting the ovarian clear cell carcinoma (OCCC) biomarker FXYD2. Dealing with ascites from ovarian cancer patients, capture of cancer cells, isolation of messenger RNA, and quantitative reverse-transcription polymerase chain reaction were integrated into a single microfluidic chip and carried out on-chip automatically. OCCC is a subtype of ovarian cancer with a high mortality risk, and a high FXYD2 gene expression level was shown to be closely associated with OCCC. The lowest limit of quantification using a benchtop protocol of this system could be as low as 100 copies per sample. By normalizing the expression to a housekeeping gene, GAPDH, a simple cycle threshold ratio index could distinguish high FXYD2 expression cells from the low-expression ones. This developed platform may therefore facilitate future OCCC diagnosis and/or prognosis.

Genomic alterations in gynecological malignancies: histotype-associated driver mutations, molecular subtyping schemes, and tumorigenic mechanisms

There are numerous histological subtypes (histotypes) of gynecological malignancies, with each histotype considered to largely reflect a feature of the "cell of origin," and to be tightly linked with the clinical behavior and biological phenotype of the tumor. The recent advances in massive parallel sequencing technologies have provided a more complete picture of the range of the genomic alterations that can persist within individual tumors, and have highlighted the types and frequencies of driver-gene mutations and molecular subtypes often associated with these histotypes. Several large-scale genomic cohorts, including the Cancer Genome Atlas (TCGA), have been used to characterize the genomic features of a range of gynecological malignancies, including high-grade serous ovarian carcinoma, uterine corpus endometrial carcinoma, uterine cervical carcinoma, and uterine carcinosarcoma. These datasets have also been pivotal in identifying clinically relevant molecular targets and biomarkers, and in the construction of molecular subtyping schemes. In addition, the recent widespread use of clinical sequencing for the more ubiquitous types of gynecological cancer has manifested in a series of large genomic datasets that have allowed the characterization of the genomes, driver mutations, and histotypes of even rare cancer types, with sufficient statistical power. Here, we review the field of gynecological cancer, and seek to describe the genomic features by histotype. We also will demonstrate how these are linked with clinicopathological attributes and highlight the potential tumorigenic mechanisms.

Report from the European Society of Gynaecological Oncology (ESGO) 2020 State-of-the-Art Virtual Meeting

This is a report from the European Society of Gynaecological Oncology State-of-the-Art Virtual Meeting held December 14-16, 2020. The unique 3-day conference offered comprehensive state-of-the-art summaries on the major advances in the treatment of different types of gynecological cancers. Sessions opened with a case presentation followed by a keynote lecture and interactive debates with opinion leaders in the field. The speakers also presented scientific reviews on the clinical trial landscape in collaboration with the European Network of Gynecological Oncological Trial (ENGOT) groups. In addition, the new ESGO-ESRTO-ESP endometrial cancer guidelines were officially presented in public. This paper describes the key information and latest studies that were presented for the first time at the conference.

Residual Tumor Diameter Predicts Progression After Primary Debulking Surgery of Ovarian Clear Cell Carcinoma (OCCC): Clinicopathologic Study of Stage II-IV OCCC Patients from a Single Institution

Introduction

Ovarian clear cell carcinoma (OCCC) is a subtype of ovarian cancer characterized by highly aggressive and poor prognosis. However, it is unclear what factors are associated with OCCC recurrence and death. The study aimed to evaluate whether residual tumor diameter after primary debulking surgery, or other clinicopathological features play roles in predicting survival outcome in stage II–IV OCCC patients.

Material and Methods

We present a retrospective study of OCCC patients with stage II–IV in our department from 2010 to 2015. Kaplan–Meier method was used to draw a survival curve. Survival analysis was performed using Log-rank test for univariate analysis and COX proportional risk regression model for multivariate analysis.

Results

In this cohort of 78 patients who underwent primary debulking surgery, 47 patients had disease recurrence and 32 cases died. On univariate analysis, FIGO stage, residual tumor diameter and ascites were significant predictors of 3-year PFS (P values<0.05) and OS (P values<0.05). On multivariate analysis, the residual tumor diameter was an independent prognostic factor for 3-year PFS and OS (P values<0.05). The outcomes of patients in residual-free group were significantly better than those in the residual tumor diameter 0–1cm and >1cm group (PFS: P=0.000, OS: P=0.001), but there was no significant difference in prognosis between 0–1cm and > 1cm group (P values >0.05). Greater residual tumor diameter predicted progression on cox analysis in patients with stage III, but not for patients with stage IV.

Conclusion

Residual tumor diameter is prognostic after surgery for OCCC. Achieving no residual disease will significantly improve the prognosis in advanced OCCC patients.

Extracellular miRNAs as Predictive Biomarkers for Glypican-3-Derived Peptide Vaccine Therapy Response in Ovarian Clear Cell Carcinoma

Ovarian clear cell carcinoma (OCCC) has been treated with surgery and chemotherapy; however, the prognosis remains poor because of chemoresistance. Therefore, immunotherapies are attracting attention, including the GPC3 peptide vaccine, which improves overall survival. However, the response rate is limited and there are no sufficient predictive biomarkers that can identify responders before treatment. Our purpose was to identify circulating serum miRNAs as predictive biomarkers for response to GPC3 peptide vaccine. Eighty-four patients in a phase II trial of a GPC3 peptide vaccine were enrolled and miRNA sequencing was performed on their serum samples. Candidate miRNAs were selected from a group of 14 patients for whom treatment was responsive and validated in an independent group of 10 patients for whom treatment was responsive. Three markedly upregulated miRNAs, miR-375-3p, miR-193a-5p, and miR-1228-5p, were identified, and the combination of those miRNAs demonstrated high value in the prediction of the response. The origin of these miRNAs was assessed by referring to OCCC tissue miRNA profiles, and they were not identified as cancer tissue-related miRNAs. Functional annotation analysis suggested that they were associated with interferon-related pathways. The miRNAs identified herein have great potential to allow the realization of liquid biopsy for predicting the immunotherapy response and precision medicine.

Tetraspanin 1 promotes endometriosis leading to ovarian clear cell carcinoma

Ovarian clear cell carcinoma (OCCC) reportedly develops from endometriosis. However, the molecular mechanism underlying its malignant progression to OCCC remains elusive. This study aimed to identify an essential gene in the malignant transformation of endometriosis to OCCC. We performed RNA sequencing in formalin‐fixed, paraffin‐embedded (FFPE) tissues of endometriosis (n = 9), atypical endometriosis (AtyEm) (n = 18), adjacent endometriosis to OCCC (AdjEm) (n = 7), and OCCC (n = 17). We found that tetraspanin 1 (TSPAN1) mRNA level was significantly increased by 2.4‐ (DESeq2) and 3.4‐fold (edgeR) in AtyEm and by 80.7‐ (DESeq2) and 101‐fold (edgeR) in OCCC relative to endometriosis. We confirmed that TSPAN1 protein level was similarly overexpressed in OCCC tissues and cell lines. In immortalized endometriosis cell lines, TSPAN1 overexpression enhanced cell growth and invasion. Mechanistically, TSPAN1 triggered AMP‐activated protein kinase (AMPK) activity, promoting endometriosis and cell growth. Upregulated levels of TSPAN1 are considered an early event in the development of high‐risk endometriosis that could progress to ovarian cancer. Our study suggests the potential of TSPAN1 as a screening candidate for high‐risk endometriosis.

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.

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.

Natural killer cell impairment in ovarian clear cell carcinoma

In the present study, we report the analysis of NK cells derived from patients suffering from a rare ovarian cancer histotype of clear cell carcinoma (OCCC) resistant to conventional chemotherapies. We analyzed the phenotype of NK cells derived from peripheral blood (PB) and peritoneal fluid (PF) and evaluated cytotoxic interactions between NK cells and autologous tumor cells (ATC) derived from patients. We provided evidence of impaired degranulation capacity of NK cells derived from patients' PF in the presence of ATC. Analyzing tumor cell ligands recognized by NK cell receptors, we found that ATC are characterized by an HLA class I⁺ phenotype (although the level of HLA-I expression varies among all patients) and by a heterogeneous expression of ligands for activating NK receptors (from normal to decreased expression of some markers). Furthermore, we observed a down-regulation of crucial NK cell activating receptors, primarily DNAX Accessory Molecule-1 (DNAM-1), on tumor-associated NK cells. Based on these results, we propose that this severe lysis defect may be due to both negative interactions between HLA-I-specific inhibitory NK cell receptors/HLA-I molecules and to defective interactions between activating NK receptors and cognate ligands. In conclusion, for the first time, the phenotypic and functional properties of tumor-associated NK cells and their ATC derived from PF of patients with advanced stage of OCCC were characterized. Taken together results indicate altered interactions between NK cells and ATC and shed light on the aggressive mechanisms of this cancer histotype. Further studies on this rare tumor will be helpful to improve and define more effective therapies.

Modeling the Diversity of Epithelial Ovarian Cancer through Ten Novel Well Characterized Cell Lines Covering Multiple Subtypes of the Disease

Cancer cell lines are amongst the most important pre-clinical models. In the context of epithelial ovarian cancer, a highly heterogeneous disease with diverse subtypes, it is paramount to study a wide panel of models in order to draw a representative picture of the disease. As this lethal gynaecological malignancy has seen little improvement in overall survival in the last decade, it is all the more pressing to support future research with robust and diverse study models. Here, we describe ten novel spontaneously immortalized patient-derived ovarian cancer cell lines, detailing their respective mutational profiles and gene/biomarker expression patterns, as well as their in vitro and in vivo growth characteristics. Eight of the cell lines were classified as high-grade serous, while two were determined to be of the rarer mucinous and clear cell subtypes, respectively. Each of the ten cell lines presents a panel of characteristics reflective of diverse clinically relevant phenomena, including chemotherapeutic resistance, metastatic potential, and subtype-associated mutations and gene/protein expression profiles. Importantly, four cell lines formed subcutaneous tumors in mice, a key characteristic for pre-clinical drug testing. Our work thus contributes significantly to the available models for the study of ovarian cancer, supplying additional tools to better understand this complex disease.

Novel monoclonal antibody against integrin α3 shows therapeutic potential for ovarian cancer

Ovarian cancer has a high recurrence rate after platinum‐based chemotherapy. To improve the treatment of ovarian cancer and identify ovarian cancer‐specific antibodies, we immunized mice with the human ovarian carcinoma cell line, SKOV‐3, and generated hybridoma clones. Several rounds of screening yielded 30 monoclonal antibodies (mAbs) with no cross‐reactivity to normal cells. Among these mAbs, OV‐Ab 30‐7 was found to target integrin α3 and upregulate p53 and p21, while stimulating the apoptosis of cancer cells. We further found that binding of integrin α3 by OV‐Ab 30‐7 impaired laminin‐induced focal adhesion kinase phosphorylation. The mAb alone or in combination with carboplatin and paclitaxel inhibited tumor progression and prolonged survival of tumor‐bearing mice. Moreover, immunohistochemical staining of ovarian patient specimens revealed higher levels of integrin α3 in cancer cells compared with normal cells. By querying online clinical databases, we found that elevated ITGA3 expression in ovarian cancer is associated with poor prognosis. Taken together, our data suggest that the novel mAb, OV‐Ab 30‐7, may be considered as a potential therapeutic for ovarian cancer.

A multicenter phase II randomized trial of durvalumab (MEDI-4736) versus physician's choice chemotherapy in recurrent ovarian clear cell adenocarcinoma (MOCCA)

BACKGROUND

The optimal treatment of recurrent ovarian clear cell carcinoma remains unknown. There is increasing rationale to support the role of immune checkpoint inhibitors targeting the programmed cell death protein 1 (PD-1)/programmed death-ligand 1 (PD-L1) axis in ovarian clear cell carcinoma.

PRIMARY OBJECTIVE

To evaluate the efficacy of durvalumab (MEDI-4736) compared with standard chemotherapy in patients with recurrent ovarian clear cell carcinoma.

STUDY HYPOTHESIS

Patients with recurrent ovarian clear cell carcinoma treated with durvalumab will have improved progression-free survival compared with those treated with chemotherapy of physician's choice.

TRIAL DESIGN

The MOCCA study is a multicenter, open-label, randomized phase II trial in patients with recurrent ovarian clear cell carcinoma, which recruited from eight sites across Gynecologic Cancer Group Singapore (GCGS), Korean Gynecologic-Oncology Group (KGOG), and Australia New Zealand Gynecological Oncology Group (ANZGOG). Enrolled patients were randomized in a 2:1 ratio to receive durvalumab or physician's choice of chemotherapy until disease progression, intolerable toxicity, or withdrawal of patient consent.

MAJOR INCLUSION/EXCLUSION CRITERIA

Eligible patients required histologically documented diagnosis of recurrent ovarian clear cell carcinoma, as evidenced by WT1 negativity. All patients must have been of Eastern Cooperative Oncology Group (ECOG) performance status 2 or better, and have had previous treatment with, and progressed or recurred after prior platinum-based chemotherapy. No more than four prior lines of treatment were allowed and prior immune checkpoint inhibitor treatment was not permitted.

PRIMARY ENDPOINTS

The primary endpoint was the median progression-free survival following treatment with durvalumab, compared with physician's choice of chemotherapy. Progression-free survival was defined as the time from the first day of treatment to the first observation of disease progression, or death due to any cause, or last follow-up.

SAMPLE SIZE

The target sample size was 46 patients.

ESTIMATED DATES FOR COMPLETING ACCRUAL AND PRESENTING RESULTS

Accrual has been completed and results are expected to be presented by mid-2021.

TRIAL REGISTRATION

Clinicaltrials.gov: NCT03405454.

Prognostic factors and effects of fertility-sparing surgery in women of reproductive age with ovarian clear-cell carcinoma: a propensity score analysis

Objective

The aim of this study was to investigate the clinical characteristics of young patients with stage I clear-cell carcinoma (CCC) and evaluate the prognostic factors and effects of fertility-sparing surgery (FSS) using propensity score (PS) adjustment.

Methods

We conducted a regional multi-institutional study between 1986 and 2017. Among 4,277 patients with ovarian tumor, clinical and pathological data of 103 fertile women with stage I unilateral CCC were collected. We evaluated survival and reproductive outcomes in these patients. Additionally, to analyze the effects of FSS, baseline imbalance between patients with and those without FSS was adjusted with an inverse probability of treatment weighting using PSs involving independent clinical variables.

Results

The mean patient age was 39.4 years, and the median follow-up period for surviving patients was 55.6 months. In multivariate analysis, stage IC2/IC3 (vs. IA/IC1) was the only independent prognostic factor for recurrence-free survival (RFS) and overall survival (OS). FSS was not associated with poorer prognosis when compared to the prognosis with non-preserving surgery with regard to both RFS and OS. No statistical difference in survival outcomes between FSS and other approaches was confirmed after PS adjustment. Among patients who underwent FSS, four deliveries with healthy neonates were noted without any gestational complications.

Conclusion

FSS can be considered in stage I CCC, specifically in stage IA and IC1 patients who strongly desire to have children in the future. Further clinical research is needed to clarify the optimal application of FSS for CCC.

Current and future strategies for treatment of ovarian clear cell carcinoma

Ovarian clear cell carcinoma (OCCC) is one of the five histological types of epithelial ovarian cancer (EOC). OCCC comprises 23% of all EOC cases in Japan, whereas the rate of OCCC in North America and Europe is much lower. OCCC is generally categorized as a rare gynecologic malignancy, and there is limited evidence for specific treatment. The clinical basis for treatment of OCCC is mostly based on retrospective studies, many of which were performed in Japan. Until recently, most randomized clinical trials for EOC have included OCCC; therefore, current treatment for OCCC is basically the same as that for other histologic types of EOC. However, the clinical characteristics of OCCC differ from those of high-grade serous carcinoma, particularly for chemosensitivity, and there is a need to develop new treatment for OCCC. The molecular background of OCCC has unique features: tumors are usually negative for p53 mutations and positive for ARID1A and/or PIK3CA mutations, whereas p53 mutations are common in high-grade serous or endometrioid carcinomas. These features may help in development of new treatment for OCCC. In this review, we described the current evidence for treatment of OCCC, including surgery, radiotherapy, chemotherapy, molecular targeted therapy and immunotherapy, and we discuss ongoing clinical trials and preclinical studies of new treatment approaches for OCCC.

[Incidence and impact of venous thrombosis in the diagnosis and therapeutic management of ovarian cancer]

OBJECTIVE

Ovarian cancer is a risk factor for venous thromboembolism (VTE), which worsens overall survival. The main objective of our study was to calculate the incidence of VTE in our population. We analyzed VTE impact on diagnosis and management of ovarian cancer.

METHODS

We conducted a retrospective, monocentric study in ovarian, fallopian tube and primary peritoneal cancer patients, divided into 2 groups (« Presence of VTE » and « Absence of VTE »). A univariate and multivariate analysis of factors associated with VTE was performed, and we compared delays of management in both groups.

RESULTS

Among 157 patients included in the study, 22.9% presented a VTE, and 52.8% were asymptomatic. The VTE was diagnosed prior to any treatment in 61.1% of patients and revealed the ovarian cancer in 27.8% of cases. In multivariate analysis, tumor size (OR=1.1, 95% CI: 1-2.21, P=0.012), malnutrition (OR=3.79, 95% CI: 1.16-12,4, P=0.028) and Ddimer level above 1.5μg/mL (OR=13.8, 95% CI 1.2-152.8, P=0.02) were significantly associated with VTE. No significant difference was found between the two groups in diagnostic or therapeutic strategy, as well as in delays of management.

CONCLUSION

We report a high incidence of VTE in ovarian cancer, including a lot of asymptomatic events. An early diagnosis with clinical examination and Ddimer level could improve its management and its prognosis.

Metastatic Ovarian Clear Cell Carcinoma in the Context of In Vitro Fertilization Pregnancy

Adnexal masses are routinely encountered in the clinical practice. However, adnexal masses during pregnancy are incidental findings and usually resolve spontaneously or can be managed conservatively during pregnancy due to their benign nature. Ovarian malignancy is a rare event to occur during pregnancy. Only a few cases of ovarian clear cell carcinoma (OCCC), a subtype of epithelial ovarian cancers, have been reported in pregnancy and all of which have undergone cystectomy or pregnancy termination prior to the last trimester of pregnancy. We present a unique case of OCCC in a pregnant 38-year old female of Asian ethnicity with endometriosis and an in vitro fertilization (IVF) pregnancy. The OCCC, initially suspected to be of benign nature, was removed via emergency cesarean section during delivery in the late preterm period. The Positron Emission Tomography scan performed a few weeks after delivery confirmed metastatic lesions. Our case study not only emphasizes the need for definitive treatment option for endometriosis but also a close surveillance of all masses diagnosed during pregnancy, in particular with a background of other risk factors such as endometriosis and Asian ethnicity. In addition, our study advocates the need for the guidelines for management of such rare cases.

Multiregion whole-genome sequencing depicts intratumour heterogeneity and punctuated evolution in ovarian clear cell carcinoma

BACKGROUND

Ovarian clear cell carcinoma (OCCC) arises from endometriosis and represents a difficult-to-treat gynaecological malignancy, in part, because its spatial intratumour heterogeneity and temporal evolutionary trajectories have not been explicitly defined.

METHODS

We performed whole-genome sequencing on six pathologically confirmed patients with OCCC. An R package named KataegisPortal was developed to identify and annotate loci of localised hypermutations. Immunohistochemical staining was conducted on a tissue microarray containing 143 OCCC specimens.

RESULTS

Multiregion analysis demonstrated considerable degrees of subclonal diversification, ascribable to dynamic mutagenic processes, as well as macroevolutionary events including the acquisition of aneuploidy and chromoplexy. KataegisPortal unveiled APOBEC-mediated kataegis in the early phases of OCCC pathogenesis. We further showed evidence that APOBEC3A and APOBEC3B were frequently expressed in OCCC and possibly regulated by the MAPK pathway. Notably, APOBEC3B-expressing OCCC displayed favourable prognosis and appreciable immunogenicity manifested by marked cytotoxic T-cell infiltration.

CONCLUSIONS

These results point to an appealing model of punctuated tumour evolution underlying OCCC neoplastic transformation and progression, which may pose formidable challenges of early detection and intervention, and indicate the intratumour heterogeneity of cancer-driving alterations, yielding important implications for molecular diagnosis and targeted treatment of this lethal disease.