Meta-Analysis of VTE Risk: Ovarian Cancer Patients by Stage, Histology, Cytoreduction, and Ascites at Diagnosis

Platelet and epithelial cell interations can be modeled in cell culture, and are not affected by dihomo-gamma-linolenic acid

Increasing evidence is implicating roles for platelets in the development and progression of ovarian cancer, a highly lethal disease that can arise from the fallopian tubes, and has no current method of early detection or prevention. Thrombosis is a major cause of mortality of ovarian cancer patients suggesting that the cancer alters platelet behavior. The objective of this study was to develop a cell culture model of the pathological interactions of human platelets and ovarian cancer cells, using normal FT epithelial cells as a healthy control, and to test effects of the anti-platelet dihomo-gamma-linolenic acid (DGLA) in the model. Both healthy and cancer cells caused platelet aggregation, however platelets only affected spheroid formation by cancer cells and had no effect on healthy cell spheroid formation. When naturally-formed spheroids of epithelial cells were exposed to platelets in transwell inserts that did not allow direct interactions of the two cell types, platelets caused increased size of the spheroids formed by cancer cells, but not healthy cells. When cancer cell spheroids formed using magnetic nanoshuttle technology were put in direct physical contact with platelets, the platelets caused spheroid condensation. In ovarian cancer cells, DGLA promoted epithelial-to-mesenchymal (EMT) transition at doses as low as 100 μM, and inhibited metabolic viability and induced apoptosis at doses ≥150 μM. DGLA doses ≤150 μM used to avoid direct DGLA effects on cancer cells, had no effect on the pathological interactions of platelets and ovarian cancer cells in our models. These results demonstrate that the pathological interactions of platelets with ovarian cancer cells can be modeled in cell culture, and that DGLA has no effect on these interactions, suggesting that targeting platelets is a rational approach for reducing cancer aggressiveness and thrombosis risk in ovarian cancer patients, however DGLA is not an appropriate candidate for this strategy.

Venous thromboembolism during neoadjuvant chemotherapy for ovarian cancer

OBJECTIVE

To determine the incidence of venous thromboembolism in patients with advanced epithelial ovarian cancer undergoing neoadjuvant chemotherapy in UK gynecological cancer centers. Secondary outcomes included incidence and timing of venous thromboembolism since cancer presentation, impact on cancer treatment, and mortality.

METHODS

All UK gynecological cancer centers were invited to participate in this multi-center retrospective audit through the British Gynecological Cancer Society. Data were captured on all patients undergoing neoadjuvant chemotherapy for International Federation of Gynecology and Obstetrics (FIGO) stage III/IV epithelial ovarian cancer within a 12-month period during 2021-2022. Patients on anticoagulation prior to cancer presentation were excluded. Patients who were diagnosed with venous thromboembolism between cancer presentation and commencing neoadjuvant chemotherapy were also excluded from our analysis of venous thromboembolism rates from neoadjuvant chemotherapy.

RESULTS

Fourteen UK gynecological cancer centers returned data on 660 eligible patients. The median age was 67 years (range 34-96). In total, 131/660 (19.8%) patients were diagnosed with venous thromboembolism from cancer presentation until discharge following cytoreductive surgery. Between commencing neoadjuvant chemotherapy and post-operative discharge, 65/594 (10.9%) patients developed venous thromboembolism (median 11.3%, IQR 5.9-11.3); 55/594 (9.3%) during neoadjuvant chemotherapy, 10/594 (1.7%) during post-operative admission. There was no significant difference across centers (p=0.47). Of these 65 patients, 44 (68%) were diagnosed with pulmonary embolism and 30 (46%) with deep-vein thrombosis (nine had both), including in major abdominal/pelvic vessels, with 36 (55%) presenting symptomatically and 29 (45%) diagnosed incidentally on imaging. Venous thromboembolism resulted in mortality (n=3/65, 5%), and delays/changes/cancelation of treatment (n=18/65, 28%).

CONCLUSION

Across a large, representative sample of UK gynecological cancer centers, one in five patients undergoing neoadjuvant chemotherapy were diagnosed with a potentially preventable venous thromboembolism, including one in nine diagnosed after commencing chemotherapy. This led to adverse clinical consequences for one third, including delay to oncological treatment and mortality. This high venous thromboembolism rate justifies the consideration of thromboprophylaxis in this patient group.

Ischemic stroke with concomitant clear cell carcinoma of the ovary: A case report and review of literature

BACKGROUND

Ischemic stroke is a rare event associated with an elevated risk of blood clot formation owing to an underlying malignancy. Herein, we present a case of ovarian carcinoma that led to cerebral infarction.

CASE SUMMARY

A 43-year-old woman experienced sudden onset right-sided paralysis and difficulty speaking two days after discovery of a large ovarian tumor measuring approximately 14 cm, which was suspected to be malignant. Further examination revealed left middle cerebral artery infarction. The patient had a history of hypertension and adenomyosis. Following stabilization with heparin treatment and vital signs management, the patient underwent debulking surgery, including total hysterectomy, bilateral salpingo-oophorectomy, omentectomy, and bilateral pelvic and para-aortic lymph node dissection. The final diagnosis was clear cell carcinoma of the right ovary (stage IA). Subsequently, the patient completed six rounds of adjuvant chemotherapy while simultaneously undergoing rehabilitation. Presently, the patient is able to walk independently, although she still experiences aphasia.

CONCLUSION

Prompt medical intervention and interdisciplinary care are crucial in the setting of incidental findings such as a large ovarian tumor.

Deep Learning-Based Dynamic Risk Prediction of Venous Thromboembolism for Patients With Ovarian Cancer in Real-World Settings From Electronic Health Records

PURPOSE

Patients with epithelial ovarian cancer (EOC) have an elevated risk for venous thromboembolism (VTE). To assess the risk of VTE, models were developed by statistical or machine learning algorithms. However, few models have accommodated deep learning (DL) algorithms in realistic clinical settings. We aimed to develop a predictive DL model, exploiting rich information from electronic health records (EHRs), including dynamic clinical features and the presence of competing risks.

METHODS

We extracted EHRs of 1,268 patients diagnosed with EOC from January 2007 through December 2017 at the National Cancer Center, Korea. DL survival networks using fully connected layers, temporal attention, and recurrent neural networks were adopted and compared with multi-perceptron-based classification models. Prediction accuracy was independently validated in the data set of 423 patients newly diagnosed with EOC from January 2018 to December 2019. Personalized risk plots displaying the individual interval risk were developed.

RESULTS

DL-based survival networks achieved a superior area under the receiver operating characteristic curve (AUROC) between 0.95 and 0.98 while the AUROC of classification models was between 0.85 and 0.90. As clinical information benefits the prediction accuracy, the proposed dynamic survival network outperformed other survival networks for the test and validation data set with the highest time-dependent concordance index (0.974, 0.975) and lowest Brier score (0.051, 0.049) at 6 months after a cancer diagnosis. Our visualization showed that the interval risk fluctuating along with the changes in longitudinal clinical features.

CONCLUSION

Adaption of dynamic patient clinical features and accounting for competing risks from EHRs into the DL algorithms demonstrated VTE risk prediction with high accuracy. Our results show that this novel dynamic survival network can provide personalized risk prediction with the potential to assist risk-based clinical intervention to prevent VTE among patients with EOC.

Haemostatic Gene Expression in Cancer-Related Immunothrombosis: Contribution for Venous Thromboembolism and Ovarian Tumour Behaviour

Ovarian cancer (OC) is the deadliest gynaecological malignancy. Identifying new prognostic biomarkers is an important research field. Haemostatic components together with leukocytes can drive cancer progression while increasing the susceptibility to venous thromboembolism (VTE) through immunothrombosis. Unravelling the underlying complex interactions offers the prospect of uncovering relevant OC prognostic biomarkers, predictors of cancer-associated thrombosis (CAT), and even potential targets for cancer therapy. Thus, this study evaluated the expression of F3, F5, F8, F13A1, TFPI1, and THBD in peripheral blood cells (PBCs) of 52 OC patients. Those with VTE after tumour diagnosis had a worse overall survival (OS) compared to their counterparts (mean OS of 13.8 ± 4.1 months and 47.9 ± 5.7 months, respectively; log-rank test, p = 0.001). Low pre-chemotherapy F3 and F8 expression levels were associated with a higher susceptibility for OC-related VTE after tumour diagnosis (χ2, p < 0.05). Regardless of thrombogenesis, patients with low baseline F8 expression had a shorter progression-free survival (PFS) than their counterparts (adjusted hazard ratio (aHR) = 2.54; p = 0.021). Among those who were not under platelet anti-aggregation therapy, low F8 levels were also associated with a shorter OS (aHR = 6.16; p = 0.006). Moving forward, efforts should focus on external validation in larger cohorts.

Venous Thromboembolism Prophylaxis in Gynecologic Oncology: A MITO-MaNGO Survey

Cancer-associated thrombosis is the second leading cause of death in cancer patients, and its incidence has been increasing in recent years. This survey was aimed at gathering information regarding the management of thromboembolic prophylaxis within the MITO (Multicenter Italian Trials in Ovarian Cancer)-MaNGO (Mario Negri Gynecologic Oncology) groups. We designed a self-administered, multiple-choice online questionnaire available only for MITO-MaNGO members for one month, starting in May 2022 and ending in June 2022. We processed one response form per center, and 50 responses were analyzed, with most of the respondents (78%) over 40 years old. We found that 82% of them consider thromboembolic prophylaxis in gynecologic oncology to be relevant. In 82% of the centers, a standardized protocol on venous thromboembolism (VTE) prophylaxis is used, which is applied to both patients undergoing surgery and those undergoing chemotherapy. In the remaining 18% of centers, prophylaxis is used exclusively for patients undergoing chemotherapy treatment. Prophylaxis of patients undergoing surgery and chemotherapy treatment is managed in most cases by the surgeon (72%) and oncologist (76%), respectively. Only 26% of respondents use a thromboembolic risk assessment scale, and of these, those used are the Caprini Score (6%), Khorana Score (6%), and Wells Score (2%). The respondents have good knowledge of low-molecular-weight heparin (90%) and average knowledge of dicumarolics (40%), direct oral anticoagulants (DOACs) (68%), and antiplatelet agents (40%). The results of our survey indicate that there is a good awareness of thromboembolic prophylaxis in gynecologic oncology. Nevertheless, it is used less in outpatients than in patients undergoing surgery. Moreover, the thromboembolic risk assessment scores are barely used.

Long Non-Coding RNAs: Bridging Cancer-Associated Thrombosis and Clinical Outcome of Ovarian Cancer Patients

Ovarian cancer (OC) and venous thromboembolism (VTE) have a close relationship, in which tumour cells surpass the haemostatic system to drive cancer progression. Long non-coding RNAs (lncRNAs) have been implicated in VTE pathogenesis, yet their roles in cancer-associated thrombosis (CAT) and their prognostic value are unexplored. Understanding how these lncRNAs influence venous thrombogenesis and ovarian tumorigenesis may lead to the identification of valuable biomarkers for VTE and OC management. Thus, this study evaluated the impact of five lncRNAs, namely MALAT1, TUG1, NEAT1, XIST and MEG8, on a cohort of 40 OC patients. Patients who developed VTE after OC diagnosis had worse overall survival compared to their counterparts (log-rank test, p = 0.028). Elevated pre-chemotherapy MEG8 levels in peripheral blood cells (PBCs) predicted VTE after OC diagnosis (Mann-Whitney U test, p = 0.037; Χ2 test, p = 0.033). In opposition, its low levels were linked to a higher risk of OC progression (adjusted hazard ratio (aHR) = 3.00; p = 0.039). Furthermore, low pre-chemotherapy NEAT1 levels in PBCs were associated with a higher risk of death (aHR = 6.25; p = 0.008). As for the remaining lncRNAs, no significant association with VTE incidence, OC progression or related mortality was observed. Future investigation with external validation in larger cohorts is needed to dissect the implications of the evaluated lncRNAs in OC patients.

Discovery and validation of serum glycoprotein biomarkers for high grade serous ovarian cancer

PURPOSE

This study aimed to identify serum glycoprotein biomarkers for early detection of high-grade serous ovarian cancer (HGSOC), the most common and aggressive histotype of ovarian cancer.

EXPERIMENTAL DESIGN

The glycoproteomics pipeline lectin magnetic bead array (LeMBA)-mass spectrometry (MS) was used in age-matched case-control serum samples. Clinical samples collected at diagnosis were divided into discovery (n = 30) and validation (n = 98) sets. We also analysed a set of preclinical sera (n = 30) collected prior to HGSOC diagnosis in the UK Collaborative Trial of Ovarian Cancer Screening.

RESULTS

A 7-lectin LeMBA-MS/MS discovery screen shortlisted 59 candidate proteins and three lectins. Validation analysis using 3-lectin LeMBA-multiple reaction monitoring (MRM) confirmed elevated A1AT, AACT, CO9, HPT and ITIH3 and reduced A2MG, ALS, IBP3 and PON1 glycoforms in HGSOC. The best performing multimarker signature had 87.7% area under the receiver operating curve, 90.7% specificity and 70.4% sensitivity for distinguishing HGSOC from benign and healthy groups. In the preclinical set, CO9, ITIH3 and A2MG glycoforms were altered in samples collected 11.1 ± 5.1 months prior to HGSOC diagnosis, suggesting potential for early detection.

CONCLUSIONS AND CLINICAL RELEVANCE

Our findings provide evidence of candidate early HGSOC serum glycoprotein biomarkers, laying the foundation for further study in larger cohorts.

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.

Crosstalk of Immune Cells and Platelets in an Ovarian Cancer Microenvironment and Their Prognostic Significance

Ovarian cancer (OC) is one of the deadliest gynecological cancers, largely due to the fast development of metastasis and drug resistance. The immune system is a critical component of the OC tumor microenvironment (TME) and immune cells such as T cells, NK cells, and dendritic cells (DC) play a key role in anti-tumor immunity. However, OC tumor cells are well known for evading immune surveillance by modulating the immune response through various mechanisms. Recruiting immune-suppressive cells such as regulatory T cells (Treg cells), macrophages, or myeloid-derived suppressor cells (MDSC) inhibit the anti-tumor immune response and promote the development and progression of OC. Platelets are also involved in immune evasion by interaction with tumor cells or through the secretion of a variety of growth factors and cytokines to promote tumor growth and angiogenesis. In this review, we discuss the role and contribution of immune cells and platelets in TME. Furthermore, we discuss their potential prognostic significance to help in the early detection of OC and to predict disease outcome.

Rivaroxaban Versus Enoxaparin for Thromboprophylaxis After major Gynecological Cancer Surgery: The VALERIA Trial : Venous thromboembolism prophylAxis after gynecoLogical pElvic cancer surgery with RIvaroxaban versus enoxAparin (VALERIA trial)

Direct oral anticoagulants (DOACs) for venous thromboembolism (VTE) prevention after major gynecological cancer surgery might be an alternative to parenteral low-molecular-weight heparin (LMWH). Patients undergoing major gynecological cancer surgery were randomized at hospital discharge to receive rivaroxaban 10 mg once daily or enoxaparin 40 mg once daily for 30 days. The primary efficacy outcome was a combination of symptomatic VTE and VTE-related death or asymptomatic VTE at day 30. The primary safety outcome was the incidence of major or clinically relevant nonmajor bleeding. Two hundred and twenty-eight patients were enrolled and randomly assigned to receive rivaroxaban (n  =  114)or enoxaparin (n  =  114). The trial was stopped due to a lower-than-expected event rate. The primary efficacy outcome occurred in 3.51% of patients assigned to rivaroxaban and in 4.39% of patients assigned to enoxaparin (relative risk 0.80, 95% CI 0.22 to 2.90; p  =  0.7344). Patients assigned to rivaroxaban had no primary bleeding event, and 3 patients (2.63%) in the enoxaparin group had a major or CRNM bleeding event (hazard ratio, 0.14; 95% CI, 0.007 to 2.73; P  =  0.1963). In patients undergoing major gynecological cancer surgery, thromboprophylaxis with rivaroxaban 10 mg daily for 30 days had similar rates of thrombotic and bleeding events compared to parenteral enoxaparin 40 mg daily. While the power is limited due to not reaching the intended sample size, our results support the hypothesis that DOACs might be an attractive alternative strategy to LMWH to prevent VTE in this high-risk population.

Risk of thrombosis in women with cancer undergoing controlled ovarian hyperstimulation for fertility preservation

PURPOSE

The study aims to evaluate the risk factors and incidence of thromboembolic events among adult women with cancer who underwent controlled ovarian hyperstimulation (COH) for fertility preservation.

METHODS

Retrospective, descriptive cohort analysis of patient demographics, medical history, cancer type/treatment, laboratory values, thrombosis within 6 months of COH.

RESULTS

4 of 127 study participants experienced a venous thromboembolic event within 6 months of COH. The median time between oocyte aspiration and the event was 0.25 years (range = 0.10-0.50). The average age at time of event was 25.3 years (SD = 5.3). Three of four thrombotic patients had ovarian cancer, one had breast cancer. All had received surgery and chemotherapy for treatment. All underwent an antagonist cycle ovarian stimulation protocol - none developed ovarian hyperstimulation syndrome. The average anti-mullerian hormone level at the time of hyperstimulation in the thrombosis group was 1.6 (SD = 1.3), compared to 3.6 in the non-thrombosis group. The average max estradiol level reached during ovarian stimulation was 1281.3 (SD = 665.3) in the thrombosis group and 1839.1 (SD = 1513.9) in the non-thrombosis group. Thromboembolic events were not directly associated with mortality.

CONCLUSIONS

Within this small descriptive study, the incidence of thromboembolic events in women with cancer undergoing COH for fertility preservation is high. Cancer may play a greater role than COH in thrombosis risk. Ovarian cancer patients who undergo ovarian stimulation may have an increased risk compared to other cancer types. These findings may inform future, prospective studies to determine the role of thromboprophylaxis.

Venous Thromboembolism in Women with Cancer with an Additional Focus on Breast and Gynecological Cancers

Cancer-associated venous thromboembolism (VTE) is common in women with cancer. Many clinical practice guidelines provide guidance for prevention and treatment; however, there are no specific recommendations for women. This is unfortunate because the proportion of women with breast- and gynecological cancers is high among patients with cancer-associated VTE. Thromboembolism often heralds cancer progression and poor prognosis and should—besides adequate anticoagulant management—also prompt reassessment and, if necessary, changes in cancer treatment. Recently, the new class of direct-acting oral anticoagulants (DOACs) has started to replace low-molecular-weight heparin as standard thromboprophylaxis and therapy in cancer patients. They are very effective, but they also carry a relevant risk of bleeding. Therefore, despite their ease of use, not every tumor patient qualifies for a DOAC, and this is especially true for gynecological tumor patients. Each prescription must be weighed individually. This review addresses specific aspects of VTE prophylaxis and management in women with cancer. Every physician who treats breast and gynecological cancers should be familiar with prophylaxis, diagnosis, and therapy of cancer-associated VTE. At the same time, patients should be informed by their physician what symptoms to look for and whom to contact if these symptoms occur, even outside of office hours and on weekends.

Molecular Correlates of Venous Thromboembolism (VTE) in Ovarian Cancer

BACKGROUND

The incidence of venous thromboembolism (VTE) in patients with ovarian cancer is higher than most solid tumors, ranging between 10-30%, and a diagnosis of VTE in this patient population is associated with worse oncologic outcomes. The tumor-specific molecular factors that may lead to the development of VTE are not well understood.

OBJECTIVES

The aim of this study was to identify molecular features present in ovarian tumors of patients with VTE compared to those without.

METHODS

We performed a multiplatform omics analysis incorporating RNA and DNA sequencing, quantitative proteomics, as well as immune cell profiling of high-grade serous ovarian carcinoma (HGSC) samples from a cohort of 32 patients with or without VTE.

RESULTS

Pathway analyses revealed upregulation of both inflammatory and coagulation pathways in the VTE group. While DNA whole-exome sequencing failed to identify significant coding alterations between the groups, the results of an integrated proteomic and RNA sequencing analysis indicated that there is a relationship between VTE and the expression of platelet-derived growth factor subunit B (PDGFB) and extracellular proteins in tumor cells, namely collagens, that are correlated with the formation of thrombosis.

CONCLUSIONS

In this comprehensive analysis of HGSC tumor tissues from patients with and without VTE, we identified markers unique to the VTE group that could contribute to development of thrombosis. Our findings provide additional insights into the molecular alterations underlying the development of VTE in ovarian cancer patients and invite further investigation into potential predictive biomarkers of VTE in ovarian cancer.

Risk of venous thromboembolism in ovarian cancer patients receiving neoadjuvant chemotherapy

PURPOSE

To determine the incidence of venous thromboembolism (VTE) and define clinical risk factors associated with the development of new-onset VTE in patients receiving neoadjuvant chemotherapy (NACT) for ovarian cancer (OC).

METHODS

An institutional ovarian cancer database was used to identify all OC patients receiving NACT from 04/2015-09/2018. VTE events were recorded and included clinically diagnosed deep venous thrombosis (DVT) and/or pulmonary embolism (PE). The incidence of VTE events was categorized according to treatment phases (P): P0) First visit/prior to induction of NACT; P1) during NACT before interval debulking surgery (IDS); P2) intraoperative through day 28 post-IDS; P3) during adjuvant chemotherapy.

RESULTS

A total of 290 patients were identified during the study period. Seventy-five (25.9%) developed a VTE at some point from time of presentation through the peri-operative period. Forty (13.8%) presented with VTE prior to initiation of NACT. An additional 27 (11.6%) developed a VTE during NACT (P1); 6 (3.9%) during the intraoperative and 28-day post-operative period (P2); and 2 (1.3%) during the adjuvant period (P3). The overall VTE rate was 25.9% (n = 75). FIGO stage IV disease was the only factor associated with increased risk for a new-onset VTE [Odds Ratio (OR): 3.9 (95% Confidence Interval [CI] = 1.2-13.6; p = 0.03].

CONCLUSIONS

Patients receiving NACT for advanced OC are at extremely high risk for developing thromboembolic events, either at initial presentation or during induction of NACT, a treatment phase that is traditionally without use of prophylactic anticoagulation. Since Khorana scoring is not predictive in this population, clinicians might need to consider increased screening or use of prophylactic anticoagulation in patients receiving NACT for OC, particularly in advanced metastatic disease.

Risk of Thrombo-Embolic Events in Ovarian Cancer: Does Bevacizumab Tilt the Scale? A Systematic Review and Meta-Analysis

Simple Summary

Thromboembolic events (TEs) are the second cause of death in cancer patients. Two forms of thromboembolic events may arise: arterial, such as ischemic stroke or myocardial infarction; and venous, such as deep vein thrombosis or pulmonary embolism. Bevacizumab is a monoclonal antibody directed against vascular endothelial-derived growth factor, and is widely used in advanced ovarian cancer. However, whether bevacizumab increases the risk of thromboembolic events in ovarian cancer is matter of debate since studies have shown conflicting results. In our systematic review and meta-analysis, we included 14 trials with bevacizumab in ovarian cancer. We found that the risk of arterial thromboembolic events more than doubled with a risk ratio of 2.45. Also the risk of venous thromboembolism increased 30% with bevacizumab treatment. Bevacizumab, therefore, can be considered an additional risk factor for selecting patients for primary prophylaxis with anticoagulants.

Abstract

Thromboembolic events are the second cause of death in cancer patients. In ovarian cancer, 3–10% of patients present with venous thromboembolism (VTE), but the incidence may rise to 36% along the disease course. Bevacizumab is a monoclonal antibody directed against vascular endothelial-derived growth factor, and in in vitro studies it showed a predisposition to hemostasis perturbation, including thrombosis. However, in vivo and clinical studies have shown conflicting results for its use as a treatment for ovarian cancer, so we conducted a systematic review and meta-analysis on the risk of arterial thromboembolism (ATE) and VTE in ovarian cancer patients treated with bevacizumab. The review comprised 14 trials with 6221 patients: ATE incidence was reported in 5 (4811 patients) where the absolute risk was 2.4% with bevacizumab vs. 1.1% without (RR 2.45; 95% CI 1.27–4.27, p = 0.008). VTE incidence was reported in 9 trials (5121 patients) where the absolute risk was 5.4% with bevacizumab vs. 3.7% without (RR 1.32; 95% CI 1.02–1.79, p = 0.04). Our analysis showed that the risk of arterial and venous thromboembolism increased in patients treated with bevacizumab. Thrombolic events (TEs) are probably underreported, and studies should discriminate between ATE and VTE. Bevacizumab can be considered as an additional risk factor when selecting patients for primary prophylaxis with anticoagulants.

Venous thromboembolism in women with ovarian cancer undergoing neoadjuvant chemotherapy prior to cytoreductive surgery: A retrospective study

INTRODUCTION

Ovarian cancer is associated with a venous thromboembolism risk of at least 7.2% by 2 years from diagnosis, and although patients undergoing surgery benefit from routine thromboprophylaxis, those undergoing neoadjuvant chemotherapy do not. This study aims to determine the venous thromboembolism incidence in patients with ovarian cancer undergoing neoadjuvant chemotherapy, and explore whether any subset is at higher risk, in order to evaluate whether thromboprophylaxis is justified in some or all of these patients.

MATERIAL AND METHODS

This was a retrospective review of all women undergoing neoadjuvant chemotherapy for FIGO radiological stages III and IV primary ovarian, fallopian tube, and primary peritoneal cancer, between 2000 and 2015, in a London tertiary cancer center. The primary outcome was venous thromboembolism rate among women undergoing neoadjuvant chemotherapy. The secondary outcomes were patient or treatment factors associated with venous thromboembolism risk, including age, body mass index, smoking status, performance status, and tumor stage.

RESULTS

We identified 278 eligible women from the ovarian cancer database. Fifty-eight women (20.9%) developed venous thromboembolism between initial presentation and the immediate postoperative period, of which 45 (77.6%) developed a pulmonary embolism. In all, 15.1% of women developed venous thromboembolism from the start of neoadjuvant chemotherapy. Age, body mass index, smoking, or other comorbidities were not significantly associated with venous thromboembolism risk. One woman died from massive pulmonary embolism, 27 women underwent inferior vena cava filter insertion, and 10 had surgery delayed.

CONCLUSIONS

This study demonstrates an unacceptably high rate of avoidable venous thromboembolism including pulmonary embolism in these women, which complicates and delays treatment. Thromboprophylaxis during neoadjuvant chemotherapy should now be assessed prospectively.

Venous thromboembolism incidence in cancer patients with germline BRCA mutations

BACKGROUND

Germline BRCA (gBRCA) mutations predispose to an increased risk of breast and ovarian cancer among other neoplasms. Recently, several genomic alterations such as ALK and ROS-1 rearrangements have been described as molecular drivers of venous thromboembolism (VTE). The association of gBRCA mutations and VTE is unknown.

MATERIALS AND METHODS

We performed an observational, retrospective, single-center study to determine the VTE incidence in consecutive patients with gBRCA mutations and cancer diagnosis attended in the multidisciplinary heredofamiliar cancer unit (HFCU) of Hospital General Universitario Gregorio Marañón, Spain, from 2010 to 2019.

RESULTS

One-hundred and forty-one patients were included in the analysis. The overall VTE incidence was 12.8%. The highest incidence was reported in ovarian cancer patients (20.0%), followed by patients with both ovarian and breast cancers (16.6%) and the lowest was found in breast cancer (4.9%). No difference in the type of gBRCA mutation (1 or 2) in terms of VTE rate was observed. Sixty one percent of the patients were receiving anti-cancer therapy at the time of VTE diagnosis and the majority of the events (83.3%) were diagnosed in ambulatory setting. Khorana score was of limited value to detect high-risk patients.

CONCLUSIONS

The VTE incidence observed in our study is consistent with prior data described in general population of breast and ovarian cancer. The risk of VTE in these patients seems to be driven by the type of cancer. We have not observed any significant interaction of gBRCA mutation status and cancer-associated thrombosis.

Biologically Active Tissue Factor-Bearing Larger Ectosome-Like Extracellular Vesicles in Malignant Effusions from Ovarian Cancer Patients: Correlation with Incidence of Thrombosis

The development of malignant effusions such as ascites reflects a massive progression of a malignant disease. In patients with ovarian carcinoma, a high amount of ascites (>500 mL) is an independent negative prognostic marker. The composition and constituents of ascites reflect the inflammatory environment of the underlying tumor. Increased cellular resistance of ascites-derived tumor cells and the development of venous thromboembolic events (VTE) are major risks for these patients, especially in patients with advanced ovarian carcinoma. In this study, we discuss the release of tissue factor-bearing extracellular vesicles (TF⁺ EVs) from tumor cells into the environment (ascites fluid) and their systemic spreading as a possible causal explanation of the pathologic coagulation status in these patients. We obtained ascites from patients with advanced ovarian carcinoma, collected during surgery or therapeutic paracentesis (n = 20). Larger ectosome-like EVs were isolated using sequential centrifugation, quantified by high-resolution flow cytometry and analyzed using nanoparticle tracking analysis. Furthermore, the pro-coagulant properties (TF activity) of EVs were determined. Compared to published TF activities of EVs from healthy persons, TF activities of EVs derived from ascites of patients with ovarian cancer were very high, with a median of 80 pg/mL. The rate of VTE, as reported in the patient files, was high as well (35%, 7 out of 20). Furthermore, all but one patient with VTE had EV concentrations above the median within their ascetic fluid (p < 0.02). Since VTE continues to be a frequent cause of death in cancer patients, prophylactic antithrombotic treatment might be worth considering in these patients. However, given the risk of bleeding, more clinical data are warranted. Although the study is too small to enable reaching a conclusion on direct clinical implementation, it can well serve as a proof of principle and a rationale to initiate a prospective clinical study with different patient subgroups. We also show ex vivo that these larger ectosome-like EVs induce intracellular ERK phosphorylation and tumor cell migration, which is not directly related to their pro-coagulative potency, but might help to understand why cancer patients with thromboembolic events have a poorer prognosis.