A risk score for prediction of venous thromboembolism in gynecologic cancer: The Thrombogyn score

Chemotherapy alters thrombomodulin and factor VIIIc expression resulting in acquired activated protein C resistance and enhanced thrombin generation in cancer associated thrombosis

BACKGROUND

Tumour type, treatment and patient related factors contribute to cancer associated venous thromboembolism (VTE), however, the role of each factor and the mechanisms involved are not understood.

AIM

To assess the role of the tumour, and of chemotherapy, in mediating the procoagulant response associated with VTE in gynaecological cancer patients.

METHODS

Gynaecological cancer patients who developed VTE during follow-up (n = 59) (VTE+) were matched with treatment naïve(treatment (-)(VTE-)(n = 120) and chemotherapy treated patients(treatment (+)(VTE-) (n = 57)). Thrombin generation, Factor V(FV), VIIIc(FVIIIc), Tissue Factor Pathway Inhibitor(TFPI), soluble Thrombomodulin(sTM), Protein S(PS), C(PC) endothelial protein C receptor(EPCR) and fibrinogen were compared in each group. EPCR and TM expression was assessed in EA.hy926 cells in vitro following addition of chemotherapy agents. mRNA expression of coagulation genes was measured in tumour biopsies.

RESULTS

Thrombin generation was increased in treatment(-)VTE(+) compared with treatment(-)VTE(-) controls but not in the treatment(+)VTE(+) patients. Using the TM modified assay, thrombin generation was increased in the treatment (+)VTE(-) group compared with treatment(-)(VTE-) with a further increase in the treatment (+) VTE(+) group. Reduced levels of sTM in treatment (+) VTE(+) patients correlated with thrombin generation. TM expression was reduced in vitro by carboplatin and paclitaxel. FVIIIc was increased in both VTE groups and was predictive of VTE. F5 mRNA levels were lower in tumours from VTE(+) patients compared with controls.

CONCLUSION

Chemotherapy alters sTM and confers an acquired activated Protein C(aPC) resistance which may be implicated in cancer associated VTE in gynaecological cancer patients. FVIIIc may be a useful predictive marker for VTE in cancer patients in this setting.

Thromboprophylaxis in patients with locally advanced cervical cancer treated with chemoradiation and brachytherapy

OBJECTIVE

To determine the incidence of clinical and subclinical venous thromboembolic events (VTE) in patients with locally advanced cervical cancer (LACC) treated with high-dose thromboprophylaxis during definitive chemoradiation and brachytherapy.

METHODS

A prospective observational study was undertaken from August 2021 to December 2023 in patients with primary LACC treated with definitive chemoradiation in two Dutch tertiary hospitals. Patients received high-dose thromboprophylaxis during chemoradiation and brachytherapy. In week 4 or 5 of the overall treatment time, plasma D-dimer levels were determined, and all patients underwent venous ultrasound imaging of the legs to screen for deep vein thrombosis (DVT). If indicated, patients received a CT-angiography to screen for pulmonary embolism (PE).

RESULTS

Among 89 included patients, cumulative incidence of clinical and subclinical (V)TE was 7.9 % (n = 7). DVT was found in two patients, PE in three patients, DVT and PE in one patient and one patient had an arterial thromboembolic event (ATE). Of these patients, three (3.4 %) had subclinical VTE, diagnosed during the screening before brachytherapy, and four (4.5 %) had clinical VTE of whom two developed VTE during chemoradiation, one during hospitalization for brachytherapy and one after completing treatment. Of the seven patients with VTE, two (28.6 %) were treated with hyperthermia. Adverse bleeding events after brachytherapy occurred in eight patients.

CONCLUSION

Routine thromboprophylaxis in patients with LACC leads to a relative low incidence of thromboembolic events during chemoradiation and brachytherapy. Further research should focus on identifying high risk factors leading to targeted screening and prevention of VTE in high risk patients.

Circulating Blood Biomarkers and Risk of Venous Thromboembolism in Cancer Patients: A Systematic Review and Meta-Analysis

BACKGROUND

 Cancer patients have an increased risk of venous thromboembolism (VTE). Currently, the availability of highly discriminatory prediction models for VTE in cancer patients is limited. The implementation of biomarkers in prediction models might lead to refined VTE risk prediction. In this systematic review and meta-analysis, we aimed to evaluate candidate biomarkers and their association with cancer-associated VTE.

METHODS

 We searched Medline, EMBASE, and Cochrane Central for studies that evaluated biomarkers in adult cancer patients from inception to September 2022. We included studies reporting on VTE after a cancer diagnosis with biomarker measurements performed at a defined time point. Median/mean differences (for continuous measures) and odds ratios (for dichotomous measures) with 95% confidence intervals were estimated and pooled using random-effects models.

RESULTS

 We included 113 studies in the systematic review. Of these, 50 studies were included in the meta-analysis. We identified two biomarkers at cancer diagnosis (factor VIII and time to peak thrombin), three biomarkers pre-chemotherapy (D-dimer, fibrinogen, and mean platelet volume), and one biomarker preoperatively (platelet count) that had significant median or mean differences. Additionally, we found that hemoglobin <100 g/L and white blood count >11 × 109/L were significantly associated with future VTE risk only when measured at cancer diagnosis. Pre-chemotherapy neutrophil-to-lymphocyte ratio ≥3 and preoperative platelet count ≥400 × 109/L were also found to be associated with future VTE risk.

CONCLUSION

 In conclusion, this study identified nine candidate blood biomarkers that may help in optimizing VTE prediction in cancer patients that should be further explored in future studies.

Machine learning models for prediction of postoperative venous thromboembolism in gynecological malignant tumor patients

AIM

To identify risk factors that associated with the occurrence of venous thromboembolism (VTE) within 30 days after hysterectomy among gynecological malignant tumor patients, and to explore the value of machine learning (ML) models in VTE occurrence prediction.

METHODS

A total of 1087 patients between January 2019 and January 2022 with gynecological malignant tumors were included in this single-center retrospective study and were randomly divided into the training dataset (n = 870) and the test dataset (n = 217). Univariate logistic regression analysis was used to identify risk factors that associated with the occurrence of postoperative VTE in the training dataset. Machine learning models (including decision tree (DT) model and logistic regression (LR) model) to predict the occurrence of postoperative VTE were constructed and internally validated.

RESULTS

The incidence of developing 30-day postoperative VTE was 6.0% (65/1087). Age, previous VTE, length of stay (LOS), tumor stage, operative time, surgical approach, lymphadenectomy (LND), intraoperative blood transfusion and gynecologic Caprini (G-Caprini) score were identified as risk factors for developing postoperative VTE in gynecological malignant tumor patients (p < 0.05). The AUCs of LR model and DT model for predicting VTE were 0.722 and 0.950, respectively.

CONCLUSION

The ML models, especially the DT model, constructed in our study had excellent prediction value and shed light upon its further application in clinic practice.

Gynecological Cancer and Venous Thromboembolism: A Narrative Review to Increase Awareness and Improve Risk Assessment and Prevention

The prevention and appropriate management of venous thromboembolism in cancer patients is of paramount importance. However, the literature data report an underestimation of this major problem in patients with gynecological cancers, with an inconsistent venous thromboembolism risk assessment and prophylaxis in this patient setting. This narrative review provides a comprehensive overview of the available evidence regarding the management of venous thromboembolism in cancer patients, focusing on the specific context of gynecological tumors, exploring the literature discussing risk factors, risk assessment, and pharmacological prophylaxis. We found that the current understanding and management of venous thromboembolism in gynecological malignancy is largely based on studies on solid cancers in general. Hence, further, larger, and well-designed research in this area is needed.

In Search of the Perfect Thrombosis and Bleeding-Associated Cancer Scale

Thrombosis and bleeding are commonly observed in cancer patients, and their management is crucial for positive patient outcomes. A comprehensive, prophylactic, and therapeutic management of venous thrombosis should focus on identifying the patients who would benefit most from treatment to reduce mortality and minimize the risk of thrombosis recurrence without significantly increasing the risk of bleeding. Existing cancer scales provide valuable information for assessing the overall burden of cancer and guiding treatment decisions, but their ability to predict thrombotic and bleeding events remains limited. With increasing knowledge of the pathophysiology of cancer and the availability of advanced anticancer therapies, new risk factors for cancer-associated thrombosis and bleeding are being identified. In this report, we analyze the current literature and identify new risk factors for venous thrombosis and bleeding which are not included in routinely used risk scores. While some existing cancer scales partially capture the risk of thrombosis and bleeding, there is a need for more specific and accurate scales tailored to these complications. The development of such scales could improve risk stratification, aid in treatment selection, and enhance patient care. Therefore, further research and development of novel cancer scales focused on thrombosis and bleeding are warranted to optimize patient management and outcomes.

Incidence of venous thromboembolism and predictive ability of age-adjusted international prognostic index for prediction of venous thromboembolism in Asian patients with diffuse large B-cell lymphoma

Diffuse large B-cell lymphoma (DLBCL) is one of the malignancies at high risk for the development of venous thromboembolism (VTE). We aimed to evaluate the incidence of VTE and the predictive ability of the age-adjusted international prognostic index (aaIPI) for the prediction of VTE among DLBCL patients. This was a retrospective cohort study including adult patients with newly diagnosed DLBCL. Differences in VTE occurrence within one year after diagnosis of DLBCL were estimated across aaIPI groups using the Kaplan-Meier model, Cox's model, and Gray's model with deaths regarded as competing events. Five hundred and ninety-one newly diagnosed DLBCL patients with a median age of 58 (range 16-93) years were included in this study. At a median follow-up time of 365 (range 2-365) days, VTE events were objectively diagnosed in 32 patients, giving a one-year cumulative incidence of VTE of 5.4% (95% confidence interval [CI], 3.7-7.6). Patients with aaIPI ≥ 2 had a significantly higher risk of VTE than patients with aaIPI < 2 (hazard ratio, 3.5; 95% CI, 1.6-7.8; p = 0.001 based on Cox's model and sub-distribution hazard ratio, 3.0; 95% CI, 1.3-6.7; p = 0.007 using Gray's model). The C-statistic of aaIPI was 0.65 (95% CI, 0.58-0.72). We demonstrated that the incidence of VTE in Asian DLBCL patients was not uncommon. The aaIPI was effective in determining the risk of VTE in DLBCL patients, even when including death as a competing event. aaIPI may be helpful in identifying patients at higher risk of VTE in DLBCL patients.

Risk of venous thromboembolism and bleeding after major surgery for ovarian cancer: standard in-hospital versus extended duration of thromboprophylaxis

BACKGROUND

Venous thromboembolism (VTE) is a frequent complication in patients with ovarian cancer after major surgery. Based on limited data, international guidelines recommend extended thromboprophylaxis for up to 28 days.

OBJECTIVES

To assess the incidence of VTE and bleeding within 30 days following major surgery in patients with ovarian cancer and to evaluate the association between VTE and thromboprophylaxis duration.

METHODS

This was a single-center, retrospective, "before-after" cohort study in patients with ovarian cancer undergoing major surgery. Before July 2019, the local protocol mandated a standard course of thromboprophylaxis during hospital stay only. From July 2019 onward, patients received extended thromboprophylaxis for 28 days. The cumulative incidences of VTE and major bleeding within 30 days after surgery were estimated using the Kaplan-Meier method, with 95% confidence intervals (CIs). Cox regression analysis was performed to evaluate the association between thromboprophylaxis duration and VTE incidence.

RESULTS

Between January 2018 and December 2020, 250 women were included, of which 118 (47.2%) received extended and 132 (52.8%) standard thromboprophylaxis. During follow-up, 12 patients developed VTE (cumulative incidence, 4.8%; 95% CI, 2.1-7.4) and 2 major bleeding (cumulative incidence 0.8%; 95% CI, 0.0-1.9). Compared with standard thromboprophylaxis, VTE incidence was numerically lower with extended duration of thromboprophylaxis (5/118 [4.2%] vs 7/132 [5.3%]) but not significantly different (hazard ratio, 0.80; 95% CI, 0.25-2.52). The risk of major bleeding was similar in both groups (1/118 [0.8%] vs 1/132 [0.8%]; hazard ratio, 1.12; 95% CI, 0.07-17.89).

CONCLUSIONS

The cumulative VTE incidence in patients with ovarian cancer following major surgery was considerable. Extended thromboprophylaxis was safe and associated with a numerically lower risk of VTE but not significantly different.

Standardization of risk prediction model reporting in cancer-associated thrombosis: Communication from the ISTH SSC subcommittee on hemostasis and malignancy

Since the development of the Khorana score to predict risk of cancer-associated venous thromboembolism (VTE), many modified and de novo risk prediction models (RPMs) have been proposed. Comparison of the prognostic performance across models requires comprehensive reporting and standardized methods for model development, validation and evaluation. To improve the standardization of RPM reporting, the Transparent Reporting of a multivariable prediction model for Individual Prognosis or Diagnosis (TRIPOD) tool was published in 2015. To better understand the quality of reporting and development of RPMs for cancer-associated VTE, we performed a literature search of published RPMs and assessed each model using the TRIPOD checklist. Our results yielded 29 RPMs for which 30 items were evaluated. There was a non-significant (p = 0.15) improvement in reporting of the 30 items in the post-TRIPOD era (81%) versus the pre-TRIPOD era (75%). Of seven items (title, sample size, missing data handling, baseline demographics, methods and results for model performance, and supplemental resources) with the lowest reporting in the pre-TRIPOD era (<70%), there was an average improvement of 22% in the post-TRIPOD era. Only two of the 22 studies published in the post-TRIPOD era acknowledged compliance with TRIPOD. Informed by the results of this assessment, the Scientific and Standardization Committee (SSC) Subcommittee on Hemostasis & Malignancy of the International Society on Thrombosis and Hemostasis (ISTH) advocates for standardization of four key elements of RPMs for cancer-associated VTE: (1) inclusion of the TRIPOD checklist, (2) clear definition of the derivation population, with justification of sample size, (3) clear definition of predictors, and (4) external validation prior to implementation.

Emerging roles of platelets in cancer biology and their potential as therapeutic targets

The main role of platelets is to control bleeding and repair vascular damage via thrombosis. They have also been implicated to promote tumor metastasis through platelet-tumor cell interactions. Platelet-tumor cell interactions promote tumor cell survival and dissemination in blood circulation. Tumor cells are known to induce platelet activation and alter platelet RNA profiles. Liquid biopsies based on tumor-educated platelet biomarkers can detect tumors and correlate with prognosis, personalized therapy, treatment monitoring, and recurrence prediction. Platelet-based strategies for cancer prevention and tumor-targeted therapy include developing drugs that target platelet receptors, interfere with the release of platelet particles, inhibit platelet-specific enzymes, and utilize platelet-derived “nano-platelets” as a targeted drug delivery platform for tumor therapy. This review elaborates on platelet-tumor cell interactions and the molecular mechanisms and discusses future research directions for platelet-based liquid biopsy techniques and platelet-targeted anti-tumor strategies.

Provider education program on the Khorana score to promote venous thromboembolism chemoprophylaxis in patients with gynecologic cancer

OBJECTIVE

To evaluate the efficacy of a healthcare improvement initiative to improve provider compliance with the American Society of Clinical Oncology (ASCO) guidelines for venous thromboembolism chemoprophylaxis in patients with gynecologic cancer receiving chemotherapy.

METHODS

A healthcare improvement initiative was implemented at our institution to improve compliance with American Society of Clinical Oncology venous thromboembolism chemoprophylaxis guidelines in patients receiving chemotherapy with a Khorana score ≥2. Baseline Khorana score and venous thromboembolism data were retrospectively collected for chemotherapy-naïve patients with gynecologic cancer initiating chemotherapy between December 2018 and November 2019. Data for the post-intervention period from December 2019 to December 2020 were captured prospectively. Primary outcome was compliance with American Society of Clinical Oncology guidelines. Secondary outcomes were incidence of venous thromboembolism and complications surrounding venous thromboembolism chemoprophylaxis.

RESULTS

We identified 62 patients in the pre-implementation cohort. Approximately half had a Khorana score of ≥2 (52%). Median Khorana score was 2 (range 1-4). None of these patients received prophylactic chemoprophylaxis. Seven (11%) of these patients were diagnosed with venous thromboembolism. Multivariate logistic regression showed increasing Khorana score was associated with increased venous thromboembolism risk (OR 4.9, p=0.01). With cut-off Khorana score of 2, there was no significant increase in venous thromboembolism. However, with a cut-off Khorana score of 3, patients were 15 times more likely to have venous thromboembolism (OR 15.2, p=0.04). In the post-intervention cohort, 22 patients were eligible for chemoprophylaxis and 11 patients were given anticoagulation (50% compliance with guidelines), with no incidence of venous thromboembolism or adverse effects of therapy noted among those receiving chemoprophylaxis.

CONCLUSION

Notifying providers of a patient's Khorana score improves compliance with American Society of Clinical Oncology guidelines for venous thromboembolism chemoprophylaxis among chemotherapy patients.

Extended thromboprophylaxis post gynaecological cancer surgery; the effect of weight adjusted and fixed dose LMWH (Tinzaparin)

OBJECTIVE

Gynaecological cancer surgery is associated with high rates of venous thromboembolism (VTE) despite recommended prophylaxis. We sought to investigate the impact of extended prophylaxis with fixed dose and weight based LMWH in patients undergoing gynaecological cancer surgery.

METHODS

VTE rates were recorded in patients who received LMWH prophylaxis (4500 IU Tinzaparin once daily) for the duration of hospital stay (2006-2012) (n = 610) and were compared with VTE rates in patients who underwent surgery after the introduction of extended prophylaxis (3500/4500 IU Tinzaparin for patients with BMI < 40kg/m2 and 75 IU/kg for BMI > 40 kg/m2) (2012-2017) (n = 651). Peak (4 h) anti-Xa levels in a subset of patients were also evaluated.

RESULTS

73 (5.7%) cases of VTE were recorded during 1 year of follow-up. 20 cases occurred during hospital stay. There was no significant difference in the rate of VTE between the extended prophylaxis cohort and the standard prophylaxis cohort. 23/24 patients who developed VTE in the extended prophylaxis cohort received a fixed (4500 units) dose of Tinzaparin. 63% of patients who received a fixed LMWH dose had peak anti-Xa levels below the target range (0.2-0.4 IU/ml). Peak anti-Xa was lower in patients who subsequently developed VTE compared with those who received either fixed dose (P = 0.041) and weight adjusted Tinzaparin (P = 0.0006).

CONCLUSIONS

Extended prophylaxis with Tinzaparin does not significantly reduce VTE rates in gynaecological cancer patients post surgery. Peak anti-Xa levels may be suboptimal in many patients receiving a fixed LMWH dose. Further studies are required to determine whether weight adjusted doses of Tinzaparin may provide more effective prophylaxis following gynaecological cancer surgery.

Venous Thromboembolism in Patients Receiving Neoadjuvant Chemotherapy for Advanced Ovarian Cancer and Impact on Survival

OBJECTIVE

To determine the incidence of venous thromboembolism (VTE) in patients with ovarian cancer receiving neoadjuvant chemotherapy (NACT), identify risk factors for VTE, and assess the effect of VTE on treatment trajectory and overall survival.

METHODS

This is a retrospective cohort study of patients diagnosed with ovarian, fallopian tube, or primary peritoneal cancer treated with NACT between 2013 to 2016 in Alberta, Canada. The primary outcome was incidence of VTE during NACT. Secondary outcomes were risk factors for VTE and overall survival. Data related to patient demographics, cancer treatment, and incidence of VTE were collected. Statistical analyses included Kaplan-Meier estimates and univariate and multivariate Cox regression analysis.

RESULTS

A total of 284 patients were included in this study. Average age at diagnosis was 63.8 years. The incidence of VTE during NACT was 13.3%. Patients with VTE were less likely to undergo interval debulking surgery (58.3%) than patients without VTE (78.6%). Kaplan-Meier estimates demonstrated a decrease in overall survival in patients who had VTE during NACT (15.0 mo; 95% CI 14.5-16.5) compared with patients who did not (26.8 mo; 95% CI 22.8-30.9) (P < 0.0001). Multivariate analysis identified albumin <35 g/L, BMI >30 kg/m², and non-serous histology as risk factors for VTE.

CONCLUSION

The risk of VTE in this cohort was 13.3%, which was associated with decreased overall survival. These findings suggest that thromboprophylaxis may have a role in this patient population.

Platelets, immune cells and the coagulation cascade; friend or foe of the circulating tumour cell?

Cancer cells that transit from primary tumours into the circulatory system are known as circulating tumour cells (CTCs). These cancer cells have unique phenotypic and genotypic characteristics which allow them to survive within the circulation, subsequently extravasate and metastasise. CTCs have emerged as a useful diagnostic tool using "liquid biopsies" to report on the metastatic potential of cancers. However, CTCs by their nature interact with components of the blood circulatory system on a constant basis, influencing both their physical and morphological characteristics as well as metastatic capabilities. These properties and the associated molecular profile may provide critical diagnostic and prognostic capabilities in the clinic. Platelets interact with CTCs within minutes of their dissemination and are crucial in the formation of the initial metastatic niche. Platelets and coagulation proteins also alter the fate of a CTC by influencing EMT, promoting pro-survival signalling and aiding in evading immune cell destruction. CTCs have the capacity to directly hijack immune cells and utilise them to aid in CTC metastatic seeding processes. The disruption of CTC clusters may also offer a strategy for the treatment of advance staged cancers. Therapeutic disruption of these heterotypical interactions as well as direct CTC targeting hold great promise, especially with the advent of new immunotherapies and personalised medicines. Understanding the molecular role that platelets, immune cells and the coagulation cascade play in CTC biology will allow us to identify and characterise the most clinically relevant CTCs from patients. This will subsequently advance the clinical utility of CTCs in cancer diagnosis/prognosis.

Procoagulant activity in high grade serous ovarian cancer patients following neoadjuvant chemotherapy-The role of the activated protein C pathway

INTRODUCTION

Ovarian cancer patients are at high risk of thrombosis particularly during chemotherapy treatment however the mechanism is not understood. The aim of this study is to investigate the role of the activated protein C (aPC) pathway in the procoagulant activity observed in ovarian cancer patients undergoing neoadjuvant chemotherapy.

PATIENTS AND METHODS

Thrombin generation was determined before and after addition of thrombomodulin (TM) in high grade serous ovarian cancer (HGSOC) patients treated with neoadjuvant chemotherapy (n = 29) compared with HGSOC patients who were chemo naïve (n = 23) and patients with benign tumours (n = 29). Plasma expression of proteins from the aPC pathway was analysed. mRNA expression was determined in endothelial (EA.hy926) and ovarian (OAW42) cell lines following addition of carboplatin and paclitaxel.

RESULTS

Lower levels of ETP (p < 0.007; p < 0.003) and peak thrombin (p < 0.0008; p < 0.0018) were found in the neoadjuvant group compared with both chemo naïve and benign groups. Following addition of TM, ETP (p < 0.0005) and peak thrombin (p < 0.0049) were higher in the neoadjuvant group compared with the benign controls indicating an increase in aPC resistance. Increased TM and lower levels of protein S were found in the neoadjuvant group compared with benign controls (p < 0.05; p < 0.003). Factor V levels were increased in the neoadjuvant group compared with the chemo naïve group (p < 0.05). Carboplatin and paclitaxel altered the expression of EPCR and thrombomodulin in OAW42 cells with a modest effect on EA.hy926 cells.

CONCLUSION

Chemotherapy induced procoagulant activity in HGSOC is associated with an alteration in expression of key members of the aPC pathway. This acquired aPC resistance may explain the procoagulant phenotype associated with ovarian cancer patients undergoing chemotherapy.