Induction therapy alters plasma fibrin clot properties in multiple myeloma patients: association with thromboembolic complications

Fibrin Clot Properties in Cancer: Impact on Cancer-Associated Thrombosis

Cancer is associated with a high risk of venous thromboembolism (VTE) and its recurrence. There is evidence that the prothrombotic fibrin clot phenotype, involving the formation of denser and stiffer clots relatively resistant to lysis, occurs in cancer patients, which is in part related to enhanced inflammation, oxidative stress, and coagulation activation, along with the release of neutrophil extracellular traps, indicating that fibrin-related mechanisms might contribute to cancer-associated thrombosis (CAT). Multiple myeloma and its therapy have been most widely explored in terms of altered fibrin characteristics, but prothrombotic fibrin clot features have also been reported in patients with active solid cancer, including lung cancer and gastrointestinal cancer. Patient-related factors such as advanced age, smoking, and comorbidities might also affect fibrin clot characteristics and the risk of CAT. Prothrombotic fibrin clot features have been shown to predict the detection of cancer in patients following VTE during follow-up. Cancer-specific therapies and anticoagulation can favorably modify the phenotype of a fibrin clot, which may alter the course of CAT. It is unclear whether the fibrin clot phenotype might help identify patients with CAT who are more likely to experience recurrent events. This narrative review summarizes the current knowledge on the role of fibrin clot structure and function in cancer patients in the context of CAT.

Thrombin Generation Markers as Predictors of Cancer-Associated Venous Thromboembolism: A Systematic Review

Venous thromboembolism (VTE) is a main contributor to morbidity and mortality in cancer patients. Biomarkers with the potential to predict cancer-associated VTE are continually sought. Of these, markers of thrombin generation present a likely option. The present systematic review examines the ability of three widely used biomarkers of thrombin generation: prothrombin fragment 1.2 (F1.2), thrombin-antithrombin complex (TAT), and ex vivo thrombin generation, to predict VTE in both solid and hematologic adult cancer patients. Relevant studies were identified in the PubMed and Embase databases, and the review conformed to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines. Each study was evaluated using the quality assessment tool from the National Heart, Lung, and Blood Institute. The review protocol was published on PROSPERO with identifier CRD42022362339. In total, 24 papers were included in the review: 11 reporting data on F1.2, 9 on TAT, and 12 on ex vivo thrombin generation. The quality ratings of the included studies varied from good (n = 13), fair (n = 8), to poor (n = 3) with a high heterogenicity. However, F1.2, TAT complex, and ex vivo thrombin generation were all found to be associated with the development of VTE. This association was most pronounced for F1.2. Furthermore, the determination of F1.2 was able to improve the precision of several established risk assessment scores. In conclusion, markers of thrombin generation were found to be elevated in cancer patients with VTE, and particularly, F1.2 was found to be a promising predictor of cancer-associated VTE.

Thrombosis in multiple myeloma: mechanisms, risk assessment and management

Multiple myeloma (MM) is associated with an increased risk of venous and arterial thrombosis. Pathophysiologic mechanisms include patient, disease and treatment related factors. Risk assessment models have been developed to determine whichpatients are at highest thrombotic risk and pursuant to this, risk adapted thrombosis prophylaxis has been suggested. Areas in which further basic and clinical research is imperative include the molecular and cellular mechanisms of thrombosis in myeloma, the inclusion of relevant biomarkers in risk assessment scores and controlled clinical trials of VTE prophylaxis and treatment using direct oral anticoagulants.

Impaired fibrinolysis and increased clot strength are potential risk factors for thrombosis in lymphoma

Thrombosis and bleeding are significant contributors to morbidity and mortality in patients with hematological cancer, and the impact of altered fibrinolysis on bleeding and thrombosis risk is poorly understood. In this prospective cohort study, we investigated the dynamics of fibrinolysis in patients with hematological cancer. Fibrinolysis was investigated before treatment and 3 months after treatment initiation. A dynamic clot formation and lysis assay was performed beyond the measurement of plasminogen activator inhibitor 1, tissue- and urokinase-type plasminogen activators (tPA and uPA), plasmin-antiplasmin complexes (PAP), α-2-antiplasmin activity, and plasminogen activity. Clot initiation, clot propagation, and clot strength were assessed using rotational thromboelastometry. A total of 79 patients were enrolled. Patients with lymphoma displayed impaired fibrinolysis with prolonged 50% clot lysis time compared with healthy controls (P = .048). They also displayed decreased clot strength at follow-up compared with at diagnosis (P = .001). A patient with amyloid light-chain amyloidosis having overt bleeding at diagnosis displayed hyperfibrinolysis, indicated by a reduced 50% clot lysis time, α-2-antiplasmin activity, and plasminogen activity, and elevated tPA and uPA. A patient with acute promyelocytic leukemia also displayed marked hyperfibrinolysis with very high PAP, indicating extreme plasmin generation, and clot formation was not measurable, probably because of the extremely fast fibrinolysis. Fibrinolysis returned to normal after treatment in both patients. In conclusion, patients with lymphoma showed signs of impaired fibrinolysis and increased clot strength, whereas hyperfibrinolysis was seen in patients with acute promyelocytic leukemia and light-chain amyloidosis. Thus, investigating fibrinolysis in patients with hematological cancer could have diagnostic value.

Thromboprophylaxis in multiple myeloma

Venous thromboembolism (VTE) in multiple myeloma (MM) can be secondary to patient-, disease-, and/or treatment-related factors. The development of VTE may result in significant morbidity with the highest risk during the first year after diagnosis. This clinical review provides an evidence-based summary to guide practicing oncologists in the use of anticoagulation to prevent VTE in multiple myeloma and includes anticoagulation efficacy and adverse effect profile. We highlight the pathophysiology of VTE in MM, the use of various risk prediction tools, and the current recommendations for the use of different anticoagulants in prophylaxis of VTE.

Multiple Myeloma and Thrombosis: Prophylaxis and Risk Prediction Tools

Thromboembolism in multiple myeloma (MM) patients remains a common complication that renders the optimization of our thromboprophylaxis practice necessary. This review aims to make clear the need for the development of more accurate risk assessment tools and means of thrombosis prevention. Current clinical practice is guided by available guidelines published by the IMWG in 2014, but the extent to which these are implemented is unclear. Recently, several groups developed clinical scores for thrombosis risk in MM in an attempt to improve risk stratification, but these have not been validated or used in clinical practice so far. Research in this field is increasingly focusing on understanding the unique coagulation profile of the MM patient, and data on potential biomarkers that accurately reflect hypercoagulability is emerging. Finally, promising evidence on the effectiveness of direct oral anticoagulants (DOACs) in the context of thrombosis prevention in MM patients is increasingly becoming available. The critical appraisal of the above research areas will establish the necessity of combining disease-specific clinical risk factors with coagulation biomarkers to allow more effective risk stratification that will eventually lead to the reduction of this significant complication. Results from ongoing clinical trials on the role of DOACs are much anticipated.

Modelization of Blood-Borne Hypercoagulability in Myeloma: A Tissue-Factor-Bearing Microparticle-Driven Process

Introduction  Hypercoagulability is a common blood alteration in newly diagnosed chemotherapy naïve patients with multiple myeloma. The identification of the procoagulant potential of cancer cells, which is principally related to tissue factor (TF) expression, attracts particular interest. The mechanisms by which myeloma plasma cells (MPCs) activate blood coagulation have been poorly investigated.

Aim  To identify the principal actors related with MPCs that boost thrombin generation (TG).

Methods  TF and annexin V expression by MPCs and MPC-derived microparticles (MPC-dMPs) was analyzed by flow cytometry. TF activity (TFa) and TF gene expression were also determined. TG in the presence of MPCs or MPC-dMPs was assessed with the calibrated automated thrombogram assay (CAT) in normal human PPP and in plasma depleted of factor VII or XII. TG was also assessed in plasma spiked with MPCs and MPC-dMPs.

Results  MPC-dMPs expressed approximately twofold higher levels of TF as compared with MPCs. The TFa expressed by MPC-dMPs was significantly higher compared with that expressed by MPCs. MPCs and MPC-dMPs enhanced TG of human plasma. TG was significantly higher with MPC-dMPs compared with MPCs.

Conclusion  MPCs indirectly induce blood-borne hypercoagulability through the release of MPC-dMPs rich in TF. Since MPCs, expressing low TFa, represent a weak procoagulant stimulus, the hypercoagulability at the microenvironment could be the resultant of MPC-dMPs rich in TF.

The hypercoagulable state in multiple myeloma: The contribution of thrombin generation test

BACKGROUND

Multiple myeloma is a hematologic malignancy which confers a high venous thromboembolic risk. This risk is linked to patient-related factors, disease-specific mechanisms, and antimyeloma therapy, especially immunomodulatory drugs. Some studies have suggested that the thrombin generation assay may be a predictive marker of thrombosis. This study aimed to assess the hypercoagulable state in patients with multiple myeloma at diagnosis and after myeloma therapy.

METHODS

Thirty-one patients with multiple myeloma were included in a prospective study and were compared with 31 matched controls with age and gender. Thrombin generation assay was performed in patients at diagnosis prior to treatment initiation and at the end of myeloma therapy, and in controls. Parameters of lag time, peak thrombin concentration, time to peak, endogenous thrombin potential, and velocity index were analyzed.

RESULTS

Median age of patients at diagnosis was 58 years (11 men and 20 women). Twenty-three patients (74%) were classified as high vascular risk and received thromboprophylaxis. No thromboembolic events have been reported during follow-up, except a symptomatic pulmonary embolism in one patient which occurred at diagnosis. At baseline, patients with myeloma had significantly elevated velocity index as compared to controls (178 vs 128 nmol/L/min; P = .013). High-risk patients showed an elevation of plasma thrombin generation as compared to low-risk patients (endogenous thrombin potential = 1244 vs 1052 nmol/L/min; P = .043). Myeloma therapy did not significantly change the thrombin generation parameters.

CONCLUSION

Thrombin generation appears to be higher in patients with myeloma compared with controls, especially in high-risk patients, and does not change significantly after treatment completion.

Thrombin generation in newly diagnosed multiple myeloma during the first three cycles of treatment: An observational cohort study

BACKGROUND

Multiple myeloma (MM) is associated with a high risk of thrombosis, particularly during the first months of treatment including immunomodulatory drugs (IMiDs). There is no consensus on prevention of thromboembolic risk in patients with de novo MM, and identification of patients requiring anticoagulant thromboprophylaxis remains challenging. Evaluating coagulability by an in vitro thrombin generation (TG) test might be a way of identifying such patients.

OBJECTIVE

To determine whether TG assessment could reveal an increase in coagulability during the first three chemotherapy cycles.

METHODS

This prospective and longitudinal observational study included patients newly diagnosed with MM. TG was determined in platelet-rich and platelet-poor plasma using calibrated automated thrombography with a low tissue factor (TF) concentration.

RESULTS

Seventy-one patients were enrolled, allowing TG analysis during 213 chemotherapy cycles. TG remained unchanged throughout follow-up irrespective of treatment regimen, but values determined before cycles 2 and 3 were significantly higher in patients receiving iMiDs-containing regimens. No association was found between TG and its changes and thrombosis occurrence during follow-up: venous thrombosis in eight patients; no cardiovascular event. A significantly (87%) lower risk of venous thrombosis was observed in patients receiving prophylaxis with a low-molecular-weight heparin (LMWH; OR: 0.13 (95% CI: 0.02-0.76). Neither bortezomib- nor dexamethasone-containing regimens were associated with thrombotic risk. Changes in TG, as studied, were not associated with thrombotic events.

CONCLUSIONS

The only factor associated with a reduction in early thrombotic risk was prophylaxis with LMWH. The issue of how to identify patients requiring prophylactic anticoagulation remains unresolved.

Altered fibrin clot properties in advanced lung cancer: impact of chemotherapy

Background

Faster formation of dense and poorly lyzable fibrin networks have been reported in patients at risk of thromboembolism, including cancer patients. We sought to investigate whether chemotherapy affects plasma fibrin clot properties and their determinants in lung cancer patients.

Methods

In this observational study we enrolled 83 consecutive patients with advanced inoperable lung cancer. Plasma fibrin clot permeability (K_s), turbidimetric analysis of clot formation, clot lysis time (CLT), microparticle-associated tissue factor (MP-TF) activity, and thrombin generation parameters were investigated at enrolment and 3-4 months after standard chemotherapy.

Results

Lung cancer patients after 4 (range, 4-5) cycles of chemotherapy had 35.6% higher D-dimer, 22.1% lower MP-TF activity, and unaltered fibrinogen compared with baseline. Chemotherapy resulted also in 7.5% increased K_s, 8.6% prolonged lag phase, and 5.4% shortened CLT, while thrombin generation was unchanged. Chemotherapy-related differences in clot structure were confirmed by scanning electron microscopy images. Fibrin clot properties after chemotherapy did not differ among histological types of lung cancer, cancer stages or chemotherapy regimens. Interestingly, never smoking (n=13, 16%) was associated with looser post-treatment fibrin structure as reflected by 12.3% higher K_s. Multiple linear regression showed that more advanced cancer stage, higher peak thrombin generation, and higher white blood cell count determined post-treatment change in K_s, while active smoking was associated with change in CLT.

Conclusions

Three-month chemotherapy in lung cancer patients improves clot properties despite unaffected thrombin generation, suggesting that anticancer treatment might quickly produce antithrombotic actions.

Early mortality in myeloma patients treated with first-generation novel agents thalidomide, lenalidomide, bortezomib at diagnosis: A pooled analysis

INTRODUCTION

Early toxic death (≤60 days of diagnosis) in elderly multiple myeloma (MM) patients is attributable to active disease, age and co-morbidities. Rate of early toxic deaths is 10% with conventional chemotherapy mainly due to infection and renal failure. Novel agents have improved MM outcome at the expense of newer toxicity.

METHODS

We analyzed 1146 individual patient data to assess toxic deaths during induction treatment with first-generation novel agents thalidomide, lenalidomide, bortezomib.

RESULTS

During first-line therapy, 119/1146 patients (10%) died for any cause, and 47/1146 (4%) due to toxicity, including 12/1146 (1%) early deaths. The 24-month cumulative incidence was 4.1% without any difference between bortezomib (18/503 patients, 4%) and lenalidomide (29/643patients, 5%; p = 0.31). Toxic deaths occurred in 34/1039 (3%) patients <80 years and 13/107 (12%) patients ≥80 years. Causes were cardiac events (28%), infections (26%) and vascular complications (15%). In a multivariate analysis, older age and unfavorable ISS stage increased the risk of death.

CONCLUSION

First-generation novel agents significantly reduced toxic deaths compared to conventional chemotherapy. One third of deaths during first-line therapy were due to cumulative drug-related toxicities, thus supportive approaches and prevention strategies should be optimized. The higher mortality rate for toxicity in octogenarians confirms the need for a careful frailty assessment.

Laboratory biomarkers for venous thromboembolism risk in patients with hematologic malignancies: A review

INTRODUCTION

Despite high rates of venous thromboembolism (VTE) among patients with hematologic malignancies, few tools exist to assist providers in identifying those patients at highest risk for this potentially fatal complication. Laboratory biomarkers, such as d-dimer, have demonstrated utility in some clinical settings to distinguish patients at increased risk.

MATERIALS AND METHODS

We performed a systematic review of the literature utilizing search terms including "biomarker", "venous thromboembolism", "hematologic malignancy", "lymphoma", "myeloma" and "leukemia" in the Medline database. A total of 25 studies investigating laboratory biomarkers of increased thrombotic risk in the setting of hematologic malignancy were identified and included in this review.

RESULTS AND CONCLUSIONS

The most studied biomarkers, d-dimer and fibrinogen, demonstrated some degree of efficacy in identifying high-risk patients at levels >4.0 mg/L or <1.0 g/L respectively. Additional markers which demonstrated promise included thrombin generation, mean platelet volume, soluble VEGF, soluble P-selectin and extracellular vesicles. Other biomarkers reviewed, which did not consistently demonstrate significant associations with VTE included prothrombin fragments F1 + 2, factor VIII, protein C, protein S, von Willebrand antigen and activity, antithrombin, thrombin antithrombin complex, antiphospholopid antibody, plasminogen activator inhibitor, tissue factor pathway inhibitor and several variants associated with known hypercoagulable states (factor V Leiden, prothrombin gene variant, methylenetetrahydrofolate reductase variant). Data to support any of the biomarkers discussed here in routine clinical decision-making are currently lacking, but additional investigation in clinical studies, ideally in combination with clinical factors known to be associated with increased thrombotic risk, is warranted.

Molecular mechanisms for vascular complications of targeted cancer therapies

Molecularly targeted anti-cancer therapies have revolutionized cancer treatment by improving both quality of life and survival in cancer patients. However, many of these drugs are associated with cardiovascular toxicities that are sometimes dose-limiting. Moreover, the long-term cardiovascular consequences of these drugs, some of which are used chronically, are not yet known. Although the scope and mechanisms of the cardiac toxicities are better defined, the mechanisms for vascular toxicities are only beginning to be elucidated. This review summarizes what is known about the vascular adverse events associated with three classes of novel anti-cancer therapies: vascular endothelial growth factor (VEGF) inhibitors, breakpoint cluster-Abelson (BCR-ABL) kinase inhibitors used to treat chronic myelogenous leukaemia (CML) and immunomodulatory agents (IMiDs) used in myeloma therapeutics. Three of the best described vascular toxicities are reviewed including hypertension, increased risk of acute cardiovascular ischaemic events and arteriovenous thrombosis. The available data regarding the mechanism by which each therapy causes vascular complication are summarized. When data are limited, potential mechanisms are inferred from the known effects of inhibiting each target on vascular cell function and disease. Enhanced understanding of the molecular mechanisms of vascular side effects of targeted cancer therapy is necessary to effectively manage cancer patients and to design safer targeted cancer therapies for the future.

Thrombin generation as a predictor of thromboembolic events in multiple myeloma patients

BACKGROUND

Multiple myeloma (MM) is characterized by an increased incidence of thromboembolic events, especially when immunomodulatory drugs are used. Currently, our ability to predict these thrombotic events is limited. We hypothesized that global coagulation tests may be predictive of thrombotic events in MM patients.

METHODS

Blood samples were taken from 36 MM patients before and during routine treatment. Thrombin generation (TG) tests including endogenous thrombin potential (ETP) and peak height were analyzed.

RESULTS

Patients were followed for a median of 2.5years. Those who developed thrombotic events were characterized by significantly higher ETP and peak height values compared to those who did not (P=0.001). In these patients, we identified a gradual increase in TG parameters that preceded the thrombotic event. Anticoagulation therapy was associated with a significant decrease in ETP and peak height values (P<0.001). There was no statistically significant difference in TG parameters between newly diagnosed MM patients and healthy subjects, as well as between MM patients prior to and during chemotherapy.

CONCLUSIONS

TG tests might predict thrombotic events in MM patients. Thus, TG tests may be incorporated into decision-making protocols of prophylactic anticoagulant therapy in MM patients.

Baseline and treatment-related changes in thrombin generation in patients with multiple myeloma

The prothrombotic risk in multiple myeloma (MM) could be potentially assessed by thrombin generation (TG) assays. TG was performed using Calibrated Automated Thrombography with 5 and 1 pM tissue factor. We compared baseline TG among 24 MM patients, 19 MGUS, and 50 healthy controls, and assessed change in TG in MM patients during the initial treatment period at 1, 2, and 3 months. MM subjects demonstrated increased FVIII and VWF:Ag levels pretreatment, and a prothrombotic TG phenotype with increased velocity index, reduced lag time and time-to-peak, and increased resistance to thrombomodulin inhibition. There were no significant changes in TG with treatment for the majority of parameters, however, MM subjects exhibited persistent elevation of velocity index throughout treatment. Two subjects developed thrombosis during the study period despite thromboprophylaxis. This study provides information on the optimal conditions for examining TG as a predictor of thrombotic risk in MM patients.

Áinle F. Plasma Thrombin Generation and Sensitivity to Activated Protein C Among Patients With Myeloma and Monoclonal Gammopathy of Undetermined Significance

The etiology of the prothrombotic state in myeloma has yet to be definitively characterized. Similarly, while recent evidence suggests that patients with monoclonal gammopathy of undetermined significance (MGUS) may also be at increased risk of thrombosis, the magnitude and the etiology of this risk have also yet to be defined. The present study aims to characterize patterns of plasma thrombin generation and sensitivity to the anticoagulant activity of activated protein C (APC) at the time of initial diagnosis of myeloma and in response to therapy in comparison to that observed among patients with MGUS and matched, healthy volunteers. Patients presenting with newly diagnosed/newly relapsed myeloma (n = 8), MGUS (n = 8), and matched healthy volunteers (n = 8) were recruited. Plasma thrombin generation was determined by calibrated automated thrombography. Peak thrombin generation was significantly higher in patients with myeloma (383.4 ± 33.4 nmol/L) and MGUS (353.4 ± 16.5 nmol/L) compared to healthy volunteers (276.7 ± 20.8 nmol/L; P < .05). In the presence of APC, endogenous thrombin potential was significantly lower in control plasma (228.6 ± 44.5 nmol/L × min) than in either myeloma (866.2 ± 241.3 nmol/L × min, P = .01) or MGUS plasma (627 ± 91.5 nmol/L × min, P = .003). Within the myeloma cohort, peak thrombin generation was significantly higher at diagnosis (353.2 ± 15.9 nmol/L) than following completion of the third cycle of therapy (282.1 ± 15.2 nmol/L; P < .005). Moreover, sensitivity to APC increased progressively with each cycle of chemotherapy. Further study of the etiology and evolving patterns of hypercoagulability among patients with these conditions is warranted and may have future implications for thromboprophylaxis strategies.