Cancer-associated thrombosis: How many patients seen in clinical practice would be eligible for a direct oral anticoagulant randomized controlled trial?

Based on the results of randomized clinical trials (RCT) assessing direct oral anticoagulants (DOACs) for the treatment of patients with cancer-associated thrombosis (CAT), DOACs have been proposed as alternative to low molecular weight heparin by several international guidelines. However, the proportion of CAT patients who would have not been eligible for such trials is currently unknown. Our primary aim was to assess the proportion of patients seen in clinical practice for acute CAT who would not have been eligible for CARAVAGGIO or HOKUSAI-VTE RCT. Secondary aim was to describe patients outcomes according to eligibility. In a multicenter, observational study, all patients consecutively admitted from January 2017 to December 2019 for an acute CAT event were retrospectively analyzed. Patients were classified according to the presence or absence of non-inclusion criteria for CARAVAGGIO or HOKUSAI-VTE RCT. Event free survival during a 6-month follow-up were analyzed as secondary endpoints. Among the 302 patients (women: 53 %, mean age: 67.9 ± 13.2) analyzed, 138 (46 %) for HOKUSAI-VTE cancer and 161 (53 %) for CARAVAGGIO met one or more non-inclusion criteria. Main criteria were upper limb and unsual site thrombosis (n = 63, 18.5 %), anemia/thrombopenia (n = 43, 14.2 %), brain tumors (n = 33, 10.9 %), ECOG PS >2 (n = 28, 9.3 %), severe renal failure (n = 16, 5.3 %). At 6 months, the event-free survival rate was not statistically different between the two groups. Almost half of CAT patients would have not been able to participate to a modern DOAC RCT. Evaluation of DOACs safety and efficacy in this subset of patients deserves further research.

Assessment of bleeding risk in cancer patients treated with anticoagulants for venous thromboembolic events.

Introduction: Anticoagulant is the cornerstone of the management of VTE at the cost of a non-negligible risk of bleeding. Reliable and validated clinical tools to predict thromboembolic and hemorrhagic events are crucial for individualized decision-making for the type and duration of anticoagulant treatment. We evaluate the available risk models in real life cancer patients with VTE. The objectives of the study were to describe the bleeding of cancer patients with VTE and to evaluate the performance of the different bleeding models to predict the risk of bleeding during a 6-month follow-up. Materials and Methods: VTE-diagnosed patient's demographic and clinical characteristics, treatment regimens and outcomes for up to 6 months were collected. The primary endpoint was the occurrence of a major bleeding (MB) or a clinically relevant non major bleeding (CRNMB) event, categorized according to the ISTH criteria. Results: During the 6-months follow-up period, 26 out of 110 included patients (26.7%) experienced a bleeding event, with 3 recurrences of bleeding. Out of the 29 bleeding events, 19 events were CRNMB and 10 MB. One patient died because of a MB. Bleeding occurred in 27 % of the patients treated with DOACs and 22% of the patients treated with LMWH. Most of the bleedings were gastrointestinal (9 events, 31%); 26.9% of the bleedings occurred in patient with colorectal cancer and 19.6% in patients with lung cancer. In our cohort, none of the 10 RAMs used in our study were able to distinguish cancer patients with a low risk of bleeding, from all bleeding or non-bleeding patients. The Nieto et al. RAM had the best overall performance (C-statistic = 0.730, 95% CI (0.619-0.840)). However, it classified 1 out of 5 patients with major bleeding in the low risk of bleeding group. The rest of the RAMs showed a suboptimal result, with a range of C-statistic between 0.489, 95%CI (0.360-0.617)) and 0.532, 95%CI (0.406-0.658)). Conclusions: The management of CAT patients is challenging due to a higher risk of both recurrent VTE and bleeding events, as compared with non-cancer patients with VTE. None of the existing RAMs was able to consistently identify patients with risk of anticoagulant associated bleeding events.

Diagnostic Approach for Venous Thromboembolism in Cancer Patients.

Venous thromboembolic disease (VTE) is a common complication in cancer patients. The currently recommended VTE diagnostic approach involves a step-by-step algorithm, which is based on the assessment of clinical probability, D-dimer measurement, and/or diagnostic imaging. While this diagnostic strategy is well validated and efficient in the noncancer population, its use in cancer patients is less satisfactory. Cancer patients often present nonspecific VTE symptoms resulting in less discriminatory power of the proposed clinical prediction rules. Furthermore, D-dimer levels are often increased because of a hypercoagulable state associated with the tumor process. Consequently, the vast majority of patients require imaging tests. In order to improve VTE exclusion in cancer patients, several approaches have been developed. The first approach consists of ordering imaging tests to all patients, despite overexposing a population known to have mostly multiple comorbidities to radiations and contrast products. The second approach consists of new diagnostic algorithms based on clinical probability assessment with different D-dimer thresholds, e.g., the YEARS algorithm, which shows promise in improving the diagnosis of PE in cancer patients. The third approach uses an adjusted D-dimer threshold, to age, pretest probability, clinical criteria, or other criteria. These different diagnostic strategies have not been compared head-to-head. In conclusion, despite having several proposed diagnostic approaches to diagnose VTE in cancer patients, we still lack a dedicated diagnostic algorithm specific for this population.

In Search of the Appropriate Anticoagulant-Associated Bleeding Risk Assessment Model for Cancer-Associated Thrombosis Patients.

Patients with venous thromboembolism events (VTE) in the context of cancer should receive anticoagulants as long as the cancer is active. Therefore, a tailor-made anticoagulation strategy should rely on an individualized risk assessment model (RAM) of recurrent VTE and anticoagulant-associated bleeding. The aim of this review is to investigate the applicability of the currently available RAMs for anticoagulant-associated bleeding after VTE in the CAT population and to provide new insights on how we can succeed in developing a new anticoagulant-associated bleeding RAM for the current medical care of CAT patients. A systematic search for peer-reviewed publications was performed in PubMed. Studies, including systematic reviews, were eligible if they comprised patients with VTE and used a design for developing a prediction model, score, or other prognostic tools for anticoagulant-associated bleeding during anticoagulant treatment. Out of 15 RAMs, just the CAT-BLEED was developed for CAT patients and none of the presented RAMs developed for the VTE general population were externally validated in a population of CAT patients. The current review illustrates the limitations of the available RAMs for anticoagulant-associated bleeding in CAT patients. The development of a RAM for bleeding risk assessment in patients with CAT is warranted.

Management of acute venous thromboembolism in patients taking antiplatelet therapy.

BACKGROUND: Concomitant anticoagulant and antiplatelet therapy increases bleeding risk, but most data are derived from patients with atrial fibrillation. Patients with venous thromboembolism (VTE) may differ. OBJECTIVE: To study the management of patients diagnosed with acute VTE while receiving antiplatelet treatment. The primary outcome was the number of patients discharged with concomitant therapy. Secondary outcomes were clinically relevant bleeding, cardiovascular events, recurrent VTE and death during follow-up, according to discharge therapy. METHODS: We performed a post-hoc analysis of patients included in two prospective registries, sharing the same case report form, from 2007 to 2017. RESULTS: Among the 1694 identified patients, 254 (15.0%) were receiving antiplatelet treatment at VTE diagnosis, of whom 61 (24.0%) were discharged with concomitant anticoagulant and antiplatelet therapy. In multivariable analysis, age ≥ 80 years-old and the use of Direct Oral Anticoagulants for VTE therapy were associated with the decision to stop the antiplatelet, while having dual anti-platelet therapy at baseline, a history of coronaropathy or peripheral arterial disease were associated with concomitant anticoagulant and antiplatelet therapy. The decision to stop antiplatelet was associated with a non-significant 46% decrease in the risk of bleeding (OR 0.54 (0.16; 1.78)), and a non-significant 68% increase in the risk of cardiovascular events (OR 1.68 (0.44; 6.46)). CONCLUSION: At acute VTE diagnosis, over 15% of patients were receiving antiplatelet agents, of whom 24% were discharged with concomitant anticoagulant and antiplatelet therapy. This therapeutic decision may be associated with a lower risk of cardiovascular events, but an increased risk of bleeding.

Reasons Influencing Long-Term Anticoagulant Treatment Beyond 6 Months for Cancer-Associated Thrombosis in USCAT, A 432-Patient Retrospective Non-Interventional Study.

Background and objectives: Few data are available about anticoagulation management beyond 6 months in patients with cancer associated thrombosis (CAT). Our objective was to describe anticoagulant treatment modalities up to 12 months. Methods: The management of the anticoagulant treatment beyond 6 months was described in this initially retrospective non-interventional French multicenter study in patients treated with low-molecular-weight heparins (LMWH) still alive at the end of an initial 6-month treatment period. Clinical outcomes, including venous thromboembolism, recurrence, bleeding and deaths have been published previously. Results: Among the 432 patients (mean age 66.5±12.7 years) included in the study, 332 were followed up to 12 months while 96 patients deceased before study end and 4 patients were lost-to-follow-up. At 6 months, anticoagulant therapy was stopped in 74 patients, 56 were switched to vitamin K antagonists (VKA) (16.1% [95%CI, 12.4%-20.4]), 30 to direct oral anticoagulants (DOAC) (8.6% [95%CI, 5.9%-12.1]). LMWHs were maintained in 256 patients (73.6% [95%CI, 68.6-78.1]). During the follow-up, LMWHs were definitively discontinued in 86 patients (33.7%), the main reason being a favorable course of the cancer (16 patients, 18.6%), or the thromboembolic disease (11 patients, 12.8%), whereas concern about bleeding risk was low (2 patients, 2.3%). Conclusion: Anticoagulation beyond 6 months and up to 12 months was in accordance with clinical practice guidelines suggesting that treatment should be continued as long cancer is active or in the absence of bleeding risk. Anticoagulant treatment discontinuation beyond 6 months was influenced by the favorable courses of both malignancy and thromboembolic disease, as well as patient's preference.

Long-Term Treatment of Cancer-Associated Thrombosis (CAT) Beyond 6 Months in the Medical Practice: USCAT, a 432-Patient Retrospective Non-Interventional Study.

BACKGROUND: extended anticoagulant therapy beyond the initial 6 months is suggested in patients with cancer-associated thrombosis (CAT) and active cancer. Few data are available on patient management and outcomes on the period between 6 and 12 months after the venous thromboembolism (VTE) event. OBJECTIVES: our objective was to document patient management and outcomes beyond 6 months and up to 12 months in CAT patients initially treated for 6 months with tinzaparin. METHODS: adult CAT patients with a cancer still alive at the end of an initial 6-month treatment period were eligible to participate in this retrospective non-interventional French multicenter study. RESULTS: a total of 432 patients aged 66.5 ± 12.7 years were available to participate in this study. Out of the patients included in the study, the anticoagulant treatment was maintained in 348 of 422 documented patients (82.5%) while it was discontinued in 74 (17.5%) patients (before the end or at the end of the initial 6-month treatment period). Between 6 and 12 months, 24 patients (5.7%) experienced VTE recurrence, while 21 (5.1%) patients had clinically relevant bleeding, 11 patients (2.7%) had major bleeding and 96 patients (22.3%) died, mostly from cancer. VTE recurrence was more frequent in patients with lung (14.3%) and colorectal cancer (6.0%) while major bleeding was more frequent in patients with colorectal cancer (6.0%). CONCLUSION: clinical outcomes were consistent with previous observations and variable according to the type of cancer. Further clinical research is required to orient the management of patients with CAT beyond 6 months based on cancer-specific treatment strategies.

Management of the antiplatelet therapy during the diagnosis of venous thromboembolism disease: A national survey of French general practitioners' compared to the French vascular physicians' management.

INTRODUCTION: Approximately 15% of patients treated by anticoagulant for a venous thromboembolic event are also treated with antiplatelet therapy; and this association increases the risk of bleeding. The aim of this survey was to evaluate general practitioner's management of antiplatelet therapy at the initiation of anticoagulation, and at six months compared to French vascular physicians' management. METHODS: A questionnaire including 4 clinical situations was established and the physicians were asked to detail antiplatelet and anticoagulant therapy management. From September 2017 to December 2017, an e-mail invitation and a reminder were sent to members of the departmental councils who participated; 218 questionnaires were obtained. RESULTS: Overall, 91.3% of physicians considered that there was an increased risk of bleeding when antiplatelet therapy is associated with anticoagulation. After initiating anticoagulation, 67% of respondents continued antiplatelet therapy, while 30% stopped. Three strategies were used: 49.0% of physicians maintained concomitant antiplatelet therapy with full-dose anticoagulant, both at anticoagulant initiation and at 6 months; 23% of physicians stopped antiplatelet therapy and prescribed full-dose anticoagulant at initiation and at 6 months; 12.4% of physicians prescribed antiplatelet therapy associated with reduced-dose anticoagulation at 6 months regardless of the strategy at anticoagulant initiation. CONCLUSION: One third of general practitioners stopped antiplatelet therapy at the initiation of an anticoagulation for a venous thromboembolic event. Prospective controlled trials are needed to clarify the best way to treat these patients in this situation.

Tinzaparin Sodium Pharmacokinetics in Patients with Chronic Kidney Disease: Practical Implications.

Low-molecular-weight heparins (LMWHs) are the mainstay of the prophylaxis and treatment of venous thromboembolism (VTE). Due to their renal elimination, the risk of accumulation with the related bleeding risk may represent a limitation for the use of LMWHs in patients with chronic kidney disease (CKD) as the risk of major bleeding is increased in patients with creatinine clearance (CrCl) < 30 mL/min, especially in patients with cancer. LMWH structure and molecular weight (MW) are heterogeneous among available agents. The elimination of tinzaparin, which has the highest mean MW among LMWHs, is less dependent on renal function as it is also metabolized through the reticuloendothelial system. A subcutaneous therapeutic dose of tinzaparin (175 IU/kg) once daily has been shown to cause no accumulation of anti-factor Xa activity in patients with CrCl ≥ 20 mL/min. Clinical experience from randomized controlled studies has shown no significant impact of CKD on bleeding risk in cancer patients receiving treatment doses of tinzaparin. This suggests that in these patients the use of treatment doses of tinzaparin does not require anticoagulation monitoring or dose adjustment.

[Cancer and venous thromboembolism recurrence: The keys for an optimal management]. / Cancer et récidive thromboembolique veineuse : les clés d'une prise en charge optimale.

Low-molecular-weight heparins (LMWH) are to date the standard for 3-to-6-month treatment of cancer-associated thrombosis (CAT) as they are consistently recommended by international clinical practice guidelines. Despite the high risk of VTE recurrence and death in patients with cancer and the favorable benefit-risk profile of LMWH demonstrated in randomized-control studies, the implementation of treatment guidelines remains insufficient in the clinical practice. A systematic review of observational studies, registries and surveys reveals that approximately only 50% of patients with CAT are treated according to practice guidelines while both physicians and patients may be accountable for this situation. Based on the few available published data, we have observed differences between guidelines and clinical practice and we have identified factors influencing patient's management with the perspective to improve adherence to clinical practice guidelines in patients with CAT. Improving the implementation of clinical practice guidelines requires a better knowledge of physician and patient-related factors that influence therapeutic decisions. A global approach of patients with CAT is warranted to optimize the therapeutic management of cancer-associated VTE.

Thrombopoietin Secretion by Human Ovarian Cancer Cells.

The thrombopoietin (TPO) gene expression in human ovary and cancer cells from patients with ovarian carcinomatosis, as well as several cancer cell lines including MDA-MB231 (breast cancer), K562 and HL60 (Leukemic cells), OVCAR-3NIH and SKOV-3 (ovarian cancer), was performed using RT PCR, real-time PCR, and gene sequencing. Human liver tissues are used as controls. The presence of TPO in the cells and its regulation by activated protein C were explored by flow cytometry. TPO content of cell extract as well as plasma of a patient with ovarian cancer was evaluated by ELISA. The functionality of TPO was performed in coculture on the basis of the viability of a TPO-dependent cell line (Ba/F3), MTT assay, and Annexin-V labeling. As in liver, ovarian tissues and all cancer cells lines except the MDA-MB231 express the three TPO-1 (full length TPO), TPO-2 (12 bp deletion), and TPO-3 (116 pb deletion) variants. Primary ovarian cancer cells as well as cancer cell lines produce TPO. The thrombopoietin production by OVCAR-3 increased when cells are stimulated by aPC. OVCAR-3 cell's supernatant can replace exogenous TPO and inhibited TPO-dependent cell line (Ba/F3) apoptosis. The thrombopoietin produced by tumor may have a direct effect on thrombocytosis/thrombosis occurrence in patients with ovarian cancer.

Adherence to treatment guidelines for cancer-associated thrombosis: a French hospital-based cohort study.

PURPOSE: French 2008 treatment guidelines recommend low-molecular-weight heparins (LMWH) for the treatment of cancer-associated thrombosis (CAT) with treatment duration of at least 3 months and up to 6 months and beyond if cancer remains active. Our aim was to assess adherence to guidelines in hospital clinical practice. METHODS: The French hospital database (PMSI) was used to identify patients with CAT admitted to three hospitals of the Paris region to be included in a retrospective cohort study. Adherence to guidelines was assessed in patients included from different treatment periods following the venous thromboembolism (VTE) episode i.e. first 10 days (T1), day 10 to 3 months (T2), months 3 to 6 (T3) and beyond 6 months (T4) when applicable. RESULTS: A total of 240 patients with CAT were included from January 2012 to December 2012 of whom 204 were analyzable. Treatment was adherent to guidelines in 55, 31 and 34 % of patients in T1, T2 and T3 treatment periods, respectively, while overall treatment adherence was found in 52 % of patients. Adherence rates were the highest among patients with pulmonary embolism (PE, 60.5 %), catheter-related thrombosis (62.5 %), class III/IV extended cancer (58.0 %) and metastatic malignancy (60.3 %) while only 40 % with deep vein thrombosis (DVT) received a treatment consistent with guidelines. CONCLUSION: Adherence to guidelines appears insufficient since only half of patients received an appropriate treatment. Adherence dropped significantly across treatment periods T2 and T3. VTE diagnosis and cancer characteristics influenced the anticoagulant prescription. Management of patients with CAT requires further education and information of health care professionals.