Direct Oral Anticoagulant Therapy for Cancer-Associated Venous Thromboembolism in Routine Clinical Practice

Mortality, Recurrent Thromboembolism and Major Bleeding in Cancer-Associated and Non-Cancer Pulmonary Embolism Patients Treated With Direct Oral Anticoagulants

BACKGROUND

Pulmonary embolism (PE) is a potentially fatal form of venous thromboembolism (VTE). This study compares the mortality, incidence of recurrent VTE, and incidence of major bleeding between non-cancer and cancer-associated PE patients treated with direct oral anticoagulants (DOACs).

METHODS AND RESULTS

This was a retrospective, observational, single-center study involving 130 consecutive patients (87 with active cancer; 43 without cancer) who received DOAC treatment for PE between January 2016 and December 2019. Kaplan-Meier analysis showed significantly higher mortality in cancer-associated PE patients than in non-cancer patients (35/87 [40%] vs. 1/43 [2%], P<0.001, log-rank test, HR 18.6 [95% CI: 2.5-136.0]). In contrast, the cumulative incidences of recurrent VTE and major bleeding were comparable between the 2 groups. Among the cancer-associated PE patients, the incidence for the composite outcome of recurrent VTE or major bleeding was significantly higher in patients undergoing chemotherapy than in those not undergoing chemotherapy (9/37 [24%] vs. 2/50 [4%], P=0.004, log-rank test, HR 6.9 [95% CI: 1.5-32.0]).

CONCLUSIONS

Although cancer-associated PE patients treated with DOACs showed higher mortality compared with non-cancer patients, presumably because of the presence of cancer, the risk of recurrent VTE or major bleeding was comparable between the 2 groups. Thus, DOAC is an important treatment option for cancer-associated PE, although underlying cancer-related risks (e.g., chemotherapy) remain.

Comparison of Edoxaban and Warfarin for the Treatment of Cancer-Associated Venous Thromboembolism - A Retrospective Observational Study

BACKGROUND

Because anticoagulant drugs for ambulatory patients with cancer-associated venous thromboembolism (CAT) are limited to warfarin and direct oral anticoagulants (DOACs) in Japan, it is important to assess the outcomes of both drugs.

METHODS AND RESULTS

We retrospectively assessed the outcomes of CAT patients who were treated with warfarin or edoxaban between 2011 and 2017. The assessment was limited to the duration of anticoagulant administration. CAT patients who did not receive anticoagulation therapy were also compared with the warfarin and edoxaban groups. We enrolled 111 CAT patients treated with warfarin (n=58, mean age 62.6 years, mean time in therapeutic range [TTR] % 61.1) or edoxaban (n=53, mean age 64.6 years). Although venous thromboembolism (VTE) recurred in 2 warfarin-treated patients, the 2 treatment groups were not significantly different (P=0.18). Bleeding during anticoagulation therapy occurred in 6 warfarin-treated patients (2 with major bleeding) and in 5 edoxaban-treated patients (no major bleeding) (P=1.0). The non-anticoagulation group (n=37) showed a high recurrence rate (P<0.01) compared with the anticoagulant group.

CONCLUSIONS

This study showed that warfarin and edoxaban are equally effective in preventing VTE recurrence and bleeding. However, warfarin control in CAT patients presented some difficulties. This study also demonstrated the efficacy of anticoagulant drugs, compared with no anticoagulation, for CAT patients to prevent VTE recurrence.

IMPROVE bleeding score predicts major bleeding in advanced gastrointestinal cancer patients with venous thromboembolism

BACKGROUND

The incidence of venous thromboembolism has been reported as 20% in cancer patients. Anticoagulation therapy is the standard treatment for venous thromboembolism. On the other hand, bleeding should be carefully managed, because advanced cancer, particularly gastrointestinal cancer, carries a high risk of bleeding. However, the optimal management for cancer-associated thromboembolism remains to be clarified.

METHODS

We retrospectively examined patients with advanced gastrointestinal cancer, including gastric cancer and colorectal cancer, who were treated with chemotherapy between 2014 and 2018 for the incidence and characteristics of venous thromboembolism and bleeding.

RESULTS

In total, 194 patients (120 men, 74 women) were enrolled in this study. The underlying pathology was gastric cancer in 74 cases and colorectal cancer in 120 cases. Of the 194 patients, 40 patients (20.6%) were diagnosed with venous thromboembolism and 10 patients (5.2%) were diagnosed with concomitant pulmonary thromboembolism. Conversely, bleeding was observed in 29 patients (15%). The location of bleeding was the primary tumor in 17 cases, metastatic tumor in 9 and hemorrhagic gastric ulcer in 3. Within the venous thromboembolism group (n = 40), bleeding was observed in 10 patients (25%). Multivariate analysis showed that International Medical Prevention Registry on Venous Thromboembolism (IMPROVE) bleeding score ≥7 correlated significantly with major bleeding (P = 0.01). In patients with a low risk of bleeding, major bleeding was observed in only three patients.

CONCLUSIONS

IMPROVE bleeding score may predict the risk for bleeding in gastrointestinal cancer patients with venous thromboembolism. Selecting patients with a low risk of bleeding using with IMPROVE bleeding score is expected to contribute to the safer management of anticoagulation therapy for cancer-associated thromboembolism.

Effectiveness and Safety of Direct Oral Anticoagulants vs. Warfarin and Recurrence After Discontinuation in Patients With Acute Venous Thromboembolism in the Real World

BACKGROUND

The efficacy of direct oral anticoagulants (DOACs) compared with warfarin for the treatment of venous thromboembolism (VTE), and the recurrence of VTE after discontinuation of anticoagulation therapy in research are limited.

METHODS AND RESULTS

This retrospective study enrolled 893 patients with acute VTE between 2011 and 2019. The cohort was divided into the transient risk, unprovoked, continued cancer treatment, and cancer remission groups. The following were compared between DOACs and warfarin: composite outcome of all-cause death, VTE recurrence, bleeding and composite outcome of VTE-related death, recurrence and bleeding. In the continued cancer treatment group, more bleeding was seen in warfarin-treated patients than in patients treated with DOACs (53.2% vs. 31.2%, [P=0.048]). In addition, composite outcome of VTE-related death and recurrence after discontinuation of anticoagulation therapy (n=369) was evaluated. The continued cancer treatment group (multivariate analysis: HR: 3.62, 95% CI: 1.84-7.12, P<0.005) and bleeding-related discontinuation of therapy (HR: 2.60, 95% CI: 1.32-5.13, P=0.006) were independent predictors of the event after discontinuation of anticoagulation therapy. VTE recurrence after discontinuation of anticoagulation therapy in the cancer remission group was 1.6% and a statistically similar occurrence was found in the transient risk group (12.4%) (P=0.754).

CONCLUSIONS

DOACs may decrease bleeding incidence in patients continuing to receive cancer treatment. In patients with bleeding-related discontinuation of anticoagulation therapy, VTE recurrence may increase. Discontinuation of anticoagulant therapy might be a treatment option in patients who have completed their cancer treatment.

Direct Oral Anticoagulant Therapy for Isolated Distal Deep Vein Thrombosis Associated with Cancer in Routine Clinical Practice

BACKGROUND

The efficacy and bleeding complications of direct oral anticoagulant (DOAC) therapy for isolated distal deep vein thrombosis (IDDVT) associated with cancer in routine clinical practice remain unclear. Moreover, prior studies on prolonged therapy for IDDVT are limited.

METHODS

This retrospective study enrolled 1641 consecutive patients with acute venous thromboembolism (VTE) who had received oral anticoagulant therapy, including warfarin or DOAC, between April 2014 and September 2018 in our institutions. In these patients, 200 patients with cancer-associated IDDVT were evaluated.

RESULTS

Mean follow-up period was 780 ± 593 days. Major bleeding and VTE recurrence were observed in 22 (11.0%) and 11 (5.5%) patients, respectively. In multivariate analysis, statistically significant factors correlated with major bleeding were advanced cancer stage, high performance status, stomach cancer, and gallbladder cancer; those correlated with all-cause death were advanced cancer stage, high performance status, liver dysfunction, pancreatic cancer, and major bleeding. Cumulative events of major bleeding and recurrence between patients with prolonged DOAC therapy (≥90 days) and those with nonprolonged therapy were not significantly different.

CONCLUSIONS

Preventing major bleeding is important because it is a significant risk factor for all-cause death. Major bleeding and recurrent events were comparable between prolonged and nonprolonged therapy.

Venous thromboembolism: Recent advancement and future perspective

Clinicians have been more and more often encountering patients with venous thromboembolism (VTE), including pulmonary embolism and deep vein thrombosis, leading to the increased importance of VTE in daily clinical practice. VTE is becoming a common issue in Asian countries including Japan. The management strategies of VTE have changed dramatically in the past decade including the introduction of direct oral anticoagulants (DOACs). In addition, there have been several landmark clinical trials assessing acute treatment strategies including thrombolysis and inferior vena cava (IVC) filter. The current VTE guidelines do not recommend the routine use of thrombolysis or IVC filters based on recent evidence; Nevertheless, the prevalence of thrombolysis and IVC filter use in Japan was strikingly high. The novel profiles of DOACs with rapid onset of action and potential benefit of a lower risk for bleeding compared with vitamin K antagonist could make home treatment feasible and is safer even with extended anticoagulation therapy. One of the most clinically relevant issues for VTE treatment is optimal duration of anticoagulation for the secondary prevention of VTE. Considering recent evidence, optimal duration of anticoagulation should be determined based on the risk for recurrence as well as the risk for bleeding in an individual patient. Despite the recent advances for VTE management, there are still a number of uncertain issues that challenge clinicians in daily clinical practice, such as cancer-associated VTE and minor VTE including subsegmental pulmonary embolism and distal deep vein thrombosis, warranting future research. Several clinical trials are now ongoing for these issues, globally as well as in Japan. The current review is aimed to overview the recent advances in VTE management, describe the current status including some domestic issues in Japan, and discuss the future perspective of VTE.