Direct Oral Anticoagulant Drugs: On the Treatment of Cancer-Related Venous Thromboembolism and their Potential Anti-Neoplastic Effect

Extended Pharmacologic Prophylaxis for Venous Thromboembolism After Colon Cancer Surgery Is Associated With Improved Long-term Survival: A Natural Experiment in the Chemotherapeutic Benefit of Heparin Derivatives

OBJECTIVE

This large database study assessed whether extended pharmacologic prophylaxis for venous thromboembolism after colon cancer resection was associated with improved oncologic survival.

BACKGROUND

Heparin derivatives may confer an antineoplastic effect via a variety of mechanisms (eg, inhibiting angiogenesis in the tumor microenvironment). Studies evaluating the oncologic benefit of heparin and its derivatives have been limited in postsurgical patients. Multiple society guidelines recommend consideration of 30-day treatment with low molecular weight heparin to reduce venous thromboembolism risk after abdominopelvic cancer surgery. However, utilization of extended prophylaxis remains low.

METHODS

Surveillance, Epidemiology, and End Results-Medicare data were used to identify patients (age 65+) undergoing resection for nonmetastatic colon cancer from 2016 to 2017. The primary outcomes were overall and cancer-specific survival. Log-rank testing and multivariable Cox regression compared survival in patients who received extended prophylaxis versus those who did not in an inverse propensity treatment weighted cohort.

RESULTS

A total of 20,102 patients were included in propensity-weighting and analyzed. Eight hundred (3.98%) received extended pharmacologic prophylaxis. Overall survival and cancer-specific survival were significantly higher in patients receiving prophylaxis on log-rank tests ( P =0.0017 overall, P =0.0200 cancer-specific). Multivariable Cox regression showed improved overall survival [adjusted hazard ratio 0.66 (0.56-0.78)] and cancer-specific survival [adjusted hazard ratio 0.56 (0.39-0.81)] with prophylaxis after controlling for patient, treatment, and hospital factors.

CONCLUSIONS

Extended pharmacologic prophylaxis after colon cancer resection was independently associated with improved overall and cancer-specific survival. These results suggest a potential antineoplastic effect from heparin derivatives when used in the context of preventing postsurgical venous thromboembolism.

Systemic Anticoagulation and Inpatient Outcomes of Pancreatic Cancer: Real-World Evidence from U.S. Nationwide Inpatient Sample

Background: Pancreatic cancer can induce a hypercoagulable state which may lead to clinically apparent thrombosis. However, the effect of anticoagulants remains ambiguous. This study aimed to investigate the potential effect of long-term systemic anticoagulant usage on hospitalization outcomes of patients with pancreatic cancer. Methods: This retrospective study extracted all data from the U.S. Nationwide Inpatient Sample (NIS) database from 2005 to 2018. We included hospitalized adults ≥18 years old with a pancreatic cancer diagnosis identified by International Classification of Diseases ninth revision (ICD-9) and tenth revision (ICD-10) codes. We utilized diagnostic codes ICD9 V58.61 and ICD10 Z79.01, i.e., 'long-term use of anticoagulant', to identify individuals who were on a long-term systemic anticoagulant. The study cohort were then further grouped as being with or without long-term systemic use of an anticoagulant. Propensity score matching was performed to balance the characteristics of the two groups. The risks of life-threatening events, e.g., acute myocardial infarction (AMI), acute heart failure (AHF), sepsis, shock, and acute kidney injury (AKI), in-hospital death, and prolonged length of stay (LOS) in the hospital were compared between the groups by univariable and multivariable logistic regression analyses. Results: The study population consisted of 242,903 hospitalized patients with pancreas cancer, 6.5% (n = 15,719) of whom were on long-term systemic anticoagulants. A multivariable regression analysis showed that long-term systemic anticoagulant use was independently associated with lower odds of sepsis (aOR: 0.81, 95% CI: 0.76-0.85), shock (aOR: 0.59, 95% CI: 0.51-0.68), AKI (aOR: 0.86, 95% CI: 0.81-0.91), in-hospital mortality (aOR: 0.65, 95% CI: 0.60-0.70), and prolonged LOS (aOR: 0.84, 95% CI: 0.80-0.89). Conclusions: Long-term systemic anticoagulant use is associated with better clinical outcomes in terms of decreased risks of some life-threatening events, in-hospital death, and prolonged LOS among hospitalized patients with pancreatic cancer in the U.S.

Structural and functional properties of the Kunitz-type and C-terminal domains of Amblyomin-X supporting its antitumor activity

Amblyomin-X is a Kunitz-type FXa inhibitor identified through the transcriptome analysis of the salivary gland from Amblyomma sculptum tick. This protein consists of two domains of equivalent size, triggers apoptosis in different tumor cell lines, and promotes regression of tumor growth, and reduction of metastasis. To study the structural properties and functional roles of the N-terminal (N-ter) and C-terminal (C-ter) domains of Amblyomin-X, we synthesized them by solid-phase peptide synthesis, solved the X-Ray crystallographic structure of the N-ter domain, confirming its Kunitz-type signature, and studied their biological properties. We show here that the C-ter domain is responsible for the uptake of Amblyomin-X by tumor cells and highlight the ability of this domain to deliver intracellular cargo by the strong enhancement of the intracellular detection of molecules with low cellular-uptake efficiency (p15) after their coupling with the C-ter domain. In contrast, the N-ter Kunitz domain of Amblyomin-X is not capable of crossing through the cell membrane but is associated with tumor cell cytotoxicity when it is microinjected into the cells or fused to TAT cell-penetrating peptide. Additionally, we identify the minimum length C-terminal domain named F2C able to enter in the SK-MEL-28 cells and induces dynein chains gene expression modulation, a molecular motor that plays a role in the uptake and intracellular trafficking of Amblyomin-X.

Capecitabine and Warfarin Interaction: A Case Report With Review of Literature and Management Options

Capecitabine is an orally active prodrug of 5-fluorouracil with improved safety and efficacy that is extensively used as an antineoplastic agent. It is converted to 5-Fluorouracil in the liver and tumor tissues. In vitro assays did not reveal any significant potential for interaction between capecitabine and its metabolites with warfarin. However, several reports provided clinical evidence of such interaction resulting in an elevated international normalized ratio (INR) and bleeding. Here, we report another case of capecitabine and warfarin concurrent administration that resulted in sub- or supra- therapeutic INR without any bleeding episode or venous-thromboembolic event through the follow-up period. Moreover, a review of available management options is also presented in this paper.

Direct Oral Anticoagulants Are Associated with Superior Survival Outcomes than Warfarin in Patients with Head and Neck Cancers

Simple Summary

Patients with head and neck cancers may suffer from cancer-associated thromboembolism and direct oral anticoagulants (DOACs) are a potential new therapeutic option. We aimed to determine the clinical impact of DOACs compared with traditional anticoagulants on the survival of patients with head and neck cancers. In our study, DOAC users had significantly better disease-specific survival (DSS) and higher overall survival (OS) rates than warfarin users and those who did not use any anticoagulant. Further, there were no significant differences in the occurrence rate of bleeding or ischemic events between DOAC and warfarin users. Our study suggested that DOACs can be a treatment choice or prophylaxis for tumor emboli in head and neck cancer patients and that they might be a better choice than traditional anticoagulants.

Abstract

Increasing clinical evidence supports the use of direct oral anticoagulants (DOACs) as a potential new therapeutic option for patients suffering from cancer-associated thromboembolism. However, the clinical impact of DOACs compared with traditional anticoagulants on the survival of patients with head and neck cancer has not been well studied. A total of 1025 patients diagnosed as having head and neck cancer, including 92 DOAC users, 113 warfarin users, and 820 nonusers of anticoagulants, were selected from the Chang Gung Research Database between January 2001 and December 2019. The patients were matched using the propensity-score method. The survival rates were estimated among the three groups using the Kaplan–Meier method. The protective effects and side effects of the two anticoagulants were compared using the chi-square test. The death rate (18 patients, 19.57%) in patients using DOACs was significantly lower than that in patients using warfarin (68 patients, 60.18%) and those not using any anticoagulant (403 patients, 49.15%). DOAC users had significantly better disease-specific survival (DSS) than warfarin users (p = 0.019) and those who did not use any anticoagulant (p = 0.03). Further, DOAC users had significantly higher overall survival (OS) rates than warfarin users and those who did not use any anticoagulant (p = 0.003). Patients with oropharyngeal and laryngeal cancer and DOAC users had a significantly lower hazard ratio for survival, whereas patients with American Joint Committee on Cancer stage IV disease and those receiving multidisciplinary treatment (e.g., surgery with radiotherapy or concurrent radiochemotherapy) had a significantly higher hazard ratio for survival. Among them, patients with laryngeal cancer (HR = 0.47, 95% CI = 0.26–0.86, p = 0.0134) and DOAC users (HR = 0.53, 95% CI = 0.29–0.98, p = 0.042) had the lowest hazard ratio from DSS analysis. Similarly, patients with laryngeal cancer (HR = 0.48, 95% CI = 0.30–0.76, p = 0.0018) and DOAC users (HR = 0.58, 95% CI = 0.36–0.93, p = 0.0251) had the lowest hazard ratio from OS analysis. As for the protective effects or side effects of anticoagulants, there were no significant differences in the occurrence rate of bleeding or ischemic events between DOAC and warfarin users. In our study, DOACs were found to be better than warfarin in terms of survival in patients with head and neck cancer. As regards thromboembolism prevention and side effects, DOACs were comparable to warfarin in our patients. DOACs can be a treatment choice or prophylaxis for tumor emboli in head and neck cancer patients and they might be a better choice than traditional anticoagulants according to the results of our study.

Arguments for Using Direct Oral Anticoagulants in Cancer-Related Venous Thromboembolism

(1) Background: Patients with cancer with a hypercoagulable state present an increased incidence of venous thromboembolism (VTE). Neoplastic patients with concurrent VTE undergoing anticoagulant treatment face a series of issues. (2) The aim of the present paper is to systematically summarize current VTE management in patients with neoplasia and to review the current clinical evidence from meta-analyses of randomized controlled trials and guidelines regarding the administration of direct oral anticoagulants (DOACs) for cancer-associated VTE. (3) Search Strategy: We performed a review on meta-analyses of randomized controlled trials and guidelines in favor of the administration of DOACs in patients with cancer-associated VTE published in the last 6 years in the Medline (PubMed) and Embase databases. (4) Results: 21 meta-analyses, 14 randomized controlled studies comparing DOACs to VKAs and LMWH, and 7 national and international guidelines were identified. We identified five studies that show the antineoplastic effect of DOAC on experimental models. (5) Conclusions: DOACs can be seen as the first choice for VTE treatment in neoplastic patients who have a low risk of bleeding, who do not have severe renal impairment, and who are not undergoing treatments that could interact with DOAC's mechanism of action.

Interactions between cardiology and oncology drugs in precision cardio-oncology

Recent advances in treatment have transformed the management of cancer. Despite these advances, cardiovascular disease remains a leading cause of death in cancer survivors. Cardio-oncology has recently evolved as a subspecialty to prevent, diagnose, and manage cardiovascular side effects of antineoplastic therapy. An emphasis on optimal management of comorbidities and close attention to drug interactions are important in cardio-oncologic care. With interdisciplinary collaboration among oncologists, cardiologists, and pharmacists, there is potential to prevent and reduce drug-related toxicities of treatments. The cytochrome P450 (CYP450) family of enzymes and the P-glycoprotein (P-g) transporter play a crucial role in drug metabolism and drug resistance. Here we discuss the role of CYP450 and P-g in drug interactions in the field of cardio-oncology, provide an overview of the cardiotoxicity of a spectrum of cancer agents, highlight the role of precision medicine, and encourage a multidisciplinary treatment approach for patients with cancer.

Biomimetic sulfated glycosaminoglycans maintain differentiation markers of breast epithelial cells and preferentially inhibit proliferation of cancer cells

Glycosaminoglycans (GAG) are key elements involved in various physiological and pathological processes including cancer. Several GAG-based drugs have been developed showing significant results and potential use as cancer therapeutics. We previously reported that alginate sulfate (AlgSulf), a GAG-mimetic, reduces the proliferation of lung adenocarcinoma cells. In this study, we evaluated the preferential effect of AlgSulf on tumorigenic and nontumorigenic mammary epithelial cells in 2D, 3D, and coculture conditions. AlgSulf were synthesized with different degrees of sulfation (DSs) varying from 0 to 2.7 and used at 100 µg/mL on HMT-3522 S1 (S1) nontumorigenic mammary epithelial cells and their tumorigenic counterparts HMT-3522 T4-2 (T4-2) cells. The anti-tumor properties of AlgSulf were assessed using trypan blue and bromodeoxyuridine proliferation (BrdU) assays, immunofluorescence staining and transwell invasion assay.  Binding of insulin and epidermal growth factor (EGF) to sulfated substrates was measured using QCM-D and ELISA. In 2D, the cell growth rate of cells treated with AlgSulf was consistently lower compared to untreated controls (p<0.001) and surpassed the effect of the native GAG heparin (positive control). In 3D, AlgSulf preferentially hindered the growth rate and the invasion potential of tumorigenic T4-2 nodules while maintaining the formation of differentiated polarized nontumorigenic S1 acini. The preferential growth inhibition of tumorigenic cells by AlgSulf was confirmed in a coculture system (p<0.001). In the ELISA assay, a trend of EGF binding was detected for sulfated polysaccharides while QCM-D analysis showed negligible binding of insulin and EGF to sulfated substrates. The preferential effect mediated by the mimetic sulfated GAGs on cancer cells may in part be growth factor dependent. Our findings suggest a potential anticancer therapeutic role of AlgSulf for the development of anticancer drugs.

Direct oral anticoagulants for the treatment and prevention of venous thromboembolism in patients with cancer: current evidence

Venous thromboembolic disease (VTED) is a common and clinically important complication in patients with cancer, contributing to its mortality and morbidity. Direct oral anticoagulant agents (DOACs), including direct thrombin inhibitors and direct factor Xa inhibitors, are as effective as vitamin K antagonists for the treatment of VTED and are associated with less frequent and severe bleeding. They have advantages over low-molecular-weight heparin, but comparative long-term efficacy and safety data are lacking for these compounds. Recent randomized clinical trials suggest a role for DOACs in the treatment of VTED in patients with cancer. This review will discuss the existing evidence and future perspectives on the role of DOACs in the treatment of VTE based on the current evidence about their overall efficacy and safety and the limited information in patients with cancer; in addition, we will briefly review their pharmacokinetic properties with special reference to potential interactions.

Direct oral anticoagulants for thromboprophylaxis in ambulatory patients with cancer

Background: Venous thromboembolism (VTE) is a common complication in cancer patients. We aim to evaluate the effect and safety of direct oral anticoagulants (DOACs) as primary prophylaxis in ambulatory cancer patients.Methods: We conducted a literature search in PubMed, EMBASE and ClinicalTrials for studies that evaluated DOACs for thromboprophylaxis in cancer patients. RevMan 5.3 software was used for this meta-analysis.Results: Three randomized controlled trials (RCTs) with a total of 1465 patients were pooled in the meta-analysis. DOACs significantly reduced the symptomatic VTE incidence during intervention period (RR 0.23, CI 0.11-0.47, P<0.0001, I²=9%). Significantly lower total VTE incidence (RR 0.53, CI 0.36-0.78, P = 0.001, I² =30%) and PE incidence (RR 0.50, CI 0.28-0.89, P = 0.02, I² =5%) were found during the observation period, and a trend for less symptomatic DVT events was found in the DOACs group (RR 0.62, CI 0.37-1.04, P = 0.07, I² =5%). No differences for all-cause mortality were found between groups (RR 0.92, CI 0.74-1.15, P = 0.47, I² =14%). DOACs did not significantly increase major bleeding risks (RR 1.66, CI 0.72-3.83, P = 0.24, I² =0%) during the intervention period or clinically relevant non-major bleeding events (RR 1.50, CI 0.90-2.49, P = 0.12, I² =0%) and total bleeding events during the observation period (RR 1.50, CI 0.98-2.29, P = 0.06, I² =0%).Conclusion: DOACs are effective for thromboprophylaxis in ambulatory cancer patients, but there is a potential risk of bleeding. DOACs may be recommended in selected patients at high risk of VTE. More high-quality studies are needed to further validate our results.Abbreviations: CAT: cancer-associated thrombosis; CI: confidence interval; DOAC: direct oral anticoagulant; DVT: deep vein thrombosis; LMWH: low molecular weight heparin; NNH: number needed to harm; NNT: number needed to treat; PE: pulmonary embolism; RCT: randomized controlled trials; RR: risk ratio; RD: rate difference; VTE: venous thromboembolism.

A systematic review on the efficacy and safety of low molecular weight heparin as an anticancer therapeutic in preclinical animal models

OBJECTIVE

The therapeutic effects of low molecular weight heparins (LMWH) may extend past thrombosis prevention, with preclinical evidence demonstrating anti-metastatic properties. Clinical evidence on the topic, however, remains controversial. A systematic review of preclinical evidence may help elucidate reasons for this contradictory evidence. The objective of our systematic review is to assess the anti-metastatic properties of LMWHs in solid tumour animal models.

METHODS

MEDLINE, Embase, Web of Science and PubMed were searched from inception to May 12th, 2020. All articles were screened independently and in duplicate. Studies that compared LMWH to a placebo or no treatment arm in solid tumour animal models were included. The primary outcome was the burden of metastasis. Secondary outcomes included primary tumour growth and mortality. The risk of bias was assessed in duplicate using a modified Cochrane Risk of Bias tool.

RESULTS

Forty-two studies were included in the review. Administration of a LMWH was associated with a significant decrease in the burden of metastasis (SMD -2.18; 95% CI -2.66 to -1.70). Additionally, the administration of a LMWH was also associated with a significant reduction in primary tumour growth (SMD -1.95; 95% CI -2.56 to -1.34) and risk of death (RR 0.39; 95% CI 0.16-0.97). All included studies were deemed to be at an unclear risk of bias for at least one methodological criterion.

CONCLUSIONS

Our results demonstrate that LMWH can effectively reduce metastatic burden and reduce tumour growth in preclinical animal models of solid tumour malignancies. Reasons for the contradiction with clinical evidence require further exploration.

Repurposing of drugs approved for cardiovascular diseases: Opportunity or mirage?

Drug repurposing is a promising way in drug discovery to identify new therapeutic uses -different from the original medical indication- for existing drugs. It has many advantages over traditional approaches to de novo drug discovery, since it can significantly reduce healthcare costs and development timeline. In this review, we discuss the possible repurposing of drugs approved for cardiovascular diseases, such as β-blockers, angiotensin converting enzyme inhibitors (ACE-Is), angiotensin II receptor blockers (ARBs), statins, aspirin, cardiac glycosides and low-molecular-weight heparins (LMWHs). Indeed, numerous experimental and epidemiological studies have reported promising anti-cancer activities for these drugs. It is worth mentioning, however, that the results of these studies are often controversial and very few data were obtained by controlled prospective clinical trials. Therefore, no final conclusion has yet been reached in this area and no final recommendations can be made. Moreover, β-blockers, ARBs and statins showed promising results in randomised controlled trials (RCTs) where pathological conditions other than cancer were considered. The results obtained have led or may lead to new indications for these drugs. For each drug or class of drugs, the potential molecular mechanisms of action justifying repurposing, results obtained in vitro and in animal models and data from epidemiological and randomized studies are described.

Use of New Oral Anticoagulants / Direct Oral Anticoagulants in Malignant Patients

Vitamin K antagonists are being used in the last five decades as an effective anticoagulant. However, for the past few years, new oral anticoagulants (NOACs) have been introduced as newer anticoagulant agents, which are gradually replacing the previously used vitamin K antagonist. Yet, these agents have not fully replaced the use of warfarin and heparin. NOACs have few advantages over the vitamin K antagonist as they act on a specific factor of coagulation cascade rather than inhibiting the whole vitamin K synthesis. In this article, all the data has been searched electronically on PubMed and PRISMA guidelines were not followed. Instead, we used MOOSE statements and the data searched on PubMed was from articles published in the last five years. A total of 12,269 patients were observed;,out of which 64.19% had active cancer and 35.80% was observed as a control group comprised of both male or female participants. Approximately 61.14% were using NOACs, 42.83% were on warfarin, and 2.72% were on low-molecular-weight heparin (LMWH). The NOACs used in different patients were in the following percentages; edoxaban (6.81%), apixaban (5.28%), dabigatran (10.09%), and rivaroxaban (10.02%). The use of NOACs has been increasing day by day but these agents have not completely replaced the warfarin or heparin, because of some demerits associated with the use of warfarin and some conditions where these drugs should be avoided. All NOACs have either hepatic or renal clearance so the hepatic activity and creatinine clearance rate must be monitored before the start of NOACs. The drug interaction between anticancer drugs and NOACs is still not fully reported. The effects of NOACs in AF and VTE are therapeutically effective, but in oncology patients several other co-factors are also involved with the use of NOACs due to which, it is either contraindicated or in some cases dose adjustment is required. However, very little information has been collected and more investigation must be done in this perspective.