Antithrombotic therapy and survival in patients with malignant disease

Unlocking the intricacies: Exploring the complex interplay between platelets and ovarian cancer

Ovarian cancer, an aggressive malignancy of the female reproductive tract, is frequently linked to an elevated risk of thrombotic events. This association is manifested by a pronounced rise in platelet counts and activation levels. Current research firmly supports the pivotal role of platelets in the oncogenic processes of ovarian cancer, influencing tumor cell proliferation and metastasis. Platelets influence these processes through direct interactions with tumor cells or by secreting cytokines and growth factors that enhance tumor growth, angiogenesis, and metastasis. This review aims to thoroughly dissect the interactions between platelets and ovarian cancer cells, emphasizing their combined role in tumor progression and associated thrombotic events. Additionally, it summarizes therapeutic strategies targeting platelet-cancer interface which show significant promise. Such approaches could not only be effective in managing the primary ovarian tumor but also play a pivotal role in preventing metastasis and attenuating thrombotic complications associated with ovarian cancer.

Venous Thromboembolic Event Following Soft Tissue Sarcoma Diagnosis is Associated with the Development of Pulmonary Metastasis

BACKGROUND

This study aimed to investigate whether venous thromboembolic events (VTEs) are clinically relevant predictors of pulmonary metastatic disease in patients with soft tissue sarcomas (STSs).

PATIENTS AND METHODS

In this retrospective cohort analysis, we included patients with STS surgically treated for sarcoma between January 2002 and January 2020. The primary outcome of interest was development of pulmonary metastasis after non-metastatic STS diagnosis. Tumor depth, stage, type of surgical intervention, chemotherapy, radiation therapy, body mass index, and smoking status were collected. Episodes of VTEs following STS diagnosis, including deep vein thrombosis, pulmonary embolism, and other thromboembolic events, were also obtained. Univariate analyses and multivariable logistic regression were used to identify potential predictors for pulmonary metastasis.

RESULTS

We included 319 patients with mean age of 54.9 ± 16 years. Thirty-seven patients (11.6%) had VTE after STS diagnosis, and 54 (16.9%) developed pulmonary metastasis. Univariate screening revealed pulmonary metastasis, pre- and postoperative chemotherapy, smoking history, and VTE after surgery as potential predictors of pulmonary metastasis. Multivariable logistic regression revealed smoking history [odds ratio (OR) 2.0, confidence interval (CI) 1.1-3.9, P = 0.04] and VTE (OR 6.3, CI 2.9-13.6, P < 0.001) as independent risk factors for predicting pulmonary metastasis in patients with STS, after adjusting for the factors in the univariate screening as well as age, sex, stage of the tumor, and neurovascular invasion.

CONCLUSIONS

Patients with VTE after STS diagnosis have an odds ratio of 6.3 for developing metastatic pulmonary disease compared with patients without venous thromboembolic events. Smoking history was also associated with future pulmonary metastases.

Mortality associated with the use of non-vitamin K antagonist oral anticoagulants in cancer patients: Dabigatran versus rivaroxaban

Objective

This study assesses the mortality outcomes of non‐vitamin K antagonist oral anticoagulants (NOACs) in cancer patients with venous thromboembolism (VTE) and atrial fibrillation (AF).

Methods

Medical records of cancer patients receiving NOACs for VTE or AF between January 1, 2011, and December 31, 2016, were retrieved from Taiwan's National Health Institute Research Database. NOACs were compared using the inverse probability of treatment weighting (IPTW) method. The primary outcome was cancer‐related death. Secondary outcomes were all‐cause mortality, major bleeding, and gastrointestinal (GI) bleeding.

Results

Among 202,754 patients who received anticoagulants, 3591 patients (dabigatran: 907; rivaroxaban: 2684) with active cancers were studied. Patients who received dabigatran were associated with lower risks of cancer‐related death at one year (HR = 0.71, 95% CI = 0.54–0.93) and at the end of follow‐ups (HR = 0.79, 95% CI = 0.64–0.98) compared with rivaroxaban. Patients who received dabigatran were also associated with lower risks of all‐cause mortality (HR = 0.81, 95% CI = 0.67–0.97), major bleeding (HR = 0.64, 95% CI = 0.47–0.88), and GI bleeding (HR = 0.57, 95% CI = 0.39–0.84) at the end of follow‐ups compared with rivaroxaban.

Conclusion

Compared with rivaroxaban, the use of dabigatran may be associated with a lower risk of cancer‐related death and all‐cause mortality.

The Role of Platelet Cell Surface P-Selectin for the Direct Platelet-Tumor Cell Contact During Metastasis Formation in Human Tumors

Mammalian platelets, devoid of nuclei, are the smallest cells in the blood stream. They are essential for hemostasis, but also transmit cell signals that are necessary for regenerative and generative processes such as inflammation, immunity and tissue repair. In particular, in malignancies they are also associated with cell proliferation, angiogenesis, and epithelial-mesenchymal transition. Platelets promote metastasis and resistance to anti-tumor treatment. However, fundamental principles of the interaction between them and target cells within tumors are complex and still quite obscure. When injected into animals or circulating in the blood of cancer patients, cancer cells ligate platelets in a timely manner closely related to platelet activation either by direct contact or by cell-derived substances or microvesicles. In this context, a large number of different surface molecules and transduction mechanisms have been identified, although the results are sometimes species-specific and not always valid to humans. In this mini-review, we briefly summarize the current knowledge on the role of the direct and indirect platelet-tumor interaction for single steps of the metastatic cascade and specifically focus on the functional role of P-selectin.

Visualizing cancer extravasation: from mechanistic studies to drug development

Metastasis is a multistep process that accounts for the majority of cancer-related death. By the end of metastasize dissemination, circulating tumor cells (CTC) need to extravasate the blood vessels at metastatic sites to form new colonization. Although cancer cell extravasation is a crucial step in cancer metastasis, it has not been successfully targeted by current anti-metastasis strategies due to the lack of a thorough understanding of the molecular mechanisms that regulate this process. This review focuses on recent progress in cancer extravasation visualization techniques, including the development of both in vitro and in vivo cancer extravasation models, that shed light on the underlying mechanisms. Specifically, multiple cancer extravasation stages, such as the adhesion to the endothelium and transendothelial migration, are successfully probed using these technologies. Moreover, the roles of different cell adhesive molecules, chemokines, and growth factors, as well as the mechanical factors in these stages are well illustrated. Deeper understandings of cancer extravasation mechanisms offer us new opportunities to escalate the discovery of anti-extravasation drugs and therapies and improve the prognosis of cancer patients.

Laparoscopic surgery in rectal cancer patients taking anti-thrombotic therapy

Background: Several previous studies have shown that laparoscopic resection of rectal cancer is a feasible option. However, its safety and efficacy in patients receiving long-term anti-thrombotic therapy (AT) remain unclear.Material and methods: We retrospectively reviewed 364 patients who underwent elective resection for rectal cancer via a laparoscopic approach between 2007 and 2018 in our institute. Patients were classified according to the long-term use of AT. AT was interrupted perioperatively with or without heparin bridging therapy in all anti-thrombotic users. Clinicopathological factors and surgical outcomes were analyzed between patient groups.Results: Thirty-two patients (9%) receiving AT were older and had lower albumin and hemoglobin levels than those not receiving AT (the non-AT group), and were predominantly male. Estimated blood loss and operative time in the AT group (median: 50 mL and 294 min) did not differ from those in the non-AT group (median: 20 mL and 295 min). There were no intergroup differences in the frequencies of other postoperative complications and oncological outcomes.Conclusions: Our results at the very least can support that laparoscopic surgery for rectal cancer is a safe and feasible option for patients taking long-term AT discontinued perioperatively.

Laparoscopic surgery in colon cancer patients treated with chronic anti-thrombotic therapy

BACKGROUND

Anti-thrombotic medications are commonly used for the treatment and prevention of cardiovascular diseases. Laparoscopic resection of colon cancer has generally been accepted with favorable outcomes being reported in randomized control trials. However, the safety and efficacy of laparoscopic surgery for colon cancer patients receiving chronic anti-thrombotic therapy (AT) remain unclear.

METHODS

We identified 951 patients who underwent elective resection for colon cancer between 2009 and 2016 from our database. Patients were classified according to the surgical approach and chronic AT. Clinicopathological factors and surgical outcomes were analyzed between patient groups. Patients' backgrounds were matched using propensity scores in laparoscopic surgery.

RESULTS

Anti-thrombotic drugs were chronically used in 135 patients. Among 714 patients who underwent laparoscopy-assisted surgery, 96 received AT. The laparoscopic approach was superior to open surgery in terms of bleeding, surgical site infections, and hospital stay in patients receiving AT. In laparoscopy-assisted surgery, the AT group patients were older and showed lower hemoglobin and albumin levels than those not receiving AT (non-AT group), and were predominantly male. After propensity score matching, estimated blood loss and operative times were similar between the two groups (93 matched patients). The frequencies of postoperative bleeding (2.2%) and thrombotic complications (0%) in the AT group did not significantly differ from those in the non-AT group (1.1 and 0%, respectively). Moreover, AT did not affect survivals.

CONCLUSION

Laparoscopic approach appears to be safer and beneficial for colonic cancer patients receiving long-term AT. Bleeding and thrombotic events associated with laparoscopic surgery were not significantly affected by AT.

Warfarin use and prostate cancer risk in the Finnish Randomized Study of Screening for Prostate Cancer

OBJECTIVE

Anticoagulants, especially vitamin K antagonists (VKAs) such as warfarin, have been hypothesized to have antitumor properties, and use of VKAs has been associated with a lower prostate cancer (PCa) risk. This study estimated PCa risk among users of warfarin and other anticoagulants.

MATERIALS AND METHODS

All anticoagulant use among 78,615 men during 1995-2009 was analyzed. Cox regression, adjusted for age, screening trial arm and use of other medications, with medication use as a time-dependent variable, was used to estimate PCa risk overall, and by tumor grade and stage.

RESULTS

In total, 6537 men were diagnosed with PCa during 1995-2009 (1210 among warfarin users). Compared to non-users, warfarin use was associated with an increased risk of PCa [multivariable-adjusted hazard ratio (HR) = 1.11, 95% confidence interval (CI) 1.01-1.22]. This was limited to short-term, low-dose use, and was not observed in long-term use. A similar overall risk increase was observed for Gleason grade 7-10 PCa. Low-dose, short-term use of warfarin was associated with an increased risk of metastatic PCa. However, the increase in risk vanished with continued use. Compared to other anticoagulants, low-dose use of warfarin was associated with a slightly elevated overall PCa risk (HR = 1.19, 95% CI 1.00-1.43). The increase in risk disappeared in long-term, high-dose use.

CONCLUSIONS

This study, which included a larger number of PCa cases with warfarin exposure than previous studies, does not support previous notions of decreased risk of PCa among warfarin users. A similar risk of PCa was found among warfarin users and the general population, and no difference in risk was found between warfarin and other anticoagulants.

Heparin regulates B6FS cell motility through a FAK/actin cytoskeleton axis

Soft tissue sarcomas are rare, heterogeneous tumors of mesenchymal origin with an aggressive behavior. Heparin is a mixture of heavily sulfated, linear glycosaminoglycan (GAG) chains, which participate in the regulation of various cell biological functions. Heparin is considered to have significant anticancer capabilities, although the mechanisms involved have not been fully defined. In the present study, the effects of unfractionated heparin (UFH) and low-molecular-weight heparin (LMWH) on B6FS fibrosarcoma cell motility were examined. Both preparations of heparin were shown to both enhance B6FS cell adhesion (p<0.01 and p<0.05), and migration (p<0.05), the maximal effect being evident at the concentration of 10 µg/ml. The utilization of FAK-deficient cells demonstrated that the participation of FAK was obligatory for heparin-dependent fibrosarcoma cell adhesion (p<0.05). The results of confocal microscopy indicated that heparin was taken up by the B6FS cells, and that UFH and LMWH induced F-actin polymerization. Heparitinase digestion demonstrated that the endogenous heparan sulfate (HS) chains did not affect the motility of the B6FS cells (p>0.05, not significant). In conclusion, both UFH and LMWH, through a FAK/actin cytoskeleton axis, promoted the adhesion and migration of B6FS fibrosarcoma cells. Thus, our findings indicate that the responsiveness of fibrosarcoma cells to the exogenous heparin/HS content of the cancer microenvironment may play a role in their ability to become mobile and metastasize.

Primary melanoma tumor inhibits metastasis through alterations in systemic hemostasis

Progression from a primary tumor to distant metastases requires extensive interactions between tumor cells and their microenvironment. The primary tumor is not only the source of metastatic cells but also can also modulate host responses to these cells, leading to an enhancement or inhibition of metastasis. Tumor-mediated stimulation of bone marrow can result in pre-metastatic niche formation and increased metastasis. However, a primary tumor can also inhibit metastasis through concomitant tumor resistance-inhibition of metastatic growth by existing tumor mass. Here, we report that the presence of a B16F10 primary tumor significantly restricted numbers and sizes of experimental lung metastases through reduction of circulating platelets and reduced formation of metastatic tumor cell-associated thrombi. Tumor-bearing mice displayed splenomegaly, correlated with primary tumor size and platelet count. Reduction in platelet numbers in tumor-bearing animals was responsible for metastatic inhibition, as restoration of platelet numbers using isolated platelets re-established both tumor cell-associated thrombus formation and experimental metastasis. Consumption of platelets due to a B16F10 primary tumor is a form of concomitant tumor resistance and demonstrates the systemic impact of a growing tumor. Understanding the interplay between primary tumors and metastases is essential, as clarification of concomitant tumor resistance mechanisms may allow inhibition of metastatic growth following tumor resection. Key messages Mice with a primary B16F10 tumor had reduced metastasis vs. mice without a primary tumor. Tumor-bearing mice had splenomegaly and fewer platelets and tumor-associated thrombi. Restoring platelets restored tumor-associated thrombi and increased metastasis. This work shows the impact that a primary tumor can have on systemic metastasis. Understanding these interactions may lead to improved ways to inhibit metastasis.

Venous thromboembolism in cancer patients: risk assessment, prevention and management

Thrombosis and thromboembolic events contribute to significant morbidity in cancer patients. Venous thrombosis embolism (which includes deep vein thrombosis and pulmonary embolism) accounts for a large percentage of thromboembolic events. Appropriate identification of cancer patients at high risk for venous thromboembolism and management of thromboembolic event is crucial in improving the quality of care for cancer patients. However, thromboembolism in cancer patients is a complex problem and the management has to be tailored to each individual. The focus of this review is to understand the complex pathology, physiology and risk factors that drive the process of venous thrombosis and embolism in cancer patients and the current guidelines in management.

Elevated Level of Circulating Platelet-derived Microparticles in Oral Cancer

Numerous studies have demonstrated that circulating microparticles (MPs) play important roles in a variety of diseases (e.g., atherosclerosis, hypertension, and diabetes), but the association between circulating MPs and oral squamous cell carcinoma (OSCC) remains largely unknown. In the present study, the circulating platelet-derived MPs (PMPs) in 63 patients with OSCC, 22 patients with infected keratocystic odontogenic tumor, and 31 healthy volunteers were characterized and quantified by flow cytometric analysis. The coagulation function of patients with OSCC was correspondingly evaluated. Meanwhile, the inflammation-related cytokines were detected in plasma by enzyme-linked immunosorbent assay and in tumor tissues by immunohistochemistry. Our results showed that the plasma level of circulating PMPs was significantly higher in OSCC patients compared with healthy volunteers and patients with infected keratocystic odontogenic tumor, and they showed positive correlation with the increased level of fibrinogen. Moreover, the coagulation time was significantly shorter after the MPs were added to the MP-free plasma. Most important, the levels of interleukin 6 and tumor necrosis factor α in plasma and tumor tissues were significantly increased in OSCC patients, which were closely correlated with the elevated level of circulating PMPs. In summary, this study suggests that the elevated level of circulating PMPs, showing close correlation with the secretion of inflammation-related factors, may contribute to the increased procoagulant activity in patients with OSCC.

Prognostic significance of arterial and venous thrombosis in resected specimens for non-small cell lung cancer

BACKGROUND

Venous thromboembolism(VTE) is common after pneumonectomy for malignancy and predicts poor survival. Routine screening for VTE with noninvasive tests has low sensitivity and specificity. Biopsy of lung has a place in establishing the nature and severity of the vascular alterations. In this study, we investigated the incidence, clinical and pathological characteristics of thrombosis in excised specimens after pneumonectomy, and its association with survival rate in patients with non-small cell lung cancer (NSCLC).

METHODS

The studied population consisted 94 consecutive patients after pneumonectomy for NSCLC in Beijing Chao-Yang Hospital, The excised tissue specimens were stained by haematoxylin & eosin staining (HE) to observe thrombosis events. All the patients were followed up for 2years. The survival data was analyzed by Kaplan-Meier analysis.

RESULTS

Overall thrombosis events occurred in 56 (59.6%) of 94 NSCLC cases, pulmonary arterial thrombosis was found in 24 cases, and pulmonary venous thrombosis was found in 32 cases. Furthermore, 30 of 56 cases with thrombosis were accompanied by tumor emboli or tumor vascular infiltrating. Thrombosis risk was associated with cancer grade (P=0.005). Kaplan-Meier analysis showed that patients with thrombosis had lower survival rate than those without thrombosis (P=0.025).

CONCLUSIONS

The incidence of thrombosis in excised tissue after pneumonectomy was high in patients with NSCLC, and it may be a marker of poor outcome.

Does low-molecular-weight heparin influence the antimyeloma effects of thalidomide? A retrospective analysis of data from the GIMEMA, Nordic and Turkish myeloma study groups

BACKGROUND/AIM

Low-molecular-weight heparin (LMWH) has been shown to prolong survival among patients with solid tumors, but its role among myeloma patients is unknown.

PATIENTS

Data from the GIMEMA (Gruppo Italiano Malattie Ematologiche dell'Adulto), Nordic and Turkish myeloma study groups comparing melphalan and prednisolone with (MPT, n: 404) or without thalidomide (MP, n: 393) are analyzed for effects of LMWH. Forty percent (159/394) of the patients on MPT and 7.4% (29/390) in the MP arm received LMWH.

RESULTS

Thalidomide improved response and progression-free survival (PFS). Regardless of thalidomide treatment, response rate was higher among those receiving LMWH vs. none vs. other anticoagulants (58.1 vs. 44.9 vs. 50.4%, p = 0.01). PFS was significantly longer (median 32 vs. 21 and 17 vs. 17 months, p = 0.004) only among international scoring system (ISS) I patients receiving MPT ± LMWH vs. MP ± LMWH. The group of MPT patients who also received LMWH had a better OS compared to those who did not [45 months, 95% confidence interval (CI) 27.7-62.3, vs. 32 months, 95% CI 26.1-37.9; p = 0.034]. When multivariate analysis was repeated in subgroups, thalidomide was no longer a significant factor (response, PFS) among those receiving LMWH.

CONCLUSION

Addition of LMWH to MPT, in particular in patients with low ISS, suggests additive effects, but the results are limited by the retrospective design of our study.

von Willebrand factor fibers promote cancer-associated platelet aggregation in malignant melanoma of mice and humans

Tumor-mediated procoagulatory activity leads to venous thromboembolism and supports metastasis in cancer patients. A prerequisite for metastasis formation is the interaction of cancer cells with endothelial cells (ECs) followed by their extravasation. Although it is known that activation of ECs and the release of the procoagulatory protein von Willebrand factor (VWF) is essential for malignancy, the underlying mechanisms remain poorly understood. We hypothesized that VWF fibers in tumor vessels promote tumor-associated thromboembolism and metastasis. Using in vitro settings, mouse models, and human tumor samples, we showed that melanoma cells activate ECs followed by the luminal release of VWF fibers and platelet aggregation in tumor microvessels. Analysis of human blood samples and tumor tissue revealed that a promoted VWF release combined with a local inhibition of proteolytic activity and protein expression of ADAMTS13 (a disintegrin-like and metalloproteinase with thrombospondin type I repeats 13) accounts for this procoagulatory milieu. Blocking endothelial cell activation by the low-molecular-weight heparin tinzaparin was accompanied by a lack of VWF networks and inhibited tumor progression in a transgenic mouse model. Our findings implicate a mechanism wherein tumor-derived vascular endothelial growth factor-A (VEGF-A) promotes tumor progression and angiogenesis. Thus, targeting EC activation envisions new therapeutic strategies attenuating tumor-related angiogenesis and coagulation.

The effect of warfarin therapy on breast, colorectal, lung, and prostate cancer survival: a population-based cohort study using the Clinical Practice Research Datalink

PURPOSE

Pre-clinical studies suggest that oral anticoagulant agents, such as warfarin, may inhibit metastases and potentially prolong survival in cancer patients. However, few population-based studies have examined the association between warfarin use and cancer-specific mortality.

METHODS

Using prescribing, cause of death, and cancer registration data from the UK Clinical Practice Research Datalink, four population-based cohorts were constructed, comprising breast, colorectal, lung, and prostate cancer patients diagnosed between 1 January 1998, and the 31 December 2010. Comparing pre-diagnostic warfarin users to non-users, multivariable Cox proportional hazard models were used to estimate hazard ratios (HRs) and 95 % confidence intervals (CIs) for cancer-specific mortality.

RESULTS

Overall, 16,525 breast, 12,902 colorectal, 12,296 lung, and 12,772 prostate cancers were included. Pre-diagnostic warfarin use ranged from 2.4 to 4.7 %. There was little evidence of any strong association between warfarin use pre-diagnosis and cancer-specific mortality in prostate (adjusted HR 1.03, 95 % CI 0.84-1.26), lung (adjusted HR 1.06, 95 % CI 0.96-1.16), breast (adjusted HR 0.81, 95 % CI 0.62-1.07), or colorectal (adjusted HR 0.88, 95 % CI 0.77-1.01) cancer patients. Dose-response analyses did not reveal consistent evidence of reductions in users of warfarin defined by the number of prescriptions used and daily defined doses.

CONCLUSIONS

There was little evidence of associations between pre-diagnostic use of warfarin and cancer-specific mortality in lung, prostate, breast, or colorectal cancer patients.

Cancer cell adhesion and metastasis: selectins, integrins, and the inhibitory potential of heparins

Cell adhesion molecules play a significant role in cancer progression and metastasis. Cell-cell interactions of cancer cells with endothelium determine the metastatic spread. In addition, direct tumor cell interactions with platelets, leukocytes, and soluble components significantly contribute to cancer cell adhesion, extravasation, and the establishment of metastatic lesions. Clinical evidence indicates that heparin, commonly used for treatment of thromboembolic events in cancer patients, is beneficial for their survival. Preclinical studies confirm that heparin possesses antimetastatic activities that lead to attenuation of metastasis in various animal models. Heparin contains several biological activities that may affect several steps in metastatic cascade. Here we focus on the role of cellular adhesion receptors in the metastatic cascade and discuss evidence for heparin as an inhibitor of cell adhesion. While P- and L-selectin facilitation of cellular contacts during hematogenous metastasis is being accepted as a potential target of heparin, here we propose that heparin may also interfere with integrin activity and thereby affect cancer progression. This review summarizes recent findings about potential mechanisms of tumor cell interactions in the vasculature and antimetastatic activities of heparin.

The role of platelets in tumour growth

Platelets, as initial responders to vascular injury, play a very important role in the initial stages of the haemostatic process. While the role of platelets in coagulation has been well studied and documented, their role in other physiological and pathological processes is just emerging. Platelets contain many biologically active molecules and, as they adhere to sites of tumour activated or injured endothelium, many of these molecules are released into the local microenvironment leading to platelet-mediated effects on vascular tone, repair and neo-angiogenesis. Platelets are likely play important roles in the tumour microenvironment that may be thought of as "a wound that never heals".