Thrombosis as a harbinger of cancer

[Thromboembolic disease and cancer: Attitude and practice of general practitioners. A qualitative study]

INTRODUCTION

Cancer is a major public health problem in France. Idiopathic venous thromboembolic disease may be one of the modes of discovery. Few studies have been performed on this subject in primary care. The general practitioner plays a key role in the diagnosis for which a more codified approach seems desirable. The aim was to study how general practitioners conceive the search for cancer in patients with idiopathic venous thromboembolic disease in primary care.

METHOD

A qualitative study, inspired by the grounded theory approach, was carried out using semi-structured interviews with 12 established general practitioners. It was conducted from May to July 2022. The interview guide was developed based on data from the literature.

RESULTS

Idiopathic venous thromboembolic disease as a mode of cancer discovery in primary care was a well-known topic among general practitioners but remained a difficult exercise in practice. Our study revealed similarities in their practices: a complete anamnesis, clinical examination, verification of screening tests, and finally a TAP scan. They emphasized the importance of collaboration with angiologists and asked for a more codified management.

DISCUSSION

The question of etiology of cancer remains unanswered. General practioners would like to be made aware of a common, codified attitude. This raises the question of the applicability of the recommendations. The aim is to avoid misdiagnosing a cancer or delaying a diagnosis, while at the same time, not unnecessarily exposing certain patients to excessive investigations when these are not needed. So, it is time to think about better dissemination of recommendations, tools to help GPs easily finding what they need among the multitude of existing recommendations and tools, to establish better collaboration between general practice and hospital medicine, and between general practice and specialist medicine in order to improve cancer diagnosis as early as possible.

Effect of tissue factor on invasion inhibition and apoptosis inducing effect of oxaliplatin in human gastric cancer cell

OBJECTIVE

Tissue factor (TF) is expressed abnormally in certain types of tumor cells, closely related to invasion and metastasis. The aim of this study was to construct a human gastric cancer cell line SGC7901 stably-transfected with human TF, and observe effects on oxaliplatin-dependent inhibition of invasion and the apoptosis induction.

METHODS

The target gene TF was obtained from human placenta by nested PCR and introduced into the human gastric cell line SGC7901 through transfection mediated by lipofectamine. Stably-transfected cells were screened using G418. Examples successfully transfected with TF-pcDNA3 recombinant (experimental group), and empty vector pcDNA3 (control group) were incubated with oxaliplatin. Transwell chambers were used to show change in invasive ability. Caspase-3 activity was detected using a colorimetric method and annexin-V/PI double- staining was applied to detect apoptosis.

RESULTS

We generated the human gastric cancer cell line SGC7901/TF successfully, expressing TF stably and efficiently. Compared with the control group, invasion increased, whereas caspase-3 activity and apoptosis rate were decreased in the experimental group.

CONCLUSION

TF can enhance the invasive capacity of gastric cancer cells in vitro. Its increased expression may reduce invasion inhibition and apoptosis-inducing effects of oxaliplatin and therefore may warrant targeting for improved chemotherapy.

The potential benefits of low-molecular-weight heparins in cancer patients

Cancer patients are at increased risk of venous thromboembolism due to a range of factors directly related to their disease and its treatment. Given the high incidence of post-surgical venous thromboembolism in cancer patients and the poor outcomes associated with its development, thromboprophylaxis is warranted. A number of evidence-based guidelines delineate anticoagulation regimens for venous thromboembolism treatment, primary and secondary prophylaxis, and long-term anticoagulation in cancer patients. However, many give equal weight to several different drugs and do not make specific recommendations regarding duration of therapy. In terms of their efficacy and safety profiles, practicality of use, and cost-effectiveness the low-molecular-weight heparins are at least comparable to, and offer several advantages over, other available antithrombotics in cancer patients. In addition, data are emerging that the antithrombotics, and particularly low-molecular-weight heparins, may exert an antitumor effect which could contribute to improved survival in cancer patients when given for long-term prophylaxis. Such findings reinforce the importance of thromboprophylaxis with low-molecular-weight heparin in cancer patients.

Genetic Link Between Cancer and Thrombosis

From the beginning of their lives, cancer cells exert a procoagulant activity in their microenvironment, which can extend systemically and become clinically evident as Trousseau's syndrome, the well-known association between tumor and thrombosis. It is becoming clear that the genetic mechanisms responsible for neoplastic transformation (activation of oncogenes such as RAS or MET, and inactivation of tumor suppressor genes such as p53 or PTEN) directly induce the expression of genes controlling hemostasis. Activation of blood coagulation results in a selective advantage for cancer cells, as fibrin provides a scaffold for anchorage and invasion, and coagulation proteins induce receptor-mediated intracellular signals promoting invasive growth. Targeting the tumor procoagulant activity can fight not only a dangerous tumor adverse effect, but also the core mechanisms of cancer onset and progression.

Trousseau's syndrome: multiple definitions and multiple mechanisms

In 1865, Armand Trousseau noted that unexpected or migratory thrombophlebitis could be a forewarning of an occult visceral malignancy. An analysis by Sack and colleagues in 1977 extended the term Trousseau's syndrome to include chronic disseminated intravascular coagulopathy associated with microangiopathy, verrucous endocarditis, and arterial emboli in patients with cancer, often occurring with mucin-positive carcinomas. In recent times the term has been ascribed to various clinical situations, ranging all the way from these classic descriptions to any kind of coagulopathy occurring in the setting of any kind of malignancy. These multiple definitions of Trousseau's syndrome are partly the consequence of multiple pathophysiologic mechanisms that apparently contribute to the hypercoagulability associated with cancer. Even the classic syndrome probably represents a spectrum of disorders, ranging from exaggerated fluid-phased thrombosis dependent on prothrombotic agents such as tissue factor to a platelet- and endotheliumum-based selectin-dependent microangiopathy associated with mucin-producing carcinomas, along with thrombin and fibrin production. Also considered here are recent hypotheses about genetic pathways within tumor cells that might trigger these thrombotic phenomena, and the reasons why therapy with heparins of various kinds remain the preferred treatment, probably because of their salutary actions on several of the proposed pathologic mechanisms.