Thrombosis and Cancer
Authors: Simon Stern
Journal: Journal of the Royal Society of Medicine (2005)

Those medical historians with a black sense of humour will already know, as we are reminded several times in this book, that Armand Trousseau, who first described the association between cancer and venous thrombosis in 1865, eventually succumbed to carcinoma of the stomach, the presenting symptom of which was thrombophlebitis. One hundred and forty years later, the fact that venous thromboembolism can be the earliest manifestation of malignant disease is still not as widely appreciated as it should be. Indeed, I am concerned that one of the very few downsides to the current trend of treating patients with deep vein thrombosis in the community is that some early cancers may be missed as a result.

No-one who reads this book is ever likely to make that mistake, although the repetitive nature of some of the content rather precludes cover-to-cover reading. Each chapter provides a useful review on the pathogenesis or treatment of venous thrombosis in oncology. Cancer is often blithely described as being a 'hypercoagulable state', but it was a salutary lesson for me to be reminded of, or taught about, the myriad mechanisms that underlie this generalization. A series of very clear chapters at the beginning of this book describe the role of platelets, leucocytes, clotting factors and cytokines produced by the tumour cells themselves in the initiation of thrombosis. While some readers may know of the central role of tissue factor (a glycoprotein overexpressed on many forms of cancer cell) in triggering what used to be known as the coagulation cascade, far fewer will be aware that tissue factor may also promote angiogenesis—a process that is essential for tumour growth and metastasis. Indeed, this may provide an intriguing and important link between thrombosis and tumorigenesis.

It is therefore not unsurprising to learn in the chapters on thromboprophylaxis in cancer patients that there is some early tentative evidence to suggest that treatment with anticoagulants, whether warfarin or low molecular weight heparin, is associated with improved survival rates. Whether this is due to the prevention of thromboembolism or the drugs' influence on tumour biology is not yet clear, but we shall hear more about this subject when current randomized trials come to fruition.

Turning from the speculative to uncontroversial best practice, the book's international contributors leave little room for doubt about the case for thromboprophylaxis in cancer patients undergoing surgery. However, the duration of treatment, the choice of the best antithrombotic agent and the most appropriate dosages remain to be clarified. Similarly the precise optimum duration for full anticoagulation following the diagnosis of proven venous thromboembolism is still not certain. While it should almost certainly be extended from the standard six months, a chapter by Breddin and Bauersachs neatly describes the delicate balancing act between preventing recurrent thrombosis and the bleeding complications of anticoagulation. Indeed, the risk of a cancer patient experiencing a major haemorrhage after twelve months of anticoagulation may be three times that of a patient without malignant disease.

In their preface, the editors state that the purpose of the book is to provide comprehensive and timely coverage of the current knowledge of cancer-associated thrombosis. They have undoubtedly succeeded. One of the book's most attractive characteristics is the contemporary nature of the references—in contrast to its rather dated layout and design. It passed my key test of providing helpful information to support the management of a current clinical problem—in this case the prevention of thrombosis associated with a long-term central venous catheter. I would certainly recommend the book to haematologists and oncologists, all of whom have to deal regularly with the thrombotic complications of malignant disease.