Guideline on aspects of cancer-related venous thrombosis

British Journal of Haematology

Volumn 170, Issue 5, 2015, Pages 640-648

  Watson, Henry G ^a   Keeling, David M ^b   Laffan, Mike ^c   Tait, Robert Campbell ^d   Makris, Mike ^e,f  

^a ABERDEEN ROYAL INFIRMARY   (United Kingdom)

^b CHURCHILL HOSPITAL   (United Kingdom)

^c HAMMERSMITH HOSPITAL   (United Kingdom)

^d GLASGOW ROYAL INFIRMARY   (United Kingdom)

^e UNIVERSITY OF SHEFFIELD   (United Kingdom)

^f British Society for Haematology   (United Kingdom)

Author keywords

Anticoagulation; Cancer; Clinical aspects; Venous thrombosis

Indexed keywords

ANTICOAGULANT AGENT; LOW MOLECULAR WEIGHT HEPARIN;

ANTICOAGULANT THERAPY; ARTICLE; CANCER PATIENT; CANCER SCREENING; CANCER SURVIVAL; CANCER THERAPY; CATHETER THROMBOSIS; DEEP VEIN THROMBOSIS; DISEASE ASSOCIATION; HUMAN; LONG TERM CARE; MALIGNANT NEOPLASTIC DISEASE; PRIORITY JOURNAL; RECURRENT DISEASE; SURGICAL APPROACH; THROMBOCYTE COUNT; THROMBOCYTOPENIA; THROMBOSIS PREVENTION; TREATMENT DURATION; TREATMENT INDICATION; TREATMENT PLANNING; VEIN THROMBOSIS; MEDLINE; NEOPLASMS; PRACTICE GUIDELINE; UNITED KINGDOM; VENOUS THROMBOEMBOLISM; VENOUS THROMBOSIS;

GREAT BRITAIN; HUMANS; NEOPLASMS; PUBMED; VENOUS THROMBOEMBOLISM; VENOUS THROMBOSIS;

EID: 84938976398     PISSN: 00071048     EISSN: 13652141     Source Type: Journal    
DOI: 10.1111/bjh.13556     Document Type: Article

References (75)

1. Ageno, W., Squizzato, A., Togna, A., Magistrali, F., Mangini, M., Fugazzola, C. & Dentali, F. (2012) Incidental diagnosis of a deep vein thrombosis in consecutive patients undergoing a computed tomography scan of the abdomen: a retrospective cohort study. Journal of Thrombosis and Haemostasis, 10, 158-160.
2. Agnelli, G. (1997) Venous thromboembolism and cancer: a two way clinical association. Journal of Thrombosis and Haemostasis, 78, 117-120.
3. Akl, E.A., Vasireddi, S.R., Gunukula, S., Yosuico, V.E., Barba, M., Sperati, F., Cook, D. & Schünemann, H. (2011a) Anticoagulation for patients with cancer and central venous catheters. Cochrane Database Systematic Reviews, 13, CD006468.
4. Akl, E.A., Vasireddi, S.R., Gunukula, S., Yosuico, V.E., Barba, M., Terrenato, I., Sperati, F. & Schünemann, H. (2011b) Oral anticoagulation in patients with cancer who have no therapeutic or prophylactic indication for anticoagulation. Cochrane Database Systematic Reviews, 15, CD006466.
5. Akl, E.A., Gunukula, S., Barba, M., Yosuico, V.E., vanDoormaal, F.F., Kuipers, S., Middeldorp, S., Dickinson, H.O., Bryant, A. & Schünemann, H. (2011c) Parenteral anticoagulation in patients with cancer who have no therapeutic or prophylactic indication for anticoagulation. Cochrane Database Systematic Reviews, 13, CD006652.
6. Baron, J.A., Gridley, G., Weiderpass, E., Nyren, O. & Linet, M. (1998) Venous thromboembolism and cancer. Lancet, 351, 1077-1080.
7. Beckers, M.M., Schutgens, R.E., Prins, M.H. & Biesma, D.H. (2006) Who is at risk for occult cancer after venous thromboembolism? Journal of Thrombosis and Haemostasis, 4, 2731-2733.
8. Bern, M.M., Lokich, J.J., Wallach, S.R., Bothe, Jr, A., Benotti, P.N., Arkin, C.F., Greco, F.A., Huberman, M. & Moore, C. (1990) Very low doses of warfarin can prevent thrombosis in central venous catheters. A randomized prospective trial. Annals of Internal Medicine, 112, 423-428.
9. Bird, J.M., Owen, R.G., D'Sa, S., Snowden, J.A., Pratt, G., Ashcroft, J., Yong, K., Cook, G., Feyler, S., Davies, F., Morgan, G., Cavenagh, J., Low, E. & Behrens, J. (2011) Guidelines for the diagnosis and management of myeloma 2011. British Journal of Haematology, 154, 32-75.
10. Browne, A.M., Cronin, C.G., English, C., NiMhuircheartaigh, J., Murphy, J.M. & Bruzzi, J.F. (2010) Unsuspected pulmonary emboli in oncology patients undergoing routine computed tomography imaging. Journal of Thoracic Oncology, 5, 798-803.
11. Carrier, M., Le Gal, G., Wells, P.S., Fergusson, D., Ramsay, T. & Rodger, M.A. (2008) Systematic review: the Trousseau syndrome revisited: should we screen extensively for cancer in patients with venous thromboembolism? Annals Internal Medicine, 149, 323-333.
12. Carrier, M., Le Gal, G., Cho, R., Tierney, S., Rodger, M. & Lee, A.Y. (2009) Dose escalation of low molecular weight heparin to manage recurrent venous thromboembolic events despite systemic anticoagulation in cancer patients. Journal of Thrombosis and Haemostasis, 7, 760-765.
13. Carrier, M., Khorana, A.A., Zwicker, J.I., Noble, S. & Lee, A.Y. (2013) Management of challenging cases of patients with cancer-associated thrombosis including recurrent thrombosis and bleeding: guidance from the SSC of the ISTH. Journal of Thrombosis and Haemostasis, 11, 1760-1765.
14. Chee, C.E., Ashrani, A.A., Marks, R.S., Petterson, T.M., Bailey, K.R., Melton, J. & Heit, J.A. (2014) Predictors of venous thromboembolism recurence and bleeding among active cancer patients: a population based cohort study. Blood, 123, 3972-3978.
15. Chew, H.K., Wun, T., Harvey, D., Zhou, H. & White, R.H. (2006) The incidence of venous thromboembolism and its effect on survival among patients with common cancer. Archives of Internal Medicine, 166, 458-464.
16. Cronin, C.G., Lohan, D.G., Keane, M., Roche, C. & Murphy, J.M. (2007) Prevalence and significance of asymptomatic venous thromboembolic disease found on oncologic staging CT. AJR American Journal of Roentgenology, 189, 162-170.
17. Davies, H.E., Wathen, C.G. & Gleeson, F.V. (2011) The risks of radiation exposure related to diagnostic imaging and how to minimise them. British Medical Journal, 342, d947.
18. Deitcher, S.R. & Gomes, M.P.V. (2004) The risk of venous thromboembolic disease associated with adjuvant hormone therapy for breast carcinoma: a systematic review. Cancer, 101, 439-449.
19. Dentali, F., Ageno, W., Becattini, C., Galli, L., Gianni, M., Riva, N., Imberti, D., Squizzato, A., Venco, A. & Agnelli, G. (2010) Prevalence and clinical history of incidental, asymptomatic pulmonary embolism: a meta-analysis. Thrombosis Research, 125, 518-522.
20. Dentali, F., Ageno, W., Pierfranceschi, M.G., Imberti, D., Malato, A., Nitti, C., Salvi, A., Siragusa, S., Squizzato, A., Vitale, J. & Agnelli, G. (2011) Prognostic relevance of an asymptomatic venous thromboembolism in patients with cancer. Journal of Thrombosis and Haemostasis, 9, 1081-1083.
21. Department of Health. (2007) Report of the Independent Expert Working Group on the Prevention of Venous Thromboembolism in Hospitalised Patients. Department of Health, London.
22. Di Nisio, M., Otten, H.M., Piccioli, A., Lensing, A.W.A., Prandoni, P., Buller, H.R. & Prins, M.H. (2005) Decision analysis for cancer screening in idiopathic venous thromboembolism. Journal of Thrombosis and Haemostasis, 3, 2391-2396.
23. Di Nisio, M., Ferrante, N., De Tursi, M., Iacobelli, S., Cuccurullo, F., Büller, H.R., Feragalli, B. & Porreca, E. (2010) Incidental venous thromboembolism in ambulatory cancer patients receiving chemotherapy. Thrombosis and Haemostasis, 104, 1049-1054.
24. Di Nisio, M., Porreca, E., Ferrante, N., Otten, H.M., Cuccurullo, F. & Rutjes, A.W.S. (2012) Primary prophylaxis for venous thromboembolism in ambulatory cancer patients receiving chemotherapy. Cochrane Database of Systematic Reviews, 29, CD008500.
25. van Doormaal, F.F., Di Nisio, M., Otten, H.M., Richel, D.J., Prins, M. & Buller, H.R. (2011a) Randomized trial of the effect of the low molecular weight heparin nadroparin on survival in patients with cancer. Journal of Clinical Oncology, 29, 2071-2076.
26. Douma, R.A., Kok, M.G., Verberne, L.M., Kamphuisen, P.W. & Büller, H.R. (2010) Incidental venous thromboembolism in cancer patients: prevalence and consequence. Thrombosis Research, 125, e306-e309.
27. Drakos, P.E., Nagler, A., Or, R., Gillis, S., Slavin, S. & Eldor, A. (1992) Low molecular weight heparin for Hickman catheter - induced thrombosis in thrombocytopenic patients undergoing bone marrow transplantation. Cancer, 70, 1895-1898.
28. Elting, L.S., Escalante, C.P., Cooksley, C., Avritscher, E.B., Kurtin, D., Hamblin, L., Khosla, S.G. & Rivera, E. (2004) Outcomes and cost of deep venous thrombosis among patients with cancer. Archives of Internal Medicine, 164, 1653-1661.
29. den Exter, P.L., Hooijer, J., Dekkers, O.M. & Huisman, M.V. (2011) Risk of recurrent venous thromboembolism and mortality in patients with cancer incidentally diagnosed with pulmonary embolism: a comparison with symptomatic patients. Journal of Clinical Oncology, 29, 2405-2409.
30. den Exter, P.L., van Es, J., Klok, F.A., Kroft, L.J., Kruip, M.J., Kamphuisen, P.W., Büller, H.R. & Huisman, M.V. (2013a) Risk profile and clinical outcome of symptomatic subsegmental acute pulmonary embolism. Blood, 122, 1144-1149.
31. den Exter, P.L., Kroft, L.J., van der Hulle, T., Klok, F.A., Jiménez, D. & Huisman, M.V. (2013b) Embolic burden of incidental pulmonary embolism diagnosed on routinely performed contrast-enhanced computed tomography imaging in cancer patients. Journal of Thrombosis and Haemostasis, 11, 1620-1622.
32. den Exter, P.L., van Roosmalen, M.J., van den Hoven, P., Klok, F.A., Monreal, M., Jiménez, D. & Huisman, M.V. (2013c) Physicians' management approach to an incidental pulmonary embolism: an international survey. Journal of Thrombosis and Haemostasis, 11, 208-213.
33. Eyer, B.A., Goodman, L.R. & Washington, L. (2005) Clinicians' response to radiologists' reports of isolated subsegmental pulmonary embolism or inconclusive interpretation of pulmonary embolism using MDCT. AJR American Journal of Roentgenology, 184, 623-628.
34. Farge, D., Debourdeau, P., Beckers, M., Baglin, C., Bauersachs, R.M., Brenner, B., Brilhante, D., Falanga, A., Gerotzafias, G.T., Haim, N., Kakkar, A.K., Khorana, A.A., Lecumberri, R., Mandala, M., Marty, M., Monreal, M., Mousa, S.A., Noble, S., Pabinger, I., Prandoni, P., Prins, M.H., Qari, M.H., Streiff, M.B., Syrigos, K., Bounameaux, H. & Büller, H.R. (2013) International clinical practice guidelines for the treatment and prophylaxis of venous thromboembolism in patients with cancer. Journal of Thrombosis and Haemostasis, 11, 56-70.
35. Font, C., Farrús, B., Vidal, L., Caralt, T.M., Visa, L., Mellado, B., Tàssies, D., Monteagudo, J., Reverter, J.C. & Gascon, P. (2011) Incidental versus symptomatic venous thrombosis in cancer: a prospective observational study of 340 consecutive patients. Annals of Oncology, 22, 2101-2106.
36. Gladish, G.W., Choe, D.H., Marom, E.M., Sabloff, B.S., Broemeling, L.D. & Munden, R.F. (2006) Incidental pulmonary emboli in oncology patients: prevalence, CT evaluation, and natural history. Radiology, 240, 246-255.
37. Hernandez, R.K., Sørensen, H.T., Pedersen, L., Jacobsen, J. & Lash, T.L. (2009) Tamoxifen treatment and risk of deep venous thrombosis and pulmonary embolism: a Danish population-based cohort study. Cancer, 115, 4442-4449.
38. Hull, R.D., Pineo, G.F., Brant, R.F., Mah, A.F., Burke, N., Dear, R., Wong, T., Cook, R., Solymoss, S., Poon, M.C. & Raskob, G. (2006) Long-term low-molecular-weight heparin versus usual care in proximal-vein thrombosis patients with cancer. American Journal of Medicine, 119, 1062-1072.
39. van der Hulle, T., den Exter, P.L., Kooiman, J., van der Hoeven, J.J., Huisman, M.V. & Klok, F.A. (2014) Meta-analysis of the efficacy and safety of new oral anticoagulants in patients with cancer associated acute venous thromboembolism. Journal of Thrombosis and Haemostasis, 12, 1116-1120.
40. Kahn, S.R., Lim, W., Dunn, A.S., Cushman, M., Dentali, F., Akl, E.A., Cook, D.J., Balekian, A.A., Klein, R.C., Le, H., Schulman, S. & Murad, M.H. (2012) Prevention of VTE in nonsurgical patients. Antithrombotic therapy and prevention of thrombosis. 9th Ed: American College of Chest Physicians evidence based clinical practise guidelines. Chest, 141(2 Suppl), e195S-e226S.
41. Kearon, C., Akl, E.A., Comerota, A.J., Prandoni, P., Bounameaux, H., Goldhaber, S.Z., Nelson, M.E., Wells, P.S., Gould, M.K., Dentali, F., Crowther, M. & Kahn, S.R. (2012) Antithrombotic therapy for VTE disease: Antithrombotic Therapy and Prevention of Thrombosis, 9th ed: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines. Chest, 141(2 Suppl), e419S-e494S.
42. Khorana, A.A. (2010) Venous thromboembolism and prognosis in cancer. Thromobosis Research, 125, 490-493.
43. Khorana, A.A., Kuderer, N.M., Culakova, E., Lyman, G.H. & Francis, C.W. (2008) Development and validation of a predictive model for chemotherapy associated thrombosis. Blood, 111, 4902-4907.
44. Khorana, A.A., O'Connell, C., Agnelli, G., Liebman, H.A. & Lee, A.Y. (2012) Incidental venous thromboembolism in oncology patients. Journal of Thrombosis and Haemostasis, 10, 2602-2604.
45. Lee, A.Y. (2012) Treatment of established thrombotic events in patients with cancer. Thrombosis Research, 129(Suppl 1), S146-S153.
46. Lee, A.Y., Levine, M.N., Baker, R.I., Bowden, C., Kakkar, A.K., Prins, M., Rickles, F.R., Julian, J.A., Haley, S., Kovacs, M.J. & Gent, M. (2003) Low-molecular-weight heparin versus a coumarin for the prevention of recurrent venous thromboembolism in patients with cancer. New England Journal of Medicine, 349, 146-153.
47. Levitan, N., Dowlati, A., Remick, S.C., Tahsildar, H.I., Sivinski, I.D., Beyth, R. & Rimm, A.A. (1999) Rates of initial and recurrent thromboembolic disease among patients with malignancy versus those without malignancy: risk analysis using Medicare claims data. Medicine (Baltimore), 78, 285-291.
48. Meignan, M., Rosso, J., Gauthier, H., Brunengo, F., Claudel, S., Sagnard, L., d'Azemar, P., Simonneau, G. & Charbonnier, B. (2000) Systematic lung scans reveal a high frequency of silent pulmonary embolism in patients with proximal deep venous thrombosis. Archives of Internal Medicine, 160, 159-164.
49. Merli, G., Spiro, T.E., Olsson, C.G., Abildgaard, U., Davidson, B.L., Eldor, A., Elias, D., Grigg, A., Musset, D., Rodgers, G.M., Trowbridge, A.A., Yusen, R.D. & Zawilska, K. (2001) Subcutaneous enoxaparin once or twice daily compared with intravenous unfractionated heparin for treatment of venous thromboembolic disease. Annals of Internal Medicine, 134, 191-202.
50. Meyer, G., Marjanovic, Z., Valcke, J., Lorcerie, B., Gruel, Y., Solal-Celigny, P., Le Maignan, C., Extra, J.M., Cottu, P. & Farge, D. (2002) Comparison of low-molecular-weight heparin and warfarin for the secondary prevention of venous thromboembolism in patients with cancer: a randomized controlled study. Archives of Internal Medicine, 162, 1729-1735.
51. Monreal, M., Lensing, A.W., Prins, M.H., Bonet, M., Fernandez-Llamazares, J., Muchart, J., Prandoni, P. & Jimenez, J.A. (2004) Screening for occult cancer in patients with acute deep vein thrombosis or pulmonary embolism. Journal of Thrombosis and Haemostasis, 2, 876-881.
52. NICE. (2010) Venous thromboembolism: reducing the risk: reducing the risk of venous thromboembolism (deep vein thrombosis and pulmonary embolism) in patients admitted to hospital. Clinical Guideline 92. National Institute for Health and Clinical Excellence, London. http://www.nice.org.uk/guidance/cg92.
53. NICE. (2012) Venous thromboembolic diseases: the management of venous thromboembolic diseases and the role of thrombophilia testing. Clinical Guideline 144. National Institute for Health and Clinical Excellence, London. http://guidance.nice.org.uk/cg144.
54. O'Connell, C.L., Boswell, W.D., Duddalwar, V., Caton, A., Mark, L.S., Vigen, C. & Liebman, H.A. (2006) Unsuspected pulmonary emboli in cancer patients: clinical correlates and relevance. Journal of Clinical Oncology, 24, 4928-4932.
55. O'Connell, C., Razavi, P., Ghalichi, M., Boyle, S., Vasan, S., Mark, L., Caton, A., Duddalwar, V., Boswell, W., Grabow, K. & Liebman, H.A. (2011) Unsuspected pulmonary emboli adversely impact survival in patients with cancer undergoing routine staging multi-row detector computed tomography scanning. Journal of Thrombosis and Haemostasis, 9, 305-311.
56. Palareti, G., Legnani, C., Lee, A., Manotti, C., Hirsh, J., D'Angelo, A., Pengo, V., Moia, M. & Coccheri, S. (2000) A comparison of the safety and efficacy of oral anticoagulation for the treatment of venous thromboembolic disease in patients with or without malignancy. Journal of Thrombosis and Haemostasis, 84, 805-810.
57. Paneesha, S., Cheyne, E., French, K., Bacchu, S., Borg, A. & Rose, P. (2006) High D-dimer levels at presentation in patients with venous thromboembolism is a marker of adverse clinical outcomes. British Journal of Haematology, 135, 85-90.
58. Piccioli, A., Lensing, A.W., Prins, M.H., Falanga, A., Scannapieco, G.L., Ieran, M., Cigolini, M., Ambrosio, G.B., Monreal, M., Girolami, A. & Prandoni, P. (2004) Extensive screening for occult malignant disease in idiopathic venous thromboembolism: a prospective randomized clinical trial. Journal of Thrombosis and Haemostasis, 2, 884-889.
59. Prandoni, P., Lensing, A.W., Buller, H.R., Cogo, A., Prins, M.H., Cattelan, A.M., Cuppini, S., Noventa, F. & ten Cate, J.W. (1992) Deep-vein thrombosis and the incidence of subsequent symptomatic cancer. New England Journal of Medicine, 327, 1128-1133.
60. Prandoni, P., Lensing, A.W., Piccioli, A., Bernardi, E., Simioni, P., Girolami, B., Marchiori, A., Sabbion, P., Prins, M.H., Noventa, F. & Girolami, A. (2002) Recurrent venous thromboembolism and bleeding complications during anticoagulant treatment in patients with cancer and venous thrombosis. Blood, 100, 3484-3488.
61. Rance, A., Emmerich, J., Guedj, C. & Fiessinger, J.N. (1997) Occult cancer in patients with bilateral deep-vein thrombosis. Lancet, 350, 1448-1449.
62. Rodger, M.A., Kahn, S.R., Cranney, A., Hodsman, A., Kovacs, M.J., Clement, A.M., Lazo-Langner, A. & Hague, W.M.; TIPPS investigators. (2007) Long-term dalteparin in pregnancy not associated with a decrease in bone mineral density: substudy of a randomized controlled trial. Journal of Thrombosis and Haemostasis, 5, 1600-1606.
63. Sahut D'Izarn, M., Caumont Prim, A., Planquette, B., Revel, M.P., Avillach, P., Chatellier, G., Sanchez, O. & Meyer, G. (2012) Risk factors and clinical outcome of unsuspected pulmonary embolism in cancer patients: a case-control study. Journal of Thrombosis and Haemostasis, 10, 2032-2038.
64. Schutgens, R.E., Beckers, M.M., Haas, F.J. & Biesma, D.H. (2005) The predictive value of D-dimer measurement for cancer in patients with deep vein thrombosis. Haematologica, 90, 214-219.
65. Shteinberg, M., Segal-Trabelsy, M., Adir, Y., Laor, A., Vardi, M. & Bitterman, H. (2012) Clinical characteristics and outcomes of patients with clinically unsuspected pulmonary embolism versus patients with clinically suspected pulmonary embolism. Respiration, 84, 492-500.
66. Singh, R., Sousou, T., Mohile, S. & Khorana, A.A. (2010) High rates of symptomatic and incidental thromboembolic events in gastrointestinal cancer patients. Journal of Thrombosis and Haemostasis, 8, 1879-1881.
67. Snowden, J.A., Ahmedzai, S.H., Ashcroft, J., D'Sa, S., Littlewood, T., Low, E., Lucraft, H., Maclean, R., Feyler, S., Pratt, G. & Bird, J.M. (2011) Guidelines for supportive care in multiple myeloma 2011. British Journal of Haematology, 154, 76-103.
68. Sorensen, H.T., Mellemkjaer, L., Olsen, J.H. & Baron, J.A. (2000) Prognosis of cancers associated with venous thromboembolism. New England Journal of Medicine, 343, 1846-1850.
69. Sun, J.M., Kim, T.S., Lee, J., Park, Y.H., Ahn, J.S., Kim, H., Kwon, O.J., Lee, K.S., Park, K. & Ahn, M.J. (2010) Unsuspected pulmonary emboli in lung cancer patients: the impact on survival and the significance of anticoagulation therapy. Lung Cancer, 69, 330-336.
70. Tait, C., Baglin, T., Watson, H., Laffan, M., Makris, M., Perry, D. & Keeling, D. (2012) Guideline on the investigation and management of venous thrombosis at unusual sites. British Journal of Haematology, 159, 28-38.
71. The PREPIC Study Group. (2005) Eight-year follow-up of patients with permanent vena cava filters in the prevention of pulmonary embolism: the PREPIC (Prévention du Risque d'Embolie Pulmonaire par Interruption Cave) randomized study. Circulation, 112, 416-422.
72. Trujillo-Santos, J., Prandoni, P., Rivron-Guillot, K., Roman, P., Sanchwz, R., Tiberio, G. & Monreal, M. (2008) Clinical outcome in patients with venous thromboembolism and hidden cancer: findings from the RIETE Registry. Journal of Thrombosis and Haemostasis, 6, 251-255.
73. Van Doormaal, F.F., Terpstra, W., Van Der Griend, R., Prins, M.H., Nijziel, M.R., Van De Ree, M.A., Buller, H.R., Dutilh, J.C., ten Cate-Hoek, A., Van Den Heiligenberg, S.M., Van Der Meer, J. & Otten, J.M. (2011b) Is extensive screening for cancer in idiopathic venous thromboembolism warranted? Journal of Thrombosis and Haemostasis, 9, 79-84.
74. Wun, T. & White, R.H. (2009) Epidemiology of cancer-related venous thromboembolism. Bailliere's Best Practice in Clinical Haematology, 22, 9-23.
75. Young, A.M., Billingham, L.J., Begum, G., Kerr, D.J., Hughes, A.I., Rea, D.W., Shepherd, S., Stanley, A., Sweeney, A., Wilde, J. & Wheatley, K. (2009) Warfarin thromboprophylaxis in cancer patients with central venous catheters (WARP): an open-label randomised trial. Lancet, 373, 567-574.