恶性肿瘤与血栓栓塞疾病关系的研究最早见于一个多世纪前，1865年Armand Trousseau报道癌症患者发生血栓是血液系统继发的特殊改变，表现为自发性血管内凝血。1878年Billroth发现在这类血栓中存在肿瘤细胞，从而认为与肿瘤转移有关。在尸检时一半以上的肿瘤病人可见到血栓栓塞的证据。但并不是所有的恶性肿瘤都伴发血栓，以腺癌最为突出，肺、胰、胃肠肿瘤较乳腺、肾肿瘤更易出现高凝。
华法林为双香豆素类抗凝药，能阻碍已形成血栓的扩展，但无溶栓作用。临床上能用华法林防治血栓栓塞性疾病，可防止血栓形成与发展，另外华法林也能用于治疗癌症病人伴发的血栓症状。
与华法林相似的另一抗凝药--低分子量肝素（Low Molecular Weight Heparin，LMWH）注射剂作为改善肿瘤病人血栓症状的一线药物在临床上已被大量使用，但LMWH注射剂的使用频率相对于另一常用治疗药物华法林来说仍较少。
近来，一项刊登在The Oncologist杂志上的研究表明：在2000年到2007年期间，以LMWH注射剂治疗晚期癌症患者血栓并发症的治疗方式占所有治疗方式中正逐年提高。
该项研究调查分析了从2000年1月至2008年12月之间，四个癌症研究网络中心关于健康计划的电子记录。发现25%的肿瘤病人接受了LMWH第一治疗药物选择，而74%的患者选择华法林作为治疗治疗。虽然2003年7月，一个随机对照研究表明：在预防肿瘤患者出现血栓复发方面，LMWH注射剂比华法林更有效，但LMWH注射剂的使用率仍没有超过华法林。
但这项研究的缺陷在于没有说明华法林为什么能继续作为治疗晚期癌症患者血栓首选药物的原因。研究人员猜测可能是因为临床医生在治疗肿瘤患者更倾向于使用华法林。其他还有一些其他原因如华法林不用注射剂，癌症患者们更倾向选择华法林。
研究人员下一步的研究将针对为什么LMWH的使用率会比华法林低，LMWH注射剂和华法林在治疗晚期癌症病人血栓上疗效有何差异性。（生物谷Bioon.com）
doi:10.1634/theoncologist.2011-0323
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Outpatient Use of Low Molecular Weight Heparin Monotherapy for First-Line Treatment of Venous Thromboembolism in Advanced Cancer
Thomas Delatea, Daniel M. Witta, Debra Ritzwollerb, Jane C. Weeksc, Lawrence Kushid, Mark C. Hornbrooke, Erin J. Aiello Bowlesf and Deborah Schragc
Abstract Background. Evidence-based treatment guidelines recommend low molecular weight heparin (LMWH) monotherapy for cancer-associated venous thromboembolism (VTE). This analysis assessed the first-line treatment strategies for VTE in patients with advanced solid tumors.
Methods. Using administrative data from advanced lung, prostate, colon, or breast cancer patients diagnosed between January 2000 and December 2007 at four HMOs with integrated delivery systems, patients with an inpatient or outpatient VTE diagnosed within 2 years after cancer diagnosis and an outpatient purchase of warfarin,LMWH, and/or fondaparinux anticoagulant within 7 days of the VTE diagnosis were identified. First-line outpatient VTE pharmacological treatment and factors independently associated with receipt/non-receipt of LMWH monotherapy were assessed.
Results. Overall, 25% of the 1,089 eligible patients received LMWH monotherapy as primary VTE treatment. The percentage increased steadily over time from 18% among patients diagnosed in 2000 to 31% among those diagnosed in 2007. Factors associated with LMWH monotherapy included VTE diagnosis year, chemotherapy within 60 days prior to VTE diagnosis, history of VTE prior to cancer diagnosis, and invasive surgery in the 90 days following VTE diagnosis. Colorectal and prostate cancer patients versus lung cancer patients and stage III versus stage IV patients were less likely to be treated with LMWH monotherapy.
Conclusions. Adoption of LMWH monotherapy as initial treatment for cancer-associated VTE was low but increased steadily over the study period. Future studies should explore reasons underlying the underutilization of this preferred evidence-based treatment as well as the comparative effectiveness of LMWH versus warfarin-based anticoagulation in real-world cancer patients with VTE.
