Bick Rodger L
University of Texas Southwestern Medical Center, Dallas 93035, USA.
J Support Oncol. 2006 Mar;4(3):115-20.
The increased risk of thrombosis-related morbidity and mortality in patients with cancer remains, even in the face of anticoagulant therapy. Moreover, recurrent venous thromboembolism (VTE) complicates the management of cancer and adversely affects quality of life and survival. Until recently, initial therapy with unfractionated heparin or low-molecular-weight heparin (LMWH) followed by long-term therapy with an oral anticoagulant was the standard of care for the secondary prevention of acute thromboembolism in most patients. However, according to the results of the CLOT trial (Randomized Comparison of Low-Molecular-Weight Heparin Versus Oral Anticoagulant Therapy for the Prevention of Recurrent VTE in Patients With Cancer), extended LMWH therapy with dalteparin represents an alternative to standard oral anticoagulation. In terms of efficacy, the incidence of recurrent VTE in patients receiving dalteparin was half that of those receiving warfarin (27 of 336 patients vs 53 of 336 patients, respectively), for a 52% relative risk reduction. The incidence of major bleeding in this trial was not significantly different in the two arms. Although this LMWH regimen is supported by the latest practice guidelines of the American College of Chest Physicians, the question of whether long-term treatment with LMWH in cancer patients actually affects survival apart from the benefits of thromboprophylaxis remains to be answered.
即便接受了抗凝治疗，癌症患者发生血栓相关发病和死亡的风险仍居高不下。此外，复发性静脉血栓栓塞（VTE）使癌症治疗变得复杂，并对生活质量和生存率产生不利影响。直到最近，大多数患者急性血栓栓塞二级预防的标准治疗方案仍是先用普通肝素或低分子量肝素（LMWH）进行初始治疗，随后使用口服抗凝剂进行长期治疗。然而，根据CLOT试验（低分子量肝素与口服抗凝剂治疗癌症患者复发性VTE的随机对照比较）的结果，使用达肝素进行延长的LMWH治疗是标准口服抗凝治疗的一种替代方案。在疗效方面，接受达肝素治疗的患者复发性VTE的发生率是接受华法林治疗患者的一半（分别为336例患者中的27例和336例患者中的53例），相对风险降低了52%。该试验中两组的大出血发生率无显著差异。尽管这种LMWH方案得到了美国胸科医师学会最新实践指南的支持，但除了预防血栓形成的益处外，癌症患者长期使用LMWH治疗是否真的会影响生存率这一问题仍有待解答。
