Venous Thromboembolism (VTE) in Hematologic Malignancies(HM)

In our series of consecutive patients (p) with objectively diagnosed VTE, cancer constitutes the most frequent ethiology (25%) followed by idiopathic (24%), clinical causes (22%), orthopedics and trauma (16%), general surgery (7%), obstetric entities (3%) and others (3%). Among the neoplastic subtypes, HM are the most prevalent ones followed by prostatic, colonic, lung and CNS cancers. A recent publication (Blom et al, JAMA2005; 293:715) shows this previously undisclosed high tendency of HM for provoking VTE. Our current study describes the experience with this association from 1996 to 2005, excluding central vein catheter thrombosis. Out of 531 p with VTE, 138 have cancer and 34 of them, HM, with the following distribution: plasma cells discrasias (PCD) 9 (4 on treatment with thalidomide), diffuse large cell lymphomas (DLCL) 8, indolent lymphomas (IL) 6, CLL 5, mantle cell lymphoma 1, Burkitt lymphoma 1, RAEB 1, AML 1, myelofibrosis 1, P vera 1. In 25/34 p, the HM was previously known at diagnosis of VTE and mostly active or on treatment. In the other 9 p, the clinical presentation was as an idiopathic VTE, and during follow-up the following HM were disclosed: PCD: 3, CLL: 2, DLCL: 1, IL: 1, myelofibrosis: 1, RAEB: 1. Table 1 Comments: PCD and DLCL constitute the two HM more frequently associated with VTE. However, the contribution of less agressive neoplasms such as indolent lymphomas and CLL is not negligible As in solid tumors, recurrences are high, specially when anticoagulated patients are off-therapy In spite of more chemotherapy related-thrombocytopenia and bone marrow involvement, bleeding rates do not differ of those observed in solid tumors Given the frequent association with VTE, and the probable heterogeneity in the thrombophilic potency of these different entities collectively grouped as HM, prospective multicentric studies are clearly needed to identify groups of patients with HM suitable for primary prophylaxis of VTE. Such studies should also be designed to provide further clue about the use of LMWH instead of oral anticoagulants for secondary prophylaxis in HM. Table 1. Main clinical findings in patients able to be evaluated during follow-up Events Hematologic Malignancies Solid Neoplasms Recurrences 6/28 (21.4%) 5 off anticoagulation 15/106 (14.1%) 7 off anticoagulation (p=ns) Major bleeding 2/28 (7.1%) 10/106 (9.4%) (p=ns)