title: OC-01 - Clinical history of cancer patients with isolated distal deep vein thrombosis: a multicenter cohort study.
abstract: BACKGROUND
  Isolated distal deep vein thrombosis (IDDVT) accounts for one-fourth to one-half of all deep vein thrombosis (DVT) of the leg. Patients with IDDVT are frequently treated for a shorter period of time compared to patients with proximal DVT and/or pulmonary embolism (PE) due to a perceived lower risk of recurrence. About 10-20% of patients with venous thromboembolic events (VTEs) have concomitant cancer. Guidelines recommend long-term anticoagulant treatment in this group of patients due to their high risk of VTE recurrence. Unfortunately, information on the clinical history of IDDVT patients is limited and, to date, no study has evaluated the long-term risk of VTE recurrence in IDDVT patients with cancer.
  
  
  OBJECTIVE
  To provide information on the clinical history of IDDVT patients with active cancer.
  
  
  METHODS
  A multicenter, cohort study including active-cancer patients with an objective diagnosis of IDDVT (between January 2011 and September 2014) was conducted. Information on baseline characteristics, thrombosis location and extension, concomitant risk factors, type and duration of treatment was collected. All patients were followed for a minimum of 12 months and up to 24 months. During follow-up, VTE recurrence, major bleeding episodes and death were registered. Potential risk factors for VTE recurrence were evaluated.
  
  
  RESULTS
  308 patients (mean age 66.2±13.2 years, female 57.1%) in 13 centers were included, Table 1; 261 patients had solid cancer and 47 patients hematologic cancer. At the time of IDDVT diagnosis, the disease was metastatic in 148 patients (48.1%); 99.0% of patients received anticoagulant treatment: 288 patients (93.5%) were initially treated with low molecular weight heparin, 15 with fondaparinux (5.2%) and 1 with unfractionated heparin; vitamin K antagonists were used in 46 patients (14.9%) only. Total follow-up was 389 patient-years, mean follow-up 15.2 months. Mean duration of treatment was 4.2 months. During the study period there were 47 episodes of VTE recurrence (36 proximal DVT or PE) for a incidence rate of 13.2 events per 100 patient-years; 7 patients had major bleeding (2.3%) and 137 died (44.5%). At multivariate analysis, previous VTE was associated with an increased risk of recurrence (OR 2.10; 95% 1.06, 4.14), whereas patients with gastrointestinal cancer had a lower risk of recurrence (OR 0.26; 95% CI 0.08, 0.86).
  
  
  CONCLUSIONS
  Cancer patients with IDDVT have a high risk of VTE recurrence. Other studies are warranted to address the adequate management of these patients.
authors.affiliation: Department of Clinical Medicine, Insubria University, Varese.
authors.forename: F
authors.initials: F
authors.lastname: Dentali
authors.affiliation: Department of Clinical Medicine, Insubria University, Varese.
authors.forename: S
authors.initials: S
authors.lastname: Pegoraro
authors.affiliation: Department of Internal Medicine, University of Pavia.
authors.forename: S
authors.initials: S
authors.lastname: Barco
authors.affiliation: Unit of Cell and Molecular Biology in Cardiovascular Diseases, Centro Cardiologico Monzino.
authors.forename: M N D
authors.initials: MN
authors.lastname: di Minno
authors.affiliation: UOSD Angiologia e Diagnostica Vascolare PO SS Filippo e Nicola Avezzano.
authors.forename: D
authors.initials: D
authors.lastname: Mastroiacovo
authors.affiliation: Department of Clinical Medicine, ASO S. Croce e Carle, Cuneo.
authors.forename: F
authors.initials: F
authors.lastname: Pomero
authors.affiliation: Thrombosis Center, IRCCS Istituto Clinico Humanitas, Milan.
authors.forename: C
authors.initials: C
authors.lastname: Lodigiani
authors.affiliation: Department of Clinical Medicine, Insubria University, Varese.
authors.forename: F
authors.initials: F
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authors.affiliation: Department of Angiology and Blood Coagulation, S. Orsola-Malpighi University Hospital, Bologna.
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authors.affiliation: Center for Hemorrhagic and Thrombotic Diseases, University Hospital of Udine.
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authors.affiliation: Department of Internal Medicine, Hospital of Livorno.
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authors.lastname: Mumoli
authors.affiliation: Haematology Unit, University of Palermo.
authors.forename: M
authors.initials: M
authors.lastname: Napolitano
authors.affiliation: Angelo Bianchi Bonomi Hemophilia and Thrombosis, Fondazione IRCCS Ca' Granda-Ospedale Maggiore Policlinico, Milan.
authors.forename: S
authors.initials: S
authors.lastname: Passamonti
authors.affiliation: Internal Medicine Unit, Hospital of Piacenza.
authors.forename: R
authors.initials: R
authors.lastname: Benedetti
authors.affiliation: Department of Clinical Medicine, Insubria University, Varese.
authors.forename: W
authors.initials: W
authors.lastname: Ageno
authors.affiliation: Department of Medical, Oral and Biotechnological Sciences, University "G. D'Annunzio" of Chieti-Pescara, Italy.
authors.forename: M Di
authors.initials: MD
authors.lastname: Nisio