title: Risk factors for incident venous thromboembolism in active cancer patients: A population based case-control study.
abstract: BACKGROUND
  Independent risk factors for cancer-associated incident venous thromboembolism (VTE) and their magnitude of risk are not fully characterized.
  
  
  OBJECTIVE
  To identify non-cancer and cancer-specific risk factors for cancer-associated incident VTE.
  
  
  METHODS
  In a population-based retrospective case-control study, we used Rochester Epidemiology Project and Mayo Clinic Cancer Registry resources to identify all Olmsted County, MN residents with active cancer-associated incident VTE, 1973-2000 (cases; n=570) and 1-3 residents with active cancer matched to each case on age, sex, date and duration of active cancer (controls; n=604). Using conditional logistic regression, we tested cancer and non-cancer characteristics for an association with VTE, including a cancer site VTE risk score.
  
  
  RESULTS
  In the multivariable model, higher cancer site VTE risk score (OR=1.4 per 2-fold increase), cancer stage≥2 (OR=2.2), liver metastasis (OR=2.7), chemotherapy (OR=1.8) and progesterone use (OR=2.1) were independently associated with VTE, as were BMI<18.5kg/m(2) (OR=1.9) or ≥35kg/m(2) (OR=4.0), hospitalization (OR=7.9), nursing home confinement (OR=4.7), central venous (CV) catheter (OR=8.5) and any recent infection (OR=1.7). In a subgroup analysis, platelet count≥350×10(9)/L at time of cancer diagnosis was marginally associated with VTE (OR=2.3, p=0.07).
  
  
  CONCLUSIONS
  Cancer site, cancer stage≥2, liver metastasis, chemotherapy, progesterone, being underweight or obese, hospitalization/nursing home confinement, CV catheter, and infection are independent risk factors for incident VTE in active cancer patients.
authors.affiliation: Division of Hematology, Department of Internal Medicine, Mayo Clinic, Rochester, MN, United States. Electronic address: ashrani.aneel@mayo.edu.
authors.forename: Aneel A
authors.initials: AA
authors.lastname: Ashrani
authors.affiliation: Division of Biomedical Statistics and Informatics, Department of Health Sciences Research, Mayo Clinic, Rochester, MN, United States.
authors.forename: Rachel E
authors.initials: RE
authors.lastname: Gullerud
authors.affiliation: Division of Biomedical Statistics and Informatics, Department of Health Sciences Research, Mayo Clinic, Rochester, MN, United States.
authors.forename: Tanya M
authors.initials: TM
authors.lastname: Petterson
authors.affiliation: Division of Medical Oncology, Department of Oncology, Mayo Clinic, Rochester, MN, United States.
authors.forename: Randolph S
authors.initials: RS
authors.lastname: Marks
authors.affiliation: Division of Biomedical Statistics and Informatics, Department of Health Sciences Research, Mayo Clinic, Rochester, MN, United States.
authors.forename: Kent R
authors.initials: KR
authors.lastname: Bailey
authors.affiliation: Division of Hematology, Department of Internal Medicine, Mayo Clinic, Rochester, MN, United States; Division of Cardiovascular Diseases, Department of Internal Medicine, Mayo Clinic, Rochester, MN, United States; Division of Epidemiology, Department of Health Sciences Research, Mayo Clinic, Rochester, MN, United States.
authors.forename: John A
authors.initials: JA
authors.lastname: Heit
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D016022:Case-Control Studies; D005260:Female; D006760:Hospitalization; D006801:Humans; D015994:Incidence; D008113:Liver Neoplasms / Q000556:secondary; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009369:Neoplasms / Q000150:complications* / Q000473:pathology; D009765:Obesity / Q000150:complications; D011374:Progesterone / Q000009:adverse effects; D011372:Progestins / Q000009:adverse effects; D012307:Risk Factors; D013851:Thinness / Q000150:complications; D054556:Venous Thromboembolism / Q000139:chemically induced / Q000209:etiology*
chemical_list: D011372:Progestins; D011374:Progesterone
keywords: Cancer; Deep vein thrombosis; Epidemiology; Pulmonary embolism; Risk factors; Venous thromboembolism