Venous thromboembolism: patients were more likely to have cancer diagnosed in the next year

Clinical bottom line (level 2c)

  1. In patients with thromboembolic disease, an increased incidence of cancer was noted in the following 12 months
  2. In patients with more than one episode of thromboembolic disease, the risk of cancer was even higher
Sorensen et al: New England Journal of Medicine 1998; 338: 1169-1173
Expires January 2003

The study

Outcome study with objective outcomes, not adjusted for confounding factors, not validated in an independent set of patients.

Setting: population study, Denmark

26653 patients (aged below 60y in 33%, approx 50% male) episode of thromboembolic disease

Excluded if
  • surgery in last 6 months
  • previous cancer
  • pregnancy


    • Cases: 26653 patients (% male, mean age ): diagnosis of VTE on basis of hospital records
    Controls: ?patients : standardised cancer rates from the population


    Outcomes studied:
  • any cancer diagnosed (1 year after VTE)
  • all cancers (2-17 years after VTE)

    • Standardised cancer rates based on mandatory national registry supplemented by autopsy findings.

    The evidence

    risk factor for
    any cancer diagnosed     		adjusted RR
    (95% CI)    		 NNH
    (95% CI)
    DVT 2.1
    (1.9 to 2.4)     		79
    (62 to 96)
    PE 2.3
    (2.0 to 2.7)     		120
    (91 to 160)
    two episodes of VTE disease 3.2
    (2.0 to 4.8)     		50
    (29 to 110)

    risk factor for
    all cancers     		adjusted RR
    (95% CI)    		 NNH
    (95% CI)
    DVT 1.1
    (1.1 to 1.2)     		200
    (100 to 350)
    PE 1.2
    (1.1 to 1.3)     		120
    (83 to 150)

    • The risk of cancer after VTE was greater among the younger (<60y) patients
    • Individual cancers with greatest increase in risk: liver, pancreas, ovarian, brain

    Comments

    1. Quoted NNF are somewhat arbitrary as baseline risk of cancer varies strongly with age.
    2. Difficult to assess if cancer subgroups are real or data-dependant with single study

    Citation

    1. Sorensen HT, Mellemkjaer l, Steffensen FH, et al: The risk of a diagnosis of cancer after primary deep venous thrombosis or pulmonary thrombosis. New England Journal of Medicine 1998; 338: 1169-1173
    Contributor: Chris Ball and Bob Phillips, May 1998
    Reviewer:

    Clinical Question.
    Patient without known cancer
    Intervention or Exposure diagnosis of thromboembolic disease
    Outcome cancer newly diagnosed