"Screening for Occult Cancer in Unprovoked Venous Thromboembolism".The New England Journal of Medicine. 2015.

Clinical Question

Does a screening strategy for occult cancer including comprehensive computed tomography (CT) of the abdomen and pelvis lead to a clinically significant benefit in patients who had a first unprovoked venous thromboembolism?

Bottom Line

The prevalence of occult cancer in patients with a first unprovoked venous thromboembolism is low, and routine CT screening of the abdomen and pelvis does not provide a clinically significant benefit in detecting missed cancers or reducing cancer-related mortality.

Major Points

Guidelines

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Guidelines for cancer screening in patients with unprovoked venous thromboembolism vary, with some recommending limited occult-cancer screening, while others suggest more extensive modalities.

Design

Multicenter, open-label, randomized, controlled trial
N=854 patients with first unprovoked symptomatic venous thromboembolism
Limited occult-cancer screening group (n=431)
Limited occult-cancer screening plus CT group (n=423)
Enrollment: October 2008 to April 2014
Follow-up: 1 year
Intention-to-treat analysis

Population

Inclusion Criteria: Patients with a new diagnosis of first unprovoked symptomatic venous thromboembolism.
Exclusion Criteria: Age <18 years, inability to provide informed consent, allergy to contrast media, creatinine clearance <60 ml/min, claustrophobia or agoraphobia, weight >130 kg, ulcerative colitis, or glaucoma.

Interventions

Patients were assigned to undergo limited screening (history, physical examination, basic blood testing, chest radiography, and age- and sex-specific cancer screening) or limited screening plus CT of the abdomen and pelvis.

Outcomes

Primary Outcome: Confirmed cancer missed by the screening strategy and detected by the end of the 1-year follow-up period.

Secondary Outcomes: Total number of occult cancers diagnosed, number of early cancers diagnosed, 1-year cancer-related mortality, 1-year overall mortality, time to cancer diagnosis, incidence of recurrent venous thromboembolism

Criticisms

Open-label design may introduce bias. The screening did not include CT of the chest as many patients had undergone CT pulmonary angiography for diagnosis of pulmonary embolism.

Funding

Heart and Stroke Foundation of Canada

Further Reading