What you need to know
The prevalence of occult cancer in patients with a first unprovoked venous thromboembolism seems to be lower (~4%) than previously reported (10%)
There is limited evidence to recommend extensive cancer screening with computed tomography in such patients
Consider history and physical examination, basic laboratory tests, and results from routine age-specific cancer screening to guide further testing as an alternative to extensive screening
How far to go in screening patients with an unprovoked venous thromboembolism (VTE) for an occult cancer is a clinical dilemma. Unprovoked VTE, either deep vein thrombosis or pulmonary embolism, can be the first manifestation of an undiagnosed cancer. Until recently, the literature suggested that up to 10% of such patients would be diagnosed with a cancer in the year after their diagnosis of VTE.1 However, the incidence of occult cancer in patients studied in two recent, high quality, randomised controlled trials was only about 4%.23 This drop in the proportion of people with occult cancer may require an adjustment in the clinical approach.
Fig 1⇓ outlines a conservative approach and a more detailed approach to investigating such patients. Extensive screening has become the standard of care, though it is based on limited data.
What is the evidence of uncertainty?
Search strategy and study selection
We searched PubMed (from inception to 31 December 2016) for randomised controlled trials and systematic reviews using the search terms “cancer screening,” “venous thromboembolism,” “unprovoked,” “meta-analysis,” and “randomized controlled trial.” We reviewed articles published in English between 2012 (publication of NICE guidelines) and 2016.