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Evidence summaries

Testing for Cancer in Patients with Unprovoked Venous Thromboembolism

There is insufficient evidence as to whether testing for undiagnosed cancer in patients with a first episode of unprovoked venous thromboembolism (VTE) is effective in reducing cancer- and VTE-related mortality and morbidity, and which tests for cancer are most useful. Level of evidence: "D"

The quality of evidence is downgraded by study limitations (early termination in 2 studies and lack of blinding of outcome assessors in 1 sudy), and by imprecise results (few patients and outcome events).

Summary

A Cochrane review [Abstract] 1 included 4 studies with a total of 1 644 subjects. Two studies assessed the effect of extensive tests including computed tomography (CT) scanning versus tests at the physician's discretion, and 2 studies assessed the effect of standard testing plus positron emission tomography (PET)/CT scanning versus standard testing alone.

There was no difference in cancer-related mortality between extensive tests versus tests at the physician's discretion (OR 0.49, 95% CI 0.15 to 1.67; 2 studies, n=396). One study (n=201) showed that malignancies were less advanced in extensively tested participants than in participants in the control group. There was no clear difference in detection of advanced stages between extensive tests versus tests at the physician's discretion (OR 0.25, 95% CI 0.03 to 2.28). Extensively tested participants were diagnosed earlier than control group (mean: 1 month with extensive tests versus 11.6 months with tests at physician's discretion to cancer diagnosis from the time of diagnosis of VTE). Extensive testing did not increase the frequency of an underlying cancer diagnosis (OR 1.32, 95% CI 0.59 to 2.93; 2 studies, n=396).

There was no difference in all-cause mortality (OR 1.22, 95% CI 0.49 to 3.04; 2 studies, n=1 248), cancer-related mortality (OR 0.55, 95% CI 0.20 to 1.52; 2 studies, n=1 248) or VTE-related morbidity (OR 1.02, 95% CI 0.48 to 2.17; 1 study, n=854) between standard testing plus PET/CT screening versus standard testing alone. There was no clear difference for detection of early (OR 1.78, 95% 0.51 to 6.17; 1 study, n=394) or advanced (OR 1.00, 95% CI 0.14 to 7.17; 1 study, n=394) stages of cancer. There was also no clear difference in the frequency of an underlying cancer diagnosis (OR 1.71, 95% CI 0.91 to 3.20; 2 studies, n=1 248). Time to cancer diagnosis was 4.2 months in the standard testing group and 4.0 months in the standard testing plus PET/CT group (P = 0.88).

Clinical comments

Note

Date of latest search:

    References

    • Robertson L, Broderick C, Yeoh SE et al. Effect of testing for cancer on cancer- or venous thromboembolism (VTE)-related mortality and morbidity in people with unprovoked VTE. Cochrane Database Syst Rev 2021;(10):CD010837. [PubMed].

Primary/Secondary Keywords