D-Dimer Testing May Safely Reduce CT Scans for PE in Cancer Patients

For the millions of cancer patients who arrive at emergency departments each year with suspected pulmonary embolism, the diagnostic pathway has long defaulted to an immediate CT pulmonary angiogram — a costly, radiation-heavy procedure — because clinical decision tools were never thought reliable in this population. New evidence now challenges that assumption in ways that could meaningfully reduce patient burden without sacrificing diagnostic accuracy.

The YEARS algorithm, a validated clinical decision rule that incorporates three criteria alongside D-dimer thresholds, was evaluated in cancer patients suspected of pulmonary embolism. The central question was whether this structured approach could safely rule out PE in a subset of patients — thereby sparing them CT imaging — without an unacceptable rate of missed clots. The study, published in JAMA, examined whether cancer's well-known prothrombotic state actually invalidates the predictive math underlying D-dimer-based exclusion, or whether it simply inflates baseline D-dimer levels in ways that can still be clinically navigated with adjusted thresholds.

This finding sits at a meaningful intersection of oncology and emergency medicine. D-dimer is a fibrin degradation product elevated not only by thrombosis but also by malignancy, inflammation, and recent surgery — all common in cancer patients — which is precisely why guidelines have historically bypassed it in this group. The YEARS algorithm attempts to correct for this by stratifying patients into low- and high-probability tiers with different D-dimer cutoffs, potentially rescuing the test's utility even in a noisy clinical environment. If confirmed in larger prospective trials, this approach could reduce radiation exposure, contrast-induced nephropathy risk, and emergency department congestion for a vulnerable population already burdened by treatment demands. The study is an important proof-of-concept signal, though widespread adoption should await replication across more diverse oncologic subgroups and disease stages.