Evaluating clinically suspected acute pulmonary embolism in oncological cohorts presents a major medical challenge. Historically, standard healthcare guidelines recommended direct computed tomographic pulmonary angiography for these high-risk patients. However, a landmark randomized clinical trial demonstrates that the YEARS algorithm in cancer provides a highly safe diagnostic alternative.
The Hydra Trial Design and Methodology
The Hydra study, a multicenter, open-label, randomized trial, took place across twenty-one clinical sites in Europe. Specifically, investigators recruited six hundred ninety-eight patients with active cancer and suspected acute pulmonary embolism. Researchers randomized these participants into two diagnostic pathways. Consequently, half of the patients underwent the YEARS diagnostic algorithm, while the other half received immediate computed tomographic pulmonary angiography. Importantly, the YEARS pathway integrated clinical criteria assessment with tailored D-dimer testing to stratify diagnostic decisions.
Implementing the YEARS Algorithm in Cancer
The clinical algorithm relies on three primary assessment criteria. First, clinicians check for active clinical signs of deep vein thrombosis. Second, they assess the patient for hemoptysis. Third, they determine if pulmonary embolism represents the most likely diagnostic possibility. If a patient displays zero criteria, clinicians use a higher D-dimer threshold of one thousand nanograms per milliliter. Conversely, if any criteria exist, they apply a standard threshold of five hundred nanograms per milliliter. Ultimately, this tiered threshold helps rule out venous thromboembolism safely.
Key Trial Results and Clinical Safety
The primary outcome evaluated symptomatic venous thromboembolism or pulmonary embolism-related mortality within ninety days of assessment. Among patients with ruled-out thromboembolism, only one point eight percent in the YEARS group experienced a primary outcome. In contrast, five point five percent in the computed tomography-only group experienced these events. Therefore, the YEARS protocol proved noninferior to immediate angiography. Furthermore, the YEARS strategy successfully prevented the need for chest computed tomography scans in twenty-two percent of patients. This represents a significant reduction in unnecessary radiation exposure and contrast administration.
Clinical Implications for Practice
These clinical findings have major implications for oncology practice. Specifically, utilizing this validated algorithm allows physicians to safely omit computed tomography scans for over one-fifth of cancer patients. Consequently, this lowers healthcare costs and avoids potential adverse events like contrast-induced nephropathy. Clinicians should now confidently integrate this protocol into emergency departments and oncology wards. Ultimately, this evidence-based triage system enhances patient care quality while optimizing hospital resource utilization.
Frequently Asked Questions
Q1: What are the three clinical criteria used in the YEARS algorithm?
The three criteria are clinical signs of deep vein thrombosis, hemoptysis, and whether pulmonary embolism is the most likely diagnosis.
Q2: How does the YEARS algorithm determine the D-dimer threshold?
If a patient meets zero criteria, the D-dimer threshold is set at one thousand nanograms per milliliter. However, if one or more criteria are present, the threshold is adjusted to five hundred nanograms per milliliter.
Q3: How much does the YEARS algorithm reduce the need for CTPA in cancer patients?
According to the Hydra trial results, using this algorithm safely avoids computed tomographic pulmonary angiography in twenty-two percent of patients with cancer.
References
- Akerboom B et al. YEARS Algorithm for Diagnosis of Suspected Pulmonary Embolism in Patients With Cancer: A Randomized Clinical Trial. JAMA. 2026 Jul 12. doi: 10.1001/jama.2026.10676. PMID: 42437322.
- Maupin CF, Anand A. Updated Review of the YEARS Algorithm for Pulmonary Embolism (PE). MDCalc Journal. 2026.
- van der Hulle T, et al. Simplified diagnostic management of suspected pulmonary embolism (the YEARS study): a prospective, multicentre, cohort study. Lancet. 2017;390(10091):289-297.