Prognostic value of systemic inflammatory markers in patients with malignancy-associated pulmonary thromboembolism

Pulmonary thromboembolism (PTE) is a severe and potentially fatal complication in patients with malignancy. Systemic inflammation plays an important role in both cancer progression and thrombogenesis. This study aimed to evaluate the association of systemic inflammatory indices with in-hospital mortality and clinical risk classification in patients with malignancy-associated PTE. This retrospective study included 75 adult patients diagnosed with both malignancy and PTE at a tertiary chest diseases center between February 2018 and June 2025. Demographic characteristics, cancer types, laboratory values at diagnosis, treatment details, and clinical outcomes were recorded. Neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), lymphocyte-to-monocyte ratio (LMR), lymphocyte-to-CRP ratio (LCRPR), systemic immune-inflammation index (SII), and systemic inflammation response index (SIRI) were calculated from blood samples obtained at diagnosis. The primary outcome was in-hospital mortality, and the secondary outcome was the association between systemic inflammatory markers and ESC PTE clinical risk classification. The mean age was 69.5 ± 11.8 years, and 56% of patients were male. Lung (24%), colorectal (13.3%), and breast (9.3%) cancers were the most common malignancies. In-hospital mortality was 20%. Neutrophil count (P = .026), NLR (P = .032), and lactate (P = .027) were significantly higher in patients who died during hospitalization. ROC analysis identified an NLR cutoff value of 4.95, with a sensitivity of 86.7% and a specificity of 51.7%. Neutrophil count and SIRI were significantly higher in the intermediate-risk group (P = .036 and P = .049, respectively), whereas troponin was highest in the high-risk group (P < .001). Neutrophil count, NLR, and lactate levels were associated with in-hospital mortality in patients with malignancy-associated PTE. Neutrophil count and SIRI were also associated with ESC clinical risk classification. These findings should be considered exploratory and require validation in larger prospective studies.