Background and objective: Pulmonary embolism is potentially life-threatening in patients with lung cancer, but the clinical studies on patients with lung cancer having asymptomatic pulmonary embolism were barely reported.
Methods: Clinical data of patients with lung cancer were obtained from the Department of Respiratory and Critical Care Medicine of Tianjin Chest Hospital during July 2012 and June 2015 and were reviewed retrospectively. A total of 28 patients with lung cancer having pulmonary embolism (LP group) were enrolled, and another 56 cases with lung cancer alone (LC group) were enrolled as controls.
Results: Seventeen (60.7%) of 28 patients in the LP group developed adenocarcinoma, which was more frequent than that in the LC group ( P < .01); the LP group displayed lower counts of hemoglobin and albumin than the LC group ( P < .05); the counts of leukocyte (white blood cell) and d-dimer of patients in the LP group were also higher than those in the LC group ( P < .05). The high-incidence period of pulmonary embolism among 17 asymptomatic cases in the LP group was 3.6 months postdiagnosis (95% confidence interval, 3.2-4.0), showing a significant difference with that of other 11 patients with symptomatic pulmonary embolism, which was 10.5 months (95% confidence interval, 8.88-12.12; P < .01). Survival analysis displayed that median survival time of patients with asymptomatic pulmonary embolism was 7.2 months (95% confidence interval, 5.86-8.56), while that of symptomatic pulmonary embolism was 2.8 months (95% confidence interval, 2.48-3.12). Log-rank examination showed that survival time of asymptomatic pulmonary embolism group was statistically longer than that of symptomatic pulmonary embolism group.
Conclusion: Lung adenocarcinoma, chemotherapy, hyperleukocytosis, and d-dimer increment were the risk factors for lung cancer combined with asymptomatic pulmonary embolism.
Keywords: lung neoplasms; pulmonary embolism; risk factors; survival time.