Factors Associated with Procedure-related Tumor Seeding in Advanced Stage Lung Cancer Patients with Malignant Pleural Effusions

Objective: Pleural procedure-related tumor seeding detected by computed tomography (CT) is common in lung cancer patients with malignant pleural effusion. This study aimed to identify the incidence of tumor seeding and the associated factors among lung cancer patients with malignant pleural effusions. Material and Methods: This retrospective cohort study was conducted on 146 lung cancer patients with malignant pleural effusions, diagnosed between 2010 and 2017, who underwent at least 1 pleural procedure and had at least 2 series of CT images. The potential factors were categorized into clinical characteristics, pleural characteristics, treatment factors, and pleural procedures. Incidence rate ratios (IRR) were analyzed by Poisson regression to identify factors that were independently associated with tumor seeding. Results: The incidence of procedure-related tumor seeding was 26%. Significantly increased IRRs of tumor seeding were found in relation to 1 time (IRR 5.653, 95% confidence interval [CI] 2.549 to 12.538) and ≥2 times of conventional intercostal chest drainage (ICD) insertion (IRR 5.837, 95% CI 1.768 to 19.266), 1 time (IRR 8.924, 95% CI 3.181 to 25.033) and ≥2 times of pleural biopsy (IRR 6.485, 95% CI 1.372 to 30.660), adenocarcinoma (IRR 8.329, 95% CI 2.804 to 24.747), and pleural thickening (IRR 12.458, 95% CI 1.360 to 114.152). Conclusion: Patients who had at least one pleural biopsy or ICD insertion, pleural fluid cytology positive or suspicious for malignancy, adenocarcinoma, or pleural thickening were found to be significantly at risk for tumor seeding.