Prediction Models for Mediastinal Metastasis and Its Detection by Endobronchial Ultrasound-Guided Transbronchial Needle Aspiration in Potentially Operable Non-Small Cell Lung Cancer: A Prospective Study

Abstract

Prediction models for mediastinal metastasis and its detection by endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) have not been developed using a prospective cohort of potentially operable patients with non-small cell lung cancer (NSCLC). Can mediastinal metastasis and its detection by EBUS-TBNA be predicted with prediction models in NSCLC? For the prospective development cohort, 589 potentially operable patients with NSCLC were evaluated (July 2016-June 2019) from five Korean teaching hospitals. Mediastinal staging was performed using EBUS-TBNA (with or without the transesophageal approach). Surgery was performed for patients without clinical N (cN) 2-3 disease by endoscopic staging. The prediction model for lung cancer staging-mediastinal metastasis (PLUS-M) and a model for mediastinal metastasis detection by EBUS-TBNA (PLUS-E) were developed using multivariable logistic regression analyses. Validation was performed using a retrospective cohort (n= 309) from a different period (June 2019-August 2021). The prevalence of mediastinal metastasis diagnosed by EBUS-TBNA or surgery and the sensitivity of EBUS-TBNA in the development cohort were 35.3%and 87.0%, respectively. In PLUS-M, younger age (< 60 years and 60-70 years compared with≥ 70 years), nonsquamous histology (adenocarcinoma and others), central tumor location, tumor size (> 3-5cm), cN1 or cN2-3 stage by CT, and cN1 or cN2-3 stage by PET-CT were significant risk factors for N2-3 disease. Areas under the receiver operating characteristic curve (AUCs) for PLUS-M and PLUS-E were 0.876 (95%CI, 0.845-0.906) and 0.889 (95%CI, 0.859-0.918), respectively. Model fit was good (PLUS-M: Hosmer-Lemeshow P= .658, Brier score= 0.129; PLUS-E: Hosmer-Lemeshow P= .569, Brier score= 0.118). In the validation cohort, PLUS-M (AUC, 0.859 [95%CI, 0.817-0.902], Hosmer-Lemeshow P= .609, Brier score= 0.144) and PLUS-E (AUC, 0.900 [95%CI, 0.865-0.936], Hosmer-Lemeshow P= .361, Brier score= 0.112) showed good discrimination ability and calibration. PLUS-M and PLUS-E can be used effectively for decision-making for invasive mediastinal staging in NSCLC. ClinicalTrials.gov; No.: NCT02991924; URL: www. gov.