Factors Associated with Diagnostic Yield of Transbronchial Biopsy for Suspected Lung Cancer

Background: Transbronchial biopsy (TBB) is an important diagnostic approach for identifying peripheral lung lesions in suspected lung cancer patients. As is known, the lesion characteristics and radiological findings may influence its diagnostic yield. Therefore, this study aimed to identify factors associated with TBB diagnostic yield to help optimize patient selection and improve diagnostic success. Method: This cross-sectional study included 77 adults with suspected lung cancer who underwent TBB at Persahabatan Hospital between September and December 2024. Factors associated with TBB diagnostic yield, including tumor size, bronchus sign, and lesion location, were assessed. Receiver operating characteristic (ROC) analysis was performed to determine the optimal tumor-size cutoff. A parsimonious multivariable logistic regression model including tumor size and bronchus sign was used to identify independent factors associated with a positive TBB result. Results: The overall diagnostic yield of TBB was 63.6%. In bivariate analysis, tumor size ≥2.95 cm and the presence of a bronchus sign were significantly associated with a positive TBB result. ROC analysis demonstrated modest discrimination for tumor size (AUC=0.693; 95% CI=0.562–0.824; P=0.005), with a cutoff of 2.95 cm yielding 87.8% sensitivity and 53.6% specificity. Lesions ≥2.95 cm had a higher diagnostic yield than lesions <2.95 cm (76.8% vs. 28.6%; OR=8.27; 95% CI=2.67–25.65; P<0.001). In multivariable analysis, tumor size ≥2.95 cm remained independently associated with a positive TBB result (aOR=6.33; 95% CI=1.91–20.83; P=0.002), whereas bronchus sign was not independently associated (aOR=0.36; 95% CI=0.07–1.77; P=0.206). Conclusion: Tumor size ≥2.95 cm was independently associated with a higher diagnostic yield of TBB in patients with suspected lung cancer. Tumor size may therefore be useful in identifying peripheral lung lesions more likely to yield a diagnostic transbronchial biopsy.