Abstract
BACKGROUND: Transbronchial biopsy (TBB) with endobronchial ultrasonography and a guide sheath (EBUS-GS) is an effective examination tool for the diagnosis of lung cancer. Factors related to making the diagnosis are still not fully understood. METHODS: A total of 367 patients who underwent EBUS-GS and were diagnosed with lung cancer in Saga University Hospital were investigated retrospectively. Clinical characteristics were compared between 244 patients who were diagnosed with lung cancer and 123 patients who were not diagnosed by TBB with EBUS-GS but were diagnosed by other examinations. RESULTS: Size of target lesion, rate of patients with target lesion size ≥20 mm, presence of the bronchus sign, and detection by EBUS imaging were significantly associated with making the diagnosis (all p < 0.01). In patients whose lesion was detected by EBUS imaging, patients with positive findings within the lesion were significantly more often diagnosed by TBB with EBUS-GS than those with positive findings adjacent to the lesion (p < 0.01). The odds ratio (OR) of patients whose lesion was detected by EBUS imaging (OR [95% confidence interval] 14.5 [8.0-26.4]) tended to be higher compared to the ORs of size of lesion ≥20 mm (3.9 [2.2-6.8]) and the bronchus sign (7.5 [4.6-12.2]). CONCLUSION: Targeted lesion diameter ≥20 mm, bronchus sign, and detection by EBUS imaging, especially within the lesion, are important factors for the diagnosis of lung cancer by TBB with EBUS-GS.