Supplementary Material for: Impact of Interventional Bronchoscopy on Long-Term Survival in Patients with Primary Tracheal Adenoid Cystic Carcinoma: A Single-Center Experience

<b><i>Introduction:</i></b> Primary tracheal adenoid cystic carcinoma (TACC) is a rare low-grade lung cancer of bronchial gland origin. Surgery is the first choice of treatment; however, in cases of recurrence or inoperability, a combination of radiation and chemotherapy is administered as a multimodality treatment. Interventional bronchoscopy is also used as a multidisciplinary treatment; however, its impact on long-term prognosis has not been thoroughly investigated. <b><i>Case Presentation:</i></b> Eight patients diagnosed with TACC and treated at Shinshu University Hospital between December 2000 and August 2023 were analyzed retrospectively. We investigated the duration of intervention and overall survival (OS) in 3 patients with recurrence who underwent interventional bronchoscopy in combination with chemotherapy and evaluated whether interventional bronchoscopy prolonged the survival. The initial treatment for the 3 patients was surgery in 1 patient and chemoradiotherapy in 2. In all patients, raised lesions were observed in the trachea at the time of recurrence. The duration of interventional bronchoscopy, the time from recurrence of the first-line treatment to death, and OS, which was defined time from induction of the first-line treatment to death, were 69.3/70.7/112.5 months, 179.2/196.1/220.4 months, and 15.4/66.3/104.4 months, respectively. <b><i>Conclusion:</i></b> Long-term survival benefits may be obtained with concomitant interventional bronchoscopy in combination with chemotherapy in patients with locally recurrent TACC.