Nivolumab therapy for lung cancer with tracheo-parenchymal fistula: A case report.

Rationale: Tracheobronchial fistulas are rare complications in lung cancer patients. These lesions are associated with a high rate of mortality caused by infection and bleeding, and there is no consensus on a definitive optimal therapy.
Patient Concerns and Diagnoses: The patient was a 59-year-old man with a right lung mass showing mediastinal invasion and tracheal compression, diagnosed with adenocarcinoma, cT4N0M0, stage IIIA. He was treated with concurrent chemoradiotherapy with carboplatin and paclitaxel, and the lesion markedly shrunk. Eleven months later, the lesion showed regrowth, and he underwent repeated chemotherapy for stabilization of the lesion. Thirty-six months after the first regrowth, the tumor showed regrowth again. The patient was then administered docetaxel and bevacizumab as fifth-line therapy. After 11 cycles of docetaxel and bevacizumab therapy, a tracheo-parenchymal fistula appeared.
Interventions and Outcomes: Docetaxel and bevacizumab therapy was stopped, and nivolumab therapy was initiated. Subsequently, the fistula and cavity became stable with slight shrinkage. To date, the patient is alive with no complaints and no disease progression and has continued nivolumab for a total of 28 months.
Lessons: Immune-checkpoint inhibitor therapy involving nivolumab therapy might be a useful alternative for the treatment of lung cancer involving a tracheobronchial fistula.