Incidental Lung Cancer of Explanted Lungs from Lung Transplant Recipients: Incidence, Characteristics, and 5-Year Survival

PURPOSE: Recent history of malignancy without 5-year disease-free interval is an absolute contraindication for lung transplantation (LTx). However, in rare cases, lung cancer may be incidentally diagnosed in the explanted lung of recipients. We evaluated the prevalence, 5-year survival, and prognosis of incidental lung cancer after LTx. MATERIALS AND METHODS: Medical records of patients who underwent LTx at Severance Hospital between January 1, 2012 and June 30, 2019 were reviewed. Patients with incidental lung cancer were included, and those with histologically proven pre-transplant lung cancer were excluded. RESULTS: Of the 247 patients who underwent LTx, 6 (2.4%) were diagnosed with incidental lung cancer. Interstitial lung disease (ILD) was the underlying lung disease in all patients. The median interval from the last preoperative computed tomography (CT) screening to LTx was 26 days. The most common histological type of incidental lung cancer was adenocarcinoma (n=4, 66.7%). All Stage IV cases were misdiagnosed as fibrosis on preoperative chest CT. Patients with incidental lung cancer showed lower 5-year survival than those without malignancy (median survival: 8.5 months vs. not reached, p=0.047, respectively). Patients with Stage III or IV demonstrated lower 5-year survival than those with Stage I or II and those without malignancy (median survival: 5 months, 19 months, and not reached, respectively, p=0.011). CONCLUSION: Multidisciplinary preoperative screening and serial imaging studies within short intervals are required to differentiate lung malignancy from fibrotic foci. Furthermore, active pathologic examination of suspicious lung lesions is required in patients at high risk for lung cancer.