Clinicopathological and Genetic Characteristics of Lung Cancer in the Lungs of Explanted from Lung Transplant Recipients

Objective:To describe the clinicopathological features of the lung cancers in the lungs explanted from lung transplant recipients, and to understand the molecular alterations of these cancers.Methods:The patients who underwent lung transplantation in China-Japan Friendship Hospital from March 2017 to December 2018 were reviewed. Clinical data of the patients with lung cancer associated with end-stage interstitial lung diseases (ILD) were collected. Hematoxylin-eosin staining and immunohistochemistry were performed to evaluate the pathological feature. Real-time quantitative PCR was performed to analyze the hotspots and targeted regions of 9 cancer-associated genes.Results:Among the 154 identified patients, 10 met the inclusion criteria and were included. The detection rate of lung cancer in the lung transplantation patients was 6.5%(10/154). All of the included 10 patients were male, with an average age of 59 years. They all had a history of heavy smoking. Three cases had a lung cancer diagnosed before operation, while the other 7 cases were concealed in the specimen of end-stage ILD. All of lung cancers were non-small-cell carcinoma, including 8 cases of adenocarcinoma and 2 cases of squamous cell carcinoma. The proportion of mucinous adenocarcinoma components was 3/10. The mutations in KRAS gene exon 2 were detected in two patients with mucous adenocarcinoma, while no alterations in NRAS, EGFR, ALK, ROS1, BRAF, HER2, PI3KCA and RET were detected in the remaining patients.Conclusions:Lung cancers are difficult to detect in patients with end-stage ILD. They are mainly adenocarcinomas and associated with a higher frequency of mutations in KRAS gene. These cancers have limited treatment options and a poor prognosis.