[Clinical characteristics of epidermal growth factor receptor-mutated advanced adenocarcinoma transformed into small-cell lung cancer].

Objective: To explore the clinicopathological characteristics and genomic characteristics of four patients with epidermal growth factor receptor(EGFR)-mutated advanced adenocarcinoma transformed into small-cell lung cancer. Methods: Four cases of EGFR-mutated advanced adenocarcinoma of the lung transformed into small-cell lung cancer were studied by clinical data, pathological morphology, immunohistochemistry and gene detection. Result: EGFR-mutated adenocarcinoma of the lung was heterogeneous in clinical and genomic profiles, of ten characterized by RB1, TP53 and PIK3CA mutations. Its transformation into small-cell lung cancer was a particularly aggressive mechanism of drug resistance, but the machanisms were not clear NSE and other tumor indicators had low diagnostic value for transformation. Conclusions: EGFR-mutated adenocarcinoma of the lung transformed into small-cell lung cancer was one of the reasons for EGFR resistance with avery poor prognosis.