Comprehensive Genomic Analysis for Small Cell Lung Cancer

Small cell lung cancer(SCLC)is one of the histological types of lung cancer showing the worst prognosis, and is often diagnosed as an inoperable advanced stage disease. Recently, several comprehensive genomic analyses for SCLC have shown that inactivating mutations of tumor suppressor genes such as TP53 and RB1 and MYC family gene amplifications are involved in the development and progression of SCLC. However, actionable gene alterations for targeted therapies have not yet been identified, and there has been no significant advance in the development of targeted therapies for SCLC. In a nationwide lung cancer genome screening project in Japan, LC‒SCRUM‒Japan, a large‒scale genomic analysis was prospectively performed for Japanese SCLC patients, and based on this genomic analysis, a clinical study to evaluate the efficacy of a targeted therapy for PI3K/AKT/mTOR pathway gene‒altered SCLC(EAGLE‒PAT trial)was conducted. In this article, we describe the results of the genomic analysis in LC‒SCRUM‒Japan and the EAGLE‒PAT trial, and also provide the overview of genetic alterations reported in SCLC and the current and future development of targeted therapies for SCLC.