P1.07-032 Most Common Genomic Alterations in SCLC

Abstract

Lung cancer is the leading cause of cancer death in US. The American Cancer Society’s estimates for lung cancer in the United States for 2016 are: approx 224,390 new cases of lung cancer and approx 158,080 deaths. Approximately 10-15% of lung cancers are classified as small cell (SCLC). These cancers portend a poor prognosis. Genomic sequencing of non-small cell lung cancer led to developing of new therapeutic modalities, i.e. targeted therapy with superior results to conventional cytotoxic chemotherapy. At this time, there is no approved targeted therapy for SCLC. In order to develop targeted therapies we need to identify and characterize molecular targets (alterations). This study aims to report our experience with genomic sequencing of SCLC. We performed a retrospective analysis of a dataset of 54 cases of SCLC, who underwent genomic sequencing. Patients were treated at 5 tertiary referral centers, between October 2012 and June 2016. The recorded data included: age at diagnosis, date of the genomic sequencing, genomic alteration (affected genes and the type of molecular alteration identified). For genomic profiling we used a platform commercially available (FoundationOne). We obtained 54 samples from 54 patients. Age range is 42 to 75 years, mean 60 and median 61 years old. All cases had a histologic diagnosis of SCLC. The genomic analysis found 88 affected genes with 230 alterations. The most common affected genes: Tp53 alteration, 45 cases (83%) and Rb1 33 cases (61%). There were an average of 4.3 mutations per patient; with a median of 4 mutations per patient, with a minimum of 0 and a maximum of 13. Sustained investigations and sequencing of larger numbers of SCLC are aiming to identify potential actionable mutations in these tumors. The ultimate goal is to determine new therapies and optimal treatment strategy based on the genomic profile.