P1.03-33 Analysis of Lipid Metabolism Genes in Advanced Small Cell Lung Cancer

Lung cancer is the leading cause of cancer death worldwide. Although most of the knowledge about metabolic dysregulation in cancer focuses on carbohydrates, the importance of alterations related to lipid metabolism is starting to be recognized. There is increasing data on lipid metabolism and non-small lung cancer, but much less is known about this in small cell lung cancer (SCLC). In order to improve our knowledge of these alterations we evaluated a genetic profile related to lipid metabolism and studied clinical outcomes We performed a retrospective analysis of 22 genes related to lipid metabolism in 37 tumoral tissue samples of SCLC patients and evaluated clinical features and outcomes. Advanced SCLC patients enrolled from November 1, 2008 through December 31, 2015 were included in this analysis. Clinical data were collected from medical records at the time of enrollment. The study was approved by an Ethics Committee and all patients signed an Informed Consent form. We used formalin-fixed, paraffin- embedded tumor tissue. Samples were deparaffinated and total RNA was extracted. A Taq-Man Low Density Array (Applied Biosystems) was specifically designed and gene-expression assays were performed in a HT-7900 Fast Real time PCR. RT-StatMiner software was used to detect and determine the quality control and differential expression analyses of data. We included 37 patients, 73 % males and 27 % women, with a median age of 62. 29 patients (78%) had stage IV tumor and nearly all of them (92%) were treated with platinum- based chemotherapy. 11 % (4/37) received thoracic radiotherapy and 5% (2/37) received whole brain radiotherapy. 6 patients (16%) were on chronic treatment with metformin and 15 (40%) on statins. We performed a multivariable analysis and found that overexpression of two metabolic genes (a mitochondrial enzyme and a lipid metabolism regulator) led to longer overall survival. (HR 0.13 (0.04-0.42), p 0.0019, padjusted 0.04 and HR 0.11 (0.03-0.35) p 0.0006, padjusted 0.01, respectively). These genes contribute to normal functioning and regulation of lipid metabolism and could be considered as potential prognostic biomarkers. There is no previous evidence of association between levels of expression of these genes and overall survival in SCLC. Validation in a larger series of patients is ongoing.