Examination of Targetable Mutations by Smoking Status

Authors: Arasada RJ, Carbone DP, BIttoni MB

Category: Early Detection & Risk Prediction
Conference Year: 2020

Abstract Body:
Purpose: The purpose of this report was to develop predictive models examining smoking status, along with demographic and clinical factors, including age, race, gender, stage and vital status, and their association with several lung cancer specific mutations, such as EGFR, ALK, ROS1. KRAS and RET. Methods: The data source for this study was The Cancer Genome Atlas (TCGA) database, which resides at the National Cancer Institute and provides publicly available genomic data for many cancers. Data from 522 histologically confirmed lung cancer cases (adenocarcinoma) were analyzed using multiple logistic regression to examine associations between genetic alterations (ALK, ROS1, EGFR, KRAS and RET) by smoking status (current, former, never) and gender, race, age at diagnosis and stage. Results: Of 522 cases, over half (54%) were female, 86% were white, the mean age was 65 years, and 61% were former smokers, 24% were current smokers and 15% reportedly had never smoked. Adjusted logistic regression models revealed almost a 5-fold increased odds of EGFR for nonsmokers versus both current and former smokers (p<0.001), and almost a 2-fold increased odds for males (p<0.05). White race showed a 2.5 higher odds of ALK mutation, which approached significance (p-0.07), ), and current and former smokers showed a 4- and 3- fold increased odds of EGFR, respectively (p<0.05). Current smokers showed a 6.5 higher odds of ROS1 mutation versus nonsmokers (p=0.004). Similarly, current and former smokers had a 3- and 5-fold increased odds of KRAS mutation versus nonsmokers (p<0.05). No significant differences were found for the RET mutation. Conclusions: This study showed diverse patterns of association between smoking and lung cancer related mutations. Never smokers had a higher odds of EGFR, which is consistent with past findings, but current and former smokers showed a strong increased odds for most of the other mutations. White race showed potential associations with ALK only and males only showed associations with EGFR. Overall, these results shed new light on smoking as a possible predictive factor for genetic alterations, which has implications for treatment and warrants further research. Future research with larger, more diverse populations is needed to further ref

Keywords: lung cancer genetic alterations smoking