Dietary and Lifestyle Patterns Among Young Patients with Lung Cancer: Analysis of Mutation-Specific Phenotypes

BACKGROUND: Lung cancer in young adults is biologically distinct with 84% harboring targetable mutations largely unassociated with active and passive tobacco exposure. Environmental risk factors remain poorly characterized in this predominantly female, non-tobacco smoking population. METHODS: We analyzed 187 patients in the Epidemiology of Young Lung Cancer study using biological pathway groupings: EGFR Pathway (EGFR+ERBB2), Fusion-Positive (ALK+ROS1+RET+NTRK), and Other/Mixed Mutations (KRAS, BRAF, MET exon 14 skipping, TP53, and additional alterations). Dietary quality was assessed using Healthy Eating Index (HEI)-2015 and compared to US reference values from NHANES. Statistical comparisons employed one-sample t-tests. RESULTS: Active and passive tobacco use diverged from traditional mutation associations. In the Other/Mixed Mutations group, 68.8% never used tobacco despite these mutations being linked to tobacco exposure. Conversely, the EGFR pathway group included 32.9% with tobacco use history. Oral contraceptive use among females was consistently elevated (81.7-90.2%). Dietary analysis revealed EGFR Pathway and Fusion-Positive patients demonstrated higher HEI-2015 scores versus US reference (64.9±10.7 and 65.5±9.8 versus 58) and consumed more total vegetables (4.2 versus 3.5), fruits (3.3 versus 2.5), and whole grains (3.9 versus 2.6). CONCLUSIONS: Young patients with lung cancer demonstrated mutation-specific environmental exposure patterns distinct from older populations. EGFR pathway and Fusion-Positive patients had the highest diet quality scores, driven primarily by higher intake of vegetables, fruits, and whole grains, food categories with established protective associations and documented pesticide residues. IMPACT: These findings highlight non-tobacco environmental exposures in young lung cancer and support further investigation of dietary patterns and hormonal factors in mutation-specific disease pathways.