Abstract C049: Genomic correlates with ancestry in lung squamous cell carcinoma

Abstract Outcome data from lung squamous cell carcinoma (SCC) show significantly lower overall and progression-free survival in Black patients. However, whether any genomic factors correlate with race and ancestry in this lung SCC, and whether this may contribute to disparities, has not been elucidated. We analyzed clinically annotated genomic data from 501 lung SCC tumor samples in the Cancer Genome Atlas (TCGA), with available ancestry admixture data. Here, we analyzed clinical data, gene expression profiles, mutations, and copy number changes to identify significantly differential events between tumors from patients of European (EUR) or African (AFR) ancestry. In tumors from AFR patients, we identified more frequent gain of chromosome arm 8q and/or the chr8q24 locus, where the oncogene MYC and its enhancers are located. 8q24 gain is associated both with global AFR ancestry and local AFR ancestry. Furthermore, expression of MYC targets is significantly increased in AFR samples relative to EUR samples, all of which suggest a role for the MYC pathway in differential cancer progression. MYC activity correlates with decreased immune infiltration and gene signaling, and patients with AFR ancestry are more likely to have decreased immune infiltrate and pathway activity. Our findings are consistent with observations in prostate cancer; this is the first study to find MYC enhancer amplification correlating with African ancestry in lung SCC. We are currently testing additional cohorts, including AACR GENIE, to validate these findings. Future studies will elucidate patient-specific treatment modalities. Citation Format: Sejal Jain, Alexandria Yao, Fatemeh Momen-Heravi, Diane Allen-Gipson, Xiaoyang Zhang, Brian S. Henick, Jian Carrot-Zhang, Alison M. Taylor. Genomic correlates with ancestry in lung squamous cell carcinoma [abstract]. In: Proceedings of the 16th AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2023 Sep 29-Oct 2;Orlando, FL. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2023;32(12 Suppl):Abstract nr C049.