Genomic aberrations in African American patients with solid tumors: A comparative institutional study.

Abstract

e15086 Background: Genomic mutations play an important role in cancer pathogenesis and can be used as targeted agents for treatment. Cancer related biomarkers in body fluids and tissues are being used to identify specific target genes. They also help in predictive and prognostic assessment related to the disease. Various platforms like guardant 360, foundation act, oncotype are commercially available. Specific genomic aberrations have enhanced the field of Precision Medicine in individualizing treatment protocols. Methods: Prospective data was collected from 45 African American patients at our institution using the commercially available Genomic Enabled Medicine ExTra cancer panel (Ashion Analytics). Sample include 18 types of cancer (10 breast, 9 colorectal, 5 endometrium, 4 prostate, 3 uterine, 2 cervical, 1 pancreas, 1 gallbladder, 1 melanoma, 1 larynx, 1 gastric, 1 carcinoid, 1 carcinosarcoma, 1 lymphoma, 1 ovary, 1 bladder, 1 thyroid). Both tumor and normal DNA were collected from year 2019 through 2020. For comparison, clinical and genomic, The Cancer Genome Atlas (TCGA) data for 1,065 African American adults with solid tumors were downloaded from the NCI Genome Data Common portal. The two data sets were eventually compared for identifying common genetic mutations and possible new targets for cancer management. Results: Of the 45 patients, 38 patients (84%) had at least one genomic alteration, and 38 known driver mutations were identified. Their median age was 56 years (range, 37 – 94). TP53 mutations were most common, identified in 44% of patients versus 37% in African Americans in TCGA. PIK3CA and KRAS mutations were next most common (22% and 20%, respectively) compared to TCGA African American samples (13% and 12%, respectively). The most frequent mutations on PIK3C were H1047R in 4 patients (8.8%), followed by E545K in 3 patients (6.6%). Oncogenic mutations were observed in APC, PTEN, ARID1A, FBXW7, NF1, PIK3R1, RNF43, ATM, CCNE1. Conclusions: In our study, we found higher prevalence of oncogenic driver gene mutations (including TP53, PIK3CA, KRAS, APC, PTEN, ARID1A) in African American cancer patients compared to TCGA African American cancer patients. It is important to note that high percentage of our patients had actionable oncogenic drivers that may be useful in treatment decision-making. Our aim is to continue to build on our database on African American patients for identifying specific and common gene mutations to enhance development of targeted agents.