Fig. 2
Differential expression and breast cancer patient survival analysis. a Differential expression analysis revealed 2501 genes downregulated (blue) and 2767 genes upregulated (orange) in Black/African American (BAA) patients as compared to White patients. b Enrichment analysis of the disease-associated datasets revealed strong association (p-value < 0.01 and q-value < 0.1) between different cancer types and genes either upregulated (red) or downregulated (blue) in BAA breast cancer patients as compared to White patients. The dash-line indicates the q-value < 0.05 cut-off for the most statistically significant enrichment. c Enrichment analysis revealed the biological processes (green), metabolic (blue), and signaling (red) pathways associated with genes overexpressed in at least 5% of BAA breast cancer patients and upregulated as compared to White patients. d The volcano plot shows the association of high gene expression with decreased survival of BAA breast cancer patients. The fold change was calculated as the ratio of mean survival time of patients with normal gene expression to mean survival time of patients with gene overexpression. Overexpression of 257 genes (blue) correlates with decreased BAA patient survival (log-rank pBAA-values < 0.05). Overexpression of 147 genes was not correlated with reduced survival of White patients with the pWT-value > 0.1 (orange). The most significant difference between BAA and White breast cancer patient survival was observed for overexpression of 32 genes highlighted in red (pBAA-values < 0.01, pWT-value > 0.1, PWT/BAA-value < 0.05, MSTWT/MSTBAA > 2). e The top-32 genes with the most BBA patient-specific contribution in decreased survival are shown. Y-axis indicates the log-rank p-values calculated for BAA and White patients with gene overexpression. The blue line indicates the p-value cut-off of 0.05. The bars are colored based on the frequency of gene overexpression in BAA breast cancer patients. Light-pink: 5–6%, pink: 6–10%, light-red: 10–15%, dark-red: > 15%