Fig. 5.

Comparison of copy number and tumor mutation burden. (A) Copy number alteration fraction is significantly higher in p-BRCA mutated group than in BRCA wild-type group. Within p-BRCA mutated group, concomitant LOH is associated with a higher copy number burden. (B) Tumor mutation burden is different depending on p-BRCA mutation and MSI status (Kruskal-Wallis test, p = 3.6e-12). Microsatellite-unstable tumors (MSI-H) are associated with high tumor mutation burdens. Within MSS subgroup, the p-BRCA mutated groups (MSS/LOH+ and MSS/LOH−) are associated with higher tumor mutation burdens than the BRCA wild-type group (Wild) (p = .003 each). The tumor mutation burden is not different according to LOH of the p-BRCA mutant allele (p = .910). (C) Representative copy number plots for tumors with high or low copy number burden are shown. Gastric cancer sample harboring a p-BRCA mutation and a high copy number burden (left) shows multiple segments with copy number gains or losses (indicated by red bars) while the BRCA wild-type tumor (right) does not. p-BRCA mutation, pathogenic or likely pathogenic BRCA1 or BRCA2 gene mutation; LOH, loss of heterozygosity; MSI-H, high microsatellite instability; MSS, microsatellite stable.