Integrative immunologic and genomic characterization of brain metastasis from ovarian/peritoneal cancer.

Brain metastasis from ovarian/peritoneal cancer is a rare disease that has a dismal prognosis. And genomic alterations and immune-profiling in primary ovarian/ peritoneal cancer and brain metastatic tumor tissues have not been fully elucidated. Multiplexed immunofluorescence and whole-exome sequencing of two matched brain metastatic tumor and primary ovarian/peritoneal cancer tissues were performed. The overall density of immune infiltrates in metastatic tissues (brain) was not significantly different from those in primary cancer tissues (case 1 primary: 2.12% and case 1 metastasis: 2.22%; case 2 primary: 1.70%, and case 2 metastasis: 3.46%). Of note, however, PD-L1 expression in the metastases was higher than that in the primary tumors. We found more non-silent mutations, cancer-related genes, loss of heterozygosity (LOH) and longer lengths of copy-number alterations (CNA) in brain metastases compared to primary ovarian/peritoneal cancers. We report immunologic and genomic profiles of primary ovarian/peritoneal cancer with brain metastasis that may not only provide useful information for understanding its pathogenesis, but also clues for further innovative therapeutic treatments for ovarian cancer.