Our computational image analyses of primary HGSOC and patient-matched pre-treatment and post-treatment peritoneal metastases show differences between primary HGSOC and synchronous and/or metachronous metastases in: (1) percentages of fibroblasts, epithelial cells, and immune cells, (2) percentages of COL11A1+ fibroblasts, (3) ECM architecture, and (4) percentages of stroma- and cancer-associated CD8+ T cells. Here, CD8A is linked to cancer.