NanoString expression profiling in metastatic ovarian cancer

Purpose: Most molecular characterizations of high-grade serous ovarian cancer (HGSOC) have been done in primary ovarian tumors. Such data may not be fully representative of HGSOC, which is characterized by widespread peritoneal metastases at the time of diagnosis and upon relapse. The most common site of HGSOC metastasis is the omentum. The omentum is characterized by strong immune and fibrotic activities and is a rich source of mesenchymal stem cells (MSCs), which have the capacity to differentiate into cancer-associated fibroblasts (CAFs) and promote ovarian cancer progression. The omentum is also rich in tertiary lymphoid structures (TLS), which are transient aggregates of leukocytes structurally and functionally comparable to secondary lymphoid tissues. Experimental design: With the goal of elucidating expression patterns in a large number of omental metastases, we profiled expression of immune- and cancer progression-related genes in pretreatment omental metastasis samples from 152 patients diagnosed with HGSOC. A total of 152 specimens from patients with HGSOC were profiled for gene expression and classified by clinicopharmacological characteristics including age, PFS, OS, debulking and BRCA mutation status.