Whole blood RNA expression profiles in ovarian cancer patients with or without residual tumors after primary cytoreductive surgery.

Significant improvements in the treatment results of ovarian cancer have been achieved during the last decades, but further improvements require additional methods identifying signs of the disease and its biological behavior, preferably by a simple blood test. We hypothesized that peripheral blood leukocytes may express genes that carry such clinical information. Therefore, we studied the relative gene expressions of 168 cancer- and metastasis-specific genes in blood samples from ovarian cancer patients with different prognoses after primary cytoreductive surgery. Total RNA was extracted from whole blood and the relative gene expression profile of 168 genes were analyzed using real-time qPCR assays. Two groups of patients were analyzed; one group with residual tumor mass after primary surgery, and one group where the tumor was macroscopically radically resected, resulting in no visible tumor mass left behind. The group with the remaining tumor mass after surgery showed significantly different gene expression profiles compared to the group with no remaining tumor mass. Differences were noted for the metastasis associated 1 family, member 2 gene (MTA2), the TNF, α-catenin, interleukin 1β, the KiSS-1 metastasis suppressor and the matrix metallo-proteinase 10 genes. All genes were downregulated with a fold-change between 1.15 to 1.57; there were no upregulated genes. Thus, a signature of genes involved in metastasis, invasion and inflammation was found to be significantly downregulated in native unstimulated blood leukocytes from ovarian cancer patients with a poor prognosis. Preoperatively it may serve as a guide to the biology of the tumor and postoperatively in the optimization of adjuvant treatment of ovarian cancer patients.