Potential tools for predicting response to chemotherapy in OC: Assessment of immune dysbiosis, participant's self-rated health and microbial dynamics.

Epithelial ovarian cancer (OC) is the deadliest female reproductive cancer; an estimated 13,270 women will die from OC in 2023. Platinum-based chemotherapy resistance mechanisms contribute to poor OC 5-year survival rates. Peripheral inflammation is linked to various disease states and we previously identified unique peritoneal microbial features predictive of OC. We hypothesized that unique peripheral immune profiles and peritoneal microbial features may be predictive of disease-free interval (time to recurrence) and response to chemotherapy in participants with OC. We also investigated self-rated health (SRH) scores in the context of peripheral inflammation as a potential screening tool for OC. Blood and peritoneal fluid were collected from participants with OC or a benign adnexal mass (BPM). Lymphocyte populations were analyzed using Fluorescence Activated Cell Sorting, serum cytokine levels were analyzed using the Human Th17 Magnetic Bead Panel assay and peritoneal fluid microbial features were analyzed using Next Generation Sequencing (NGS). Participants completed a standardized questionnaire on self-rated physical and emotional health. Participants were classified into three chemotherapy response categories: platinum-refractory, platinum-resistant or platinum-sensitive. A significant positive correlation was found between elevated inflammatory status on the day of surgery and longer disease-free interval. SRH measures did not correlate with immune status in participants with OC or a BPM. We identified a correlation between peritoneal microbial features and chemotherapy response. We conclude that immune dysbiosis may be useful in predicting OC recurrence. The immune findings reported here set the framework for additional studies utilizing immune profiles to predict platinum-based chemotherapy responsiveness in OC.