Abstract 768: Predictive role of circulating tumor cells in women with ovarian cancer

Abstract

Abstract Background: “Liquid biopsy”, where body fluids is screened for biomarkers is gathering substantial research. We aimed to examine women with suspected ovarian cancer for the presence of circulating tumor cells (CTCs) and study its role in prediction of chemoresistance and survival. Methods: Magnetic powder labeled monoclonal antibodies for epithelial cell adhesion molecule (EpCAM), Mucin 1 cell surface associated ( MUC1) ,mucin 16, cell surface associated MUC16 or CA125 were prepared according to the manufacturer's protocol. Expression of three ovarian cancer related genes were detected in CTCs using multiplex reverse transcriptase-polymerase chain reaction (Multiplex RT-PCR). CTCs and serum CA125 were measured in 100 patients with suspected ovarian cancer. Correlations with clinicopathological parameters and treatment were analyzed. Results: CTCs were detected in 18/70 (25.7%) of women with malignancy compared to 0/30 (0.0%) in those with benign gynecologic diseases (p=0.001). The sensitivity and specificity of the CTC test for predicting a malignant histology in pelvic masses was 27.7% (95% CI :16.3%,37.7%) and 100% (95% CI: 85.8%, 100%), respectively. The number of CTCs correlated with stage of ovarian cancer (p=0.030). The presence of EpCAM+CTC at primary diagnosis in ovarian cancer was found to be an independent predictor of a poor progression free survival (PFS) (HR,3.3; 95% CI, 1.3-8.4; p=0.010), overall survival (OS) (HR, 2.6; 95% CI,1.1-5.6; p=0.019) and resistance to chemotherapy (OR 8.6; 95% CI, 1.8-43.7; p=0.009). Conclusion: Expression of EpCAM in CTC positive patients predicts chemotherapy resistance and prognosis, could aid clinicians in individualizing therapy, saving the patient from unnecessary side effects and systemic toxicity of platinum-based chemotherapy. Also, EpCAM expression can be a strong basis for further investigating anti-EpCAM targeted therapies in ovarian cancer. Citation Format: Swarnima Singh, Uday Kumar. Predictive role of circulating tumor cells in women with ovarian cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 768.