Plasma Exosome-Derived Fragile-Site Associated Tumor Suppressor is a Powerful Predictor of Prognosis in Patients with Ovarian Cancer

Objective: To investigate the levels of plasma exosome-derived fragile-site associated tumor suppressor (FATS) and evaluate its predictive ability in ovarian cancer (OC) patients. Patients and Methods Exosome-rich fractions were isolated from the plasma of enrolled 90 patients with OC. The levels of plasma exosome-derived FATS were detected with ELISA. Results: The levels of exosome-derived FATS in OC patient were significantly lower than in healthy controls ( P < 0.001). The levels of plasma exosome-derived FATS were obviously higher in OC patients with low grade (1/2), FIGO stages I/II than high grade (3/4), stages III/ IV disease ( P = 0.003; P < 0.001). The levels of plasma exosome-derived FATS were significantly higher in OC patients with no lymph node metastasis, no ascites than those with lymph node metastasis, ascites (both P < 0.001). The levels of plasma exosome-derived FATS were obviously higher in OC patients with CA-125 less than 35U/ml than more than 35U/ml ( P < 0.001). Among all enrolled OC patients, both 5-DFS and 5-OS were shorter in patients who had low plasma exosome-derived FATS levels than that high levels (both P < 0.001). The AUROC of plasma exosome-derived FATS were 0.85(95% CI: 0.76-0.91) for 5-DFS, 0.91(95% CI: 0.83-0.96) for 5-OS prediction in patients with OC, respectively. Conclusions: Plasma exosome-derived FATS levels in OC patient were significantly down-regulated. Low levels of plasma exosome-derived FATS had close relationship with FIGO stages I/II, low grade, ascites, higher levels of CA-125, lymph node metastasis and prognosis of OC patients. Our findings may provide a new strategy in treating OC.