Objective: Studies have confirmed that patients with circulating tumor cells (CTCs) in their peripheral blood (PB) or disseminated tumor cells (DTCs) in bone marrow (BM) might have bad prognosis. In this paper, we discuss whether CTCs/DTCs would be an appropriate biomarker to predict the prognosis of ovarian cancer.
Methods: We systematically searched PubMed, EMBASE, Cochrane library, and Chinese National Knowledge Infrastructure to collect relevant studies published from the time the database were created to February 2014. Studies quality was assessed by Newcastle-Ottawa Scale. The effect size was estimated by hazard ratio (HR) and corresponding 95% confidence interval (95% CI). Meta-analysis was conducted with STATA Version 12.0.
Results: Eight studies of 1184 patients were included in the final analysis. In the PB group, it showed that patients with positive CTCs had significantly shorter overall survival and disease-free survival than patients with negative CTCs (HR, 2.09; CI, 1.13-3.88 and HR, 1.72; CI, 1.32-2.25, respectively). The same result was shown with DTCs in the BM group (HR, 1.61; CI, 1.27-2.04 and HR, 1.44; CI, 1.15-1.80, respectively). We also discussed the influence of CTCs/DTCs on International Federation of Gynecology and Obstetrics stage, pathological grade with odds ratio and 95% CI. However, it did not show any statistical significance.
Conclusions: The CTCs/DTCs might be a new biomarker to predict the prognosis of ovarian cancer. Future studies are needed to confirm this consequence.