Table 1. Main results of the review and implications for research.

Main results
CA 125 is the most extensively used biomarkers in standard clinical practice for epithelial OC surveillance and to predict prognosis. To date, CA125 is of a greater interest in a series of biomarkers panels, to obtain the best surveillance of ovarian cancer
HE4 has been approved by the FDA to monitor disease progression or recurrence of EOC
A combination of CA125 and HE4 could be more useful to monitor response to treatment and early detect relapses if compared to each marker used individually
Limitations
The literature on this issue is very scant
Implications for future research
The efforts of researchers should be focused on:
Identification of reliable serum biomarkers for standardized surveillance strategies of recurrence
Additional clinical trials to assess the potential clinical utility of adding new biomarkers, such as OPN, MSLN and FOLR1, to routine CA125 measurement during follow up of ovarian cancer
Discover definitive markers for the identification of the different CSCs to develop new antigenic and molecular targets for therapy

OC, ovarian cancer; FDA, Food and Drug Administration; CA 125, Cancer Antigen 125; HE4, Human Epididymis Protein 4; OPN, osteopontin; MSLN, Mesothelin; FOLR1, Folate receptor alpha 1; CSCs, cancer stem cells.