Introduction/Background Our objective was to determine the role of HE-4 in diagnosing epithelial ovarian cancer (EOC) recurrences, in order to stablish the value of adding HE-4 to Ca-125 determination in EOC surveillance.

Methodology All patients included in our project were diagnosed of any stage of EOC, from January 2014 to June 2020. All women had undergone surgical treatment and adjuvant chemotherapy. All patients were considered as optimal cytoreduction and showed a radiological complete response after the surgery. 43 subjects met the inclusion criteria and were included in the analysis.

Ca-125 normal levels were considered when <35 U/mL. HE-4 normal levels were based on the age of the patient. The nadir value was considered the lowest biomarker level achieved after the treatment. For CA-125, the elevation of the marker despite being negative was considered when it increased >5 U/mL from the nadir value. For HE-4, it was considered when we registered an elevation by ≥25%.

We took the nadir value of each patient as a reference. Then, we analyzed the levels of these markers during the monitoring until the relapse.

Results The 59% and 48.8% of the patients had HE-4 and Ca-125 positive levels respectively at relapse diagnostic. The 26.3% of the patients had Ca-125 negative but HE-4 positive values at recurrence.

In the 30% of the patients the levels of Ca-125 increased >5 UI remaining below the pathological limit. The median time between the elevation of the tumor markers and the radiologic diagnostic of relapse was 4 months for HE-4 and 3.5 months for Ca-125.

Conclusion It seems that adding HE-4 determination to EOC follow-up can improve the detection of recurrences. In some recurrences the levels of Ca-125 increased remaining below the pathological limit. It seems that the tendence of elevation during the follow-up can be useful to diagnose EOC recurrence, especially for Ca-125.

Disclosures All authors declare no conflict of interest.