Use of a novel biomarker HE4 for monitoring patients with epithelial ovarian cancer

Abstract

5535 Background: The serum biomarker CA125 is effectively used for monitoring response to therapy and monitoring for recurrent disease in patients with epithelial ovarian cancer (EOC). However, CA 125 is not elevated in approximately 20% of patients. The novel tumor marker HE4 has been shown to be elevated in the majority of EOC patients as well as in patients that do not express CA125. The object of this study was to determine the concordance between HE4 and CA125 in patients being followed with EOC. Methods: This was a retrospective study utilizing serum samples obtained from an IRB approved serum bank. Serial samples from patients either undergoing treatment for EOC or being monitored for recurrence were obtained. Clinical status of the patients was assessed through serial CA125 and CT imaging with documentation of regression or progression of disease or absence of disease over time. Serum CA125 and HE4 levels were measured using the Architect CA 125II assay and the HE4 EIA assay. Serial changes in the serum CA125 and HE4 levels were compared to the documented clinical status using a cutoff of 25%. Concordance between HE4 and CA125 was determined and the performance of CA125 and HE4 was compared directly using a non-inferiority approach. Results: A total of 434 serial samples from 80 patients either undergoing treatment for EOC or being monitored for recurrence were obtained. Longitudinal analysis of the serum sample sets showed that changes in HE4 values were not inferior to changes in CA125 values in accordance with clinical status (p=0.039). CA125 correlated with clinical status in 78.8% (63/80) and HE4 correlated in 76.2% (61/80). In patients where CA125 did not correlate with clinical status, HE4 correlated in 23.5% (4/17). In patients where HE4 did not correlate with clinical status, CA125 correlated in 31.6% (6/19). In consideration of all cases either CA125 or HE4 correlated with clinical status for 83.8% (67/80). Conclusions: HE4 is a valuable biomarker for the majority of patients with EOC and behaves in concordance with CA125 in patients with EOC. As well, HE4 is a valuable marker for the management of some patients where CA125 is not of clincal utility. Author Disclosure Employment or Leadership Consultant or Advisory Role Stock Ownership Honoraria Research Expert Testimony Other Remuneration Fujirebio Diagnostics, Inc Fujirebio Diagnostics, Inc, Thiel Statistical Consultants Fujirebio Diagnostics, Inc Fujirebio Diagnostics, Inc