The Clearance of Serum Human Epididymis Protein 4 Following Primary Cytoreductive Surgery for Ovarian Carcinoma.

Objective: The aim of this study was to examine the clearance of serum human epididymis protein 4 (HE4) in the immediate postoperative period in patients undergoing maximal effort cytoreductive surgery for ovarian carcinoma.

Methods: The study was performed at a tertiary gynecologic oncology center. The surgery was performed by accredited gynecological oncologists.

Results: Preoperative and serial postoperative venous blood samples at 4, 8, 24, 48, 72, 96, and 120 hours were taken from 10 sequential patients. Pretreatment HE4 is considered elevated at greater than 70 pmol/L. Human epididymis protein 4 was greater than 70 pmol/L in 7 patients, including all patients with high-grade serous carcinoma. Patients with preoperative elevation of serum HE4 and complete cytoreduction cleared more than 80% of serum HE4 in the first 4 hours and more than 88% within 5 days of surgery. One patient with incomplete cytoreduction of high-grade serous carcinoma had 66% clearance at 4 hours and a plateau thereafter.

Conclusions: Human epididymis protein 4 derived from ovarian carcinoma had a short half-life of less than 4 hours in the circulation when cytoreductive surgery was complete. Sustained low HE4 following surgery could be a useful indicator of the completeness of cytoreduction. Plateau or rise in serum HE4 could suggest persistent disease. Comparison of values on day 1 and day 4 or 5 might have value in assessing the completeness of cytoreduction.