HE4 in ovarian cancer: from discovery to clinical application.

Despite the relatively low prevalence, ovarian cancer is the fifth leading cause of death from cancer among women. As such, an early diagnosis for establishing a timely surgical and/or chemotherapeutic treatment is essential for improving the outcome. The most reliable, but not always straightforward, approach to diagnose ovarian cancer relies on multiple, time-consuming and expensive investigative tools. These typically include clinical presentation (i.e., pelvic or abdominal pain, urinary frequency or urgency, increased abdominal size or bloating) with pelvic examination, transvaginal ultrasonography (US), and measurement of carbohydrate antigen 125 (CA125). Although the conventional pathway to develop and market a clinically useful biomarker is challenging, recent advances in genomic and proteomic technologies have led to the identification of previously unknown candidate markers of ovarian cancer. Some of these are currently under clinical validation. The human epididymis protein 4 (HE4) has recently been approved by the Food and Drug Administration for monitoring recurrence or progression of epithelial ovarian cancer. Nevertheless, reliable clinical evidence demonstrates that HE4, used alone or in combination with CA125, substantially improves the accuracy of screening and/or disease monitoring. This chapter will review the current knowledge on biologic and clinical applications of ovarian cancer biomarkers, with particular emphasis on the newly proposed marker, HE4.