**3.1 CA 125**

Four studies have evaluated the role of CA 125 in evaluation of patients with endometrial cancer. All four conclude that a high CA 125 cut-off, ranging from 20 to 40U/ml., is an independent risk factor for extra-uterine disease or lymph node metastasis. Nevertheless, its sensitivity and specificity are only around 80% (Chung et al., 2006; Han et al., 2010; Hsieh et al., 2002; Sood et al., 1997). This means that 1 in 5 patients will be over-treated and 1 in 5 undertreated.
