CA 125 also known as mucin 16 or MUC16 is a large membrane glycoprotein belonging
to the wide mucin family, encoded by the homonymous MUC16 gene. Following its
discovery in the blood of some patients with specific types of cancers or other
benign conditions, CA125 has found application as a tumor marker of ovarian
cancer. Thirty years after its discovery, use of CA 125 is still FDA-recommended
to monitor response to therapy in patients with epithelial ovarian cancer and to
detect residual or recurrent disease in patients who have undergone first-line
therapy and would be considered for second-look procedures. However, due to its
limited specificity and sensitivity, CA 125 alone cannot still be an ideal
biomarker. Increased clinical performance, in terms of better sensitivity and
specificity in identifying epithelial ovarian cancer relapse, has been obtained
by combined use of CA 125 with HE4, another ovarian cancer marker recently
introduced in clinical use. Significant advancements have been achieved more
recently, due to the introduction of FDA-approved ROMA and OVA1 algorithms to
evaluate the risk of ovarian cancer for patients with a pelvic mass