Serum CA 125 antigen levels and disease severity in patients with endometriosis

We wished to test whether there was a relationship between CA 125 levels and the severity of endometriosis that would allow CA 125 to be used to monitor disease progression. CA 125 levels were measured in 52 women with laparoscopically staged endometriosis and in eight women with normal pelvic findings at laparoscopy. There was a positive correlation (r = 0.63; P less than .0001) between disease severity and CA 125 levels. CA 125 was also elevated, compared with women with a normal pelvis, in patients with mild and moderate disease. There was no relationship between CA 125 levels and the day of the menstrual cycle. These results suggest that after malignancy has been excluded, CA 125 levels may offer a useful method of monitoring disease progress.