CA125 as a serum marker for poor prognosis in ovarian malignancies.

In cancer of the ovary, a tumor marker is much needed to assist the conventional methods for monitoring the disease course. All published reports of the CA125 serum immunoassay to date have indicated that rising or falling CA125 levels correlated with disease progression or regression in patients with ovarian malignancies. Our experience with CA125 at the University of Alabama at Birmingham shows that rising CA125 levels are highly suggestive of progressive disease. However, the significance of our findings with CA125 is that, contrary to other reports, falling CA125 levels are not a reliable indicator for regressive disease. Thus, falling CA125 levels are not clinically useful whereas rising CA125 levels may be interpreted as indicative of poor tumor response to therapy, and of the presence of persistent or recurrent disease either prior to second-look laparotomy or during post-treatment follow-up.