Tumor antigen CA 125 as a marker of ovarian epithelial carcinoma.

Serum CA 125 was measured in 100 patients with ovarian epithelial carcinoma at diagnosis and in follow-up. Levels over 35 U/ml were found in 43 (75.4%) of 57 cases at diagnosis and in 21 (48.8%) of 43 cases in follow-up. A correlation was found between tumor burden and marker positivity: advanced Stages (III and IV) and recurrences had 84.2 and 91% of positivity, compared to 59.1% in early disease (Stages I and II). Analysis by histotype and FIGO grade revealed a difference between the mucinous type and the others and a positive association with less differentiated tumors. In the 30 patients submitted to second-look laparotomy a correlation was found between CA 125 levels and pathological response in 86.7% of cases. This ovarian cancer marker may thus be more useful in monitoring the response to treatment and in long-term follow-up than in diagnosis.