Preoperative value of CA 125 as a reflection of tumor grade in epithelial ovarian cancer.

A retrospective study of 60 patients with invasive epithelial ovarian cancer was conducted. The significance of preoperative serum CA 125 level with respect to tumor grade and tumor stage was determined. Tumor grade bears a strong influence on the preoperative CA 125 level; the correlation is high and statistically significant (r = 0.74, P < 0.01). The influence of FIGO stage on preoperative CA 125 level is also significant (r = 0.51, P < 0.01), but the results of the multivariate analysis show that the influence of tumor grade on preoperative CA 125 level is stronger (P < 0.01). It is believed that tumor grade is the decisive factor dictating the level of CA 125 in a certain stage of the disease and so influences the preoperative CA 125 level. It is also believed that low preoperative antigen levels of well-differentiated ovarian carcinomas in FIGO stage I are the cause of poor sensitivity of the CA 125 test, thus limiting its applicability for screening purposes.