Preoperative CA 125 levels: an independent prognostic factor for epithelial ovarian cancer.

OBJECTIVE: To estimate the association of preoperative CA 125 levels with outcome in primary ovarian cancer patients.

METHODS: One hundred forty-two patients with epithelial ovarian cancer, who had a serum CA 125 level drawn before surgery, were retrospectively evaluated. The relationship of preoperative CA 125 levels and various preoperative and postoperative variables was evaluated. CA 125 levels were determined using a solid-phase immunoassay.

RESULTS: The median CA 125 value for all patients was 582 U/mL (range 7-52,930 U/mL). Preoperative CA 125 values did not correlate with increasing age (P =.40), but were found to be significantly associated with serous histology compared with other histology (median CA 125 of 870 versus 334 U/mL, P =.02), high-stage (III/IV) compared with low-stage (median CA 125 of 893 versus 174 U/mL, P <.001), high tumor grade (3) compared with grade 1 or 2 (median CA 125 of 928 versus 323 U/mL, P <.001), and the presence of ascites compared with absence of ascites (median CA 125 of 893 versus 220 U/mL, P <.001). Suboptimal cytoreduction (more than 1 cm residual) was associated with significantly higher CA 125 levels (1067 U/mL) compared with individuals with optimal cytoreduction (399 U/mL, P <.001). Preoperative CA 125 values less than 500 U/mL had a positive predictive value for optimal cytoreduction of 82%, but a poor negative predictive value of 48%. After adjusting for covariates, there was a significant association between CA 125 levels and disease-specific survival. As preoperative CA 125 levels increased, the risk of death increased except at the highest values of CA 125.

CONCLUSION: Preoperative CA 125 is an independent risk factor for death due to disease in ovarian cancer, but not a reliable predictor of optimal cytoreduction.