CA-125 change after chemotherapy in prediction of treatment outcome among advanced mucinous and clear cell epithelial ovarian cancers: a Gynecologic Oncology Group study.

Abstract

There are limited data regarding unique clinical or laboratory features associated with advanced clear cell (CC) and mucinous (MU) epithelial ovarian cancers (EOC), particularly the relationship between CA-125 antigen levels and prognosis. A retrospective review of 7 previously reported Gynecologic Oncology Group phase 3 trials in patients with stage III/IV EOC was conducted. A variety of clinical parameters were examined, including the impact of baseline and changes in the CA-125 level after treatment of CC and MU EOC on progression-free (PFS) and overall survival (OS). Clinical outcomes among patients with advanced CC and MU EOC were significantly worse when compared with other cell types (median PFS, 9.7 vs 7.0 vs 16.7 months, respectively, P < .001; median OS, 19.4 vs 11.3 vs 40.5 months, respectively, P < .001). Suboptimal debulking was associated with significantly decreased PFS and OS among both. Although baseline CA-125 values were lower in CC (median, 154 micron/mL) and MU (100 micron/mL), compared with other cell types (275 micron/mL), this level did not appear to influence outcome among these 2 specific subtypes of EOC. However, an elevated level of CA-125 at the end of chemotherapy was significantly associated with decreased PFS and OS (P < .01 for all). Surgical debulking status is the most important variable at prechemotherapy predictive of prognosis among advanced CC and MU EOC patients. Changes in the CA-125 levels at the end treatment as compared with baseline can serve as valid indicators of PFS and OS, and likely the degree of inherent chemosensitivity.