For stage III epithelial ovarian cancer the initial level of expression of CA125 does not correlate with survival in women who respond to treatment

Abstract

There is experimental evidence to suggest that the amount of CA125 antigen produced by tumor cells is related positively to the cells9 proliferation. This suggests that the serum concentration of the CA125 antigen which a tumor sheds might give prognostic information about the tumor. The aim of this study was to see if survival was associated with the initial serum CA125 concentration in women presenting with ovarian cancer with an elevated serum CA125 concentration who then responded to treatment as assessed by the serum CA125 concentration falling to normal. A sample population consisted of women with ovarian cancer recorded on the Gynaecological Tumor Registry at the Royal Adelaide Hospital and the Queen Elizabeth Hospital. The study was retrospective and the data were obtained from the Gynaecological Tumor Registry and the Department of Clinical Chemistry at the Queen Elizabeth Hospital. There were 237 women with ovarian cancer entered on the Tumor Registry who had been followed up for between 3¼ years and 11 years and for whom definite survival data were available. Of these 237, 153 had a recorded pretreatment serum CA125 concentration. An association was shown between tumor stage and serum CA125 concentration. Multivariate analysis did not show that CA125 was a predictor of survival independent of stage. Within stage (for which there were only meaningful numbers for stage III), a negative correlation of survival with serum CA125 concentration amongst9responders9 was not found—ie stage III patients do just as well (or badly) if they have a very elevated CA125 that drops to normal or a much lower CA125 that drops to normal. Patients with an elevated serum CA125 concentration that did not fall with treatment to ≤35 U ml-1 had significantly worse survival that those who did. In women whose CA125 levels drop to normal with treatment for ovarian cancer, the initial serum concentration of CA125 does not correlate with survival.