Survival analysis in advanced epithelial ovarian carcinoma in relation to proliferative index of MIB-1 immunostaining

To evaluate the survival of patients with advanced epithelial ovarian carcinoma in relation to MIB-1 immunostaining, to determine the association between MIB-1 and clinicopathologic variables, and to identify an appropriate cut-off point for MIB-1 immunostaining as a prognostic marker.

We retrospectively reviewed the medical records of women diagnosed with advanced epithelial ovarian carcinoma during 1987-1998. The paraffin-embedded tissue of recruited women was stained with MIB-1 immunostaining for review.

The records of 105 patients were included. The percentage staining of MIB-1 ranged from 0.3 to 100%, with a median of 11.9%. MIB-1 staining was generally higher in serous tumors than in other types (P = 0.048), but was not associated with other potential prognostic indicators. The 5-year survival rate among advanced epithelial ovarian carcinoma patients was 25.7%, while that in the high MIB-1 (greater than or equal to median) and low MIB-1 (less than median) patients was 15.1% (95% confidence interval [CI] = 7.1-26.0) and 36.5% (95% CI = 23.8-49.4), respectively. Median survival times in the two groups were 1.8 years and 3.0 years, respectively (P < 0.008). Division of the MIB-1 staining percentage into quartiles showed that the risk of death increased from the first to the second quartile (>/=7.6 to <11.9%, hazard ratio = 2.36, 95% CI = 1.22-4.54) with no further increase in higher quartiles.

Among patients with advanced epithelial ovarian carcinoma, MIB-1 immunostaining was higher in serous than in other histologic types. Levels of MIB-1 staining above the cut-off point of 7.6% had significantly poorer survival.