Improved Prediction of Survival in Advanced Adenocarcinoma of the Ovary by Immunocytochemical Analysis and the Composition Adjusted Receptor Level of the Estrogen Receptor

Conventional cytosol estrogen receptor analysis is not a significant prognostic variable in serous ovarian carcinoma. Although the use of immunocytochemical receptor analysis for estrogen does provide prognostically useful information in enhanced accuracy of predicting survival in patients with ovarian cancer, its usefulness can still be improved. Surgical samples from ovarian carcinomas are heterogeneous in tissue composition. Immunocytochemical receptor analysis allows for the specific assessment of the tumorous portions of a histological specimen. However, it is limited by its dependence on staining intensity as the determining factor. Biochemical receptor analysis does provide objective information concerning the number of receptor molecules present in a given sample, but the value is not adjusted for histological composition of the tumor section. Therefore, we have attempted to combine the advantages of both methods. By adjusting the conventional receptor analysis for the percentage of tumor present in the specimen, we have eliminated the tissue heterogeneity as a confounding variable. The resulting value is named Composition Adjusted Receptor Level or CARL. A prospective study was performed on the estrogen receptor concentrations in 61 ovarian cancers. Minimum follow-up was 8 years. For the percentage of tumor in the specimen, a highly significant correlation of the assessment of the two pathologists was observed. Stage (P < 0.05) and grade (P < 0.05) as well as cell type (P < 0.05) were found to be significant prognostic variables. In an attempt to eliminate the confounding influences of these variables, the CARL of the estrogen receptor was assessed with regard to its prognostic significance in 32 grade 2 and 3 serous carcinomas of the ovary, stage m and IV. A linear correlation between CARL and survival was found above a threshold estrogen receptor concentration of 15 fmol/mg cytosol protein using a correlation of the Cox proportional hazards model (P < 0.02). Our data suggest that (a) the assessment of the percentage of tumor in a given sample is not significantly observer dependent, (b) CARL is a significant predictor of survival in serous ovarian carcinoma, and (c) a CARL should be determined for the analysis of any cytosol receptor in solid tumors.