[Serodiagnostic tests by factor analysis and stepwise discriminating analysis with tumor markers for the detection of ovarian cancer]

We measured five tumor markers simultaneously for serodiagnostic testing as a method for the early detection of ovarian cancer. To decrease both false negativity and false positivity in the results of combination assay, statistical analysis including factor analysis and stepwise discriminating function was applied in this study. At least one of these tumor markers was detected as positive in 75.2% (76 of 101 patients) of sera from patients with ovarian cancer before treatment. Six hundred and ninety-three of 7,097 normal sera (9.8%) gave spuriously positive combination assay results. Falsely positive combination assay results were observed in 1,107 of 3,139 patients with benign disease, which could largely be attributed to the high CA125 values in patients with endometriosis. On the basis of factor analysis in order to decrease false positivity, CA125, TPA, and CA125/TPA were selected as the best parameters for distinguishing between ovarian cancer and benign conditions including those pelvic endometriosis showing positive results in combination assays. Subsequently, the function derived by factor analysis made possible the correct classification of 58 of 71 patients with ovarian cancer detected by combination assay, and 84.8% of pelvic endometriosis and benign ovarian tumor subjects were correctly classified into the non-cancer group. Next, in order to decrease false negativity, statistical analysis was also applied. Malignancy could be correctly diagnosed by this procedure in 14 of 25 patients whose tumor was undetectable by combination assay, whereas of subjects without cancer 14.5% were errorenously classified into the ovarian cancer group. In the search for the best method for accurately detecting ovarian cancer, we used image diagnosis (ultrasonography) in combination with serological diagnosis.(ABSTRACT TRUNCATED AT 250 WORDS)