Selective decrease in serum immunoglobulin G1. A tissue nonspecific tumor marker detecting early stages of gynecologic malignant disease with high efficiency.

BACKGROUND: Malignant diseases of various tissue origin have previously been found to be associated with a characteristic shift in the serum pattern of IgG subclasses, i.e., a highly significant reduction of the percent of IgG1 and an increase of the percentage of IgG2 relative to the total IgG. In the present study we examined the diagnostic performance of this indirect tumor marker in patients with carcinomas of various sites within the female reproductive tract. METHODS: Using quantitative affinity chromatography, the percents of IgG1 and IgG2 in the total IgG were determined for 207 patients with carcinoma of the ovary, cervix, or corpus uteri, prior to any treatment. The data were compared with those of 135 age matched healthy females and 52 patients with benign gynecologic diseases. RESULTS: It was found that (1) mean values for the percents of IgG1 and IgG2 of all of the cancer patients differed significantly from those of the patients with benign disease and healthy controls; (2) no differences were noted between carcinomas of the ovary, corpus or cervix uteri; (3) early stages of carcinoma exhibited the effect to the same extent as late stages; (4) the specificity of the percent of IgG1 to discriminate between controls and cancer patients ranged between 90 and 100%, regardless of localization and stage of tumor; and (5) whereas with ovarian cancer CA 125 showed a slightly greater sensitivity, the percent of IgG1 was by far more sensitive than the conventional markers CA 125, TPA, CEA, Ferritin, and SCC to diagnose carcinoma of the cervix and corpus uteri, notably at early stages. Combined analysis of the percent of IgG1 and CA 125 and/or TPA led to an increase in sensitivity with tumors of all three sites. CONCLUSIONS: Thus, the determination of the percent of IgG1 by itself and/or in combination with conventional markers may provide relevant information regarding the noninvasive detection of early stages of gynecologic carcinoma.