CA 125 and CA 19-9 immunolocalization in normal, hyperplastic, and carcinomatous endometrium.

BACKGROUND

Elevated levels of tumor-associated antigens, such as CA 125, have been reported in patients with endometrial carcinomas. This study was done to evaluate the frequency and tissue distribution of CA 125 and CA 19-9 in normal and neoplastic endometrium.

METHODS

Consecutive tissue sections were immunohistochemically evaluated using primary antibodies directed against CA 125 and CA 19-9. Antibody-antigen binding was demonstrated using the avidin-biotin technique.

RESULTS

CA 125 expression was related to the phase of the menstrual cycle and was most prominent during secretory phase. Positive staining (5% or more of the glandular epithelium) for CA 19-9 was noted in only 4 of 20 patients with normal endometrium. Positive staining for CA 125 (5% or more of the epithelium) was present in 68% of the carcinomas; another 8% of the tumors contained focal staining for CA 125. Positive staining for CA 19-9 was demonstrated in 60% of tumors; another 8% of the tumors showed focal staining for CA 19-9. The markers were concordant in 76% of the tumors evaluated.

CONCLUSIONS

Although CA 125 was uniformly expressed by the glandular cells in normal endometrium, CA 19-9 expression appeared to be related to the prevalence of the Lewis A phenotype. Endometrial carcinomas also frequently express these antigens, and the degree of expression was related to the grade and cell type of the tumor.