The prognostic value of human chorionic gonadotropin expression in colorectal adenocarcinomas. An immunohistochemical study of 102 stage B2 and C2 nonmucinous adenocarcinomas.

Several recent studies have detected human chorionic gonadotropin (hCG) expression in colorectal adenocarcinomas and have concluded that its expression is an adverse prognostic indicator. The patient population and length of follow-up has varied. Therefore, we reviewed a defined group of cases with long-term (> 5 years) follow-up. We studied 102 stage B2 and C2 nonmucinous adenocarcinomas immunohistochemically for the production of hCG. Expression of hCG was detected in paraffin sections, including tumor and adjacent mucosa, using immunolabeling with a polyclonal rabbit antibody and the avidin-biotin-peroxidase complex technique. Cytoplasmic positive staining was evaluated semiquantitatively in every low-power microscopic field containing tumor. Expression of hCG was noted in at least one field in 42% (43/102) of the carcinomas. There was no expression in adjacent mucosa. Although the staining was usually focal (< 5% of tumor cells), some cases did stain diffusely. There was no significant correlation of hCG expression with survival, stage, differentiation, age, race, sex, or site of tumor. We therefore conclude that hCG expression is not a significant prognostic indicator in stage B2 and C2 colorectal carcinomas.