Tissue expression of human chorionic gonadotropin beta predicts outcome incolorectal cancer: A comparison with serum expression

Production of the glycoprotein hormone human chorionic gonadotropin beta (h CG beta) has been associated with more aggressive behavior in non-trophobla stic tumors, In this study, the prognostic value of immunohistochemical hCG beta expression was evaluated in 239 patients with colorectal cancer. Para ffin-embedded, formalin-fixed specimens were stained with hCG beta -specifi c monoclonal antibody, and the results were compared with serum levels dete rmined with an assay based on the same antibody. hCG beta immunoreactivity was seen in 52 of 239 tumors (22%), The difference in survival time between patients with histologically hCG beta -negative (median survival 94 months ) and -positive (median survival 27 months) tumors was statistically signif icant (p = 0.014), The risk ratio during follow-up for patients with positi ve hCG beta tissue expression was 1.65 (95% Cl 1.1 1-2.46), In a Cox multiv ariate analysis, Dukes' stage, hCG beta and age remained independent progno stic factors. There was moderate agreement between immunohistochemical and serum expression levels of hCG beta (kappa = 0.30). Using a combination of histological and serum levels of hCG beta, the difference between survival rates was highly significant (p < 0.001), The accuracy when predicting 5-ye ar survival status with the combined results of serum and tissue expression was 1.3% higher compared to hCG<beta> tissue expression alone. Our results show that hCG beta expression in both tumor tissue and serum has prognosti c significance independent of other clinicopathological variables. Positive tumor staining does not always occur together with elevated serum levels, and the prognostic accuracy can slightly be increased by combining the resu lts. (C) 2001 Wiley-Liss. Inc.