Immunohistochemical expression of T, Tn and sialyl-Tn antigens and clinical outcome in human breast carcinoma.

BACKGROUND: The extent of expression of reactive T (Thomsen-Friedenreich), Tn and sialyl-Tn antigens has been assumed to predict carcinoma aggressiveness. We studied the expression of T, Tn and sialyl-Tn antigens in a relatively large cohort of breast carcinoma patients with known long-term outcome to assess the clinical and biological significance of these antigens.

MATERIALS AND METHODS: T, Tn and sjalyl-Tn antigens were examined in 72 consecutive primary breast carcinomas by immunohistochemistry using well defined monoclonal antibodies and their semiquantitative values were correlated with established clinicopathologic prognostic parameters of the disease to determine their relationship with long-term clinical outcome.

RESULTS: Of the 72 carcinomas, 63 (87.5%) each expressed T or Tn antigens, while 16 (22%) expressed sialyl-Tn antigens. Most carcinomas (81%) expressed more than one of the antigens simultaneously, being the most frequent combination T/Tn antigen expression. No significant correlation was noted between the expression of T, Tn and sialyl-Tn antigens (whether individually or in combination) and the prognostic parameters including patient age, disease stage, tumor size, lymph node status, nuclear and histologic grades, histologic types, hormone receptor status and menopausal status. Univariate survival analyses showed that disease stage, tumour size and lymph node metastasis were significant predictors of overall survival. Interestingly, a significant inverse correlation was found between the Tn antigen expression (p = 0.04), as well as the combined T/Tn (p = 0.03) and Tn/sialyl-Tn (p = 0.02) antigen expressions and long-term overall survival. In a multivariate Cox proportional hazard model, disease stage and a negative or low Tn antigen expression emerged as significant predictors of overall survival.

CONCLUSION: Our data suggested that the expression of T, Tn and sialyl-Tn antigens does not appear to predict the outcome of patients with breast carcinoma in a long-term run. Moreover, the findings signified a potential value for a negative or low Tn antigen expression in prognostic stratification of breast carcinomas.