THE THOMSEN-FRIEDENREICH (T) SIMPLE MUCIN-TYPE CARBOHYDRATE ANTIGEN IN SALIVARY-GLAND CARCINOMAS

The simple mucin-type T (Thomsen-Friedenreich) antigen is a marker of carcinomas, and has been related to aggressiveness of malignant tumour s. We studied the expression of T, sialosyl-T, A and H blood group ant igens in salivary gland carcinomas. The aim was to study whether the t umours, based on the expression of these structures, could be divided into new diagnostic groups that may later show prognostic significance . Formalin fixed paraffin-embedded tissue sections from 77 salivary gl and carcinomas of different histological types were studied using immu nohistology and monoclonal antibodies (MAbs). Fresh frozen tissue was examined in 30 of the cases. Frozen sections were superior to paraffin sections in demonstrating T and H antigens. Aberrant glycosylation wi th accumulation of T (in cytoplasm) and sialosyl-T antigens (in cytopl asm, membrane and mucin) was found in all tumour types except acinic c ell carcinomas. In carcinomas in pleomorphic adenomas (CinPA) the effe ct of fixation was minimal and T antigen location was different. In ca rcinomas with myoepithelial cell (MEC) participation, the MECs had ret ained a normal glycosylation pattern. H antigen was expressed in all t umour types, except acinic cell carcinomas and CinPA. A antigen was ex pressed in all tumour types from blood group A patients, except in Cin PA. The expression of T, sialosyl-T, H and A antigens in relation to d ifferentiation grade varied with tumour type in poorly differentiated areas. High and moderate differentiated areas were always stained, whe reas poorly differentiated areas in some tumour types expressed T and sialosyl-T antigens and others did not. The accumulation versus lack o f expression of the investigated structures in poorly differentiated a reas of the tumours may be of prognostic significance.