Schmitt F C, Figueiredo P, Lacerda M
Department of Pathology, Botucatu School of Medicine, UNESP, São Paulo, Brazil.
Virchows Arch. 1995;427(3):251-8. doi: 10.1007/BF00203391.
Immunohistochemical analysis of the expression of simple mucin-type carbohydrate antigens (Tn, sialyl-Tn and T) was performed in a series of 43 cases of intraductal hyperplasia without atypia, 9 cases of intraductal hyperplasia with atypia, 54 cases of ductal carcinoma in situ (DCIS) and 26 cases of invasive breast carcinoma. We also studied 36 cases of isolated breast normal epithelium, 20 cases of "normal" breast epithelium adjacent to neoplasms and 14 cases of apocrine metaplasia. All antigens were detected in different frequencies in normal, hyperplastic, metaplastic and neoplastic breast epithelium. Tn and sialyl-Tn are expressed more frequently in malignant than in benign breast epithelium; while Tn expression increases from normal to invasive carcinomas, sialyl-Tn increases until DCIS and drops in invasive carcinomas, suggesting that either there is a failure of a proportion of DCIS to progress to invasive carcinoma or loss of expression of sialyl-Tn when some carcinomas become invasive. The high frequency of Tn and sialyl-Tn expression in breast intraductal proliferations probably reflects incomplete glycosylation in these lesions, which is a well-known tumour-associated phenomenon and supports the assumption that such lesions are putative precursors of breast cancer. T antigen was expressed in all groups studied, but its prevalence differed significantly between normal and neoplastic epithelium. The expression of these antigens in epithelium adjacent to carcinomas is similar to that found in isolated normal breast epithelium, whereas apocrine metaplasia has a pattern of simple mucin-type glycosylation that is specific and distinct from that of the normal breast epithelium, with a high frequency of marked expression of Tn and sialyl-Tn. The similarity of the pattern of expression of simple mucin-type antigens in metaplasia and malignant neoplasia reduces the usefulness of these markers from a diagnostic standpoint.
对43例无异型性的导管内增生、9例有异型性的导管内增生、54例导管原位癌（DCIS）和26例浸润性乳腺癌进行了简单粘蛋白型碳水化合物抗原（Tn、唾液酸-Tn和T）表达的免疫组织化学分析。我们还研究了36例孤立性乳腺正常上皮、20例肿瘤旁“正常”乳腺上皮和14例大汗腺化生。在正常、增生、化生和肿瘤性乳腺上皮中，所有抗原的检出频率各不相同。Tn和唾液酸-Tn在恶性乳腺上皮中的表达频率高于良性乳腺上皮；虽然Tn的表达从正常乳腺组织到浸润性癌逐渐增加，唾液酸-Tn的表达在DCIS之前增加，而在浸润性癌中下降，这表明要么一部分DCIS未能进展为浸润性癌，要么一些癌变为浸润性癌时唾液酸-Tn表达缺失。乳腺导管内增生中Tn和唾液酸-Tn的高表达频率可能反映了这些病变中糖基化不完全，这是一种众所周知的肿瘤相关现象，支持了这些病变是乳腺癌假定前体的假设。T抗原在所有研究组中均有表达，但其在正常上皮和肿瘤上皮中的发生率差异显著。这些抗原在癌旁上皮中的表达与孤立性正常乳腺上皮中的表达相似，而大汗腺化生具有一种简单粘蛋白型糖基化模式，该模式具有特异性，与正常乳腺上皮不同，Tn和唾液酸-Tn的显著表达频率较高。从诊断角度来看，化生和恶性肿瘤中简单粘蛋白型抗原表达模式的相似性降低了这些标志物的实用性。
