The basement membrane (BM), of which laminin is a major glycoprotein component, is an important barrier to @entity5 cells which must be breeched before metastatic spread can occur. We have compared the pattern of laminin expression in a range of benign and malignant breast lesions to better understand the process of @entity5 progression. A total of 162 cases of breast samples, comprising 18 @entity1557 , 22 cases of @entity3923 , 96 cases of @entity513 and 26 @entity189 with intraductal components, were evaluated for laminin expression by a standard immunoperoxidase method on @entity406 -fixed, @entity982 -embedded histological sections, using a commercial antibody against @entity1 laminin. The pattern of laminin expression was charted as follows: Type I, > 70% of BM complete/continuous; Type II, > 70% of BM moderately disrupted; Type III, > 70% of BM completely disrupted. The Type I pattern was observed in all cases of @entity1557 and @entity3923 , and in 77% of @entity3821 components. Various patterns of BM disruption were observed in @entity513 . Severity of BM disruption correlated with histological grade of the @entity189 (P < 0.001). @entity5 , those without lymphatic invasion and lymph node-negative @entity5 showed more complete patterns of laminin expression. The current study suggests that @entity5 cells with high histological grade possess an enhanced capacity to disrupt the basement membrane, an important step in the metastatic process. The detection of BM disruption by immunohistochemical staining for laminin is technically easy and may be usefully applied for the differentiation of in situ and microinvasive @entity189 .

A comparison of the patterns of laminin expression in @entity1557 , XXXX , pre-invasive and invasive ductal breast carcinoma.

@entity1 :: ('9606', 'Species') :: ['human'] @entity3821 :: ('MESH:D002285', 'Disease') :: ['intraductal carcinoma'] @entity5 :: ('MESH:D009369', 'Disease') :: ['tumour', 'Small-sized tumours', 'tumours'] @entity406 :: ('MESH:D005557', 'Chemical') :: ['formalin'] @entity189 :: ('MESH:D002277', 'Disease') :: ['carcinomas', 'carcinoma'] @entity3923 :: ('MESH:D005348', 'Disease') :: ['fibrocystic disease', 'fibrocystic diseases'] @entity513 :: ('MESH:D044584', 'Disease') :: ['invasive ductal carcinoma'] @entity982 :: ('MESH:D010232', 'Chemical') :: ['paraffin'] @entity1557 :: ('MESH:D018226', 'Disease') :: ['fibroadenoma', 'fibroadenomas']
@entity3923 :: (MESH:D005348,Disease) :: ['fibrocystic diseases']
