The matrix of
mammary dysplasia, noninvasive
ductal carcinoma, and invasive lobular and
ductal carcinoma was analyzed by indirect immunofluorescence using
antibodies to types I, proIII, III, and IV
collagens, and
laminin and
fibronectin. Types proIII and III
collagens were present in increased amounts in invasive
carcinomas and were most abundant in the "young" edematous mesenchyme, areas corresponding to the peripheral invasive cellular front.
Type I collagen was distributed throughout the matrix of invasive
carcinomas but was most prominent within the central sclerotic zone of the
neoplasms.
Mammary dysplasia and noninvasive
ductal carcinomas showed a uniform fibrillar and granular distribution of all types of
collagen. In all but two cases of invasive
carcinoma, staining with anti-
laminin and anti-
type IV collagen demonstrated the loss of basement membranes around
tumor cells. In contrast, fluorescence pattern in noninvasive
ductal carcinoma and dysplasia revealed an intact basement membrane. The distribution of
fibronectin was similar to types proIII and III
collagen. These findings support and extend our previous studies which suggested an analogy between the dynamics of matrix changes in granulation tissue and invasive
carcinomas. These data also strengthen the concept that the myofibroblast could be a pivotal cell involved in the synthesis and redistribution of matricial
proteins. The loss of basement membrane in invasive
carcinomas appears to be an initial step for inducing the matricial alterations.