Significant Correlation between the Presence of Type W Collagen in the Duct Wall and the Development of Wide Intraductal Cancerous Extension in Breast Cancer.

To identify the characteristics of cases with an wide intraductal cancerous extension (WICE), we examined the relationship between WICE and type IV collagen distribution, and the relationship between WICE and the content of the proliferation-associated proteins in human breast cancer. The immunohistochemical distribution of type IV collagen and proliferating cell nuclear antigen (PCNA) were investigated in formalin-fixed tissue sections from 21 breast cancer cases. We demonstrated a significant correlation (p=0.014) between the presence of WICE and immunostaining of type IV collagen in the cancerous ducts (ducts occupied by cancer cells) in the central invasive area of breast cancer. However, no correlation was found between the presence of WICE and the PCNA index (percentage of positive cells per 1000 tumor cells). These findings suggest that the lack of the process of the loss of type IV collagen in the duct wall is more important than the nature of the tumor cells in the development of WICE.