Immunohistochemical fibronectin staining pattern and prognosis in invasive breast carcinoma.

Fibronectin (FN) in 99 female patients with invasive breast carcinomas (IBCs) was studied by immunohistochemistry using a monoclonal antibody to human plasma FN. Sixty-five (65.7%) of 99 IBCs were FN-positive and 34 (34.3%) were FN-negative. The FN staining pattern was not correlated with patient characteristics, such as age, tumor size, nodal involvement and estrogen receptor status. Relapse-free survival (RFS) of patients with FN-positive tumors was significantly better than that of patients with FN-negative tumors. A multivariate analysis using the Cox proportional hazards model showed that the FN staining pattern was independently correlated with RFS as well as nodal status. The results show that FN staining pattern may be an independent prognostic factor in IBCs. It is suggested that patients with FN-negative tumors should be carefully followed up, even if axillary nodal invasion is absent.