ObjectiveTo explore the expression of collagen Ⅳ in breast cancer and its clinical significance. We analyzed the correlation of the results with other prognostic parameters which included tumor size, status of estrogen receptor, axillary nodal status, TNM grade, and 5 years survival. The expression of collagen Ⅳ in 93 cases of human primary breast cancer as well as 5 cases of benign breast masses were examined.MethodsUsing monoclonal antibodies of collagen Ⅳ, the expression of collagen Ⅳ in breast masses were detected with immunohistochemical technique (LSAB).ResultsThe absent expression of collagen Ⅳ in the tumor masses was correlated with axillary lymph node involvement, tumor size and poor prognosis (5 years survival). The patients who had no expression of collagen Ⅳ in tumor masses had a shorter survival. ConclusionThe expression of collagen Ⅳ in tumor samples are correlated with axillary node involvement and prognosis. Collagen Ⅳ would be helpful for evaluation of invasion and treatment in breast carcinoma.