In 187 node-negative breast cancers, the expression of laminin receptors and collagenase IV was directly related in 52% of cases, independently of pathological (tumor size and histology) and biological (estrogen receptors and proliferative activity) features. Moreover, the presence of laminin receptors and collagenase IV did not appear to influence tumor proliferative activity, evaluated as 3H-thymidine labelling index. In this case series, relapse-free survival and overall survival at 6 years were significantly affected by tumor size, hormone receptor status and proliferative activity. Conversely, high levels of laminin receptors and collagenase IV failed to influence relapse-free or overall survival, whereas they were strong indicators of local-regional diffusion of the disease.