High-risk early breast cancer patients are usually identified by the number of metastatic axillary nodes. To study whether other easily and inexpensively detectable morphological factors are able to detect high-risk patients, we performed a retrospective analysis of tumor size, and skin/fascia and nipple invasion. The data consisted of 941 node-positive cases registered between 1978 and 1991. Tumour size, and skin/fascia and nipple invasion were closely associated with the number of metastatic nodes (chi 2 test). The number of metastatic nodes, tumour size, skin/fascia and nipple invasion significantly affected disease free survival (DFS) and overall survival (OS) at univariate analysis. These results were confirmed by multivariate analysis with a model containing the number of metastatic nodes, tumour diameter categories, skin/fascia invasion, nipple invasion and adjuvant therapy as covariates: all variables significantly and independently affected risk of relapse and of death. All the variables studied were prognostic, within individual nodal categories, for both DFS and OS. In conclusion, the number of metastatic nodes is not the only prognostic tool with which to select high-risk patients for new intensive adjuvant programmes. Tumour size, and skin/fascia invasion or nipple invasion, taken singly or combined, are valuable prognostic factors that can identify patients with few metastatic nodes and poor outcome. On the basis of our data, we believe that a reconsideration of the pT4 category within the pTNM classification is in order, that is, chest wall invasion should be substituted by fascia invasion, and combined skin/fascia invasion could be a subcategory of each class defined by tumour size.