Clinical progression of breast cancer malignant behavior: What to expect and when to expect it

Purpose: Seemingly localized breast cancer is a heterogeneous mix of truly localized cancers and cancers with occult metastases. Our purpose is to det ermine the parameters of metastatic proclivity for the different clinical p resentations of operable breast cancer and to present quantitative prognost ic information useful to both doctors and patients. Patients and Methods: A series of regionally treated breast cancer patients was analyzed to determine the likelihood and time of the appearance of cli nical metastases for different clinical subgroups. patients operated on at the University of Chicago from 1927 to 1987 for clinically regionally local ized breast cancer, who received no systemic therapy as a part of their ini tial treatment, were included. Overall survival and distant disease-free su rvival in this mature series are analyzed. Results: Metastagenicity, the metastatic proclivity of a tumor, increases w ith both tumor size and nodal involvement. This is also true for virulence, which is the rate at which these metastases appear. Each clinical group ha s a cured population, even those with extensive nodal involvement. A table provides a tool for determining the proportion of risk expended in each cli nical group as a function of the distant disease-free survival. Whereas the likelihood of metastasis increases with tumor size and nodal involvement, the time to their appearance decreases. Conclusion: Breast cancer metastagenicity and virulence are heterogeneous e ven within clinically similar groups of operable breast cancer patients. Tu mor progression is correlated with increasing tumor size and nodal involvem ent. Markers are needed to identify individual tumor virulence and metastag enicity. J Clin Oncol 18:591-599. (C) 2000 by American Society of Clinical Oncology.