An analytic critique of existing classification systems for cancer of the breast

The most popular systems of histologic typing for cancer of the breast have been analyzed as far as details of construction and results of application. The constituents of all systems are debatable. Lack of uniformity and standardization is obvious, while meaningful comparisons in terms of results and prognostic evaluation are unfeasible. Although the attempts to classify histologic patterns are hampered by the observers' variability and by the existence of different patterns within the same tumor, efforts have to be made to further standardize the terms used for designating histologic types. Additional aid can be expected from histologic grading and morphologic host defense reaction evaluation to substantiate the prognostic evaluation of individual cancers of the breast.