It is only by classifying cases of cancer that comparisons of the results of different therapeutic procedures can be analyzed equitably. There are many reports in the medical literature about the results of treatment of cancer of the breast in which cases are not classified, and therefore unjustifiable conclusions are drawn. Also, in some reports either clinical or pathologic criteria are the basis for statistical analyses. None of these classifications has been entirely satisfactory or generally accepted because of limited applicability.
Classification based solely on histologic criteria, such as one outlined by Ewing1 or the “grading” plan of Broders,2 is unsatisfactory because the histologic structure of most, if not all, of these neoplasms varies in many areas. The histologic name, or grade, given a tumor is subject to individual interpretation of microscopic sections examined but does not describe the whole tumor or the anatomic extent of involvement. Also, patients will survive with cancers considered to be highly malignant from the histology, whereas others will succumb from neoplasms of seemingly low degree of malignancy depending upon anatomic extent of involvement and whether or not the cancers can be eradicated.
Another classification has been based primarily upon pathologic evidence of the presence or absence of metastases in axillary lymph nodes. However, the degree of axillary involvement is most important. Also, there are other clinical and pathologic manifestations of prognostic significance.
Classifications of cases of cancers of the breast based only upon clinical criteria, such as those suggested by Steinthal,3 Lee and Stubenbord,4. . .