This article is only available in the PDF format. Download the PDF to view the article, as well as its associated figures and tables. This question can be answered today with confidence only if four basic principles are followed in comparing case series. Precise Method of Classification.— A precise method of clinical classification must be used so that the case series being compared are truly at the same stage of advancement. We use the Columbia Clinical Classification9 (Table 2) because it defines the various clinical stages of advancement of breast carcinoma more simply and precisely than any other clinical classification. In the Columbia classification, stage A is defined as follows: no grave signs of locally advanced disease, ie, edema, or ulceration of skin, or solid fixation of the tumor to the chest walls, and no clinically involved axillary nodes (other classifications refer to palpable nodes, a much less precise category). It will be noted that the size and position of the primary tumor are not factors in this classification. Stage A in the