Varying Degrees of Malignancy in Cancer of the Breast

Differences in the degree of malignancy of malignant tumors have been recognized by pathologists for many years. Indeed, Virchow9s original conception of a malignant tumor was one composed of cells, derived from the tissue cells of the individual, but differing from the normal cells in the rapidity and independence of their growth. Hansemann (1) carried this idea somewhat further and introduced the word “anaplasia” to indicate the process by which cancer cells came to differ from the normal type cell of the body tissue concerned. Anaplasia involves a loss of differentiation and an increase of reproductive power, so that the anaplastic cell fulfils only in abortive fashion, if at all, its normal function, such as secretion or keratinization; while it shows by increased number of mitotic figures, and especially by the irregularity and abnormality of its nuclear chromatic elements and figures, the increase in rapidity of cell division and of cell growth which is characteristic of malignancy. A number of attempts have been made to grade the malignancy of different breast tumors by distinguishing their histological characteristics, such as adenocarcinoma, medullary, scirrhus, colloid, etc.; but with the exception of adenocarcinoma and colloid, these divisions have proved of little value in prognosis. There the matter rested till 1921, when, under the influence of MacCarty (2) of the Mayo Clinic, Broders published a paper suggesting the classification of cancer tissue according to the degree of malignancy, as estimated by loss of differentiation and increase of reproductive characteristics.