The progressive increase in the incidence of carcinoma as the middle period of life is approached and reached has long been recognized. Most writers have contented themselves with a statement of this fact, leaving the reader to understand that even in advanced years the progressive increase is maintained. For instance, Bashford1 says : "Carcinoma appears in the human subject with increasing frequency as life advances." He recognizes, however, that the carcinoma incidence in those organs which undergo a definite phase of involution long before senile changes in the organism as a whole are marked, is highest during such involutionary processes. This he bases on statistics of breast and uterine cancer.
Senn2 gives a suggestion that in extreme old age the cancer incidence is decreased, as the following quotation shows : "Carcinoma manifests a predilection for the conditions incident to senile marasmus, occurring most frequently in persons between 50 and 70