THIS paper is the report of an attempt to discover what happens eventually to women who have undergone the Halsted radical mastectomy and have survived five years or longer. Since the opening of its department of surgery, thirty years ago, 598 such operations have been performed at the Henry Ford Hospital, 412 of them up to the end of 1941, with a mortality rate of 2.2 per cent. As the result of an intensive follow-up study of all radically treated patients with cancer of the breast, begun in 1930 and carried on without interruption despite obstacles of the war years, my colleagues and I have current follow-up information on all but 6 of the 412 patients (table 1). By recent check, we find that 177, or 43 per cent, survived their operation five years and more. Of these 177 patients, we have lost track of only 2 (table 2). Three