AbstractBreast cancer continues to represent a major threat to the American woman despite two decades of improved early detection methods, better chemotherapy, major advances in understanding and usefulness of prognostic factors, a clearer concept of the risk/benefit ratios in therapy, and a more fully informed public as a result of a vast application of public education and communication. Approximately 41,000 women will die of breast cancer this year in the United States. One out of 11 American women are faced with this scourge in their lifetime. The annual death rate now seems to be rising after several years of a slight decline. The anticipated rise is fully described in Public Health Service releases published in theNew York Timesrecently. In Denmark, a current study indicates that about25%of all Danish women can be expected to manifest carcinoma in situ in their lifetimes. This kind of data can probably be replicated in the United States, which has the highest overall breast cancer rate in the world. Japanese women residing in Japan show one quarter of the incidence of the rates in the United States, but their sisters who grow up in our country now show an incidence almost equal to that of American women. The uneven distribution of incidence rates in the United States is notorious, with affluent urban and surburban areas showing the highest rates especially here in New York and on Long Island. Among ten million women in the Greater New York metropolitan area, about 20,000 above the age of 40 could be identified as likely to develop breast cancer at twice the normal rate.