Host resistance to carcinoma of the breast.

The recent demonstration that tumor cell circulation occurs early in the development of a growing neoplasm allows us to hypothesize that the growth of a primary lesion provides the patient with sufficient exposure to disseminating tumor cells to define the lower limit of her own threshold of host resistance. The biologic behavior of carcinoma of the breast is discussed by examining the significance of local recurrence in the contralateral breast, the residual breast tissue, and adjacent lymphatic tissue.