This is a resume of a Breast Cancer Survey carried out by the American College of Surgeons in 1978. Four hundred and ninety-eight hospitals in 47 states, Washington, D.C., and Puerto Rico participated, contributing a total of 24,136 female patients with histologically confirmed breast cancer. In these patients, five-year cure rates were 60.5% for clinically localized disease and 33.9% for regional disease. Five-year survival rates were 72.8% for localized disease and 49.1% for regional disease. From the 1960's into the early 1970's, there was a gradual shift away from radical mastectomy towards so-called modified radical mastectomy. In a group of patients treated by either radical or modified mastectomies, the axillary nodal status, size of the tumor, and location of the tumor were examined in relation to the prognosis. In the study of number of metastatic nodes in the axilla, there were reduced cure and survival rates in patients with one or more positive nodes as compared to those with negative axillary nodes. With the increase in the number of positive nodes, there was a continuing associated decline in survival and cure. The clinical size of the tumor also correlated well to the prognosis. With the increase in the size of the tumor, there was a gradual increase in the probability of axillary nodal involvement. However, in the group of patients with tumor size smaller than 1 cm, axillary metastasis occurred in 25%. When the axillary nodes were involved, the cure rate in those patients was not significantly better than the rates for those with larger primary tumors in this study. Tumors located in the medial half of the breast were associated with a slightly lower cure rate than those in the lateral half. Young women under 35 years of age had poorer survival and cure rates, although in women 35-44 years of age, the five-year results were comparable to the older group of patients. In blacks, breast cancer was diagnosed in a relatively more advanced stage than in whites. Survival and cure rates were generally lower for blacks, and such lower rates seem to be associated with the relatively advanced stage of the disease.