Clinical benign disorders of the breast and carcinoma of the breast.

Among 2,506 women with breast disorders seen in consecutive consultations, 345 had carcinoma. Clinical benign breast disorders occurred 6.3 times as frequently as carcinoma of the breast. The lifetime risk of clinical benign breast disorder was calculated to be more than 50 per cent. Clinical benign breast disorders occurred chiefly in young women and carcinoma occurred chiefly in older women. Thus, clinical benign breast disorders precede carcinoma because of the age at which the disorders occur. The incidence of a previous benign biopsy in women with carcinoma was 10.4 per cent and was estimated to be at least 8.2 per cent in the general population. Only a small number of women with carcinoma had previous benign biopsy. The likelihood of finding carcinoma in those women with a previous benign biopsy was 9.2 per cent and in those without 14.6 per cent. Thirty-one of the 36 patients with carcinoma of the breast with a previous benign biopsy were more than 50 years old and 18 were more than 60 years old. It is concluded that women with clinical benign breast disorders do not have an increased risk of having carcinoma of the breast develop.