Ductal carcinoma in situ of the breast

Ductal carcinoma in situ of the breast is a heterogeneous group of lesions with diverse malignant potential. It is the most rapidly growing subgroup i n the breast cancer family; it is projected that more than 39,000 new cases will be diagnosed in the United States during 1999. Most new cases are non palpable and are discovered mammographically. Treatment is controversial an d ranges from excision only, to excision with radiation therapy, to mastect omy. Genetic changes routinely precede morphologic evidence of malignant tr ansformation. Medicine must learn how to recognize these genetic changes, e xploit them, and in the future, prevent them.