Noninvasive breast cancer: Part 1. Ductal carcinoma in situ--incidence, presentation, guidelines to treatment.

In situ breast cancer, both ductal and lobular, is being diagnosed more often today because of improved screening programs and more sensitive mammography. Unfortunately, treatment options in the disease are based on retrospective studies with the natural history obscured. While considered a noninvasive cancer, it has been theorized that ductal carcinoma in situ is a preinvasive stage that will eventually evolve into an invasive cancer. The author reviews results of studies comparing treatment methods, including wide local excision, mastectomy, and radiation, and concludes that prospective studies must be performed before optimal therapy can be determined.