Ductal carcinoma in situ
Ductal carcinoma in situ (DCIS) is characterized by cancerous cells that are confined to the lining of the milk ducts and have not spread through the duct walls into surrounding breast tissue. If DCIS lesions are left untreated, over time cancer cells may break through the duct and spread to nearby tissue, becoming an invasive breast cancer.
DCIS is the most common type of noninvasive breast cancer, with about 60,000 new cases diagnosed in the United States each year. About one in every five new breast cancer cases is ductal carcinoma in situ.
DCIS is divided into several subtypes, mainly according to the appearance of the tumor. These subtypes include micropapillary, papillary, solid, cribriform and comedo.
Women with DCIS are typically at higher risk for seeing their cancer return after treatment, although the chance of a recurrence is less than 30 percent. Most recurrences occur within five to 10 years after the initial diagnosis, and may be invasive or noninvasive. DCIS also carries a heightened risk for developing a new breast cancer in the other breast. A recurrence of DCIS will require additional treatment.
Ductal carcinoma treatment options: The type of therapy selected may affect the likelihood of recurrence. Treating ductal carcinoma in situ with a lumpectomy (breast-conserving surgery) without radiation therapy carries a 25 – 35 percent chance of recurrence. Adding
radiation therapy to the treatment decreases this risk to approximately 15 percent. Currently, the long-term survival rate for women with DCIS is nearly 100 percent.