Ductal carcinoma in situ (DCIS) is a non-invasive breast cancer. Ductal carcinoma in situ (DCIS) is the presence of abnormal cells inside a milk duct in the breast. DCIS is usually found during a mammogram done as part of breast cancer screening or when there is another concern with a woman's breast.
Age adjusted annual incidence of DCIS in the 1990s was the lowest in Switzerland (3.95 per 100,000) and Italy (6 per 100,000), with the highest incidence in The Netherlands (11 per 100,000). DCIS is often detected with mammographies but can rarely be felt. With the increasing use of screening mammography, noninvasive cancers are more frequently diagnosed and now constitute 15% to 20% of all breast cancers. A series of autopsy studies examined the prevalence of undiagnosed DCIS among women who died of reasons other than breast cancer.
DCIS forms when genetic mutations occur in the DNA of breast duct cells. The genetic mutations cause the cells to appear abnormal, but the cells don't yet have the ability to break out of the breast duct. Factors that may increase your risk of DCIS include increasing age, obesity, personal history of benign breast disease, such as atypical hyperplasia, family history of breast cancer, first pregnancy after age 30, taking combination estrogen-progestin hormone replacement therapy for more than three to five years after menopause, genetic mutations that increase the risk of breast cancer, such as in the breast cancer genes BRCA1 and BRCA2.
Treatment options for DCIS include Lumpectomy and radiation therapy, Simple mastectomy. The drug tamoxifen is also suggested in few cases. Lumpectomy is surgery to remove the area of DCIS and a margin of healthy tissue that surrounds it. Lumpectomy followed by radiation therapy is the most common treatment for DCIS. For treating DCIS, a simple mastectomy, removing the breast tissue, skin, areola and nipple, and possibly the underarm lymph nodes is one option. The drug tamoxifen is used as an adjuvant therapy that blocks the action of estrogen, a hormone that fuels some breast cancer cells and promotes tumor growth to reduce your risk of developing invasive breast cancer.