Ductal carcinoma in situ (DCIS), also known as intraductal carcinoma, is a pre-cancerous or non-invasive cancerous lesion of the breast. DCIS is classified as Stage 0. It rarely produces symptoms or breast lumps, and it is usually detected through screening mammography. In this condition abnormal cells are found in the lining of one or more milk ducts in the breast. In situ means "in place" and refers to the fact that the abnormal cells have not moved out of the mammary duct and into any of the surrounding tissues in the breast (precancerous means that it has not yet become an invasive cancer). In some cases, DCIS may become invasive cancer and spread to other tissues, although it is not currently known how to predict which lesions will become invasive. DCIS encompasses a wide spectrum of diseases ranging from low-grade lesions that are not life-threatening to high-grade (i.e. potentially highly aggressive) lesions. DCIS has been classified according to architectural pattern (solid, cribriform, papillary, and micropapillary), tumor grade (high, intermediate, and low grade), and the presence or absence of comedo histology. DCIS can be detected on mammograms by examining tiny specks of calcium known as microcalcifications. Since suspicious groups of microcalcifications can appear even in the absence of DCIS, a biopsy may be necessary for diagnosis.
DCIS doesn't cause any signs or symptoms in most cases. However, DCIS can sometimes cause signs and symptoms, such as: A breast lump, Bloody nipple discharge. DCIS is usually found on a mammogram and appears as small clusters of calcifications that have irregular shapes and sizes. Most of the women who develop DCIS do not experience any symptoms. The first signs and symptoms may appear if the cancer advances. Because of the lack of early symptoms, DCIS is most often detected at screening mammography. In a few cases, DCIS may cause: Alump or thickening in or near the breast or under the arm, A change in the size or shape of the breast, Nipple discharge or nipple tenderness, the nipple may also be inverted, or pulled back into the breast, Ridges or pitting of the breast, the skin may look like the skin of an orange, A change in the way the skin of the breast, areola, or nipple looks or feels such as warmth, swelling, redness or scaliness. About 20–30% of those who do not receive treatment develop breast cancer. It is the most common type of pre-cancer in women. There is some disagreement as to whether, for statistical purposes, it should be counted as a cancer: some include DCIS when calculating breast cancer statistics while others do not. 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. Cases of DCIS have increased 5 fold between 1983 and 2003 in the United States due to the introduction of screening mammography. In 2009 about 62,000 cases were diagnosed. Surgical removal with or without additional radiation therapy or tamoxifen is the recommended treatment for DCIS. Surgery may be either a breast-conserving lumpectomy or a mastectomy (complete or partial removal of the affected breast). If a lumpectomy is used it is often combined with radiation therapy. Tamoxifen may be used as hormonal therapy if the cells show estrogen receptor positivity. Chemotherapy is not needed for DCIS since the disease is noninvasive. While surgery reduces the risk of subsequent cancer, many people never develop cancer even without treatment and there are associated side effects.
There is no evidence comparing surgery with watchful waiting and some feel watchful waiting may be a reasonable option in certain cases. There are two treatment methods they are: i. Radiation therapy ii. Mastectomy Radiation therapy: Use of radiation therapy after lumpectomy provides equivalent survival rates to mastectomy, although there is a slightly higher risk of recurrent disease in the same breast in the form of further DCIS or invasive breast cancer. Systematic reviews (including a Cochrane review) indicate that the addition of radiation therapy to lumpectomy reduces recurrence of DCIS or later onset of invasive breast cancer in comparison with breast-conserving surgery alone, without affecting mortality. The Cochrane review did not find any evidence that the radiation therapy had any long-term toxic effects. While the authors caution that longer follow-up will be required before a definitive conclusion can be reached regarding long-term toxicity, they point out that ongoing technical improvements should further restrict radiation exposure in healthy tissues. They do recommend that comprehensive information on potential side effects is given to women who receive this treatment. The addition of radiation therapy to lumpectomy appears to reduce the risk of local recurrence to approximately 12%, of which approximately half will be DCIS and half will be invasive breast cancer, the risk of recurrence is 1% for women undergoing mastectomy. Mastectomy There is no evidence that mastectomy decreases the risk of death over a lumpectomy. Mastectomy; however, may decrease the rate of the DCIS or invasive cancer occuring in the same location. Mastectomies remain a common recommendation in those with persistent microscopic involvement of margins after local excision or with a diagnosis of DCIS and evidence of suspicious, diffuse microcalcifications. Some institutions that have encountered high rates of recurrent invasive cancers after mastectomy for DCIS have endorsed routine sentinel node biopsy (SNB). Others reserve SNB for only certain people. Most agree that SNB should be considered with tissue diagnosis of high risk DCIS (grade III with palpable mass or larger size on imaging) as well as in people undergoing mastectomy after a core or excisional biopsy diagnosis of DCIS.