Ductal Carcinoma in Situ (DCIS)
By Priyanka Varma
Jan. 11th, 2022
Ductal Carcinoma In situ (DCIS) means that the cancer or abnormal cells are present in the lining of the milk duct in the breast. It is staged as Stage 0, as the earliest form of breast cancer and is classified as non-invasive, meaning that the cancer has not spread beyond the milk duct into the surrounding normal breast tissue [1; Fig1]. The incidence of DCIS is estimated to be 60,000 per year by the American Cancer Society, accounting for 20% of all newly diagnosed breast cancer cases . A registry study observed that the mean age at the diagnosis of DCIS was 53 years and the breast-cancer associated mortality was higher if the diagnosis was done before 35 years of age .
Histopathologically, DCIS is an intraductal neoplastic proliferation of epithelial cells, separated from the breast stroma by an intact layer of basement membrane and myoepithelial cells .
DCIS is usually detected on a screening mammogram. When suspicious findings (microcalcifications) are seen, a breast biopsy is recommended to confirm the diagnosis. The histopathological examination of the biopsied tissue confirms the type and grade of DCIS, margin status of the lesion and hormone receptor status for the hormones estrogen and progesterone. DCIS is classified into comedo, cribriform, solid, micropapillary and other subtypes histopathologically. The guidelines recommend 2mm margin as clear margin and application of clinical judgment for re-excision of lesions with 0-2mm margin [1, 5].
Once diagnosed, DCIS is mostly treated with breast conservation surgery or lumpectomy with removal of diseased segments as well as a margin of healthy breast tissue around it. It is usually followed up with radiation therapy which reduces the rate of recurrence in ipsilateral or same side breast by half. Radiation therapy can be external or internal. In some cases with very low rates of recurrence, radiation therapy is not given. Mastectomy is recommended when there is a very wide area of DCIS, there are more than one area of DCIS, strong positive family history is present, DCIS is near the margin of healthy tissue or patient cannot get radiation therapy. Addition of hormone therapy (like Tamoxifen) can reduce the rate of recurrence in both ipsilateral and contralateral breasts. The chances of recurrence for a patient diagnosed with DCIS is usually under 30% [2, 6].
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- Diagnosis of DCIS (breastcancer.org)
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