Surgery to remove the cancerous tissue and surrounding healthy tissue is the typical treatment for carcinoma in situ, according to the American Cancer Society. Carcinoma in situ is a non-invasive form of cancer that has not yet spread, and early treatment often keeps it from spreading anywhere else.
In cases involving carcinoma in situ, lymph node removal is not always necessary. If the site that has carcinoma in situ also has cancerous tissue that is more invasive, then lymph node removal is an option. The larger the tumor is, and the higher the nuclear grade, then the greater the likelihood is that invasive cancer is also present, as stated by the American Cancer Society.
Radiation therapy is another option after the removal of the cancerous tissue. It reduces the chances that the cancer returns. Radiation therapy is typically used when the area containing the cancer and the noncancerous surgical margins is small enough, reports the American Cancer Society.
In ductal carcinoma in situ in the breast, mastectomy is necessary if the cancerous area is large enough or if there are multiple areas within the same breast. Many women who have a mastectomy choose reconstructive surgery. Catching the cancer in situ is vastly preferable as the likelihood of advanced staging and metastasis is much lower, notes the National Breast Cancer Foundation.