Non-invasive or in situ cancers consist of lobular carcinoma in situ and ductal carcinoma in situ (intraductal carcinoma). These cancers are often small and may be discovered incidentally by mammography before a mass can be felt. They may also be in several locations in one or both breasts. In situ cancer can also be found in the presence of invasive cancer , in which case the cancer is staged and treated according to the invasive cancer.
Standard Treatment Both types are generally curable.
• For small intraductal carcinoma, conventional therapy is a wide excision of the tumor . It is critical to remove
an additional uninvolved area around the initial biopsy if the edges of the biopsy showed tumor cells . Axillary
lymph nodes were usually removed in the past, but several studies have shown that positive nodes are rare for
this type of cancer. Accordingly, axillary sampling is usually omitted.
Following surgical excision of the tumor, radiation therapy can be given to the remaining breast tissue , since this significantly reduces the chances of additional cancer developing in the same breast. Another option is to remove the entire breast tissue (total mastectomy), with or without axillary dissection especially in cases where there may be several areas of in situ cancer. This is the usual treatment if the ductal carcinoma in situ is large.
