Ductal carcinoma in situ (DCIS)
Ductal carcinoma in situ (DCIS) is the most common form of non-invasive breast cancer, and refers to abnormal cells that are confined to the milk ducts of the breast. “In situ” refers to the cancer being restricted to its original site; that is, it has not invaded the tissue surrounding the milk duct.
DCIS generally does not present as a palpable lump in the breast, and is most often found instead on mammography. DCIS is associated with areas of “calcification” or “microcalcification”, as calcium accumulates in broken-down cancer cells.
If your mammogram shows areas of suspicion, such as microcalcifications, a core biopsy will be performed, in order to provide a clear diagnosis. These biopsies are minimally invasive, although occasionally a surgical biopsy may be required if earlier results are unclear.
DCIS must be removed surgically, typically through a “lumpectomy” also known as a wide local excision. Radiotherapy to the breast is usually required post operatively. A mastectomy with or without immediate breast reconstruction may be performed if there are large areas of DCIS, as clear margins of healthy tissue must be excised to ensure that the entire tumour is removed. Patients undergoing a mastectomy for DCIS will not require post operative radiotherapy.
Having DCIS increases the risk of an invasive cancer developing. There is always a small risk of recurrence (of either DCIS or invasive cancer) after a lumpectomy. The likelihood of recurrence is reduced when radiation therapy is given following surgery. Typically recurrence occurs within five to ten years following the initial diagnosis although it may occur many years after the initial diagnosis. The risk of recurrence is reduced if a good margin of normal tissue is taken around the DCIS.
Early breast cancer
Early breast cancer is an invasive cancer that has spread into the tissue surrounding the ducts or lobules, and possibly to the axillary lymph nodes in the armpit. The majority of breast cancers are identified once they are invasive.
Invasive ductal carcinoma (IDC)
Roughly 8 in 10 breast cancers are invasive ductal carcinomas (IDCs), or cancers originating in the milk ducts. The tumours break through the wall of the milk duct and invade the surrounding fatty tissue, upon which lymphatic spread and metastasis by the blood vessels and thus spreading, to other parts of the body become possible.
Invasive lobular carcinoma (ILC)
Invasive lobular carcinomas (ILCs) originate in the milk-producing glands, or lobules, and account for roughly 1 in 10 breast cancers. ILCs spread in a similar fashion to IDCs, and may be more difficult to see on mammography and ultrasound. They are more likely to present as a thickening in the breast rather then a discrete breast lump.
Uncommon types of breast cancer
Other types of breast cancer include inflammatory breast cancer and Paget disease of the nipple, although these forms occur very rarely, together accounting for approximately 2-4% of all breast cancers. Paget disease of the nipple affects the nipple and areola.
Inflammatory breast cancer (IBC)
Inflammatory breast cancer (IBC), a rare but aggressive form of breast cancer, often does not produce a discrete, palpable tumour, the cancer cells block the lymphatic drainage of the breast
This produces symptoms similar to mastitis, although it is unresponsive to antibiotic therapy. Early in the course of IBC, a persistent, itchy rash, or small patches of irritation similar to an insect bite, may be the only signs.
The breast often becomes red, swollen and warm, as it becomes inflamed. A sign called “peau d’orange”, where the skin appears pitted like the peel of an orange, may develop, and the nipple may become inverted or flat.
Locally advanced breast cancer
Locally advanced breast cancer refers to an invasive cancer that has spread from the breast to surrounding regions, such as the chest, affecting skin, muscles or bones.
Secondary breast cancer
Secondary, or advanced, breast cancer refers to an invasive cancer that has metastasised, or spread, from the breast to other regions. The liver, lungs and bones are some commonly affected sites.