The different types of breast cancer
Breast Cancer Awareness Month begins today, and throughout the course of the month, we will share material on breast cancer, as well as treatment options, cancer stories and other useful information.
Here is some information on the different types of breast cancer, sourced from the Jamaica Cancer Society.
THE different types of breast cancer will vary in their prognosis — that is the outlook for chances of survival — and their treatment options.
Adenocarcinoma: This is a general type of cancer that starts in glandular tissues anywhere in the body. Nearly all breast cancers start in the glandular tissue of the breast and therefore are adenocarcinomas. The two main types of breast adenocarcinomas are ductal carcinomas and lobular carcinomas.
Ductal carcinoma in situ (DCIS): Ductal carcinoma in situ (also known as intraductal carcinoma) is the most common type of noninvasive breast cancer. There are cancer cells inside the ducts but they have not spread through the walls of the ducts into the fatty tissue of the breast. Nearly 100 per cent of women diagnosed at this early stage of breast cancer can be cured. The best way to find DCIS is with a mammogram. With more women getting mammograms each year, a diagnosis of DCIS is becoming more common. DCIS is sometimes subclassified based on its grade and type, in order to help predict the risk of cancer returning after treatment and to help select the most appropriate treatment. Grade refers to how aggressive cancer cells appear under a microscope. There are several types of DCIS, but the most important distinction among them is whether or not tumour cell necrosis (areas of dead or degenerating cancer cells) is present. The term comedocarcinoma is often used to describe a type of DCIS with necrosis.
Infiltrating (or invasive) ductal carcinoma (IDC): Starting in a milk passage or duct of the breast, this cancer has broken through the wall of the duct and invades the fatty tissue of the breast. At this point, it has the potential to metastasize or spread to other parts of the body through the lymphatic system and bloodstream. Infiltrating ductal carcinoma accounts for about 80 per cent of invasive breast cancers.
Infiltrating (or invasive) lobular carcinoma (ILC): ILC starts in the milk-producing glands. Similar to IDC, this cancer has the potential to spread (metastasize) elsewhere in the body. About 10 to 15 per cent of invasive breast cancers are invasive lobular carcinomas. ILC may be more difficult to detect by mammogram than IDC.
Inflammatory breast cancer: This rare type of invasive breast cancer accounts for about one per cent of all breast cancers. Inflammatory breast cancer makes the skin of the breast look red and feel warm, as if it was infected and inflamed. The skin has a thick, pitted appearance that doctors often describe as resembling an orange peel. Sometimes the skin develops ridges and small bumps that look like hives. Doctors now know that these changes are not due to inflammation or infection, but the name given to this type of cancer long ago still persists. Cancer cells blocking lymph vessels or channels in the skin over the breast cause these symptoms.
In situ: This term is used for an early stage of cancer in which it is confined to the immediate area where it began. Specifically in breast cancer, in situ means that the cancer remains confined to ducts (ductal carcinoma in situ) or lobules (lobular carcinoma in situ). It has not invaded surrounding fatty tissues in the breast nor spread to other organs in the body.
Lobular carcinoma in situ (LCIS): While not a true cancer, LCIS (also called lobular neoplasia) is sometimes classified as a type of noninvasive breast cancer. It begins in the milk-producing glands, but does not penetrate through the wall of the lobules. Most breast cancer specialists think that LCIS itself does not become an invasive cancer, but women with this condition do have a higher risk of developing an invasive breast cancer in the same breast, or in the opposite breast. For this reason, it's important for women with LCIS to have a physical exam two or three times a year, as well as an annual mammogram.
Medullary carcinoma: This special type of infiltrating breast cancer has a relatively well defined, distinct boundary between tumour tissue and normal tissue. It also has some other special features, including the large size of the cancer cells and the presence of immune system cells at the edges of the tumour. Medullary carcinoma accounts for about five per cent of breast cancers. The outlook or prognosis for this kind of breast cancer is better than for other types of invasive breast cancer.
Mucinous carcinoma: This rare type of invasive breast cancer is formed by mucus-producing cancer cells. The prognosis for mucinous carcinoma is better than for the more common types of invasive breast cancer. Colloid carcinoma is another name for this type of breast cancer.
Paget's disease of the nipple: This type of breast cancer starts in the breast ducts and spreads to the skin of the nipple and then to the areola, the dark circle around the nipple. It is a rare type of breast cancer, occurring in only one per cent of all cases. The skin of the nipple and areola often appears crusted, scaly, and red, with areas of bleeding or oozing. The woman may notice burning or itching. Paget's disease may be associated with in situ carcinoma, or with infiltrating breast carcinoma. If no lump can be felt in the breast tissue, and the biopsy shows DCIS but no invasive cancer, the prognosis is excellent.
Phyllodes tumour: This very rare type of breast tumour forms from the stroma (connective tissue) of the breast, in contrast to carcinomas which develop in the ducts or lobules. Phyllodes tumors are usually benign but on rare occasions may be malignant (having the potential to metastasize). Benign phyllodes tumors are successfully treated by removing the mass and a narrow margin of normal breast tissue. A malignant phyllodes tumour is treated by removing it along with a wider margin of normal tissue, or by mastectomy. These cancers do not respond to hormonal therapy and are not so likely to respond to chemotherapy or radiation therapy. In the past, both benign and malignant phyllodes tumors were referred to as cystosarcoma phyllodes.
Tubular carcinoma: Accounting for about two per cent of all breast cancers, tubular carcinomas are a special type of infiltrating breast carcinoma. They have a better prognosis than usual infiltrating ductal or lobular carcinomas.