There are many different types of breast cancer which can start in various parts of the breast. Learning about your particular type of cancer will arm you with the knowledge and provide you with the confidence to begin navigating your path to wellness with your doctor. You can read about these 15 different types of breast cancer below.
DCIS – Ductal Carcinoma in Situ: This is the most common kind of cancer that is not invasive. “Ductal” means that the cancer has started in the milk ducts, which are tubes that carry milk to the nipple; “Carcinoma” is cancer that starts in the skin or any tissue that cover internal organs; and “in Situ” means “in place” meaning that the cancer has not spread outside of the milk duct. Although it is not lethal, having this type of cancer means that you are susceptible to developing cancer at another time, as you have about a 30% chance of developing invasive cancer within 5-10 years after your initial diagnosis.
IDC – Invasive Ductal Carcinoma: This is the most common type of cancer, also known as infiltrating ductal carcinoma, makes up 80% of all diagnoses. “Invasive” means that the cancer has spread or invaded throughout the surrounding breast tissues; “Ductal” means that the cancer has started in the milk ducts, which are tubes that carry milk to the nipple; and “Carcinoma” is cancer that starts in the skin or any tissue that cover internal organs. Therefore, this type of cancer has moved from the wall of the milk duct to move throughout the breast; from there it can spread to the lymph nodes then to the rest of the body. Over 180,000 women are diagnosed with this cancer yearly.
IDC Type: Tubular Carcinoma of the Breast: A type of Invasive Ductal Carcinoma, this cancer consists of small tubules, which are tube-shaped structures. These structures are considered “low grade” which means that they grow slowly and look like healthy cells. Thanks to improvements in detection technology and screening, these are detected far earlier, and it is considered to be a cancer that responds positively to treatment and is not very aggressive.
IDC Type: Medullary Carcinoma of the Breast: A type of Invasive Ductal Carcinoma, this cancer is very rare, accounting for 3-5% of all cancers. This is named after the medulla, as the tumors are soft and fleshy and look like the medulla part of the brain. Women who have the BRCA1 gene may be susceptible to this type of cancer. Although the tumors appear to be high-grade (fast-growing, aggressive cells), they do not grow rapidly and do not typically spread beyond the breast to the lymph nodes. This cancer may be easier to treat than other cancers.
IDC Type: Mucinous Carcinoma of the Breast: A type of Invasive Ductal Carcinoma, this cancer is very rare and consists of a tumor that consists of abnormal cells that float in pools of mucin, which is an ingredient that makes up mucous in the body. Most types of cancer cells make mucus, but in this cancer, mucin becomes part of the tumor and surrounds the breast cancer cells. This type of cancer only makes up about 2-3% of all cancers, while about 5% of cancers have a combination of both mucinous carcinoma cells and regular cancer cells. This cancer is not very aggressive and is not likely to spread to the lymph nodes.
IDC Type: Papillary Carcinoma of the Breast: A type of Invasive Ductal Carcinoma, this cancer is very rare, as it accounts for only 1-2% of all cancers. This cancer occurs in post-menopausal women and consists of finger-like projections with a defined border. These cells, on a scale from one to three, one being normal-looking and behaving cells, and three being aggressive and abnormal-looking cells, these objects look around a grade two. Ductal carcinoma in situ can also occur with this type of cancer.
IDC Type: Cribriform Carcinoma of the Breast: A type of Invasive Ductal Carcinoma, this cancer occurs in the stroma, which are the connective tissues of the breast, in formations that look like webbing or nests between the lobules and the ducts. Inside the tumor are small holes in between the cancer cells, which resemble Swiss cheese. Cancer cells are low-grade, which means that the cancers closely resemble healthy cells and do not grow rapidly. Ductal carcinoma in situ can also occur with this type of cancer.
ILC – Invasive Lobular Carcinoma: This is the second most common breast cancer type, consisting of 10% of all cancer diagnoses. “Invasive” means that the cancer has spread or invaded throughout the surrounding breast tissues; “Lobular” refers to the lobules, which create the milk that flows into the ducts, which transport the milk to the nipple; and “Carcinoma” is cancer that starts in the skin or any tissue that cover internal organs. Essentially this cancer is when the cancer starts in the lobules and goes through the wall of the lobules to spread to other parts of the breast tissue. This cancer can spread to the lymph nodes as well as to other parts of the body.
Inflammatory Breast Cancer: This is a very rare and aggressive type of cancer, occurring in less than 1% of cancer cases. Instead of showing up as a lump, the entire breast becomes red and inflamed, and symptoms can worsen in hours or days. If you see these types of symptoms, seeking immediate medical attention is very important.
LCIS – Lobular Carcinoma in Situ: Although it is not considered to be a true breast cancer, more so a collection of abnormal cells, this diagnosis presents a higher risk of having cancer in the future. “Lobular” refers to the lobules, which create the milk that flows into the ducts, which transport the milk to the nipple; “Carcinoma” is cancer that starts in the skin or any tissue that cover internal organs; and “in Situ” means “in place” meaning that the cancer has not spread outside of the lobules. This affects multiple lobules.
Male Breast Cancer: Breast cancer in men is extremely rare, as less than 1% of breast cancer occurs in men, and men have a 1 in 1,000 risk of developing breast cancer over a lifetime. Also, men do have breast tissue, and sometimes hormonal imbalances can cause breast tissue to grow breast gland tissue.
Paget’s Disease of the Nipple: This is a very rare form of cancer, as it accounts for only 5% of cancer diagnoses. The disease occurs when cancer affects the milk ducts of the nipple, then it spreads to the nipple surface and outwards to the areola. Symptoms of this disease are a scaly, red, irritated and itchy nipple. This is why noticing any difference in your breast is important, as over 97% of those diagnosed with Paget’s Disease also have cancer in another part of the breast, and noticing these changes can be the first step in identifying and later treating the cancer.
Phyllodes Tumors of the Breast: These extremely rare tumors account for less than 1% of all breast tumors. Derived from the Greek word phyllode, meaning “leaf”, these tumors grow in a pattern that resembles a leaf. Most of these tumors are benign, but some can be malignant, and some can be both benign and malignant; all are recommended to be surgically removed so that the tumor does not grow back. Women can be diagnosed with these tumors at any age, but are more prone to this diagnosis when in their 40s. Benign tumors are more likely to be diagnosed at a younger age than malignant tumors are to be diagnosed. It is incredibly rare for a man to be diagnosed with this type of tumor.
Triple Negative Breast Cancer (TNBC): This type of cancer is determined by a pathology report; it means that you have tested negative for estrogen receptors (ER-), progesterone receptors (PR-) and HER2 (HER2-). This type of cancer accounts for about 10-20% of all cancers. These results mean that your cancer is not supported by the hormones estrogen and progesterone, and is not supported by having too many HER2 receptors. As a result, this type of cancer cannot be treated by hormonal therapy or by HER2-targeting therapy. Other types of treatments are used to fight triple negative cancer. Learn more about TNBC here.