Breast cancer is a malignant disease that occurs when the cells in the breast start to grow out of control. The exact causes of the disease are unknown, but the development of breast cancer has been found to be related to acquired or inherited gene mutations. Patients often experience symptoms like breast lumps or masses, swelling in all or part of a breast, skin irritation or dimpling, breast or nipple pain, nipple retraction, nipple discharge other than breast milk, or redness, scaliness, or thickening of the nipple or breast skin.

The disease mainly affects women, and it can be divided into different types according to the appearance of tumor cells when observed under a microscope. The majority of breast cancer patients are diagnosed with carcinomas, which means that the disease started in the epithelial cells that line organs and tissues like the breast. Understanding the different types of breast cancer can help tailor a more effective treatment plan as well as provide a clearer prognosis.

Ductal Carcinoma in Situ (DCIS)

Ductal carcinoma in situ (DCIS) is the second most common type of breast cancer, and it is classified as a non-invasive cancer. The disease is related to cancerous cells that grow in the lining of the breast tubes, known as ducts, but have not spread outside of the ducts into the surrounding breast tissue. Carcinoma means cancer, while in situ refers to the fact that it is confined to its original site. Ductal carcinoma in situ is usually an early stage cancer and highly treatable. However, if not treated, the cancer may spread into the surrounding breast tissue and beyond.

Invasive Ductal Carcinoma

Invasive ductal carcinoma is similar to ductal carcinoma in situ, sharing the place of origin, but here the cancer is not limited to the ducts. “The abnormal cancer cells that began forming in the milk ducts have spread beyond the ducts into other parts of the breast tissue. Invasive cancer cells can also spread to other parts of the body. It is also sometimes called infiltrative ductal carcinoma. IDC is the most common type of breast cancer, making up nearly 70–80% of all breast cancer diagnoses. IDC is also the type of breast cancer that can most commonly affects men,” the Breast Cancer Foundation, Inc., said.

Triple Negative Breast Cancer

Triple negative breast cancer gets its name from the absence of the three most common types of receptors responsible for breast cancer growth. In patients diagnosed with triple negative breast cancer, estrogen, progesterone, and the HER-2/neu gene are not present in the cancer tumor. According to the Breast Cancer Foundation, “this means that the breast cancer cells have tested negative for hormone epidermal growth factor receptor 2 (HER-2), estrogen receptors (ER), and progesterone receptors (PR).” While common treatments like hormone therapy and drugs target these receptors, the absence of estrogen, progesterone, and the HER-2/neu gene make these treatments ineffective. Therefore, chemotherapy tends to be the only option for triple negative breast cancer patients.

Inflammatory Breast Cancer

Inflammatory breast cancer is both aggressive and fast growing. In patients with this form of the disease, cancer cells infiltrate the skin and lymph vessels of the breast. However, in the majority of the cases, a breast lump or mass cannot be felt, which may delay the diagnosis. Symptoms are usually only noticeable when the cancer blocks the lymph vessels. These include persistent itching, a rash or small irritation similar to an insect bite, redness, swelling, and warmth in the breast, and nipple inversion, flattening, or dimpling.

Metastatic Breast Cancer

Metastatic breast cancer represents stage 4 of the disease, during which cancer has spread to other parts of the body, most commonly the lungs, liver, bones, or brain. Cancer spread may occur when cancer cells invade nearby healthy cells, cancer cells penetrate into the circulatory or lymph system, cancer cells migrate through circulation, cancer cells lodge in capillaries, or when new small tumors grow. Symptoms vary according to how far the cancer has spread. When it affects the bones, patients often experience severe, progressive pain, swelling, and easily broken bones, while metastasis to the brain can cause persistent, progressively worsening headaches or feelings of pressure to the head, vision disturbances, seizures, vomiting or nausea, and behavioral or personality changes. Symptoms of metastasis to the liver include jaundice, itchy skin or rash, abnormally high enzymes in the liver, and abdominal pain, appetite loss, nausea, and vomiting. Finally, metastasis to the lungs may cause chronic cough or inability to get a full breath, abnormal chest X-rays, and chest pain.

Rare Types of Breast Cancer

There are also rare types of breast cancer, such as medullary carcinoma, tubular carcinoma, mucinous carcinoma, and Paget’s disease. The Breast Cancer Foundation notes that “Medullary carcinoma accounts for 3-5% of all breast cancer types.  The tumor usually shows up on a mammogram, but does not always feel like a lump. At times, it feels like a spongy change of breast tissue.” About 2% of all cases are of tubular carcinoma, a type of cancer whose cells have a distinctive tubular structure when viewed under a microscope, and that can feel like a spongy area of breast tissue instead of a lump. Mucinous carcinoma represents about 1% to 2% of all breast cancers, and it causes the production of mucus with poorly defined cells. Paget’s disease is particularly rare and affects the skin of the nipple and areola.

Breast cancer is also possible in men and pregnant women, although such cases are rare.

Note: Breast Cancer News is strictly a news and information website about the disease. It does not provide medical advice, diagnosis or treatment. This content is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition. Never disregard professional medical advice or delay in seeking it because of something you have read on this website.