Invasive ductal carcinoma (IDC), sometimes called infiltrating ductal carcinoma, is the most common type of breast cancer. About 80% of all breast cancers are invasive ductal carcinomas. Invasive means that the cancer has “invaded” or spread to the surrounding breast tissues. Ductal means that the cancer began in the milk ducts, which are the “tubes” that carry milk from the milk-producing lobules to the nipple. Invasive ductal carcinoma” refers to cancer that has broken through the wall of the milk duct and begun to invade the tissues of the breast. Over time, invasive ductal carcinoma can spread to the lymph nodes and possibly to other areas of the body.
Ductal carcinoma in situ (DCIS) is the next common breast cancer. It occurs when abnormal cells grow inside the milk ducts, but stays confined inside the milk duct (has not spread to nearby breast tissue). “In Situ” means in place. The abnormal cells stay inside the milk ducts. You may also hear DCIS called pre-invasive breast cancer.
Invasive lobular carcinoma (ILC) starts in the milk-producing glands (lobules). Like IDC, it can spread (metastasize) to other parts of the body. About 1 in 10 invasive breast cancers is an ILC. Invasive lobular carcinoma may be harder to detect by a mammogram than invasive ductal carcinoma.
Triple-negative breast cancer describes a type of breast cancer that do not have estrogen or progesterone receptors, nor do they have an excess of Her2 protein on their surfaces. 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). Anyone can get triple-negative breast cancer. However, researchers have found that it is more likely to occur in younger patients, African American women, and patients with a BRCA 1 mutation. Triple negative breast cancer can be more aggressive and difficult to treat. Also, the cancer is more likely to spread and recur than other cancers. Patients with triple negative breast cancer cannot be treated with two of the more notable and effective breast cancer treatments: Herceptin and hormone therapy. Although triple negative breast cancer does not respond to these standard breast cancer treatments, it has fortunately been shown to be receptive to certain chemotherapeutic regimens, and therefore chemotherapy remains the primary treatment option.
Inflammatory breast cancer is an uncommon form of invasive breast cancer accounting for 1%-3% of all breast cancers. Patients will present with skin changes such as redness or warmth. The skin may appear thick with dimpling (like an orange peel). The changes in the skin are due to cancer cells blocking the lymphatic vessels. You may not feel a single lump or tumor. The breast may become swollen, larger, tender, or itchy. It may be mistaken for an infection of the breast in the early stages. Symptoms may be initially treated with antibiotics due to this. If symptoms are caused by breast cancer, the appearance of the breast will not improve and a biopsy will be necessary to find cancer cells. This type of breast cancer tends to have a higher chance of spreading to lymph nodes.