What are Different Types of Breast Cancer? Plus Treatment Options
Breast cancer is known to have existed at least 3,500 years ago in ancient Greece and Egypt based on knowledge from the Edwin Smith Surgical Papyrus, dating back to 3,000–2,500 B.C., which provides authentic accounts of breast cancer referring to “bulging tumors of the breast that has no cure.” The only “so-called” medicine at the time was a votive offering that the ancient Greeks made to the god of medicine.
Jumping ahead thousands of years, modern-day treatments have now resulted in saving the lives of many people with breast cancer compared to ancient times. According to the American Cancer Society, there are more than 4 million breast cancer survivors – including those still being treated and those who have finished their treatment – in the United States. And there is more good news. While slowing slightly in recent years, breast cancer death rates have been decreasing since 1989 for an overall decline of 43% through 2020. Thanks, in part, to screening methods and to new innovative treatments.
Breast cancer can be separated into two main categories – invasive, where cancer has escaped from the ducts and has the potential to spread, and non-invasive, which does not go beyond the milk ducts or lobules in the breast. Invasive breast cancer accounts for nearly 80% of all breast cancers, while about 20% are non-invasive.
Invasive Breast Cancer
Invasive breast cancer is when abnormal cells that begin in the breast ducts or lobules of the breast then invade the surrounding breast tissue, and may involve lymph nodes and potentially spread to distant organs. Women have a 1 in 8 chance of developing invasive breast cancer during their lifetime. Men have a 1 in 800-1000 chance.
Invasive ductal carcinoma (IDC)
IDC, also referred to as infiltrating ductal carcinoma, accounts for about 80% of all breast cancer diagnoses. It starts in the cells that line the milk ducts and from there the cancer cells invade breast tissue beyond the walls of the duct, possibly spreading (metastasizing) to other parts of the body through the lymph system and bloodstream.
Invasive lobular carcinoma (ILC)
The second most common form of breast cancer diagnosed in the United States, constituting about 10% of all breast cancers, begins in the glands in the breast that produce milk called lobules. More likely to affect both breasts compared to other invasive carcinomas, similar to IDC it can spread to other parts of the body.
Non-Invasive Breast Cancer
Non-invasive breast cancer is when cancer cells are found in the lobules or milk ducts of the breast, but have not invaded other tissue or organs beyond the breast. It accounts for about 20% of all breast cancers and can include ductal carcinoma in situ (DCIS), or the rare Paget’s disease. Lobular neoplasia (LCIS) is sometimes included in this category but is not cancer. All DCIS cancers are considered as stage 0 (breast cancer stages 0, 1, 2, 3 or 4 identify how widespread the cancer is in the breast tissue to other parts of the body – the higher the number, the more the cancer has spread) which is the earliest stage possible, and are highly treatable. A more complete look at staging can be found on the American College of Surgeons website.
“Patients with non-invasive breast cancer do not die from the disease,” Dr. Makari-Judson said.
Ductal carcinoma in situ (DCIS)
DCIS occurs when a tumor is found in the milk ducts, but has not spread beyond them, treatment is advised since it may become invasive over time.
Lobular neoplasia
Lobular neoplasia is a condition when abnormal cells are discovered in the lobules of the breast. It is not considered cancer, but increases the risk of developing breast cancer.
Paget’s disease of the breast
A rare type of breast cancer involving the skin of the nipple and extending to the dark circle of skin around the nipple called the areola, it accounts for approximately 1-4% of all breast cancers. It can be invasive if it has a lump or non-invasive if there is no lump. Prognosis is excellent if it hasn’t spread beyond the milk ducts.
Treatment for Breast Cancer
Treatment for invasive breast cancer is based on the stage of cancer and biologic subtype, including hormone receptors and HER2 status. Treatment for early-stage breast cancer may include surgery, radiation, hormonal treatments, chemotherapy, immunotherapy and/or HER2-directed monoclonal antibodies.
Surgery
Options for breast cancer surgery include a mastectomy, which removes the whole breast, or a lumpectomy to remove the cancer and some normal tissue around it, but not the entire breast. It includes evaluation of lymph nodes under the arm. Survival following breast-conserving surgery is similar to mastectomy.