Breast cancer is one of the most prevalent cancers affecting women in the United States. The American Cancer Society says that about 12 percent of women will develop breast cancer at some point in their lives.
There are several different types of breast cancer. One type begins in the milk ducts, while another originates in the milk glands. A rare form of breast cancer results from cancerous cells in the lymph vessels in the skin. The type of cancer you have determines how the cancer acts and the best treatment plan for you.
Non-invasive breast cancer is also known as in situ breast cancer. This is when the cancer cells are present, but they have not spread beyond where they originated. If left untreated, a non-invasive cancer may eventually become an invasive cancer. Invasive cancers begin in a duct or lobule of the breast and can spread throughout the breast or to other parts of the body.
According to the American Cancer Society, about 20 percent of all new breast cancer cases are ductal carcinoma in situ (DCIS). It starts out in the lining of the milk ducts, which are the tubes that carry milk from the lobules to the nipple. DCIS is sometimes referred to as a pre-cancer because it is not yet an invasive cancer. Doctors can’t predict which DCIS cases will spread, so treating DCIS early is important.
Cancer that starts in a milk duct and spreads to the fatty tissue of the breast is known as invasive ductal carcinoma (IDC). According to the American Cancer Society, it is the most common form of breast cancer. It can spread to other parts of the body through the lymph system and the bloodstream. About 80 percent of invasive breast cancers are IDCs. An IDC is usually first found as a lump during a breast examination, or is seen in a mammogram. There may be no symptoms at first. In some cases, signs can include swelling, a thickening of breast skin, nipple pain, or a change in the appearance of the nipple.
When a cancer begins in the lobules and spreads elsewhere, it’s an invasive lobular carcinoma (ILC). The American Cancer Society says that this type accounts for about one in 10 new breast cancers. An ILC can be difficult to see on a standard mammogram. Additional screenings—such as ultrasounds, MRIs, or biopsies—may be needed. Treatment for ILC is dictated by stage.
A triple-negative breast cancer is usually an IDC, but it differs from most. The cancer cells don’t have estrogen and progesterone receptors, and they lack excessive HER2 proteins on their surfaces. Triple-negative breast cancers are often more aggressive than other breast cancers. They can be harder to treat because they don’t respond to hormonal therapy or the use of the drug trastuzumab (Herceptin). Triple-negative breast cancers are more common in younger women and in African-American women.
According to the American Cancer Society, less than 4 percent of all breast cancers are inflammatory breast cancers (IBCs). An IBC is also unusual because there is typically no lump or tumor to detect. It’s first noticed when the skin on the breast becomes red and feels warm. The skin may also start to look pitted, and the breast itself may appear swollen. In early stages, an IBC may look like a common breast infection known as mastitis. If antibiotics don’t help, a biopsy may be the next step to determine whether cancer is present. The chances of an IBC spreading are higher than ductal or lobular cancers. Early response to signs of an IBC is critical.
Several subtypes of invasive carcinomas have been identified. Those with a more encouraging prognosis include adenoid cystic carcinoma, low-grade adenosquamous carcinoma, medullary carcinoma, mucinous (or colloid) carcinoma, papillary carcinoma and tubular carcinoma. Those with a worse outlook include metaplastic carcinoma, micropapillary carcinoma, and mixed carcinoma, which includes features of invasive ductal and lobular carcinomas.
Breast cancer remains a leading cause of death among women. But the American Cancer Society indicates that early detection and improved treatment are bringing those numbers down. This is especially true for women under the age of 50. Mammograms and self-checks can help you find cancer in its early stages. And that may lead to effective treatments to keep you thriving for years to come.