A Look at Common and Uncommon Types of Breast Cancer

Did you know there are many different types of breast cancer? From pre-cancerous breast disease to breast cancer in men, different types of cancer impact your treatment options and outcomes.

Making sense of the words and terms associated with a cancer diagnosis can help you to be a more informed patient. Here’s a look at the common – and not so common – types of breast cancer.

Common Types of Breast Cancer

Breast cancer begins when normal cells in the breast begin to change and grow uncontrollably, forming a mass called a tumor. The most common types of breast cancer start in the milk duct of the breast. Most breast tumors – about 85 to 90 percent – are considered to be ductal carcinoma. If the tumor is well contained, it is called ductal carcinoma in situ (DCIS), which means the cells haven’t spread or grown out of the breast ducts into surrounding tissue. DCIS is considered pre-cancerous, and typically can be successfully treated. It is often found during a mammogram or as part of a routine breast cancer screening. If left untreated, DCIS can lead to cancer.

If ductal carcinoma has broken or spread into nearby breast tissue, it is called invasive carcinoma. Recommended treatments may include a mastectomy and chemotherapy. Other forms of breast cancer start in the lobes or glands that are deeper inside the breast, under the ducts. This accounts for about 8 to 10 percent of breast cancers. If the cancer is lobular carcinoma in situ, the cancer has not spread and may be removed during a lumpectomy. Those that are capable of spreading — invasive lobular carcinoma – may require a mastectomy and chemotherapy. Lobular breast cancer tends to occur later in life. Some research suggests the use of hormone replacement therapy during and after menopause can increase the risk of invasive lobular carcinoma.

Less Common Types of Breast Cancer

Medullary carcinoma, tubular carcinoma, mucinous carcinoma and Paget disease of the nipple are less common types of breast cancer that affect a small percentage of people.

Inflammatory breast cancer is a rare but aggressive type of breast cancer that can be difficult to diagnose. A lump may not be detected in an exam or mammogram, and dense breast tissue can make it more difficult to detect. It is called inflammatory because the breast often looks swollen, red or inflamed.

Breast Cancer in Men

Less than one percent of all breast cancer cases occur in men. Male breast cancer occurs when hormones are out of sync and stimulate the growth of male breast tissue. Warning signs may include a lump, hard knot or thickening in the breast, chest or underarm area. Any changes in the breast or nipple should be checked by a physician.

Metastatic Breast Cancer

This is not a specific type of breast cancer, but rather the most advanced stage of breast cancer in which the cancer has spread beyond the breast to other organs in the body, most often the bones, lungs, liver or brain. Precision medicine is helping clinicians choose effective therapies for patients with metastatic breast cancer, including a research study, co-authored by a scientist from Northwestern Medicine. There are many other clinical trials underway that are working to find new ways to treat cancer.

Breast cancer remains a leading cause of cancer death in women, second only to lung cancer. Early detection is key to catching breast cancer when it’s most treatable, and when it’s possible to create your own road map to navigate your breast health.

Learn more about the specialty breast care available through Northwestern Medicine.