Definition of breast cancer: Cancer that forms in tissues of the breast. The most common type of breast cancer is ductal carcinoma, which begins in the lining of the milk ducts (thin tubes that carry milk from the lobules of the breast to the nipple). Another type of breast cancer is lobular carcinoma, which begins in the lobules (milk glands) of the breast. Invasive breast cancer is breast cancer that has spread from where it began in the breast ducts or lobules to surrounding normal tissue. Breast cancer occurs in both men and women, although male breast cancer is rare.
Estimated new cases of breast cancer in the United States in 2016: 249,260 (female); 2,600 (male)
In the United States, breast cancer is the most common non-skin cancer and the second leading cause of cancer-related death in women. Each year, a small number of men are diagnosed with breast cancer.
The incidence of breast cancer is highest in white women for most age groups, but African American women have higher incidence rates before 40 years of age.
Studies have identified numerous risk factors for breast cancer in women, including increasing age, personal history of certain benign breast diseases or breast cancer, early menstruation, late menopause, never having been pregnant or having a first pregnancy after age 30, use of oral contraceptives, family history of breast cancer, presence of certain inherited genetic changes, history of radiation therapy to the chest, long-term use of combined hormone therapy, use ofdiethylstilbestrol (DES), increased breast density, alcohol use, and obesity after menopause. For women at high genetic risk due to a harmful mutation in BRCA1 or BRCA2, bilateral prophylactic mastectomy can reduce the risk of breast cancer by at least 95 percent. Other genetic mutations can increase your risk for breast cancer — ILCC offers genetic counseling and testing to help guide prophylactic surgery decisions. Risk factors for male breast cancer include obesity, a rare genetic condition called Klinefelter syndrome, and the presence of excess breast tissue. Mammograms and clinical breast exams are commonly used to screen for breast cancer. Standard treatment options for breast cancer include surgery, radiation therapy,chemotherapy, hormone therapy, and targeted therapy.
The following stages are used for breast cancer:
Stage 0 (Carcinoma In Situ)
There are 3 types of breast carcinoma in situ:
- Ductal carcinoma in situ (DCIS) is a noninvasive condition in which abnormal cells are found in the lining of a breast duct. The abnormal cells have not spread outside the duct to other tissues in the breast. In some cases, DCIS may become invasive cancer and spread to other tissues. At this time, there is no way to know which lesions could become invasive.
Stage I
In stage I, cancer has formed. Stage I is divided into stages IA and IB.
- In stage IA, the tumor is 2 centimeters or smaller. Cancer has not spread outside thebreast.
- In stage IB, small clusters of breast cancer cells (larger than 0.2 millimeter but not larger than 2 millimeters) are found in the lymph nodes and either:
- no tumor is found in the breast; or
- the tumor is 2 centimeters or smaller.
Stage II
Stage II is divided into stages IIA and IIB.
- In stage IIA:
- no tumor is found in the breast or the tumor is 2 centimeters or smaller. Cancer(larger than 2 millimeters) is found in 1 to 3 axillary lymph nodes or in the lymph nodes near the breastbone (found during a sentinel lymph node biopsy); or
- the tumor is larger than 2 centimeters but not larger than 5 centimeters. Cancer has not spread to the lymph nodes.
Stage IIIA
In stage IIIA:
- no tumor is found in the breast or the tumor may be any size. Cancer is found in 4 to 9axillary lymph nodes or in the lymph nodes near the breastbone (found during imaging tests or a physical exam); or
- the tumor is larger than 5 centimeters. Small clusters of breast cancer cells (larger than 0.2millimeter but not larger than 2 millimeters) are found in the lymph nodes; or
- the tumor is larger than 5 centimeters. Cancer has spread to 1 to 3 axillary lymph nodes or to the lymph nodes near the breastbone (found during a sentinel lymph node biopsy).
Stage IIIB
In stage IIIB, the tumor may be any size and cancer has spread to the chest wall and/or to the skin of the breast and caused swelling or an ulcer. Also, cancer may have spread to:
- up to 9 axillary lymph nodes; or
- the lymph nodes near the breastbone.
Cancer that has spread to the skin of the breast may also be inflammatory breast cancer.
Stage IIIC
In stage IIIC, no tumor is found in the breast or the tumor may be any size. Cancer may have spread to the skin of the breast and caused swelling or an ulcer and/or has spread to the chest wall. Also, cancer has spread to:
- 10 or more axillary lymph nodes; or
- lymph nodes above or below the collarbone; or
- axillary lymph nodes and lymph nodes near the breastbone.
Cancer that has spread to the skin of the breast may also be inflammatory breast cancer
For treatment, stage IIIC breast cancer is divided into operable and inoperable stage IIIC.
Stage IV
In stage IV, cancer has spread to other organs of the body, most often the bones, lungs, liver, or brain.
All information was taken from the NCI (National Cancer Institute)