Breast self-examination should be performed at the
same time each month, three to five days after your menstrual period ends. If
you have stopped menstruating, perform the exam on the same day of each month.
What are the types of breast cancer?
The most common types of breast cancer are:
- Infiltrating (invasive) ductal carcinoma. This cancer starts in the milk
ducts of the breast. It then breaks through the wall of the duct and invades
the surrounding tissue in the breast. This is the most common form of breast
cancer, accounting for 80% of cases.
- Ductal carcinoma in situ is ductal carcinoma in its earliest stage
(stage 0). In situ refers to the fact that the cancer hasn't spread beyond
its point of origin. In this case, the disease is confined to the milk ducts
and has not invaded nearby breast tissue. If untreated, ductal carcinoma in
situ may become invasive cancer. It is almost always curable.
- Infiltrating (invasive) lobular carcinoma. This cancer begins in the
lobules of the breast where breast milk is produced, but has spread to
surrounding tissues or the rest of the body. It accounts for 10% to 15% of
breast cancers. This cancer can be more difficult to diagnose with mammograms.
- Lobular carcinoma in situ is a marker for cancer that is only in the
lobules of the breast. It isn't a true cancer, but serves as a marker for
the increased risk of developing breast cancer later, possibly in both or
either breasts. Thus, it is important for women with lobular carcinoma in
situ to have regular clinical breast exams and mammograms.
Cancers can also form in other parts of the breast but are less common.
What are the stages of breast cancer?
Stage 0 breast cancer is when the disease is
localized to the milk ducts (carcinoma in situ).
Stage I breast cancer: The cancer is smaller
than 1-inch across and hasn't spread anywhere.
Stage II breast cancer is one of the following:
- The tumor is less than an inch across but has spread to the underarm
lymph nodes (IIA); or
- The tumor is between 1 and 2 inches (with or without spread to the lymph
nodes); or
- The tumor is larger than 2 inches and has not spread to the lymph nodes
under the arm (both IIB).
Advanced breast cancer (metastatic) results after
cancer cells spread to the lymph nodes and to other parts of the body.