Primary breast cancer refers to breast cancer which is confined to the breast and/or the surrounding area (for example the lymph nodes under the arms). However, breast cancer is not just one single disease. There are several types of breast cancer, all of which can be detected at different stages of development and grow at different rates.
Breast cancer that has the potential to spread to other areas of the body is described as invasive breast cancer. This does not mean the cancer has spread to another part of the body but that it has the potential to spread. Treatments are therefore designed to reduce the risk of this happening.
Sometimes a new primary breast cancer can develop, either in the same breast after breast conserving surgery or, more commonly, in the opposite breast.
People who have breast cancer in one breast are at slightly higher risk of developing a new primary breast cancer on the other side. This would be treated as a new cancer and is not recurrence.
We have in-depth information on the types of breast cancer listed below.