Most of the more than 232,000 cases of breast cancer that will be diagnosed in the United States this year are not due to a faulty gene passed down through families. As with most other cancers, they happen because of genetic mutations that happen as we age.
But about 15% of women with breast cancer have at least one relative who has also had the disease, and 5% to 10% have specific inherited mutations in one of two genes that have been linked to breast cancer, known as BRCA1 and BRCA2.
Breast cancer can recur or come back in three ways:
The cancer can return at the original site. This is called a local recurrence.
The cancer can recur nearby, such as in the chest. This is called a regional recurrence.
The cancer can spread to a distant location in the body, such as lymph nodes, bone marrow, or lungs. This is called a distant recurrence, or a metastasis.
Your doctor will order more tests to see if the breast cancer has spread, beginning with a physical exam and often a biopsy. The doctor is checking to see if cancer is present and, if so, if it is a recurrence of the same type of cancer or a completely new cancer (which is called a second primary cancer.)