The most important factor in determining treatment is the stage of the disease. The stage is determined by the size of the tumor and whether the tumor is confined to the breast or has spread to nearby lymph nodes or other organs. Specific treatments are most often used for each stage of the disease. However, other treatment options may also be appropriate.
Ductal carcinoma in situ (DCIS) is the earliest form of breast cancer. In DCIS, cancer cells are located within a duct and have not invaded the surrounding fatty breast tissue. Lobular carcinoma in situ (LCIS), which is sometimes classified as stage 0 breast cancer, occurs when abnormal cells grow within the lobules or milk-producing glands, but they do not penetrate through the wall of these lobules. In all cases, the cancer has not spread to lymph nodes or distant sites.
Stage I and II
Stage I and Stage II are the early stages of breast cancer. This means the cancer has already invaded nearby breast tissue.
Stage I cancer indicates the cancer cells have not spread beyond the breast, and the tumor is no more than about an inch across. If the cancer has been diagnosed as Stage II, this means the tumor in your breast is one to two inches across and/or the cancer has spread to your underarm lymph nodes.
Options you and your physician may consider for treatment include breast-conserving surgery, followed by radiation therapy as the primary local treatment, or a mastectomy. The method of treatment usually depends on the size and location of the tumor, type or grade of tumor, the size of your breasts, certain features of the mammogram, and how you feel about preserving your breast. With either approach, the lymph nodes under your arm are generally removed.
To prevent the cancer from returning, your treatment may also include chemotherapy and/or hormonal therapy.
If the breast cancer has been diagnosed as Stage III, the tumor in your breast can be any size, but the cancer has spread to your underarm lymph nodes, other lymph node areas or to other tissues near the breast.
Your treatment will usually include local treatment to remove or destroy the cancer in your breast, as well as systemic treatment to stop the disease from spreading throughout your body. The local treatment may be surgery and/or radiation therapy to your breast and underarm. The systemic treatment may include chemotherapy, hormonal therapy, or both. The systemic treatment may be given before or after your local treatment.
Stage IV is metastatic cancer. This means the cancer cells have spread from your breast to other organs of your body.
Your treatment will include chemotherapy and/or hormonal therapy to shrink the tumor or destroy the cancer cells. You may also have surgery or radiation therapy to control the cancer in your breast. Radiation may also be used to control tumors in other parts of your body.