Radiation Therapy for Breast Cancer

Radiation After Mastectomy

After a mastectomy, your doctor may suggest radiation therapy for the chest wall and possibly nearby lymph node areas.

• Many patients treated with mastectomy will not require radiation therapy afterwards.
• The role for post-mastectomy radiation therapy is limited to people who are at high risk of the cancer returning to the lymph nodes or to the chest wall (where the breast lived before being removed surgically).
• Whether you are considered at high risk for the cancer returning to the chest wall or lymph nodes depends on several factors. These include your age, whether you have experienced menopause, other medical conditions, tumor type, tumor size and number, tumor grade (i.e., how malignant does the cancer look under the microscope), the scope of the surgery, surgical margins (i.e., how close was the cancer to the edge of the removed tissue), whether the lymph nodes were affected by the cancer, hormone receptors and other tests.
• Many people needed radiation therapy after a mastectomy also need chemotherapy. For breast cancer, these two treatments are usually done one after the other instead of at the same time. However, your medical oncologist and radiation oncologist will discuss their recommendations with you.
• Radiation therapy after a mastectomy usually starts six weeks after surgery or after you complete chemotherapy.
• Radiation therapy treatments then usually last six weeks with treatments every day, Monday through Friday.