Learning About External Beam Radiation Therapy for Early-Stage Breast Cancer

What is external beam radiation therapy for early-stage breast cancer?

External beam radiation therapy uses doses of radiation to kill cancer cells. A beam of radiation is aimed at the tumor from outside the body. This treatment is given to most people with early-stage breast cancer who choose breast-conserving surgery such as lumpectomy.

What is the schedule?

Many people with early breast cancers are treated with radiation 5 days a week for about 3 weeks. This treatment schedule is called "hypofractionated." Some people are treated for a longer period of time. Talk with your doctor about which schedule is right for you. It will depend on:

• The type of breast cancer you have.
• Any other health problems.
• Your preference.

Why is it used?

Radiation therapy is used to destroy any trace of cancer cells that might remain in the body after surgery. It is given to most people with early-stage breast cancer who choose breast-conserving surgery such as lumpectomy. It may also be given after a mastectomy if there's a high risk of the cancer coming back.

How well does it work?

Radiation therapy works well to keep cancer from coming back in early-stage breast cancer.

What are the side effects?

Some short-term side effects of this treatment for breast cancer are common. They include fatigue, skin changes in the treated area, and swelling in the treated breast. Most will go away within a few weeks after treatment. Long-term side effects may only show up months or years after treatment. One example is arm numbness.