Side effects from radiation therapy to the breast

Radiation treatment to the breast area could affect the heart, causing things like hardening of the arteries (which can make you more likely to have a heart attack later on), heart valve damage, or irregular heartbeats. It might also cause swallowing problems, cough, or shortness of breath. Be sure you understand what to look for and tell your cancer care team if you notice any of these side effects.

If you get radiation therapy after surgery for breast cancer, try to go without wearing a bra whenever you can. If this isn’t possible, wear a soft cotton bra without underwires so that your skin isn’t irritated. If your shoulders feel stiff, ask your cancer care team about exercises to keep your arms moving freely.

Other side effects can include breast soreness, skin irritation and color changes, and swelling from fluid build-up in the treated area. These side effects most likely will go away a month or 2 after you finish radiation therapy. If fluid build-up (lymphedema) continues to be a problem, ask your cancer care team what steps you can take. You can also call us at 1-800-227-2345 or see Lymphedema for more information.

Radiation therapy after breast surgery may cause other long-term changes in the breast. Your skin may be slightly darker, and pores may be larger and more noticeable. The skin may be more or less sensitive and feel thicker and firmer than it was before treatment. Sometimes the size of your breast changes – it may become larger because of fluid build-up or smaller because of scar tissue. These side effects may last long after treatment.

If your treatment includes internal radiation implants, you might notice breast tenderness or tightness. After the implants are removed, you may have some of the same side effects that happen with external radiation treatment. If so, follow the advice given above and let your cancer care team know about any problems you notice.

After about a year, you shouldn’t have any new changes. If you do see changes in breast size, shape, appearance, or texture after this time, tell your cancer care team about them right away.

Radiation pneumonitis is inflammation of the lungs that can be caused by radiation treatment to the breast. It may occur from about 6 weeks to up to 6 months after completing external radiation therapy. The risk of developing it depends on the radiation dose, the amount of lung that was affected by radiation, whether you had radiation in the past, and whether you’re getting chemo at the same time. It’s also more likely if you have other lung diseases, like COPD.

Common symptoms of radiation pneumonitis include:

  • Shortness of breath that usually gets worse with exercise
  • Chest pain, which is often worse when taking in a deep breath
  • Cough
  • Pink-tinged sputum
  • Low-grade fever
  • Weakness

In some cases, no symptoms are noticed, and radiation pneumonitis is found on a chest x-ray.

Radiation pneumonitis is treated by trying to decrease the inflammation. Steroids, like prednisone, are usually used. With treatment, most people recover without any lasting effects. But if it goes untreated or persists, it can lead to pulmonary fibrosis (stiffening or scarring of the lungs). When this happens, the lungs can no longer fully inflate and take in air. If a large area of the lungs is treated with radiation, these changes can cause shortness of breath, especially during physical activity.

The American Cancer Society medical and editorial content team
Our team is made up of doctors and master’s-prepared nurses with deep knowledge of cancer care as well as journalists, editors, and translators with extensive experience in medical writing.

Last Medical Review: June 30, 2015 Last Revised: June 30, 2015

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