Breast cancer radiotherapy side effects

• A quick guide to what's on this page
• Side effects during treatment
• Side effects after treatment
• Long term side effects
• Where to find more information

Radiotherapy sometimes causes side effects during the treatment. You may have

• Reddening and soreness of the skin
• Discomfort and swelling of your breast or chest area
• Tiredness

You may not notice these effects until you've had a couple of weeks of treatment. They start to get better when your treatment ends. But you may feel tired for some months afterwards.

For most women the appearance of the breast is very good after radiotherapy. But if you are concerned about the possible side effects, speak to your radiotherapist or breast care nurse. You may also find it helpful to look at the main section on radiotherapy side effects.

Radiotherapy may affect your chance of having some types of breast reconstruction, even if otherwise they may be suitable for you. Tissue expansion reconstruction is not usually possible after radiotherapy to the chest, as the skin is less stretchy afterwards. Some types of breast reconstruction using body tissue may not be possible, as the breast area needs a good blood supply for this type of surgery. Radiotherapy lowers the blood flow to the area.

The radiotherapy may have some lasting effects on your skin and any breast tissue left behind after breast conserving surgery. You may find that you have

• Firmer breast tissue
• Shrinking of breast tissue
• Swelling of the breast area
• Small red marks on your skin
• Darker skin

Firmer breast tissue

The breast may feel hard due to a side effect called radiation fibrosis. The breast tissue becomes more fibrous and less stretchy. For many women, this is quite mild. But for some, the breast can become tender.

Shrinking of breast tissue

The breast tissue may also shrink over many years. The radiotherapy may make the breast tissue contract and this may make the breast gradually get smaller.

Swelling of the breast area

If your breast becomes swollen, see your doctor or breast care nurse. The radiotherapy may have caused problems with the natural drainage of fluid from the tissues. This is called lymphoedema (pronounced lim-fo-dee-ma) and is rare in the breast. Your doctor or nurse can refer you to a lymphoedema specialist, who can arrange for a type of massage called manual lymphatic drainage.

Small red marks on your skin

You may get small, red lines on the skin of the treated area due to tiny broken blood vessels. This is called telangiectasia (pronounced teel-an-gee-ek-tay-zee-a). This is quite a common side effect after radiotherapy. The broken blood vessels affect the look of the breast, but they do not cause any harm and are nothing to worry about.

Darker skin

The skin in the treated area may gradually darken in the years after your radiotherapy. It can look like a deep tan.

By far the most common long term side effects of radiotherapy are the change in appearance described above.

Some women get a swelling in the arm called lymphoedema after radiotherapy to the armpit, particularly if they have had surgery there too. These days, specialists do not recommend having both surgery and radiotherapy to the armpit because of the increased risk of lymphoedema. But surgery and radiotherapy to the armpit may both be needed if the lymph nodes there contain cancer cells.

Other more severe, but much rarer, long term side effects may occur. They are not common though, because the treatment planning is much more exact.

Rarely, you can get a continuing cough or breathlessness some years after radiotherapy to the chest. This is due to changes in the lung tissue caused by radiotherapy. The changes are called 'radiation fibrosis'. Doctors cannot predict who will get this rare side effect. Researchers are looking into the possibility of a gene that increases sensitivity to radiation in some people.

Some people who have radiotherapy to the left side of their chest may have changes in their heart many years later. But this is very rare.

Women having radiotherapy for breast cancer are often treated from more than one angle. In the past, sometimes part of the shoulder was treated twice - once from each angle. Doctors call that 'overlapping treatment fields'. Nerves in the shoulder were sometimes badly damaged by having a high radiotherapy dose. That caused severe pain and difficulty in using the arm. These days, modern radiotherapy planning includes checks for overlapping radiation fields and so this should not happen.

There is detailed information about radiotherapy side effects in the main radiotherapy section of CancerHelp UK. There are also books and booklets about radiotherapy, some of which are free. Look on our breast cancer reading list. Or get in touch with one of the organisations listed on our breast cancer organisations page. Many offer counselling. To find out more about counselling look in our section about what is counselling? There are a few questions for your doctor about breast radiotherapy at the end of this section.

You may want to look at our information about types of breast reconstruction. Radiotherapy may affect the type of reconstruction you can have.

If you are worried about side effects, particularly long term side effects, it is best to talk to your radiotherapy specialist and breast care nurse. They may be able to relieve your concerns. If you think you are developing any long term side effects, you need to see your own specialist.