This information is for women who are concerned about the possible long-term (delayed) side effects of radiotherapy to the breast. If you develop any new symptoms after your treatment is over, or if you are concerned that the side effects you developed during your treatment are not clearing up, you should contact your doctor, radiographer or nurse at the hospital for advice. There is often a simple explanation for these symptoms and they do not necessarily mean that you are developing long-term side effects.

The main long-term side effects are:

Most women will develop changes in the look and feel of their treated breast due to radiotherapy, although for many women these changes are very slight.

Changes to the skin

During treatment some women develop a skin reaction similar to sunburn, known as erythema. Pale skin may become red and itchy, and darker skin may appear darker with a blue or black tinge. Usually this side effect will settle down two to four weeks after radiotherapy, but sometimes it can continue. A few women find that their scar remains tender or sensitive for some time after radiotherapy.

Some women may develop changes which can include red blotches on the breast caused by dilated blood vessels under the skin. This condition is known as telangiectasia. Although this affects how the breast looks, it shouldn’t cause any other problems.

Skin care

If you have a skin reaction, your doctor, nurse or the radiographer will give you advice on how to look after your skin. The following tips may be helpful:

• avoid using perfumed soaps, talcum powder and deodorants/antiperspirants until the reaction has settled
• avoid shaving under your arm on the affected side
• showers are better than baths, and you should avoid soaking the affected area for too long if you have a bath
• after washing, pat the area dry rather than rubbing it with a towel
• loose clothing may be more comfortable to wear
• avoid exposing the area to strong sunlight for at least a year, as your skin will continue to be more sensitive.

Breast swelling

A few women will develop swelling of the breast area during, or shortly after treatment. The swelling is known as oedema, and should go away a couple of months after treatment has finished.

Sometimes, a different type of swelling called lymphoedema can develop. This can occur if the lymph nodes have been removed or are damaged by radiotherapy, causing a build-up of lymph fluid. It more commonly affects the arm, but can also cause swelling of the breast. Lymphoedema can develop many months or years after treatment has finished. Talk to your breast care nurse or doctor if you think you may have lymphoedema. If necessary they can refer you to a lymphoedema specialist.

Soreness or pain

Many women find that the area in the breast that has been treated feels uncomfortable or sore. This tends to become less of a problem year by year. If this occurs and is causing you a problem, your doctor can prescribe painkillers to help relieve any pain. Some women find that the pain can be relieved by wearing a support bra. It can also help to wear a soft bra at night, but to make sure it has no under-wire.

Shrinking of the breast

It is fairly common for the breast to shrink slightly over time, but for it to feel the same. A few women may develop a hardening or thickening of the breast tissue (fibrosis). This can cause the breast to become harder and smaller than it was, although the effect is mostly very mild. In severe cases this can make the breasts look very different to each other.

It is fairly common for a woman’s breasts to get bigger as she gets older, or if she puts on weight. A breast that has been treated with radiotherapy may not increase in size as much as the untreated breast. If this is a problem for you, talk to your doctor or breast care nurse, as surgery can sometimes be done to correct an imbalance.

Radiotherapy can affect how well you can move your shoulder. It is fairly common for women who have radiotherapy to the underarm (axilla) to experience some restriction in shoulder movement, especially if they have had surgery to their underarm area as well. This may make it difficult to carry heavy bags, do household chores or some types of exercise, such as swimming. A physiotherapist can show you exercises to help improve the movement of the shoulder.

There is a very small risk of damage to the heart muscle or the major blood vessels around the heart. This is only a possible problem if you have had cancer in your left breast, as the heart is on the left side of the chest. Radiotherapy is now very carefully planned, so that the heart is not within the radiation area. As a result, the risk of developing any heart problems has been greatly reduced.

If your heart has been damaged by radiotherapy you may find that you get tired very easily or get breathless when climbing the stairs. You may also notice that you sometimes feel dizzy or get chest pains. It is important to remember that these symptoms can be caused by many things and that they are not always a result of damage to the heart.

Treatment for heart changes

The treatment will depend upon the part of the heart that has been damaged and how it is affecting you. You may just be advised to avoid things that could cause further damage, such as alcohol, smoking and stress, or to improve your diet.

Treatment may include medicines to improve the heart rhythm (anti-arrhythmics), or improve the blood flow around the heart to help reduce chest pain (anti-anginals).

Your doctor or nurse will explain more about the treatment that you need and can answer any questions you may have.

Approximately one in 50 women develop symptoms such as breathlessness, a dry cough or chest pain. These symptoms may happen because the radiotherapy can affect the cells lining the lungs; causing inflammation or a hardening and thickening (fibrosis). If you are going to get these symptoms, they usually develop two to three months after the radiotherapy has finished. The changes are usually temporary, lasting a month or two, but occasionally can become a long-term side effect.

Your risk of developing lung problems is slightly higher if:

• radiotherapy is also given to the lymph nodes in your chest area
• you are older when you have the treatment
• if you have had chemotherapy.

These symptoms may be made worse if you already have a lung problem such as asthma, or if you smoke.

Treatment for lung problems

Most lung problems are treatable and it is unusual for them to remain a problem over time. Treatment depends on exactly what is wrong with your lungs and may simply involve advice on cutting down or giving up smoking and maintaining a healthy weight.

You may be given inhalers that contain drugs to help open up the airways (bronchodilators). Steroids can be given as tablets or inhalers to reduce inflammation. You may be given antibiotics if you have an infection in the lung.

Your doctor or nurse will explain more about the treatment you need and will teach you how to use an inhaler if necessary. 

A rare late side effect of radiotherapy to the breast is damage to the bones, especially the ribs and collar bones. This affects fewer than one in 100 women. The bones can become thinner and more brittle. If this happens, it can cause pain and make it hard for you to lift heavy objects or to exercise. The bone may become infected and may break if it is weakened enough. This is rare.

It is important to be aware that this problem can occur, so that if you have any symptoms you can get them checked by your doctor. Radiotherapy damage to the bones is uncommon so it is likely that if you have any symptoms they will have another cause.

Treatment for bone damage

You may be treated to relieve any symptoms that occur. This may involve taking painkillers or anti-inflammatory drugs. Sometimes calcium supplements, vitamin D, or drugs called bisphosphonates, which can help to strengthen the bones, may be helpful.

Very rarely, if the bone has been severely damaged, a treatment known as hyperbaric oxygen therapy may help to prevent further weakening of the bone and improve symptoms. This is a new type of treatment and the exact benefits are still being researched. It is not available in many places in the UK. The treatment involves being given high concentrations of oxygen, while under pressure in a hyperbaric chamber. The chamber is similar to those used to treat divers who have decompression illness (the 'bends'). The treatment may help the bones to repair.

If you have pain, this can usually be controlled with painkillers. If the bone is infected, it can often be treated with antibiotics. You may also need to see a physiotherapist or occupational therapist if the damaged bone is making it difficult to carry out daily activities. Very occasionally surgery may be suggested to remove the damaged ribs.

Lymphoedema is a type of swelling. It can occur if lymph nodes in the armpit have been removed or are damaged by radiotherapy. Lymph fluid normally flows along the lymph vessels and through the lymph nodes. If the lymph vessels are damaged, excess fluid may build up in the arm, causing swelling.

Lymphoedema can occur in women who had radiotherapy to the armpit (axilla) as part of their treatment for breast cancer. Some women have radiotherapy after having a few lymph nodes removed from under the arm; in this situation, lymphoedema is uncommon, affecting approximately one in 25 women. In women who have radiotherapy after removal of most or all of their lymph nodes, lymphoedema is more common, affecting one in three women.

Lymphoedema in the arm can also occur after radiotherapy to the breast and chest wall, but this is very rare.

If your arm is swollen because of lymphoedema it may become stiff, uncomfortable and awkward to move. This can make daily activities like dressing difficult. The skin of your arm may become tight and stretched. Once lymphoedema occurs it can never be completely cured. However, many things can be done to help reduce the swelling and discomfort and allow women to use their arm normally.

Preventing lymphoedema

If you are at risk of developing lymphoedema, it may help not to put too much strain on your lymphatic system. This means trying to avoid any infection or inflammation, as these can cause more lymph fluid to be produced and increase the risk of lymphoedema. It is important to avoid getting any cuts or grazes on your arm and to look after your skin by using moisturisers.

Treating lymphoedema

If you develop lymphoedema, you will usually be referred to a lymphoedema specialist for treatment and advice. This may be a nurse, physiotherapist or doctor. The treatment will depend upon how much lymphoedema you have, and aims to help reduce the swelling, prevent further swelling and to relieve any discomfort. There are four main types of treatment:

• care of the skin
• supporting the arm using compression stockings or bandages
• positioning and movement, or exercising the arm
• a particular type of massage called manual lymphatic drainage (MLD) or simple lymphatic drainage (SLD).

About one in 100 women who have radiotherapy to the underarm as part of their treatment will develop some numbness and tingling in the hand; weakness in the hand; or pain around the shoulder, arm or hand. These symptoms will usually be quite mild but very occasionally may be more severe and troublesome.

They are due to damage to the nerves going into the arm, which can sometimes occur after radiotherapy to the armpit. These nerves are known as the brachial plexus and the long-term side effect is often called radiation-induced brachial plexus neuropathy or brachial plexopathy.

Treatment of brachial plexopathy

Usually this is a mild symptom, but if severe brachial plexus neuropathy develops it can’t be reversed. However, treatments can help to control symptoms such as pain, and make the practical aspects of life easier.

One of the priorities of treatment is to find the best way of controlling the pain. People often describe the pain as 'shooting' or 'burning', but you may also have pins and needles, numbness or tightness. There are various painkillers that may be helpful, depending upon how severe the pain is, and your doctor will be able to give you advice on these. Your doctor may prescribe low-dose antidepressants or antiepileptic drugs, as these can be effective in controlling nerve pain. You may be referred to a specialist pain clinic for further advice.

Your doctors may also suggest other treatments, such as massage or applying heat and cold to the painful areas. Another possibility is using a TENS (transcutaneous electrical nerve stimulation) machine. This can be very effective at relieving pain. It involves placing sticky pads that contain electrodes onto your skin. A weak electrical current is passed through the pads. The electrical current can make the body release its own natural painkillers (endorphins), which can help to control pain.

Some women find acupuncture helpful, and some GP or hospital clinics now offer this. Other complementary therapies may also be useful, but you should always discuss these with your doctor first.

You may be referred to a physiotherapist and an occupational therapist (OT). A physiotherapist will help you to keep your arm as mobile and strong as possible. This will involve exercises to strengthen the muscles and keep them supple. The physiotherapist will also be able to show you how to use slings or splints to support your arm. The OT will assess how the nerve damage has affected the use of your arm, and look at how this interferes with your daily life. The physiotherapist and OT can then suggest practical ways of helping you to carry on as normally as possible.

If you are not able to work because of the damage to your arm, you may be entitled to some benefits. A social worker, either at the hospital or in the community, or your local DSS office will be able to advise you about this.

Our work and cancer section has helpful information about work, disability and financial issues.

This is a very rare long-term problem following radiotherapy for breast cancer. Fewer than one in 1000 women will develop a second cancer, known as a sarcoma, within the treatment area. This can occur many years later. Secondary cancers are very rare but any new symptoms should always be checked with your doctor.

You may have all kinds of emotions if you are diagnosed as having damage caused by your radiotherapy treatment. Radiotherapy damage is uncommon and it can take a long time to find out that the problem is related to radiotherapy. You may feel angry about this. You may be relieved that you now know the reasons for your symptoms, or feel cheated that you have survived cancer only to be damaged by the treatment. You may be worried about how you will cope with any disability or about money problems if you have to give up work.

These are all normal reactions and part of the process that many women go through. Everyone has their own way of coping. Some women find it helpful to talk to friends or family members, while others prefer to seek help from people outside their situation, such as counsellors. Other people prefer to keep their feelings to themselves. There is no right or wrong way to cope, but help is there if you need it.

A number of organisations and support groups can help and support you. Our nurses can give you details of those that are local to you.