Thymus gland cancer

Cancer of the thymus gland is rare. Most cancers that start in the thymus gland are called thymomas. There’s also a much rarer form of thymus gland cancer called thymic carcinoma .

What is the thymus gland?

The thymus gland is in your chest, in between your lungs.

A gland is an organ in your body that makes and releases substances such as hormones.

The thymus gland is part of our lymphatic system . It’s involved in the development of a type of white blood cell called a T lymphocyte. These white blood cells are part of your immune system . They help us fight infections.

Types of thymus gland cancer

There are 2 main types of thymus gland cancer:

• thymomas
• thymic carcinomas

These types of cancers develop in the cells that line the thymus gland. These are called epithelial cells. 

Thymomas and thymic carcinomas are more common in people between the ages of 40 and 60. But younger people can also get these cancers.

Thymoma

Doctors put thymomas into different groups based on how the cells look under the microscope. There are 2 main types, A and B.

Type A thymomas usually grow slowly, but type B can grow quicker. They can spread to the lungs or the covering of the lungs (pleura). But it’s unusual for them to spread anywhere else in your body.

Like many other cancers, we don't know exactly what causes thymomas.

Up to 50 out of 100 people with thymoma (50%) have symptoms of myasthenia gravis (MG). MG is a rare condition that affects the immune system and causes muscle weakness.

Thymoma is also linked to other diseases, such as:

• red cell aplasia

• hypogammaglobulinemia

• pernicious anaemia

• systemic lupus erythematosus (SLE)

• rheumatoid arthritis

Thymic carcinoma

Thymic carcinomas are much rarer than thymomas. They often grow more quickly and are more likely to spread to other parts of your body such as the bones and liver. Because of this, they are usually harder to cure.

Symptoms of thymus gland cancer

Often thymus gland cancer doesn’t cause any symptoms. They are found by chance when you're having tests for something else. When they do cause symptoms, it’s usually because the cancer has grown to press on nearby areas in the chest. Symptoms can include:

• chest pain

• a cough that won’t go

• shortness of breath

• hoarseness of the voice

The thymus is close to a large blood vessel in the chest. This is called superior vena cava. This vein carries blood to the heart. Thymus gland cancer can press on it and cause superior vena cava syndrome. Symptoms can include:

• swelling in the face, chest and upper neck

• shortness of breath

• chest pain

How common is thymus gland cancer

Thymus gland cancer is rare. In the UK, around 345 people are diagnosed with thymus cancer each year. This includes thymoma and thymic carcinoma.

Tests you might have

Your doctor will arrange for you to have tests if you have symptoms of thymus gland cancer. One of the first tests you might have is a CT scan. You may also have:

• blood tests

• PET scan

• MRI scan

Your doctor might take a tissue sample (biopsy) of the cancer. You might not need a biopsy if they think that it’s very likely that you have thymus gland cancer based on your scans and blood tests results.

Deciding which treatment you need

A team of doctors and other professionals who specialise in thymus gland cancer discuss the best treatment and care for you. They are called a multidisciplinary team (MDT).

The main treatment for thymus gland cancer is surgery. This gives the best chance of curing the cancer, if possible.

The treatment you have after surgery depends on the type of thymus gland cancer you have. And how far it has spread (the stage).

Treatment after surgery to completely remove thymoma

You might have radiotherapy if your surgeon thinks they haven’t been able to completely remove the cancer. Or if there is a high risk of the cancer coming back.

Treatment after surgery to completely remove thymic carcinoma

After surgery, you usually have one of the following:

• radiotherapy alone

• chemotherapy and then radiotherapy

Treatment for people who can’t have surgery to completely remove the cancer

Some people with thymus gland cancer can’t have surgery to completely remove the cancer. This is because the cancer has already spread too far. Or they are not well enough to have surgery.

If this happens, your doctor might suggest you have chemotherapy first. Chemotherapy can help to shrink the cancer. You then may be able to have surgery, if possible.

You may also have radiotherapy as your main treatment if you can’t have surgery.

Surgery

The most common surgery for thymus gland cancer is a thymectomy. Your surgeon makes a cut down the middle of the chest to remove the whole of the thymus gland. They may also remove part of nearby organs such as the:

• lymph nodes
• lungs
• layer of tissue covering the heart (pericardium)

Sometimes you might have keyhole or robotic surgery instead. This means that your surgeon makes small cuts (incisions) rather than a large cut. They then carry the surgery out through these small cuts.

Radiotherapy

Radiotherapy means the use of radiation, usually x-rays, to treat cancer cells. You have external radiotherapy to treat thymus gland cancer. External radiotherapy uses a machine from outside of the body. It directs radiation beams at the cancer to destroy it.

You usually have radiotherapy every weekday, for 4 to 6 weeks.

Chemotherapy

Chemotherapy uses anti cancer (cytotoxic) drugs to destroy cancer cells. Chemotherapy drug combinations are usually used to treat thymus gland cancer. These include:

• etoposide and cisplatin (EP)

• paclitaxel and carboplatin (PC, CarboTaxol)

• gemcitabine and capecitabine (GemCap)

• cisplatin, etoposide and ifosfamide (VIP)

• cisplatin, Doxorubicin and Cyclophosphamide (CAP)

• doxorubicin, cisplatin, vincristine and cyclophosphamide (ADOC)

• cyclophosphamide, vincritine and dacarbazine (CVD)

Check the name of the chemotherapy treatment with your doctor or nurse, then find out about it on our A to Z list of cancer drugs.

Treatment for thymus gland cancer that has come back (recurrent)

Unfortunately, if your thymus gland cancer comes back, it can be difficult to get rid of it altogether. Treatment can often keep it under control for some time. You might have:

• surgery to remove the cancer

• chemotherapy

The treatment you have depends on how well the cancer responded to previous treatment. Your doctor will be able to tell you more about what treatments you may have.

Coping

Coping with a diagnosis of a rare cancer can be especially difficult. Being well informed about your cancer and its treatment can help. It can make it easier to make decisions and cope with what happens.

Talking to other people who have the same thing can also help.

Our discussion forum Cancer Chat is a place for anyone affected by cancer. You can share experiences, stories and information with other people.

You can call our nurse freephone helpline on 0808 800 4040. They are available from Monday to Friday, 9am to 5pm. Or you can send them a question online.

The Rare Cancer Alliance offer support and information to people with rare cancers. It has a forum where you might be able to meet others with the same cancer as you. 

ThymicUK is a support group for people with cancers of the thymus gland. They aim to address the feeling of isolation that can come with a rare disease. They share information and experiences as well as support each other.