• Patients with thymus cancers are treated by members of the BC Cancer Agency’s Lung Tumour Group.
• For healthcare professional information on treating this cancer, please see our Cancer Management Guidelines. 
• The thymus organ is inside the chest, behind the breastbone. It sits just in front of and above the heart and may extend to the root of the neck.
• The thymus is large in infants. It grows until puberty and then gradually decreases in size during adulthood as it is replaced with fat.
• The thymus is divided into two lobes that are surrounded by a thin layer of tissue.
• The thymus is made up of two types of cells: epithelial cells and lymphocytes.
• Epithelial cells are the cells that line the thymus, and are the cells of origin for thymic-related cancers such as thymoma and thymic carcinoma.
• The thymus is part of the lymphatic system.  T Lymphocytes are a type of white blood cell that develop in the thymus, especially in early life. These cells help protect the body from infections and viruses.  If lymphocytes become cancerous, they can develop into lymphoma.
• Thymus cancers have different names including thymomas, thymic carcinomas, thymic epithelial tumor or thymic carcinoid tumors.
• Thymus cancers are rare compared with other types of cancer and may be more difficult to diagnose and treat.

What causes it and who gets it?
Listed below are some of the known risk factors for this cancer.  Not all of the risk factors below may cause this cancer, but they may be contributing factors.

• The cause of thymus cancer is unknown.
• Patients are usually between 40 and 60 years of age.
• Men and women are equally affected.
• Thymus cancer and myasthenia gravis (a chronic disease that causes muscle weakness) are often associated.
• This cancer is sometimes accompanied by immune disorders and low red blood cell counts.
• Statistics
• These cancers are very rare so incidence rates have been combined with other unspecified cancers.
• BC
• Canada 

Can I help to prevent it?

• There is no known way to prevent thymus cancer.

Screening for this cancer

• Patients with myasthenia gravis are regularly checked for thymus cancer.

Signs and Symptoms

• There are often no symptoms of thymus cancer.
• If the growing tumour presses against other organs, the following chest symptoms may result:
• coughing
• difficulty breathing (dyspnea)
• difficulty swallowing (dysphagia)
• chest tightness
• Advanced tumours may cause chest pain.
• If the tumour is large, the neck and face may swell.

Diagnosis
This is a list of some or all of the tests used to diagnose this type of cancer.   

• A chest x-ray or CT Scan is used as a beginning assessment.
• 40% of tumours are discovered on chest x-rays that have been done for unrelated reasons. 
• Magnetic Resonance Imaging (MRI) may show if the tumour has spread.
• A biopsy (removal and examination of a small bit of tissue) is needed for a definite diagnosis of thymus cancer.
• For more information on all cancer diagnostic tests, see our Recommended Websites, Diagnosis section.

Types and Stages
Staging describes the extent of a cancer. The TNM classification system is used as the standard around the world.  In general a lower number in each category means a better prognosis. The stage of the cancer is used to plan the treatment.

• T describes the site and size of the main tumour (primary);
• N describes involvement of lymph nodes;
• M relates to whether the cancer has spread (presence or absence of distant metastases).

Types

• There are three main types of thymus cancer:
• Thymoma (most common)
• Thymic carcinoma (uncommon)
• Thymic carcinoid tumour (rare)

Stages

Treatment
Cancer therapies can be highly individualized – your treatment may differ from what is described below.

Surgery

• The most effective treatment is the complete surgical removal of the tumour.
• If the tumour is non-invasive and is completely removed by surgery, the long-term survival rate is 95%.
• Patients who have had minimally invasive tumours surgically removed and then have been treated with radiotherapy should have a 5-year survival rate of 80%.

Radiotherapy

• Radiotherapy is given after the surgery to avoid recurrence of the cancer.

Chemotherapy

• Chemotherapy can be used in advanced stages of thymus cancer.
• When the tumour has spread a lot, chemotherapy or chemoradiation may be given before surgery to shrink the tumour.

Prognosis

• The majority of thymus cancer cases are curable.

Follow-up after Treatment

• Guidelines for follow-up after treatment has ended have been developed by the BC Cancer Agency and are listed on our website.
• You will be returned to the care of your family doctor or specialist for regular follow-up.
• Follow-up testing is based on your type of cancer and your individual circumstances.
• The BCCA Survivorship Research Centre focusses on the issues that cancer survivors can face.

Coping with Cancer

The Coping with Cancer section of our website is a joint project among different BC Cancer Agency departments and programs. This website section provides information and links that can help cancer patients with the physical, emotional, nutritional, psychological and practical aspects of care. Each cancer experience is different, but in one way or another, many cancer patients share the same needs.

The effects of cancer and its treatment can present unique challenges: from practical concerns like money and housing, to emotional concerns like anxiety and grief. If you need support with the practical and emotional impacts of cancer, or in managing symptoms and side effects you can use the information in Coping with Cancer to connect to these resources.

Search our library catalogue

• The BC Cancer Agency Library has many resources about cancer, coping, talking to children, etc.  Please visit the Library in your Centre, call a librarian, or visit the Library online to see the many resources available.

Recommended websites 
The BC Cancer Agency has selected and evaluated these useful websites for your further information.

Thymus cancer
Shortness of breath (Dyspnea)
Swallowing difficulties (Dysphagia)
Websites for cancer survivors, and how to stay healthy after treatment

Videos
View videos on cancer-related topics that the BC Cancer Agency produces.

How can I help with research at BCCA?
BC Cancer Agency patients are very helpful when it comes to the fight against cancer.  Here are a few ways that you can help:

• The BCCA is deeply involved in cancer research.  We operate various Research Programs, the BC Cancer Research Centre and Canada's Michael Smith Genome Sciences Centre.
• Clinical Trials – join our treatment-based research.  Ask your oncologist if you qualify for a clinical trial. What are the pros and cons of joining a clinical trial?
• Tumour Tissue Bank – support our research by donating some of your cancer tissue.
• BC Cancer Foundation – support our research with a donation of money.

This information has been reviewed and approved by a member of the Lung Tumour Group.