Thymoma & Thymic Carcinoma

The UCSF Thoracic Oncology Program is a regional, national, and international referral center for lung cancer. Our surgeons are known for their willingness to be aggressive in the appropriate case. We are also a high volume center for thoracic surgery, the largest on the West Coast. Our post-operative mortality rates are among the lowest anywhere.

We have extensive experience in performing minimally invasive thoracic surgery. That means shorter hospital stays, less post-operative pain, and a more rapid return to normal activities. For patients who need chemotherapy after surgery, it means they can begin their treatment faster and are better able to tolerate higher doses.

Our medical oncology group is led by Matthew A. Gubens, MD, one of the region's foremost and highly regarded thoracic oncologists. . Other specialists treating patients, from radiation oncology, pulmonology, pathology, and imaging, are similarly dedicated and highly skilled. All have special expertise in treating patients with lung cancer and other thoracic malignancies.

The following information is from the National Cancer Institute (NCI)

Thymoma and thymic carcinoma are diseases in which malignant (cancer) cells form on the outside surface of the thymus. The thymus, a small organ that lies in the upper chest under the breastbone, is part of the lymph system. It makes white blood cells, called lymphocytes, that protect the body against infections.

Thymomas vs. Thymic carcinomas

There are different types of tumors of the thymus. Thymomas and thymic carcinomas are rare tumors of the cells that are on the outside surface of the thymus. The tumor cells in a thymoma look similar to the normal cells of the thymus, grow slowly, and rarely spread beyond the thymus.

On the other hand, the tumor cells in a thymic carcinoma look very different from the normal cells of the thymus, grow more quickly, and have usually spread to other parts of the body when the cancer is found. Thymic carcinoma is more difficult to treat than thymoma. Certain factors affect prognosis (chance of recovery) and treatment options.

Prognosis & Treatment

Prognosis and treatment options depend on the following:

• The stage of the cancer.
• The type of cancer cell.
• Whether the tumor can be removed completely by surgery.
• The patient's general health.
• Whether the cancer has just been diagnosed or has recurred (come back).

These are discussed in more detail below.

Risk Factors

• Having a disease called myasthenia gravis can affect the risk of developing thymoma.
• People with thymoma often have other diseases as well. These diseases may include, polymyositis, lupus erythematosus, rheumatoid arthritis, thyroiditis, Sjögren syndrome, and hypogammaglobulinemia.

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Symptoms

Possible signs of thymoma and thymic carcinoma include a cough and chest pain.
Sometimes thymoma and thymic carcinoma do not cause symptoms. The cancer may be found during a routine chest x-ray. The following symptoms may be caused by thymoma, thymic carcinoma, or other conditions.

• A cough that doesn't go away.
• Chest pain.
• Trouble breathing.

Diagnosis & Staging

Thymoma and thymic carcinoma are usually diagnosed, staged, and treated during surgery.

A biopsy of the tumor is done to diagnose the disease. The biopsy may be done before or during surgery, using a thin needle to remove a sample of cells. This is called a fine-needle aspiration (FNA) biopsy. A pathologist will view the sample under a microscope to check for cancer. If thymoma or thymic carcinoma is diagnosed, the pathologist will determine the type of cancer cell in the tumor. There may be more than one type of cancer cell in a thymoma. The surgeon will decide if all or part of the tumor can be removed by surgery. In some cases, lymph nodes and other tissues may be removed as well.

Staging Thymoma and Thymic Carcinoma

The following tests and procedures may be used to detect (find) thymoma or thymic carcinoma:

• Physical exam and history: An exam of the body to check general signs of health, including checking for signs of disease, such as lumps or anything else that seems unusual. A history of the patient's health habits and past illnesses and treatments will also be taken.
• Chest x-ray: An x-ray of the organs and bones inside the chest. An x-ray is a type of energy beam that can go through the body and onto film, making a picture of areas inside the body.
• CT scan (CAT scan): A procedure that makes a series of detailed pictures of areas inside the body, such as the chest, taken from different angles. The pictures are made by a computer linked to an x-ray machine. A dye may be injected into a vein or swallowed to help the organs or tissues show up more clearly. This procedure is also called computed tomography, computerized tomography, or computerized axial tomography.
• MRI (magnetic resonance imaging): A procedure that uses a magnet, radio waves, and a computer to make a series of detailed pictures of areas inside the body, such as the chest. This procedure is also called nuclear magnetic resonance imaging (NMRI).1
• Thymoma and thymic carcinoma are usually diagnosed, staged, and treated during surgery.
• A biopsy of the tumor is done to diagnose the disease. The biopsy may be done before or during surgery, using a thin needle to remove a sample of cells. This is called a fine-needle aspiration (FNA) biopsy. A pathologist will view the sample under a microscope to check for cancer. If thymoma or thymic carcinoma is diagnosed, the pathologist will determine the type of cancer cell in the tumor. There may be more than one type of cancer cell in a thymoma. The surgeon will decide if all or part of the tumor can be removed by surgery. In some cases, lymph nodes and other tissues may be removed as well.

Tests done to detect thymoma or thymic carcinoma are also used to stage the disease.

Staging is the process used to find out if cancer has spread from the thymus to other parts of the body. The findings made during surgery and the results of tests and procedures are used to determine the stage of the disease. It is important to know the stage in order to plan treatment.

Stages for Thymoma:

Noninvasive thymoma (stage I)

• In stage I, cancer is found only within the thymus. All cancer cells are inside the capsule (sac) that surrounds the thymus.

Invasive thymoma (stage II, stage III, and stage IV)

• In stage II, cancer has spread through the capsule and into the fat around the thymus or into the lining of the chest cavity.
• In stage III, cancer has spread to nearby organs in the chest, including the lung, the sac around the heart, or large blood vessels that carry blood to the heart.
• Stage IV is divided into stage IVA and stage IVB, depending on where the cancer has spread.
  • In stage IVA, cancer has spread widely around the lungs and heart.
  • In stage IVB, cancer has spread to the blood or lymph system.

Stages for Thymic Carcinomas

• The staging system used for thymomas is sometimes used for thymic carcinomas.
• Thymic carcinomas have usually spread to other parts of the body when diagnosed.

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Treatment Overview

Three types of standard treatment are used:

Surgery

Surgery to remove the tumor is the most common treatment of thymoma.

Even if the doctor removes all the cancer that can be seen at the time of the surgery, some patients may be given radiation therapy after surgery to kill any cancer cells that are left. Treatment given after the surgery, to increase the chances of a cure, is called adjuvant therapy.

Radiation Therapy

Radiation therapy is a cancer treatment that uses high-energy x-rays or other types of radiation to kill cancer cells or keep them from growing. There are two types of radiation therapy. External radiation therapy uses a machine outside the body to send radiation toward the cancer. Internal radiation therapy uses a radioactive substance sealed in needles, seeds, wires, or catheters that are placed directly into or near the cancer. The way the radiation therapy is given depends on the type and stage of the cancer being treated.

Hormone Therapy

Hormone therapy is a cancer treatment that removes hormones or blocks their action and stops cancer cells from growing. Hormones are substances produced by glands in the body and circulated in the bloodstream. Some hormones can cause certain cancers to grow. If tests show that the cancer cells have places where hormones can attach (receptors), drugs, surgery, or radiation therapy is used to reduce the production of hormones or block them from working.

Hormone therapy with drugs called corticosteroids may be used to treat thymoma or thymic carcinoma.

New types of treatment are being tested in clinical trials.

Chemotherapy

Chemotherapy is a cancer treatment that uses drugs to stop the growth of cancer cells, either by killing the cells or by stopping them from dividing. When chemotherapy is taken by mouth or injected into a vein or muscle, the drugs enter the bloodstream and can reach cancer cells throughout the body (systemic chemotherapy). When chemotherapy is placed directly into the spinal column, an organ, or a body cavity such as the abdomen, the drugs mainly affect cancer cells in those areas (regional chemotherapy). The way the chemotherapy is given depends on the type and stage of the cancer being treated.

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Treatment Options by Stage & Recurrence

Noninvasive Thymoma and Thymic Carcinoma

• Surgery to remove the tumor.
• Radiation therapy.

Invasive Thymoma and Thymic Carcinoma

Treatment of invasive thymoma and thymic carcinoma that can be completely removed by surgery includes the following:

• Surgery followed by radiation therapy.
• A clinical trial of other new treatments.

Treatment of invasive thymoma and thymic carcinoma that cannot be  completely  removed by surgery includes the following:

• Surgery to remove part of the tumor, followed by radiation therapy with or without chemotherapy.
• A clinical trial of chemotherapy using one or more anticancer drugs.
• A clinical trial of chemotherapy before surgery, with or without radiation therapy.
• A clinical trial of combination chemotherapy followed by radiation therapy.
• A clinical trial of other new treatments.

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Recurrent Thymoma and Thymic Carcinoma

Recurrent thymoma and thymic carcinoma is cancer that has recurred (come back) after it has been treated. The cancer may come back in the thymus or in other parts of the body. Thymic carcinomas commonly recur. Thymomas may recur after a long time. There is also an increased risk of having another type of cancer after having a thymoma. For these reasons, lifelong follow-up is needed

Treatment of recurrent thymoma and thymic carcinoma may include the following:

• Surgery with or without radiation therapy.
• Radiation therapy.
• Hormone therapy.
• A clinical trial of chemotherapy using one or more anticancer drugs.
• A clinical trial of other new treatments.