Chemotherapy and Other Drugs for Thymus Cancer

When is chemotherapy used for thymus cancer?

When treating thymus tumors (thymomas and thymic carcinomas), chemo may be used in these situations:

• It might be given after surgery to try to kill any cancer cells that may have been left behind because they were too small to see. This is called adjuvant treatment.
• It might be given before surgery to try to shrink tumors so that they can be completely removed. This is called neoadjuvant therapy.
• It may be the main treatment for people who have advanced cancer or are not healthy enough for surgery.
• It is sometimes combined with radiation to help it work better. This is known as chemoradiation or chemoradiotherapy.

How is chemotherapy given?

Chemo is given in cycles, with each period of treatment followed by a rest period to allow the body time to recover. Chemo cycles generally last about 3 to 4 weeks, and treatment typically involves 4 to 6 cycles. Chemo is often not recommended for people in poor health, but advanced age by itself is not a barrier to getting chemo.

Several chemo drugs may be used in the treatment of thymomas and thymic carcinomas, including:

• Doxorubicin (Adriamycin)
• Cisplatin
• Carboplatin
• Cyclophosphamide
• Ifosfamide
• Vincristine
• Etoposide (VP-16)
• Paclitaxel
• Pemetrexed
• 5-fluorouracil (5-FU)
• Gemcitabine

The corticosteroid drug prednisone is often given with chemo.

These drugs usually are given in combination to try to increase their effectiveness. For example, the combination of cisplatin, doxorubicin, and cyclophosphamide (called CAP), with or without prednisone, is often used to treat thymoma. The combination of carboplatin and paclitaxel may be used to treat thymic carcinoma.

Possible side effects of chemotherapy for thymus tumors

Chemo drugs work by attacking cells that are dividing quickly, which is why they work against cancer cells. But other cells in the body, such as those in the bone marrow, the lining of the mouth and intestines, and the hair follicles, also divide quickly. These cells are also likely to be affected by chemo, which can lead to certain side effects.

The side effects of chemo depend on the type and dose of drugs you are given and how long they are used. Side effects can include:

• Hair loss
• Mouth sores
• Loss of appetite
• Nausea and vomiting
• Fatigue and weakness

Chemo can also affect the blood-forming cells of the bone marrow, leading to:

• Increased chance of infections (due to low white blood cell counts)
• Easy bruising or bleeding (due to low blood platelet counts)
• Fatigue and weakness (due to low red blood cell counts)

Most side effects usually go away over time after treatment ends and there are often ways to lessen them. For instance, drugs can be used to help prevent or reduce nausea and vomiting. If you do have side effects, be sure to ask your doctor or nurse about medicines to help reduce or manage them.

Some chemo drugs can also have other side effects. For example:

• Cisplatin and paclitaxel can damage nerves (called neuropathy). This can sometimes lead to pain, burning or tingling sensations, sensitivity to cold or heat, or weakness in the hands and feet.
• Cisplatin can also affect the nerves of the ear, leading to hearing loss.

Most often these problems get better or even go away once treatment is stopped, but they may last a long time in some people. You should report any side effects or changes you notice while getting chemo to your medical team so that you can get prompt treatment for them. In some cases, the doses of the chemo drugs may need to be reduced or treatment may need to be delayed or stopped to keep the effects from getting worse.

Other drugs that might be used to treat thymus tumors

Some other types of drugs that are not standard chemo drugs might also be helpful in treating thymus tumors, usually after chemo has been tried.

Octreotide (Sandostatin or Sandostatin LAR) may help some people with advanced thymoma. This is a man-made version of a hormone called somatostatin. This drug works by attaching to the thymoma cells and causing them to stop growing or die. Side effects of this drug can include pain or burning at the injection site, stomach cramps, nausea, vomiting, headaches, dizziness, and fatigue. It is also linked to increased risk of gallstones.

Targeted drugs such as sunitinib and lenvatinib can sometimes be helpful in treating thymic carcinomas if chemo is no longer working. These drugs target specific parts of cancer cells, or the blood vessels that tumors need to grow. They tend to have different side effects from standard chemo drugs.

Pembrolizumab (Keytruda) is a type of immunotherapy drug known as an immune checkpoint inhibitor. It works by helping the body's immune system attack the cancer cells. It is sometimes helpful in treating thymic carcinoma if chemo is no longer working. Side effects tend to be milder than with standard chemo drugs, although serious side effects are also possible.