Chemotherapy for malignant mesothelioma

Chemotherapy (chemo) is treatment with anti-cancer drugs. There are 2 main ways that chemotherapy can be given to treat mesothelioma. 

In systemic therapy, chemotherapy is injected into a vein. The drug enters the bloodstream and travels throughout the body to reach and destroy the cancer cells wherever they may be.

Chemo drugs can also be placed directly into the body cavity where the cancer is – either intrapleurally (directly into the chest) or intraperitoneally (into the abdomen) – with a small catheter (tube) placed through a small cut in the chest or abdominal wall. Chemo drugs given this way are still absorbed into the bloodstream, but the highest concentration of the drug goes directly to where the cancer cells are. 

Chemo drugs are sometimes heated before they are placed directly into a body cavity (called hyperthermic chemotherapy), which may help them work better. Sometimes this treatment is given as a single dose in the operating room, right after surgery to remove the cancer. This approach is called heated intraoperative chemotherapy or HIPEC. It is more often used to treat peritoneal cancers, in which case it may be called heated intraperitoneal chemotherapy.

For mesotheliomas that can be treated with surgery, chemotherapy may be given before surgery to try to shrink the cancer and lower the risk of spread. This is called neoadjuvant therapy. 

Chemo can also be given after surgery to try to try to kill any cancer cells that were left behind because they were too small to be seen. This type of treatment, called adjuvant therapy, may help delay or prevent the cancer growing back. 

For cancers that are not resectable, chemotherapy may be the main treatment (alone or along with radiation therapy). Chemotherapy may slow the progression of the disease, but it is very unlikely to make it go away completely. 

Doctors usually give chemotherapy 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. Chemotherapy is often not recommended for patients in poor health, but advanced age by itself is not a barrier to getting it.

Several chemo drugs have been used to treat mesothelioma. Most doctors now use a combination of the drugs pemetrexed (Alimta^®) and cisplatin. Pemetrexed lowers levels of folic acid and vitamin B12 in the body, so patients get these as well to help avoid certain side effects. Other combinations that may be used include pemetrexed with carboplatin and cisplatin with gemcitabine (Gemzar^®).

Other drugs used to treat mesothelioma include:

• Methotrexate
• Vinorelbine
• Mitomycin
• Doxorubicin (Adriamycin^®)
• Epirubicin (Ellence^®)
• Cyclophosphamide (Cytoxan^®)
• Ifosfamide (Ifex^®)

These may be given as combinations of 2 drugs, but single drugs can be used in people who may not be able to tolerate more than one drug. Several other drugs are also being studied for use against mesothelioma.

For HIPEC, either mitomycin or the combination of cisplatin plus doxorubicin are most often used.

Possible side effects

Chemo drugs attack 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 chemotherapy, which can lead to side effects. 

The side effects of chemotherapy depend on the type and dose of drugs you are given and how long they are used for. Common side effects include:

• Hair loss
• Mouth sores
• Loss of appetite
• Nausea and vomiting
• Diarrhea
• Increased chance of infections (from too few white blood cells)
• Easy bruising or bleeding (from too few blood platelets)
• Fatigue (from too few red blood cells)

These side effects are usually short-term and go away after treatment is finished. There are often ways to lessen these side effects. For example, drugs can be given to help prevent or reduce nausea and vomiting. Be sure to ask your doctor or nurse about medicines to help reduce side effects, and let him or her know if you have side effects, so they can be managed effectively.

Some drugs can have other side effects. For example, cisplatin can damage nerves (called neuropathy). This can sometimes lead to hearing loss or symptoms in the hands and feet such as pain, burning or tingling sensations, sensitivity to cold or heat, or weakness. In most cases this goes away once treatment is stopped, but it may last a long time in some people. 

Be sure to report any side effects or changes you notice while getting chemotherapy to your medical team so that you can get them treated promptly. In some cases, the doses of the drugs may need to be reduced or treatment may need to be delayed or stopped to prevent the effects from getting worse.