The first-line of treatment for most patients with mesothelioma is chemotherapy. It involves using medications that kill cancer cells during their rapid growth and cell division. Unfortunately, these medications are not specific to tumors. This means that while they kill cancer cells, they also damage healthy cells that grow quickly, like blood cells and hair follicles.
There are only a few drugs approved for first-line use in chemotherapy for mesothelioma: pemetrexed, cisplatin, and gemcitabine. In spite of the unpleasant and often difficult side effects that they can cause, chemotherapy medications are one of the best and most effective treatments for a number of cancers, including mesothelioma. Patients must endure these side effects to receive the benefits.
This doesn’t mean that other chemotherapy drugs cannot be used in mesothelioma treatment. Doctors may prescribe other chemotherapy agents such as carboplatin, doxorubicin, and navelbine, but these alternatives have not been clinically proven to be as effective, or they are still in trials to prove safety and efficacy.
Chemotherapy Side Effects
Although chemotherapy is the most effective type of treatment for mesothelioma, it is not always easy. Because the medications are not specific to cancer cells, patients may experience a range of side effects from mild to severe. Because of their side effects, chemotherapy drugs are typically given in cycles with a couple of weeks of break between administering doses to give the body time to recover.
Chemotherapy medications may be given orally, but most often they are administered intravenously. This allows the drugs to go immediately into the bloodstream where they can circulate throughout the whole body and attack any cells growing and dividing at a rapid pace. Common side effects of chemotherapy drugs can include:
- Hair loss
- Nausea and vomiting
Another type of medication that may be used in mesothelioma treatment is described as a photosensitizer, a photodynamic drug, or a photosensitizing agent. These are agents that become activated to kill cancer cells when exposed to light.
Different drugs of this type are activated by different wavelengths of light, which can travel varying distances through the body. The location of the tumor determines the choice of drug and wavelength of light.
To be treated by this method, a patient is injected with the optimal photosensitizing agent. This drug travels to all areas of the body, but stays longer in cancer cells than in healthy cells. After two or three days, most of the medication has been eliminated from the healthy part of the body, but it lingers in the tumors. A light on the end of an endoscope can then be inserted into the body and aimed at the tumor to activate the medication, which then kills cancer cells.
Another very important line of research in targeted therapy is called anti-angiogenesis treatment. Angiogenesis is the process of making new blood vessels, which is usually a normal and healthy process in the body. However, in cancer this process is exploited to rapidly build new blood vessels to provide the tumor with oxygen and nutrients. If this process can be halted, it may slow the growth or kill the cells in the tumor by limiting their blood flow. Some anti-angiogenesis medications have proven to be disappointing in trials, but others show promise. These agents often work best when used in conjunction with chemotherapy.
Immunotherapy Mesothelioma Medications
Another novel line of attack against mesothelioma is immunotherapy. While there are a few similar agents, the general idea for all of them is to stimulate the immune system to recognize and attack cancer cells.
Cancer cells are too similar to healthy cells in the body for the immune system to recognize and attack them. The immune system is unable to see them as foreign or harmful. In order to convince the immune system to attack, it must be pushed in some way.
One type of immunotherapy medication works by making the immune system more active. Another method is to overcome the cancer’s ability to evade detection. A third method is to specifically train the immune system by exposing it to small pieces of the cancer in the hope it will recognize the tumor. Some immunotherapy works better for certain types of cancers than others, and trials are ongoing to test for new options in patients with mesothelioma. Even more trials are ongoing that attempt to find more effective combinations of treatment, focusing right now on the combination of chemotherapy and immunotherapy.
Immunotherapy Side Effects
Immunotherapy is often better tolerated than chemotherapy but can still have side effects. While chemotherapy may have side effects for a few days to weeks, immunotherapy may not have noticeable side effects for weeks to months. Their effects can also be seen well after the drug has been stopped. Because the medications work by increasing the activity of the immune system, some of the adverse effects can resemble autoimmune diseases. Common side effects of immunotherapy include:
- Thyroid dysfunction: such as a low thyroid level
- Pneumonitis: inflammation of the lung tissue causing shortness of breath or a cough
- Colitis: inflammation of the colon causing diarrhea, abdominal cramping, or vomiting
- Nephritis: inflammation of the kidney leading to kidney (or renal) damage
- Muscle or bone aches and pains
- Dermatitis: inflammatory response of your skin cells, causing a rash, color changes, or itching
- Neurological complications
One of the upcoming lines of treatment in mesothelioma and other types of cancers is the development of drugs that are more specific than chemotherapy drugs. These are medications that recognize, target, and kill cancer cells only. These drugs are so specific that some are being designed to target cells from specific types of cancer. For instance, mesothelin is a protein that has been found to be expressed mostly in mesothelioma tumors. Drugs that can specifically target this compound are currently being tested.
There are a variety of medications used to treat mesothelioma, with chemotherapy drugs as the usual first line of treatment. They have proven to be the most effective drugs in treating this type of cancer, but the side effects are a major drawback. As research continues, doctors and patients are hopeful that newer medications will be even more effective and will cause fewer side effects. Photodynamic drugs, anti-angiogenesis agents, immunotherapy, and targeted medications all show promise and can be better tolerated than chemotherapy. Much more research needs to be done, but even now patients with mesothelioma and their doctors have a lot of options for medication treatment.
Page Medically Reviewed and Edited byLuis Argote-Greene, M.D.
Luis Argote-Greene is an internationally recognized thoracic surgeon. He has trained and worked with some of the most prominently known thoracic surgeons in the United States and Mexico, including pioneering mesothelioma surgeon Dr. David Sugarbaker. He is professionally affiliated with University Hospitals (UH). His areas of interest and expertise are mesothelioma, mediastinal tumors, thoracic malignancies, lung cancer, lung transplantation, esophageal cancer, experimental surgery, and lung volume reduction. Dr. Argote-Greene has also done pioneering work with video-assisted thoracoscopic surgery (VATS), as well as robotic assisted minimally invasive surgery. He has taught the procedures to other surgeons both nationally and internationally.