Mesothelioma Treatments

Manufactured by Eli Lilly, Alimta inhibits cell growth to prevent the spread of cancer to other areas of the body. Alone, Altima treats those suffering from non-small cell lung cancer. However, when Altima is combined with the chemotherapy drug cisplatin, it can treat mesothelioma and prolong a patient’s life.

In 2004, the FDA approved the use of Alimta in combination with cisplatin to treat pleural mesothelioma. It is currently the only drug approved to treat mesothelioma. Altima works by blocking three enzymes that are used in the synthesis of purine and pyrimidine, which are needed in the formation of DNA and RNA. By preventing this formation, the chemotherapy drug can hinder cell growth and ultimately stop the cancer from spreading.

Patients receiving this combination are usually too ill to undergo surgery. Several clinical studies have shown that patients treated with Alimta/cisplatin live for an average of three months longer than those receiving cisplatin alone. While Alimta cannot cure mesothelioma, it can prolong life and improve lung function for the patient.

Angiogenesis occurs when new blood vessels form within the body. In healthy people, this is a normal process that helps heal wounds. However, in a mesothelioma patient, angiogenesis feeds the growth of cancerous tumors.

Malignant tumors signal surrounding blood vessels by releasing naturally occurring proteins known as Vascular Endothelial Growth Factors (VEGF). This secretion causes blood vessel growth into the tumor, supplying the oxygen and nutrients needed for its expansion. Without this help from blood vessels, new cancerous tumors cannot grow past a certain size.

Many mesothelioma patients have high levels of VEGF. Luckily, research has found a new group of anti-angiogenesis drugs that can help stop the production of these proteins. This will prohibit new blood vessels from forming and ideally stop the growth of the tumor.

A relatively new development in cancer treatment, anti-angiogenesis drugs has proved more successful in animals than in humans. In animals, these drugs have killed and shrank cancer cells. Researchers believe human testing will eventually produce similar results.

Made by VasGene Therapeutics, Inc., Veglin is an anti-angiogenesis drug designed to treat mesothelioma and other cancers. Veglin binds with DNA genes that help produce the naturally occurring group of proteins known as Vascular Endothelial Growth Factors (VEGF). Researchers hope that Veglin can stop the production of VEGF, which in turn will stop tumors from growing past a certain size.

Although Veglin is still undergoing Phase II testing at the University of California’s Keck School of Medicine, Phase I results were promising. The Phase I testing showed that Veglin could lower the amount of VEGF in the body and in some cases reduce or stabilize tumor size. Of the 35 participants, VEGF-A levels were reduced by 47% and VEGF-C levels by 21%.

Current clinical trials involve patients with mesothelioma, lymphoma, leukemia and renal cell carcinoma. These patients were given Veglin through an IV for two hours over a period of five days. The participants then went a week without any treatment. This pattern is expected to last for about four months. Researchers believe that these studies will produce similar results as the Phase I trials.

PXD101 is an anti-angiogenesis drug designed for mesothelioma patients whose cancer cannot be removed by surgery. Administered orally, PXD101 is a histone deacetylase inhibitor that is used as a second line therapy. The drug is believed to stop tumor growth by inhibiting enzymes necessary for cell growth and by blocking blood flow to the tumor.

PXD101 is currently being tested in clinical trials across the country including at the Yale Cancer Medical Center. Head of the research team, Dr. Scott Gettinger has gotten PXD101 into FDA clinical testing. The drug has just completed the Phase II clinical trials; results have yet to be revealed.

Reported side effects of PXD101 include fatigue and nausea. However, this anti-angiogenesis drug has caused less severe side effects than radiation or chemotherapy.

Intense Modulated Radiation Therapy (IMRT) treats patients with malignant mesthelioma by delivering targeted doses of radiation to cancerous tumors regardless of shape or size. The main advantage of this new treatment is that it limits the amount of damage done to healthy cells. IMRT allows doctors to treat tumors that were once deemed untreatable because of their closeness to vital organs. While IMRT has the best results in prostate, head and neck cancers, this new radiotherapy may be able to improve local control in mesothelioma patients.

Also known as biological therapy, immunotherapy manipulates the immune system to further fight off disease. Immunotherapy has been developed because the body recognizes the cancerous cells as normal ones and therefore cannot fight them off. Fortunately, research has shown that the immune system may be able to distinguish between healthy and cancerous cells.

In immunotherapy, doctors use chemicals known as biological response modifiers (BRMs). These chemicals cause the body to identify mesothelioma cells as harmful and begin to attack them. While the body naturally produces BRMs, doctors need to enhance this defense in mesothelioma patients. BRMs currently being tested include interleukins, interferons, monoclonal antibodies and tumor necrosis factor.

Gene therapy attempts to treat mesothelioma by correcting the illness at the DNA level. This new method aims to understand why proteins within cells make them resistant to cancer while others do not. Years ago, scientists believed that genes could not be affected after birth. However, it is now known that many factors, such as smoking, can affect our DNA.

Mesothelioma is a multifactorial disease, which means many factors contribute to its development. While the primary cause of mesothelioma is asbestos, inherited gene mutations may also be a variable. Gene therapy aims to replace cancer-causing genes with those programmed to die when exposed to cancerous growths. These “suicide genes” may be able to stop the replication of cancerous cells. Tests have been conducted to replace cancer-causing genes with those vulnerable to specific drugs, from which cancer can possibly be eliminated. In other words, mesothelioma patients could receive a “healthy virus” that alters the genetic structure of “bad” cells.

Two types of gene therapy exist. Replacement gene therapy substitutes a defective gene with a normal copy. Knockout gene therapy targets the abnormal genes and makes them inactive.

Gene therapy is still being researched and carries possible risks. However, because the survival rates of mesothelioma patients are dismal, some choose to participate in gene therapy clinical trials as the possibility of survival may outweigh any risks.

In a pleurectomy, the patient’s parietal pleura is removed from the lung. When used as palliative treatment, this procedure may be done when more extensive surgery is not an option. A pleurectomy is an effective way of controlling pleural effusion in patients whose lung expansion is restricted by mesothelioma. A pleurectomy can also be performed as a possibly curative measure in patients with Stage I or Stage II mesothelioma.

During a pleurectomy, an incision is made at the back and side of the chest that is affected by the tumor. In addition, the surgeon may remove a rib to access the diseased lung. Next, the parietal pleura is stripped from the lung. Lastly, tubes are placed between the ribs to drain blood and manage any air leaks.

A pleurectomy should only be performed if the normal space between the parietal and visceral pleurae remains and the two layers of the pleura have not merged together. If the pleural layers have merged, the surgeon must also strip the underlying lung tissue known as the decortication.

Patients who receive a pleurectomy for mesothelioma survive an average of 6 to 21 months after the procedure. Approximately 9% to 40% of patients live up to two years. These statistics have a wide range because research groups use varying treatment combinations. For example, one treatment group may receive a pleurectomy along with chemotherapy while another group may not.

An extrapleural pneumonectomy is one of the most radical, aggressive surgeries performed on patients with malignant mesothelioma. During an extrapneumonectomy, the surgeon opens the chest wall at the back and side of the chest, with a cut extending towards the diaphragm. The physician will then remove the sixth rib. He or she will extract the pericardium, diaphragm, the affected lung and both layers of the pleura. Lastly, the surgeon will place grafting materials to patch the diaphragm and pericardium. Also, chest tubes will be placed between the ribs to manage air leaks from the lungs and drain any blood.

Because of the aggressiveness of an extrapneumonectomy, complications may occur. Approximately 5% to 10% of patients have died during or immediately following the surgery. In addition, approximately 25% of patients receiving this procedure experience complications such as heart attacks, breathing difficulties and vocal cord paralysis.

On average, a mesothelioma patient will survive between 4 to 21 months after the procedure. In addition, 10% to 38% of patients live up to two years. Like the pleurectomy, these statistics have a broad range because research groups may or may not choose to administer radiation or chemotherapy along with the extrapneumonectomy. In addition, patients with epithelioid mesothelioma tend to do better than those with other forms of mesothelioma. Patients interested in receiving an extrapneumonectomy should only receive surgery at a facility that has performed at least 10 of these procedures annually.

Many patients suffering from mesothelioma may experience shortness of breath due to a fluid buildup in the pleural cavity. To ease this symptom, a surgeon may perform a pleurodesis, which can stop this buildup of fluid. A pleurodesis is a form of palliative surgery, meaning it can treat symptoms, but not the disease itself.

During a pleurodesis, the space between the pleura is sealed so fluid cannot accumulate there. To do this, a chemical agent is introduced into the space, causing the tissues to inflame and consequently close the space between the layers.

For low-risk mesothelioma patients, a pleurodesis can be performed outside an operating room. The patient will be administered a sedative and general anesthetic. Then, a chest tube will be inserted to remove any excess fluid. After the fluid buildup has been removed, a chemical agent, usually talc or doxycycline, will be inserted via the chest tube. Next, a suction device will bring the two lung surfaces together. If the procedure needs to be performed in an operating room, a general anesthetic will be given to the patient. A physician will make a cut in the chest and place a video-assisted thorascope (VAT) to help see inside the lung. This will also help the surgeon to insert the talc or doxycycline onto the pleural surface.

External beam radiation therapy treats mesothelioma by administering a beam of high-energy x-rays to the tumor. This form of radiation aims to kill the cancerous cells while doing little harm to the normal cells.

During external beam radiation, the radiation therapist will take an x-ray or CT scan to help determine the size of the tumor. The oncologist will then decide how to arrange the beams to best treat the cancer. Next, the patient will be placed on the treatment couch using alignment lasers. The team of radiation specialists will then determine the amount of radiation to deliver to the tumor.

After the patient is positioned on the treatment couch, the radiation can begin. Immobilization devices may be used to ensure the patient stays in place. While the treatment does not hurt, a mesothelioma patient may experience various side effects from the radiation.

Brachytherapy, also known as internal radiation, is a precise radiation treatment that can be used on mesothelioma patients. This form of radiation involves placing radioactive seeds near or inside malignant tumors. Brachytherapy allows a strong dose of radiation to be delivered without harming normal cells. The procedure usually takes up to an hour and a hospital stay is not required. After a brachytherapy, the seeds deliver radiation for approximately one year.

These radioactive seeds can be implanted in two ways. The first method known as intracavitary treatment passes radioactive sources in special containers through body cavities, such as the windpipe. An alternative method is known as interstitial treatment. This form of brachytherapy delivers the radiation into the tumor through thin needles. Depending on the patient’s health and location of the tumor, the doctor will determine which treatment method should be used. Patients receiving brachytherapy usually have less side effects than those receiving localized forms of radiation.

During systemic radiation therapy, radiation can be given as a drink, capsule or through a vein. Mesothelioma patients who receive systemic radiation therapy need to stay in hospital for several days following the procedures. Although some the radiation may leave a patient’s body through urine, sweat or saliva, certain safety measures must be taken. For instance, due to high radiation levels, a patient may not be able to have visitors during the first few days following the treatment.

Systemic radiation therapy is not painful and mesothelioma patients cannot feel the radiation inside their body. Some patients may be able to receive this treatment in the home, but certain safety precautions still must be taken. A team of radiation specialists will inform the patient on what they must do after receiving systemic radiation therapy.