Surgery
People who are diagnosed with mesothelioma have three main conventional treatment options: surgery, chemotherapy, and radiation therapy.
Surgery for Different Purposes
Surgical options for mesothelioma and other cancers are split into three different categories: diagnostic, curative, and palliative surgery.
· Diagnostic surgery is carried out to determine what is causing a patient’s symptoms. In these cases a sample of tissue or fluid is removed from a site and tested for the presence of diagnostic markers, such as cancer cells.
· Curative surgery attempts to remove as much cancer as possible, in an effort to cure the patient permanently. This type of surgery is usually followed up by chemotherapy or radiation therapy to kill residual cancer cells.
· Palliative surgery is carried out when curing a patient is not an option. These procedures are designed to provide symptomatic relief.
Surgical Procedures for Mesothelioma Diagnosis and Treatment
Biopsy:
This diagnostic procedure removes suspected cancer cells from a site so they can be tested to determine whether cancer is present. There are three types of biopsy procedures: core biopsy (not usually used to diagnose mesothelioma), excisional biopsy, and needle aspiration biopsy.
In an excisional biopsy the intent is to determine how far the cancer has spread. In some cases, the purpose of the surgery may change during the operation itself, and as much cancerous tissue as possible may be removed before completing the procedure.
Needle aspiration uses a very long needle to remove a small sample of cells and fluid from the area. The cells are then tested for the presence of cancer by looking at the shape of cells, the types of proteins they produce, and other diagnostic indicators.
Paracentesis:
This palliative procedure is carried out to remove fluid that has built up in the abdominal cavity of patients with peritoneal mesothelioma. In patients with peritoneal mesothelioma, built-up fluid can cause considerable pain and discomfort because the fluid places pressure on internal organs. During this procedure a very long, hollow needle is inserted into the abdomen to remove the fluid. This procedure can also be diagnostic. In this case, the fluid is removed and tested for the presence of cancer cells.
Pleurodesis:
This is another palliative treatment in which symptomatic relief is achieved for people with pleural mesothelioma (which develops in the lining of the lungs). Undergoing this procedure prevents a side effect of pleural mesothelioma, called pleural effusion. Pleural effusion occurs when fluid builds up in the lungs, causing considerable pain and difficulty with breathing.
During a pleurodesis procedure the pleural spaces are drained of fluid, then treated with a chemical that causes inflammation. The inflammation causes the pleural membrane spaces to close up so fluid cannot build up again.
Pneumonectomy:
This curative procedure involves the complete removal of one lung. This procedure can be carried out on patients who have pleural mesothelioma in one of their lungs. A patient with mesothelioma in both lungs is not usually a good candidate for a pneumonectomy. Similarly if a patient has mesothelioma in one lung but the cancer has metastasized to other organs, they may not be a suitable candidate. A person who undergoes this procedure must also be otherwise healthy, to reduce the possibility of complications that might endanger their health.
Thoracentesis:
This palliative procedure is carried out to remove fluid that has built up in the lungs of patients with pleural mesothelioma. This built-up fluid can cause considerable pain and discomfort because the fluid places pressure on the lungs, and prohibits breathing. During this procedure a very long, hollow needle is inserted to remove the fluid. A thoracentesis may be followed by a pleurodesis to prevent further fluid build-up. In some cases a thoracentesis is also a diagnostic procedure. In this case, the fluid is removed and tested for the presence of cancer cells.
Thoracoscopy:
This procedure is a diagnostic surgery used to diagnose pleural mesothelioma and other lung diseases. In this procedure an incision is made in the chest, through which a long thin tube is inserted. This allows doctors to view the interior of the pleural spaces to determine whether disease is present, and perhaps make a preliminary diagnosis. Samples of suspected cancerous tissue are usually removed so diagnostic tests can be carried out to confirm what type of disease is present.
Thoracotomy:
This generic term refers to lung surgery in which part of one or both lungs are removed. A thoracotomy may be diagnostic, curative, or palliative depending on the circumstances under which the procedure is performed.
There are three main types of thoracotomy surgery: wedge resection, lobectomy, and pneumonectomy. A wedge resection is carried out when tumors are small and localized, and involves removing a section of tissue that is as small as possible. A lobectomy involves the removal of one of the five lobes of the lungs, while a pneumonectomy involves the removal of one entire lung.
Chemotherapy
Broadly speaking, the word chemotherapy can apply to drugs that treat disease by killing cells, but most often, it is used to describe drugs used in cancer treatment.
Most chemotherapy drugs work by targeting specific metabolic processes in cells that are dividing rapidly, and work by preventing cell division or killing these cells. The method of action of these drugs means cancer cells—which are constantly and rapidly dividing—are killed by chemotherapy drugs.
The drawback, however, is that these drugs are not specific. Rather than specifically targeting cancer cells, they target all cells that are dividing rapidly. This means that cells involved in hair growth and cells of the immune system may also be killed when a person undergoes chemotherapy. Furthermore, this means a person undergoing chemotherapy may lose their hair, and is also highly vulnerable to infections.
There are seven chemotherapeutic drugs that are most commonly used to treat mesothelioma. Most of these drugs cause side effects such as nausea, vomiting, and loss of appetite, as well as hair loss and come with a higher risk of developing infections.
Deciding which chemotherapy option is best depends on factors such as the type of mesothelioma , the stage of development, and whether you have any other treatment options. Overall physical health is also important.
Alimta (AKA Premextred):
This drug is usually used in conjunction with Cisplatin to treat people with pleural mesothelioma. In most cases, people who receive this treatment are not good candidates for surgery. Treatment is administered every three weeks, and each session usually lasts around two hours. People receiving these chemotherapy drugs must take B vitamins and folate (also a B vitamin) supplements to help counteract side effects.
Cisplatin:
This chemotherapy drug is used in the treatment of several types of cancer in addition to mesothelioma. When used to treat mesothelioma it is usually used in conjunction with Alimta, as combining the two drugs makes them both more potent. Treatments are administered in two hour sessions every three weeks. Patients must take supplements of folate and other B vitamins to counteract side effects.
Carboplatin:
This drug is a modified version of Cisplatin that has reduced side effects and is generally used in conjunction with non-chemotherapy mesothelioma treatments. For example, it is often administered following surgery to kill any remaining cancer cells. Cisplatin is commonly administered every 28 days, but may be given more frequently in some cases.
People with impaired liver or kidney function are not usually considered candidates to receive Carboplatin treatment due to toxicity issues and side effects.
Gemcitabine:
While this drug is most often used in the treatment of lung, breast, pancreatic, and bladder cancer, it is also a treatment for pleural mesothelioma. In people with pleural mesothelioma, Gemcitabine is usually used after surgery. The surgery is carried out to remove as much of the cancer as possible, and chemotherapy treatment follows this to kill residual cancer cells the surgery could not remove.
Patients may receive Gemcitabine as often as once a week, for up to seven weeks. Depending on the circumstances some patients may be treated for more than seven weeks. A session of treatment usually takes around 30 minutes. As with Carboplatin, this drug is not safe for people who have impaired kidney or liver function.
Navelbine:
This relatively new chemotherapy drug is a semi-synthetic drug derived from the Periwinkle plant. Navelbine is usually administered once a week for several weeks, depending on the individual. This drug has produced positive results for many people with mesothelioma, and has actually been shown to slow the spread of the cancer temporarily. Most people suffer fewer unpleasant side effects when being treated with Navelbine.
Onconase:
This is another new semi-synthetic chemotherapy drug that is derived from an unusual source—the eggs and embryos of the leopard frog. Onconase has been used to treat a wide range of cancers, including mesothelioma. Clinical trials have shown promising results. Many mesothelioma patients have had increased survival times, some up to two years. The drug is administered once per week for several weeks, and each session lasts for around 30 minutes.
Heated Chemotherapy:
This type of chemotherapy treatment is very different from others. While most chemotherapy treatments are administered intravenously, heated chemotherapy is administered during surgical procedures carried out on people with peritoneal mesothelioma (this type of chemotherapy is not an option for any other types of mesothelioma).
Heated chemotherapy proceeds following surgery, which aims to remove the bulk of cancerous tumors from the peritoneal cavity. During the chemotherapy treatment the cavity is perfused with chemotherapy drugs that have been heated slightly above body temperature. The increased heat allows the drugs to penetrate deeper into the tissues. This type of treatment is particularly advantageous in patients for this reason, and because patients experience fewer side effects due to the site-specific delivery of the drugs.
Radiation
Along with surgery and chemotherapy, radiation therapy is one of the three most commonly used treatments for mesothelioma.
Radiation: The Basics
Radiation therapy uses ionizing radiation to kill or slow down the growth of cancer cells. Radiation therapy can be used as a stand-alone treatment, or in conjunction with other treatments such as chemotherapy or surgery. The exact treatment regime a given patient receives depends on the type of cancer, stage of development, and overall general health.
Radiation therapy can be used both as a curative treatment and as a palliative treatment. When used for curative reasons it is commonly administered following surgery that removes the bulk of tumors. In this case the radiation is given to kill any remaining cancer cells not removed during surgery.
In the case of palliative treatment, the cancer is usually too far advanced for surgery to be an effective treatment option. Radiation therapy is given to provide relief from pain by shrinking tumors slightly.
In terms of mesothelioma, radiation therapy is often palliative because mesothelioma cancer is aggressive and highly resistant to treatment. In addition, mesothelioma is often diagnosed too late for curative surgery to be possible. For these reasons, it is very rare for any type of mesothelioma treatment to be effective in the long term. Mesothelioma has an almost 100 percent mortality rate.
There are three main types of radiation therapy: external beam radiotherapy, unsealed source radiation therapy, and brachytherapy. Generally only external beam radiotherapy and brachytherapy are used to treat mesothelioma, while unsealed source radiotherapy is used for other reasons. The type of radiation treatment patients receive depends on several factors, including the type of mesothelioma they have, the stage the disease is at, and whether they have any other treatment options.
External Beam Radiotherapy
External Beam Radiotherapy is the most commonly used type of radiation therapy for the treatment of cancer, and for mesothelioma. During this procedure, the patient sits or lies down in a position that exposes the treatment area, and a beam of radiation is directed at the treatment area.
A patient will usually receive several treatments. The net result is that the radiation kills cancer cells and limits the rate at which new cancer cells can grow and spread. However, it is not typically feasible for all tumor cells to be killed. External beam radiotherapy is usually a palliative treatment carried out to relieve pain, or is carried out in conjunction with surgery or chemotherapy.
Brachytherapy
Also known as “sealed source radiation therapy,” brachytherapy involves the implantation of tiny radioactive rods in or near tumors. In addition to mesothelioma, this type of radiation therapy is used to treat breast, cervical, and prostate cancer.
The radioactive “seeds” used in brachytherapy are tiny rod-shaped objects that emit radiation in a radius of approximately one centimeter. This very short distance means that the radioactive seeds can deliver concentrated doses of radiation that can be targeted to tumors much more accurately than other types of radiation therapy. In the case of mesothelioma this is an important advantage, because the increased accuracy and penetration is useful in treating a disease that is highly resistant to treatment.
Another important advantage of this type of radiotherapy is that the concentrated and specific dose means healthy tissue is largely unaffected. A radioactive seed can be implanted in a tumor, and then emits radiation in only a one centimeter range, so the healthy tissue surrounding the tumor receives very little radiation and the patient also benefits from side effects that are much less severe. Overall, the patient is in much better health following this type of radiation therapy, and experiences fewer complications or side effects.
People with mesothelioma may receive temporary or permanent treatment, in which radioactive seeds are placed in the patient for a short time and then removed, or are placed and then left in the tumor permanently. In the latter case the seeds emit radiation for only a limited period of time, usually for three to twelve months.
Unsealed Source Radiation Therapy
This type of treatment involves giving a patient a soluble dose of a radioactive substance. It is administered orally or via an injection for the treatment of a limited number of cancers. This treatment is used rarely because people who receive unsealed source radiation actually become radioactive, and can pose a health risk to other people, particularly children and pregnant women. However, unsealed source radiation is not a treatment for mesothelioma.
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