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Sunday, November 4, 2007
Saturday, November 3, 2007
Mesothelioma
Mesothelioma
Mesothelioma is a rare form of cancer in which malignant (cancerous) cells are found in the mesothelium, a protective sac that covers most of the body’s internal organs. Most people who develop mesothelioma have worked on jobs where they inhaled asbestos particles.
What is the mesothelium?
The mesothelium is a membrane that covers and protects most of the internal organs of the body. It is composed of two layers of cells: One layer immediately surrounds the organ; the other forms a sac around it. The mesothelium produces a lubricating fluid that is released between these layers, allowing moving organs (such as the beating heart and the expanding and contracting lungs) to glide easily against adjacent structures.
The mesothelium has different names, depending on its location in the body. The peritoneum is the mesothelial tissue that covers most of the organs in the abdominal cavity. The pleura is the membrane that surrounds the lungs and lines the wall of the chest cavity. The pericardium covers and protects the heart. The mesothelial tissue surrounding the male internal reproductive organs is called the tunica vaginalis testis. The tunica serosa uteri covers the internal reproductive organs in women.
Mesothelioma (cancer of the mesothelium) is a disease in which cells of the mesothelium become abnormal and divide without control or order. They can invade and damage nearby tissues and organs. Cancer cells can also metastasize (spread) from their original site to other parts of the body. Most cases of mesothelioma begin in the pleura or peritoneum.
How common is mesothelioma?
Although reported incidence rates have increased in the past 20 years, mesothelioma is still a relatively rare cancer. About 2,000 new cases of mesothelioma are diagnosed in the United States each year. Mesothelioma occurs more often in men than in women and risk increases with age, but this disease can appear in either men or women at any age.
Working with asbestos is the major risk factor for mesothelioma. A history of asbestos exposure at work is reported in about 70 percent to 80 percent of all cases. However, mesothelioma has been reported in some individuals without any known exposure to asbestos.
Asbestos is the name of a group of
minerals that occur naturally as masses of strong, flexible fibers that can be separated into thin threads and woven. Asbestos has been widely used in many industrial products, including cement, brake linings, roof shingles, flooring products, textiles, and insulation. If tiny asbestos particles float in the air, especially during the manufacturing process, they may be inhaled or swallowed, and can cause serious health problems. In addition to mesothelioma, exposure to asbestos increases the risk of lung cancer, asbestosis (a noncancerous, chronic lung ailment), and other cancers, such as those of the larynx and kidney.Smoking does not appear to increase the risk of mesothelioma. However, the combination of smoking and asbestos exposure significantly increases a person’s risk of developing cancer of the air passageways in the lung.
Who is at increased risk for developing mesothelioma?
Asbestos has been mined and used commercially since the late 1800s. Its use greatly increased during World War II. Since the early 1940s, millions of American workers have been exposed to asbestos dust. Initially, the risks associated with asbestos exposure were not known. However, an increased risk of developing mesothelioma was later found among shipyard workers, people who work in asbestos mines and mills, producers of asbestos products, workers in the heating and construction industries, and other tradespeople. Today, the U.S. Occupational Safety and Health Administration (OSHA) sets limits for acceptable levels of asbestos exposure in the workplace. People who work with asbestos wear personal protective equipment to lower their risk of exposure.
The risk of asbestos-related disease increases with heavier exposure to asbestos and longer exposure time. However, some individuals with only brief exposures have developed mesothelioma. On the other hand, not all workers who are heavily exposed develop asbestos-related diseases.
There is some evidence that family members and others living with asbestos workers have an increased risk of developing mesothelioma, and possibly other asbestos-related diseases. This risk may be the result of exposure to asbestos dust brought home on the clothing and hair of asbestos workers. To reduce the chance of exposing family members to asbestos fibers, asbestos workers are usually required to shower and change their clothing before leaving the workplace.
Symptoms of mesothelioma may not appear until 30 to 50 years after exposure to asbestos. Shortness of breath and pain in the chest due to an accumulation of fluid in the pleura are often symptoms of pleural mesothelioma. Symptoms of peritoneal mesothelioma include weight loss and abdominal pain and swelling due to a buildup of fluid in the abdomen. Other symptoms of peritoneal mesothelioma may include bowel obstruction, blood clotting abnormalities, anemia, and fever. If the cancer has spread beyond the mesothelium to other parts of the body, symptoms may include pain, trouble swallowing, or swelling of the neck or face.
These symptoms may be caused by mesothelioma or by other, less serious conditio
How is mesothelioma diagnosed?
Diagnosing mesothelioma is often difficult, because the symptoms are similar to those of a number of other conditions. Diagnosis begins with a review of the patient’s medical history, including any history of asbestos exposure. A complete
physical examination may be performed, including x-rays of the chest or abdomen and lung function tests. A CT (or CAT) scan or an MRI may also be useful. A CT scan is a series of detailed pictures of areas inside the body created by a computer linked to an x-ray machine. In an MRI, a powerful magnet linked to a computer is used to make detailed pictures of areas inside the body. These pictures are viewed on a monitor and can also be printed.A
biopsy is needed to confirm a diagnosis of mesothelioma. In a biopsy, a surgeon or a medical oncologist (a doctor who specializes in diagnosing and treating cancer) removes a sample of tissue for examination under a microscope by a pathologist. A biopsy may be done in different ways, depending on where the abnormal area is located. If the cancer is in the chest, the doctor may perform a thoracoscopy. In this procedure, the doctor makes a small cut through the chest wall and puts a thin, lighted tube called a thoracoscope into the chest between two ribs. Thoracoscopy allows the doctor to look inside the chest and obtain tissue samples. If the cancer is in the abdomen, the doctor may perform a peritoneoscopy. To obtain tissue for examination, the doctor makes a small opening in the abdomen and inserts a special instrument called a peritoneoscope into the abdominal cavity. If these procedures do not yield enough tissue, more extensive diagnostic surgery may be necessary.If the diagnosis is mesothelioma, the doctor will want to learn the stage (or extent) of the disease. Staging involves more tests in a careful attempt to find out whether the cancer has spread and, if so, to which parts of the body. Knowing the stage of the disease helps the doctor plan treatment.
Mesothelioma is described as localized if the cancer is found only on the membrane surface where it originated. It is classified as advanced if it has spread beyond the original membrane surface to other parts of the body, such as the lymph nodes, lungs, chest wall, or abdominal organs.
Mesothelioma Risk
Mesothelioma and Asbestos
Asbestos-related deaths have increased fourfold in the past three decades. Although asbestos exposure causes mesothelioma, the latency period after exposure could last 15 to 50 years. This means if you worked in a job with asbestos 40 years ago you could be developing mesothelioma now. If you were exposed to loose asbestos fibers, you should be tested regularly for mesothelioma.
Virtually all cases of mesothelioma are related to inhaling of asbestos fibers. There are about 3,000 cases per year (mostly men over the age of 40) and there will be about 300,000 cases before 2030. Mesothelioma usually spreads rapidly through the mesothelial cells to the heart and abdominal organs. The life span is typically 24 months after diagnosis, but it depends on what stage the cancer is detected, the health of the patient and other factors.
The onset of mesothelioma symptoms usually takes a long time. The first symptom is often a constant chest pain. This pain is later accompanies by difficulty breathing due to an accumulation of fluid in the chest. Other symptoms include coughing, fever and weight loss. Mesothelioma can be diagnosed by your doctor with a chest CT-scan.
The FDA recently approved a new drug used to treat malignant pleural mesothelioma, a rare cancer usually associated with asbestos exposure.
The drug is called Alimta, or pemetrexed disodium, and it's distributed by Eli Lilly and Company. Alimta is intended to be used along with cisplatin. If you have mesothelioma, you should ask your doctor about this drug to see if it is right for you.
MESOTHELIOMA TREATMENT OPTIONS
The treatment program for mesothelioma depends on many factors, including: the stage of the cancer, where the cancer is, how far the cancer has spread, how the cancer cells look under the microscope and the patient’s age and desires.
TIME MATTERS
People diagnosed with this disease are often told the expected survival rate is only eight to twelve months. However, specialists in treating malignant mesothelioma at the leading cancer centers often have better statistics.
For instance, the five-year survival rate has approached 40% for selected patients of Dr. David Sugarbaker at Brigham and Women’s Center in Boston. To qualify for Dr. Sugarbaker’s treatment you must meet certain criteria. One of them is being in the early stages of the disease, so time is of the essence.
TRADITIONAL CARE
There are three traditional kinds of treatment for patients with malignant mesothelioma:
--Surgery (taking out the cancer)
--Chemotherapy (using drugs to fight the cancer)
--Radiation Therapy (using high-dose x-rays or other high-energy rays to kill cancer cells)
Often two or more of these are combined in the course of treatment.
MESOMARK BLOOD TEST
In January 2007, the Food and Drug Administration (FDA) approved the MESOMARK assay to help monitor response to treatment in epithelial and bi-phasic malignant mesothelioma patients. A specific protein, or biomarker, called Soluble Mesothelin-Related Peptide (SMRP), may be released into the blood by mesothelioma cancer cells. By measuring the amount of SMRP in a blood sample, doctors may be able to better monitor a patient's progress. Based on the limited amount of data currently available, use of this test may be beneficial, but effectiveness has not been determined at this time. The MESOMARK blood test has NOT yet been approved for the early diagnosis of mesothelioma.
This test has been approved as a Humanitarian Use Device (HUD), meaning that physicians must follow certain procedures to qualify their patients for testing. Once the physician is certified, informational brochures will be sent to be distributed to each applicable patient.
Those wishing to take part in MESOMARK testing will be asked to provide one or more samples of blood. The blood samples will then be sent to a national reference laboratory for testing. In conjunction with other clinical and laboratory data obtained by your doctor, decisions regarding your treatment and care may be simplified. You may discontinue testing at any time.
The costs associated with the MESOMARK blood test may not be covered under health insurance, therefore, you may be required to pay all or part of the costs out of pocket. It is recommended that you check with your insurance carrier to determine whether coverage is available under your policy.
SURGERY
Diagnostic Procedures
As previously mentioned in the "Symptoms" section of this website, a diagnosis of mesothelioma from fluid is many times inconclusive. Given this fact, diagnostic surgery becomes a necessary next step in confirming and staging mesothelioma.
Thoracoscopy enables a physician to evaluate the pleural cavity and to conduct multiple tissue biopsies under direct vision. In up to 98% of cases, a definitive diagnosis can be obtained. Often, chemical pleurodesis aimed at relieving the accumulation of fluid in the intrapleural space, can be accomplished during the same procedure. It is also possible to gauge the extent of the tumor, and make a determination of surgical resectability. While less invasive than an open biopsy, it can only be performed on patients where tumor has not obliterated the pleural space.
VATS, or video-assisted thoracic surgery is an alternative to thoracoscopy, although because of its more invasive nature, concerns of tumor seeding increase. By utilizing small incisions, the physician can view the pleural space with the assistance of a camera, and obtain sufficient tissue samples for analysis by a pathologist. Extent of the tumor (i.e., pleural involvement, chest wall invasion) may also determined, and recommendation as to the type of debulking procedure necessary can be made at this time.
Mediastinoscopy is sometimes used as an aid in staging extent of disease when enlarged nodes are seen using imaging techniques.
Laproscopy is used in mesothelioma patients in cases where imaging techniques suggest possible invasion of the tumor through the diaphragm. This information can be important in evaluating a patient for potential pleurectomy or extrapleural pneumonectomy.
Palliative Procedures
Palliative surgical procedures are those which treat a symptom of mesothelioma, without aggressively treating the disease itself.
Chest Tube Drainage and Pleurodesis is considered the most common of palliative treatments. Fluid build-up, or pleural effusion, is most often the first symptom which will prompt mesothelioma patients to seek medical attention. Once this effusion has occurred, it is many times persistent, returning rapidly after initial thoracentesis (draining of the fluid). In order to eliminate this problem, the pleural space must be closed. This is accomplished by use of a talc slurry or other sclerosing agent which produces an adhesion.
Thoracoscopy and Pleurodesis is done in conjunction with VATS using a powdered form of talc versus talc slurry. Both this and chest tube drainage and pleurodesis will be only effective if there is no tumor encasing the lung which restricts its expansion.
Pleuroperitoneal Shunt plays a limited role in palliation for several reasons. It involves placement of a catheter run under the skin from the pleural to the peritoneal cavity. Obstruction of the catheter and possible seeding of the tumor into the abdominal cavity may be concerns.
Pleurectomy, used as a palliative procedure, may be performed where more extensive surgery is not an option. In these cases, it is understood that all visible or gross tumor will not be removed. It is considered the most effective means of controlling pleural effusion in cases where the lung's expansion is restricted by disease.
Potentially Curative Procedures
These procedures are performed with "curative intent". Their goal is removal of all gross disease, with the knowledge that microscopic disease will most likely remain. Adjuvant therapy (another form of treatment in addition to the primary therapy) is typically aimed at eliminating residual disease.
For Pleural Mesothelioma:
Pleurectomy/Decortication is usually performed on patients with early stage disease (Stage I and selected Stage II), and attempts to remove all gross tumor. If it is found that all tumor can not be removed without removing the lung, this may be done at the same time and is called pneumonectomy.
Extrapleural Pneumonectomy is considerably more radical than other surgical approaches, and should be carried out by surgeons with great expertise in evaluating patients and performing the procedure itself. Because in the past surgery alone has failed to effect a cure, or even to help prolong life for any extended period of time, it is currently being combined with traditional chemotherapy and/or radiation, or other new approaches such as gene therapy, immunotherapy or photodynamic therapy.General Patient Selection Criteria for Extrapleural Pneumonectomy Extrapleural pneumonectomy is a serious operation, and doctors experienced in this procedure choose their patients carefully. It is up to each individual surgeon to advise the patient on its feasibility and to conduct whatever tests he/she feel are necessary to optimize the patient=s chances for survival and recovery. Following is a general list of patient selection criteria. This list may not be all inclusive, and may vary according to the preference of the surgeon.
Karnofsky Performance Status score of >70. This score relates to what symptoms of disease the patient may be experiencing and how well they are able to conduct their daily activities. Some surgeons may require a higher performance status than others.
Adequate renal (kidney) and liver function tests; no significant kidney or liver disease.
-Normal cardiac function per electrocardiogram and echocardiography.
-Adequate pulmonary function to tolerate the surgery.
-Disease limited to the ipsilateral hemithorax (the same side of the chest in which the mesothelioma is located) with no penetration of the diaphragm, extension to the heart or extensive involvement of the chest wall.
Age of the patient is taken into consideration, but may not be as important as their overall status. Surgeries of this nature should always be done with a complete understanding of the possible benefits and risks involved. If you are considering surgery as a treatment option, speak openly with your doctor about your concerns, and be sure all of your questions are answered to your satisfaction.
For Peritoneal Mesothelioma:
Cytoreductive Surgery is aimed at removing all or nearly all of the gross or visible tumor in the peritoneal cavity. In order to treat any remaining cancer cells, Intra-Peritoneal Hyperthermic (heated) Chemotherapy (IPHC) is then delivered to the abdominal cavity. The type of chemotherapy drug used may vary according to the physician’s preference.
CHEMOTHERAPY
Chemotherapy is defined as the treatment of cancer using chemical substances. When cancer occurs, abnormal cells continue to divide uncontrolled. Anticancer, or chemotherapy drugs, work to destroy cancer cells by preventing them from multiplying.
Purposes of Chemotherapy
Chemotherapy may be used to achieve different goals, depending on the stage of the cancer at the time of diagnosis and the age and health of the patient. Since chemotherapy for mesothelioma is not considered "curative", the goal is:
-To control the cancer by stopping its spread or slowing its growth.
-To shrink tumors prior to other treatments, such as surgery. This is called neoadjuvant chemotherapy.
-To destroy microscopic disease which may remain after surgery. This is called adjuvant chemotherapy.
-To relieve symptoms, such as pain. This is called palliative chemotherapy, and is given in cases when a drastic reduction in the tumor is not expected.
The most common use for chemotherapy in mesothelioma patients, is as an option for those who are not surgical candidates, however, various cancer centers are now conducting trials using the neoadjuvant approach. Alimta (pemetrexed) is a new drug recently approved by the Food and Drug Administration (FDA) for use with Cisplatin in the treatment of patients with malignant pleural mesothelioma whose disease is either unresectable or who are not candidates for curative surgery. Alimta is the first drug approval specific to mesothelioma.
The Alimta/Cisplatin chemotherapy regimen is the first Food and Drug Administration (FDA) approved treatment specifically for malignant pleural mesothelioma. This is currently considered the most effective first-line treatment for mesothelioma patients who are not surgical candidates. A multi-targeted antifolate drug, Alimta works by blocking the enzymes necessary for DNA copying and cell division. During the clinical trial process, Alimta/Cisplatin improved median survival for pleural mesothelioma patients by approximately three months over treatment with Cisplatin as a single agent.
As with any medical treatment, it is important to discuss the use of Alimta with your doctor. This conversation should include all pertinent information regarding effectiveness, administration and possible side effects of the drug combination. It is also important to begin vitamin supplementation of B12 by injection during the week prior to treatment (to be repeated every 9 weeks), and folic acid by mouth daily (to be continued until 21 days after the last cycle of Alimta). Additionally, you will be given an oral steroid medication to minimize the risk of skin rash or other possible side effects. Your doctor will have information on the correct dosages of each medication. Be sure to tell your doctor of any other medications you are taking (including non-prescription drugs) so he may be aware of any adverse interactions.
Alimta/Cisplatin is administered to patients on an outpatient basis every 21 days. This cycle of treatment involves a 10-minute IV infusion of Alimta followed by a 2 hour infusion of Cisplatin. How many cycles of treatment you receive will be dependent on your response rate to the drug (regression of the tumor or halt to progression of the disease) and the side effects you might experience.
Side effects of Alimta/Cisplatin are mild to moderate for most mesothelioma patients, i.e., nausea, vomiting and fatigue, and can usually be managed by your doctor. For some patients, however, side effects may be debilitating, and may require a decrease in dosage or removal from the program. All potential side effects should be mentioned to your doctor. Never assume any complaint is minor.
Administration of Chemotherapy
The most common way to administer chemotherapy is intravenously, or through a vein. A thin needle is inserted into a vein in the hand or in the lower arm. Intravenous administration of drugs allows for rapid entry into the blood stream. Drugs may also be delivered via catheters and/or ports.
Catheters are soft, thin, flexible tubes placed into a large vein in the body. They remain in place for as long as they are needed.
The catheter may sometimes be attached to a port, a small round plastic or metal disc placed under the skin on the chest. Ports also remain in place for as long as necessary.
Intraperitoneal chemotherapy may also be delivered through a catheter or a port. The catheter is inserted through the abdominal wall. Chemotherapy drugs can then be infused directly into the abdominal cavity. Ports may also be placed under the skin of the abdominal wall and the catheter tunneled between the skin and muscle into the peritoneum.
Side Effects of Chemotherapy
Cancer cells grow and divide more rapidly than normal cells, but some normal cells also multiply quickly, particularly those in the digestive tract, reproduction system, and hair follicles. It is the damage done to normal cells that causes side effects. The type of side effects you might experience and how severe they are, depend on the type of chemotherapy you are receiving, the dosage given and how your own body reacts. Before beginning any chemotherapy treatment, you will be asked to sign a consent form. Before signing the form, be sure your doctor informs you of all the facts regarding the treatment he/she will be administering, including information about the particular drug or combination of drugs to be used, the possible risks or side effects, the number of treatments you will receive and how often, and whether it will be given during a hospital stay or on an outpatient basis.
Note to Patients:
Chemotherapy treatment should be a cooperative effort between you and your doctor. The interaction that takes place is important to your health. It will not only help you feel better, but will also address any potential problems with miscommunication.
It is necessary for your doctor to be aware of any side effects which may result from your chemotherapy treatment.
These may include:
-Fever of, or greater than 101 degrees
-Nausea or vomiting
-Diarrhea or constipation
-Fatigue
-Tingling or numbness in the fingers or toes
-Ringing in the ears
-Bruises or rashes
-Sores in the mouth or throat
Taking other medication of any kind can alter the effects of chemotherapy or cause undesirable interactions.Be sure you report all over-the-counter and prescribed medicines to your doctor. Don’t take aspirin unless it has been approved by your doctor. Ask your pharmacist if aspirin is contained in any drugs you plan to purchase.
Take extra care with your daily health.Try to maintain a stable weight by eating a healthy diet and drinking plenty of fluids. If your stomach is upset, ask your doctor for helpful hints or work with a nutritionist who can tailor a program to your needs. Brush your teeth after every meal, or if you can’t brush, rinse your mouth thoroughly with water.Stay away from people who have colds or the flu. Chemotherapy can compromise your immune system and lower your resistance to germs. Make sure you keep appointments for blood work – these tests help your doctor monitor your health.
Be open about your feelings regarding your treatment.It is normal to feel sad, angry or afraid, however, letting these emotions get out of control can be detrimental to your overall well-being. Seek out the help of family, friends, your doctor, a counselor or a support group.
RADIATION THERAPY
Radiation therapy, also called radiotherapy, treats cancer by using penetrating beams of high energy or streams of particles called radiation. In treating mesothelioma, radiation may be used aggressively in combination with surgery, or palliatively to control symptoms.
In an aggressive combined modality approach, radiation is used to attack microscopic or residual disease remaining in the chest cavity after extrapleural pnuemonectomy. An example of this is Intensity Modulated Radiation Therapy (IMRT), which uses x-rays of varying intensities in conjunction with computer generated images to deliver targeted radiation directly to cancer cells while reducing the amount of radiation to surrounding healthy tissue.
Used palliatively, radiation can help control metastases (spread) of the tumor along tracks left by invasive procedures such as thoracoscopy, needle biopsy and chest tube drainage, or to control disease symptoms, such as pain or shortness of breath.
