Mesothelioma Questions

Post-operatively, curative or palliative, or as a noninvasive palliative treatment plan, radiation therapy, or radiotherapy, may be utilized. High-energy beams or particle-streams penetrate the affected areas. After an extrapleural pneumonectomy, intensity modulated radiation therapy (IMRT) can be used to eradicate remaining disease, inhibit growth, or prevent metastases.

Current treatment mechanisms:

• External uses an x-ray machine to administer the radiotherapy.
• Internal involves radioactive substances placed within the body. The radioactive materials are contained within a catheter, needle, seed or wire.
• To control radiation so that is does not adversely affect nearby tissue, a multi-modality approach may be employed. With IMRT, computer images guide the radiation to a specific cancerous area.
• Helical Tomotherapy, the newest, uses 3-D images from a CT scanner to determine the tumor/target size and location, and at-risk areas nearby. The computer generates specifics for the patient’s position, exact dosage and x-ray machine settings.

Depending upon the patients age, health and desires, and the cancer’s stage, location, and extent/metastases, the following may be possible:

Pleural: When surgery is not considered curative, treating just the symptoms, palliative surgical intervention, is aimed mostly at pleural effusion. To reduce/remove the excessive fluid, one or more of the following may be utilized:

chest Tubes, pleurodesis, or pleuroperitoneal shunt. Curative, more radical, approaches are pleurectomy or decortication to remove larger areas of the pleura or most/all of a tumor, and pneumonectomy to excise part or all of a lung. Extrapleural pneumonectomy is the most radical and also removes part of the chest wall, pericardium and diaphragm.

Peritoneal: Cytoreductive surgery for tumor-removal or peritonectomy to remove part of the peritoneum.

Pericardial: If diagnosed early and the tumor(s) is/are small, removal can be considered, but if in close proximity to the heart, it is high-risk.

Non-invasive:

• Comprehensive physical exam to determine general health
• Personal/medical history with regard to amount or period of exposure to asbestos
• X-rays, or a more-detailed Computed Tomographs (CTs), of the chest and abdomen to determine the extent of fluid, size and location of a tumor/mass,and rule out other cancers
• Magnetic Resonance Imaging (MRI) for a nonradiological look at the chest and abdomen for the above determinations
• Pulmonary function tests indicate the extent to which the lungs’ capabilities have been compromised

Invasive:

• Thoracentesis to determine the composition of the pleural fluid (cloudy exudates for mesothelioma), and to rule out congestive heart disease (clear transudates); or Paracentesis of the abdomen.
• Thoracoscopy or Video-Assisted Thoracic Surgery(VATS) for pleural, Laparoscopy for peritoneal, or Mediastinoscopy (examine sternal lymph nodes) to view the areas, and take a biopsy to determine the cancer’s origin and to rule out other types.

Mesothelioma is caused by prolonged exposure to asbestos. Most cases occur in those working in direct contact, but it can be acquired indirectly by the asbestos that workers bring into their homes or by living near a

manufacturer.

Pleural: Most common symptom, pleural effusion, occurs when mesothelial cells in the visceral and parietal pleura overproduce fluid. This may lead to shortness of breath, pain/difficulty breathing and a persistent cough. Less often, fever, weight-loss and/or night sweats. Patients may have no symptoms or just a feeling of malaise or being unwell.

Peritoneal: Accumulated peritoneal fluid causes abdominal swelling, pain with nausea and weight-loss, and possibly a palpable mass. Less commonly is anemia, pedal edema, bowel obstruction and/or abnormal clotting.

Pericardial: Symptoms can be very similar to pleural mesothelioma and other maladies of the heart and/or lungs, but may also include exertion-induced chest pain, palpitations, and face and upper-extremity swelling.

Mesothelioma is a cancer that can affect the lungs, abdomen and/or heart. This type of lung cancer is considered rare. It affects the thin mesothelium membranes, both parietal and visceral, that surround the lungs.

Instead of creating tumors, as with most cancers, mesothelioma expands outward from the thin layers of tissue in the mesothelium to compress the lung, heart or abdominal organs/cavity. In pleural mesothelioma, the tissue surrounding the lungs becomes hardened, causing friction with the chest wall. This makes it very painful to breathe, as the lungs attempt to expand to normal capacity. The types are named for the anatomy affected: pleural (comprises approximately two-thirds of the cases), peritoneal (stomach/abdomen in less than one-third of the cases) and pericardial (the rarest form, affecting the sac surrounding the heart).

Asbestos is a mineral with silicate fibers and it occurs naturally in the environment. There is no acceptable level of exposure to asbestos.

The occupations in which the workers are known to be at greatest risk of developing mesothelioma include: mining, construction, electrical, heating, insulation, carpentry, roofers, milling and shipyard work. The families are also at risk for secondary exposure from the asbestos fibers carried home on clothing and hair.

Asbestos was used for roof and wall insulation, furnace, duct, and pipe insulation, in textured wall and ceiling paints, vinyl flooring, cement, wood pulp, deck under sheeting, and walls behind stoves and fireplaces.

A qualified environmental technician should be called to evaluate the removal or sealing of the asbestos. If the materials containing asbestos are not frayed or broken, they are usually left in place.

Once asbestos fibers are inhaled, they are deposited in the parenchyma of the lungs where they may penetrate the visceral pleura, to be carried to the pleural surface where the malignancy may form. The route of peritoneal and pericardial involvement has not been proven, but one theory is that the asbestos fibers travel via the lymphatic system. Another possibility for peritoneal involvement is through ingestion of the fibers from swallowing sputum that is contaminated with asbestos.

Serum Osteopontin testing might be used for ascertaining exposure to asbestos. The soluble mesothelin-related protein is elevated in 75% of patients diagnosed with mesothelioma. The Mesomark Assay, developed in 2007, measures the soluble mesothelin-related proteins (SMRP’s) released by the affected mesothelioma cells. This level correlates with the tumor size, permitting less invasive and improved assessment or tumor treatment response.

The symptoms of peritoneal mesothelioma vary due to the location and may include abdominal mass, mild to severe abdominal pain, distention of the abdomen, bowel obstruction, fatigue, weight loss, anemia, ascites and fever.

Since these symptoms are frequently mistaken for other illnesses, the diagnosis if often missed.  A thorough patient history is very important to determine any past exposure to asbestos.

Traditional x-rays, CT scan, MRI, PET scans, and Peritoneoscopy with tissue biopsy are used to determine the diagnosis. Peritoneal mesothelioma is often diagnosed at a late stage.

Treatments include: Cytoreductive surgery, debulking of the tumor which results in no peritoneal seeding found or only nodules of less than 2.5 cm are left. These nodules are thought to be responsive to intraperitoneal chemotherapy, intraperitoneal hyperthermic chemotherapy (IPHC) and/or radiation. Thermotherapy may also be used to increase the cellular response to the chemotherapy agents.

The Columbia Protocol is a clinical trial in which exploratory thorascopic surgery is used to administer intraoperative intrapleural chemotherapy. It differs from traditional surgical approaches in that it is less invasive and does not involve removal of the lung. A mediport-attached catheter is placed in the pleural space to allow for chemotherapy treatments post surgery. The goal is to achieve regression of the tumor by local therapy in combination with minimal surgery and radiation. The catheter is removed after several weeks, and the tumor is biopsied to assess the effects of the treatment.

This clinical trial is meant to demonstrate that extremely debilitating lung-removing surgeries may not be necessary in the future for the desired results in treating pleural mesothelioma.

Asbestos enters the body by way of inhalation or ingestion. Those fibers that enter the airways, work their way through the lung tissue and end up in the pleural cavity. Epithelial or sarcomatoid cells react and form nodules that progress into a solid tumor surrounding the lungs. This process can take 20 to 50 years from the time of exposure. The length of exposure as little as 1-2 months can cause mesothelioma to develop many years later. The symptoms of the malignancy usually begin with shortness of breath. Chest pain that is non-pleuritic (does not increase on inhalation) is common. As the disease progresses, shortness of breath increases, there is loss of appetite, weight loss, change in voice, decreased function of the diaphragm, and swelling of the abdomen. The accumulation of fluid between the lungs and chest cavity is a classic symptom. Testing methods include X-rays, MRI’s CT scans, Thoracoscopy and Bronchoscopy. A definitive diagnosis is made using a pathological examination from a biopsy.