Mesothelioma: Diagnosis & Treatment

Diagnosis

Only a physician can properly diagnose mesothelioma. A review of the patient's medical history, including any past exposure to asbestos, should be conducted for any patient displaying dyspnea, chest pain, fluid build-up, or pain and/or swelling in the abdomen. This review is followed up with a complete physical examination, which should involve the use of imaging techniques. X rays, computed tomography (CT) scans, and magnetic resonance (MRI) scans of the chest and/or abdomen, as well as lung function, can provide the doctor with critical diagnostic information. Although positron emission tomography scans are expensive and not covered under most insurance, this diagnostic tool has proven very useful in determining tumor sites and staging of the disease.

If indicated, the doctor may wish to internally examine the patient's chest and/or abdominal cavity. These diagnostic procedures, known as thoracoscopy(chest) and peritoneoscopy (abdomen), are usually conducted in a hospital setting. Both procedures involve a fiber-optic imaging tool being inserted into the patient through an incision. These endoscopic tools will provide the doctor with a closer look at the body cavity, and any abnormal tissue or fluid build-up found therein. Excess fluid can be suctioned out through a needle or tube, in a process known as thoracentesis (for the chest) or paracentesis(for the abdomen). Additionally, the doctor may perform a biopsy of any abnormal tissue they discover during this time. Pathological examination of abnormal tissue, as well as fluid, remains the only effective method of confirming the diagnosis of mesothelioma. Biopsy will also assist the doctor in properly staging the disease's progression.

Once a confirmation of malignant mesothelioma has been established, the doctor will conduct further tests to determine the extent to which the primary disease has spread. This diagnostic process is known as "staging." Malignant pleural mesothelioma of can be broken into four stages:

• Localized Malignant Mesothelioma (Stage 1)—Cancer is present in the right or left pleura. May involve the lung, the pericardium, or diaphragm on that side.
• Advanced Malignant Mesothelioma (Stage 2)—Cancer has spread beyond the right or left pleura to lymph nodes on that side. May involve the lung, the pericardium, or diaphragm on that side.
• Advanced Malignant Mesothelioma (Stage 3)—Cancer has spread into the chest wall, diaphragm, ribs, heart, esophagus, or through the abdominal lining. Nearby lymph nodes may or may not be involved.
• Advanced Malignant Mesothelioma (Stage 4)—Cancer shows evidence of metastasis or spread through the bloodstream to distant organs and/or tissues.

Recurrent malignant mesothelioma may also occur, where the cancer returns in its original location or elsewhere in the body even after treatment.

Treatment

There are three traditional treatment modalities for mesothelioma: surgery, radiation therapy, and chemotherapy. The location and the stage of the disease, as well as the patient's age and general health, will determine which treatment should be utilized. Additionally, these modalities can be combined if indicated. Indeed, the multimodality approach appears to provide the most positive results for treating mesothelioma.

Surgery, the most common treatment, involves the removal of the tumor. In the early stages of mesothelioma, this only involves removal of a section of the mesothelium and surrounding tissue, but may require removing part of the diaphragm as well. For more advanced stages of the disease, removing the entire lung may be the only option, which is known as pneumonectomy.

Radiation therapy, also known as radiotherapy, destroys and shrinks the cancer cells through various types of radiation. Both external (such as a machine) and internal (such as radioisotopes) radiation therapies can be utilized effectively to treat malignant mesothelioma.

Finally, chemotherapy, a systemic treatment modality, uses anticancer drugs to destroy the cancerous cells throughout the body. The majority of drugs used to treat mesothelioma are delivered intravenously. The effectiveness of intracavitary chemotherapy, the process of directly injecting the drugs into the chest or abdominal cavity, is being studied.

Pain and other symptoms caused by fluid build-up around the chest and/or abdomen can be treated by drain excess fluid through a needle or tube. These procedures are known as thoracentesis (chest) and paracentesis (abdomen). Drugs, radiotherapy, and surgery can also relieve or prevent further fluid accumulation.

Physicians are currently studying other treatment modalities, such as immunotherapy, gene therapy, and intraoperative photodynamic therapy.

Alternative treatment

Due to the poor prognosis associated with mesothelioma, regardless of proper treatment, in many cases palliative care is the preferred, and only, option available to patients. This is particularly true for the advanced stages of the disease. By treating the symptoms rather than the disease itself, the goal of this approach is to obtain "quality" of life instead of "quantity" of life. Palliative care aims to relieve the patient s discomfort caused by dyspnea and pain. Chemotherapy, radiation, and/or surgical pleurodeis, in combination with effective management of pain and respiratory function should form the basis of proper palliative care of mesothelioma. Techniques to reduce stress, such as acupuncture, aromatherapy, massage, and reflexology, can provide addition benefit to the patient's sense of well-being.