Physicians around the country who treat patients with malignant pleural mesothelioma are getting familiar with the first-ever guidelines for handling this rare disease. The new guidelines were presented in March at the 15th Annual Conference of the National Comprehensive Cancer Network (NCCN) by Lee M. Krug, MD of Memorial Sloan-Kettering Cancer Center in New York.
Mesothelioma is an aggressive cancer of the lining around the lungs and other organs and is caused primarily by exposure to asbestos. In the United States, about 2,000 people annually are diagnosed with the disease, which can lay dormant for 20 to 50 years after contact with asbestos. It is four times more common in men than in women.
Although there have been accepted practice standards for treating mesothelioma since the disease first began to attract the attention of the medical community in the 1970’s, the NCCN guidelines represent the first comprehensive blueprint for tackling this hard-to-treat cancer. Diagnosis is typically made through a combination of CT or PET scanning, X-rays, history of asbestos exposure, blood serum tests and/or tissue biopsy. Although mesothelioma can affect other parts of the body, pleural mesothelioma, which occurs in the space around the lungs, is the most common type.
When mesothelioma is suspected, the new NCCN guidelines recommend Positron Emission Tomography (PET) scanning for pretreatment evaluation. Dr. Krug says this test can detect metastases – or places in the body to which the cancer has spread – in about ten percent of cases. Size and location of these metastases will impact treatment approach.
For Stage I and Stage II mesothelioma, surgery is usually recommended as long as the patient is healthy enough to tolerate it. There are two main types of surgery for pleural mesothelioma – pleurectomy/decortication and extrapleural pneumonectomy. During pleurectomy/decortication, the surgeon removes the involved pleura (in the space between the lung and the chest wall) and frees the lung to expand again, reducing symptoms.
Extrapleural pneumonectomy removes not only the cancerous pleura, but the affected lung, diaphragm and pericardium, as well. Major complications may occur in 20 to 40 percent of cases. Although the NCCN guidelines support extrapleural pneumonectomy as a reasonable option for otherwise healthy patients, Dr. Krug says it is unclear whether either surgery offers a survival advantage.
For most mesothelioma patients, the new guidelines recommend a multi-modality approach, combining surgery with chemotherapy and post-surgical radiation. In one study, patients who completed all three of these treatments had a median survival of 29.1 months, compared to 16.8 months for patients who did not complete all of these treatments.
The guidelines recommend a combination of premetrexed and cisplatin chemotherapy drugs as the ‘standard first-line treatment’, but leave it up to individual physicians to decide whether it should be administered before or after surgery. Because of its tendency to damage healthy lung tissue, radiation is only recommended after surgery or as a palliative measure. Dr. Krug said the new mesothelioma guidelines are derived from evidence-based research and are the consensus of a panel of thirty-five oncologists, surgical oncologists, radiation oncologists, pathologists and hematology oncologists.
Sources: Mulcahy, Nick. “First-Ever Guideline on Mesothelioma Issued by NCCN”, March 17, 2010. Medscape Medical News. Video Interview. NCCN 2010: Dr. Lee Krug, Memorial Sloan-Kettering Cancer Center, March 17, 2010. HCP Live Network.