Once rare, malignant pleural mesothelioma can no longer be considered uncommon because widespread use of asbestos since the 1950s has led to increases in incidence and deaths of the asbestos-related disease, eleven Italian physicians say in a consensus opinion.

In industrialized countries, the prevalence of malignant pleural mesothelioma, a cancer of the lining of the lung, has increased considerably in the past two decades and is expected to peak by 2020, the doctors say.

In Italy, nearly 1,200 people a year are diagnosed with the disease. Mesothelioma is most prevalent among people ages 55 to 74 years and the incidence varies widely by region. The median survival was about 10 months, based on a study of 4,100 cases, and 10 percent of patients were alive three years after their diagnosis. In the United States, 2000 to 3000 new cases of mesothelioma are diagnosed each year.

Patients with malignant mesothelioma usually experience symptoms of excess fluid in the chest cavity. Other symptoms including labored breathing, chest pain and a persistent cough often accompany the excess fluid.   Diagnosis of malignant mesothelioma often starts with examination of samples of the fluid from the chest cavity. But a reliable diagnosis based exclusively on examination of pleural fluid is extremely challenging, the physicians say.  In fact, malignant mesothelioma is a famously difficult tumor to evaluate, they say.

A biopsy of tissue of the lining of the lung is the primary method to diagnose malignant mesothelioma. But a definitive diagnosis should always be based on a multi-step approach including medical and work history, clinical findings as well as a tissue biopsy.

 The collection of tissue with a thorascope, a narrow-diameter tube with a camera attached, provides the highest diagnostic accuracy. Mesothelioma can be diagnosed by thorascopy in more than 90 percent of cases. Needle biopsies and examination of pleural fluid have less value as diagnostic tools, providing a diagnosis in about 40 percent of cases, the physicians say.

Doctors and clinicians still rely on a CT scan of the chest and upper abdomen to assess the stage of the malignant mesothelioma. A CT scan is a picture of structures inside the body created by a computer using multiple xrays. But non-invasive imaging tests understate how advanced the cancer is in about half of patients with malignant mesothelioma, the physicians say. In patients with apparently removable tumors, a more aggressive examination approach involving insertion of a pleuroscope into the chest cavity can be worthwhile, they say.

Patients who are candidates for surgery should undergo a lung function evaluation. Patients with abnormal lung function are at increased risk of complications from surgery and long-term disability.  The pulmonary function assessment is particularly important for patients who are to undergo an extrapleura pneumonectomy—radical surgery to remove a diseased lung, part of the membrane lining the chest and covering the heart, and part of the diaphragm. The goal is to remove the entire mesothelial lining.

Patients best suited for radical surgery will have mesothelioma confined to only half their chest cavity, no indications that the cancer has spread to other organs or lymph nodes and no evidence of abnormal accumulation of fluid around the heart. Patients with stage I, stage I and, in selected cases, stage III mesothelioma may be candidates for this surgery.

The identification of any spread of malignant mesothelioma to the lymph nodes is important. Invasive approaches are preferable for more accurate assessment of the lymph nodes before surgery. The presence of cancer in the lymph nodes argues against radical surgery. When the cancer has spread to the lymph nodes, the cancer has reached an advanced stage and the patient’s prognosis is poor.

 In addition, surgery often reveals cases of mesothelioma that has spread to the lymph nodes without detection. Patients with mesothelioma that has moved  to lymph nodes have a survival rate that is nearly 50 percent lower than the patients in whom the disease remains contained.

Surgery should be considered as part of a multi-pronged approach to treating mesothelioma. The largest published study of treating mesothelioma patients with radical surgery followed by chemotherapy is the experience of Dr. David Sugarbaker and colleagues at Brigham and Women’s Center  in Boston, who treated 183 patients over nearly two decades with extrapleural pneumonectomy followed by platinum-compound chemotherapy and radiation. The median survival was 19 months. More than a third of the patients survived two years and 15 percent remained alive at five years after surgery. A retrospective analysis of 633 patients treated at Sloan Kettering Memorial, National Cancer Institute and Karmanos Cancer Center —half of whom received chemotherapy and radiation after surgery—showed some improvement in survival.

Approximately 85 to 90 percent of mesothelioma patients have inoperable tumors by the time they are diagnosed, the physicians say. Such patients require palliative treatment to ease the pain and discomfort of the disease. A wide variety of chemotherapy drugs have been evaluated in the treatment of mesothelioma. The response rate and survival are generally better for patients taking combinations of chemotherapy drugs than just one drug and also better for platinum-containing compounds. The combination of cisplatin and pemetrexed is the only registered chemotherapy for malignant pleural mesothelioma. It is considered the standard first-line therapy for younger patients with generally good well-being and no diseases or disorders besides mesothelioma. Gemcitabane in combination with cisplatin or carboplatin also has been reported to be effective in 20 to 47 percent of patients, though no comparative studies are available.

The panel of physicians recommended chemotherapy with a pemetrexed-platinum combination for patients with advanced malignant pleural mesothelioma and generally good well-being. They agreed that chemotherapy should begin early at the time of diagnosis and delivered for a maximum of four to six courses.