PNDRI | Nov 11, 2003: PNRI Team Develops New Blood Test for Mesothelioma

Frequently Asked Questions

Here are some of the most frequent questions about mesothelioma diagnosis and the detection of SMR proteins in serum. For more detailed background information, contact Rich Murphy, Director of Community Relations at PNRI, 206-726-1200, rmurphy@pndri.org.

What is mesothelioma?

Mesothelioma is a relatively rare cancer that begins in the mesothelium, the protective membrane lining of the abdomen or chest cavity. In almost 75% of cases, mesothelioma occurs in the lining around the lungs, though it may also begin in the peritoneum or around the heart.

Like other cancers, mesothelioma progresses through multiple stages-from the lining to the lymph nodes, then to the chest wall, abdomen, or heart, and then to distant organs and tissues.

(source: National Cancer Institute)

What is the incidence of mesothelioma?

The American Cancer Society estimates that there are between 2000 and 3000 new cases of mesothelioma each year, with the numbers rising. Though still rare, mesothelioma is a very serious disease. Most cases are diagnosed in late stages, and the average survival rate for patients with mesothelioma at all stages is only one year.

(source: American Cancer Society)

What is the major risk factor for mesothelioma?

Mesothelioma is most frequent among persons who have been exposed to high and prolonged levels of asbestos. Some patients, however, have developed mesothelioma without any apparent asbestos exposure. According to the National Cancer Institute, 70%-80% of mesothelioma patients report asbestos exposure at work--in asbestos mines, shipbuilding, or construction, especially since World War II. Men are more likely to develop mesothelioma than women. Symptoms may not appear for thirty to fifty years after exposure.

(source: National Cancer Institute)

How is mesothelioma traditionally diagnosed?

Early symptoms are typically general and thus often not recognized as manifesting mesothelioma. Tests currently used for diagnosing the cancer are imaging tests, tissue samples, and surgery. Even with the most invasive of these tests, mesothelioma cells are difficult to identify.

(source: American Cancer Society)

What does the current study in Lancet show?

Researchers demonstrate that mesothelioma can be detected in a new, reliable, and less invasive way than has been available up to now. They show that a family of proteins very common to mesothelioma, but very rare in other cells-soluble mesothelin-related proteins, SMR-can be used to recognize the presence of mesothelioma tumor cells. This finding suggests that for the first time a clinical blood test for malignant mesothelioma may be possible and earlier diagnosis of the disease may be within reach.

How many patients were tested in the new study?

Blood samples from 273 human subjects were assayed in blind, coded tests. 44 of the samples came from patients with histologically proven mesothelioma, and 68 from matched healthy controls. (40 of the healthy controls had been exposed to asbestos, 28 had not.) 161 of the samples came from patients with other inflammatory or malignant lung and pleural diseases, but not mesothelioma.

84% of those with mesothelioma contained the SMR marker, while only 1.9% of those with other lung and pleural diseases did. Of the 28 samples from subjects who had not been exposed to asbestos, none contained the marker.

Seven of the 40 healthy individuals who had been exposed to asbestos also exhibited increased serum SMR levels. Three of those 7 developed mesothelioma within 1 to 5 years. None of the 33 asbestos-exposed subjects whose sera had normal SMR levels and who were followed for over 8 years developed mesothelioma.

Which researchers were involved in the Lancet study?

The principal investigator of the mesothelioma study is Dr. Ingegerd Hellstrom of the Pacific Northwest Research Institute in Seattle. In collaboration with Dr. Karl Erik Hellstrom, the Hellstrom group designed the SMR assay and conducted all the coded tests. The serum samples were provided by Bruce W. S. Robinson and his colleagues at the University of Western Australia and the Queen Elizabeth II Medical Centre, in Perth, Australia. Dr Robinson has been working with mesothelioma patients for many years. His collaboration with the Hellstroms grew out of this experience and from his interest in devising better means to diagnose and treat patients.

What commercial application of these research findings is underway?

Fujirebio Diagnostics (FDI), of Malvern, Pennsylvania, has acquired the rights from Pacific Northwest Research Institute (PNRI, now PNDRI) to develop the newly discovered mesothelioma tumor marker. A leading oncology diagnostics company, FDI is working to create an effective clinical blood test using SMR for improved diagnosis of mesothelioma. FDI is in the process of initiating the clinical development and commercialization phases of this project.