The development of a simple and effective blood test for the diagnosis of mesothelioma is one of the primary goals of current research into the disease. If researchers could identify biological markers specific to pleural mesothelioma or peritoneal mesothelioma, doctors would likely be able to diagnose the disease in its earlier stages. As it currently stands, mesothelioma is not often diagnosed until symptoms indicative of advanced disease require a trip to one’s doctor. If physicians were able to diagnose the disease earlier, treatments would also begin much earlier, which could greatly maximize a patient’s overall prognosis. A number of studies have shown that early stage diagnosis is one of the most important factors in achieving significant survival figures after mesothelioma treatment.

A number of markers have been proposed for this purpose, but a single one has not yet emerged as standard from the wide variety of studies that are currently being conducted. The mesothelin gene family produces a number of candidate markers that are under active investigation. Researchers from Japan have recently released the results of a study they conducted which compared two of these potential markers: megakaryocyte potentiating factor (MPF) and mesothelin variants (MSLN). Their study hopes to identify which of these substances is a more effective marker for the diagnosis of mesothelioma.

Overview of the Study

MPF and MSLN are separate products from the same glycoprotein precursor, which probably explains their shared sensitivity to mesothelioma. While both have been studied in other programs, their efficacy in the diagnosis of the disease has not yet been compared. To answer this question, the authors collected serum samples from 27 patients with pleural mesothelioma, as well from patients from the following control groups:

1. 47 lung cancer patients.
2. 35 patients with other forms of cancer.
3. 9 asbestos-exposed individuals, presently asymptomatic of any asbestos-related disease.
4. 38 healthy adults without a history of asbestos exposure.

Of the 27 mesothelioma patients, 21 had properly-identified histological subtypes, while 6 were unclassified. Within the histological types identified, 13 were epitheloid mesothelioma, 3 were sarcomatous mesothelioma and five presented with biphasic mesothelioma.

MPF and MSLN concentrations were each measured by a specific sandwich ELISA developed by the authors. Levels were first compared between MPF and each group, and then MSLN and each group, and then a comparison was made regarding which of the two was the most sensitive and specific to mesothelioma.

Results

When comparing MPF levels between the mesothelioma group and the control groups, the authors found a statistically significant difference in median MPF levels between the study group and the controls, with MPF levels always higher in the mesothelioma group as compared to the controls. They also found a significant difference in higher MSLN median levels between the mesothelioma group and all of the control groups, but less so than the MPF group. When comparing between the two, 74.1% of the pleural mesothelioma group had elevated levels of MPF, while 59.3% of the MSLN group demonstrated higher levels. Even though both MPF and MSLN were possibly indicative of mesothelioma, the authors feel that MPF has a higher diagnostic sensitivity than does MSLN.

There were no differences in either MPF or MSLN levels between the mesothelioma group’s histological sub-types.

Due to their success with MPF in this study, the authors are preparing another MPF study that will examine the relationship between MPF and disease stage, prognosis and histology.

Conclusion

The development of a truly effective serum marker for mesothelioma will be an important step in our ability to treat mesothelioma patients. The ability to return a diagnosis before the onset or spread of serious symptoms will mean that patients will have a much better chance to fight the disease. While early stage diagnosis is not the only important factor in the development of a good prognosis, it is certainly a major one, so the positive results of some of the research into more effective diagnostic tools is an encouraging sign for the future of mesothelioma treatment.

Labels: mesothelioma