Mesothelioma Blood Test Osteopontin Clinical Trial
Continued from: Mesothelioma Diagnosis
Research conducted by Dr. Harvey Pass at Wayne State University focused on the development of a blood test that would detect the presence of early-stage mesothelioma cancer. This experimental blood test was based on the hypothesis that high blood levels of a bone-based glycoprotein called osteopontin is linked with the development of malignant pleural mesothelioma. The study, funded by the National Cancer Institute (NCI), was initially documented in the October 13, 2005 edition of the New England Journal of Medicine.
Dr. Pass' osteopontin blood test clinical study involved 190 people placed into one of three groups: 76 people suffering from malignant mesothelioma, 69 people suffering from a nonmalignant asbestos disease and 45 smokers with no previous history of asbestos exposure.
Preliminary results from the study found that smokers with no previous history of asbestos exposure did not exhibit high levels of osteopontin. Those people suffering from a nonmalignant asbestos disease showed higher levels of osteopontins in accordance with the length of time they were exposed to asbestos. Those suffering from a lung-based nonmalignant asbestos disease who had 10 or more years of exposure to the fibrous mineral had the highest levels.
With respect to the 76 people suffering from malignant mesothelioma, the results were emphatic. Mesothelioma sufferers had osteopontin levels that were approximately six times higher than normal levels. Although these results and the study itself are preliminary, researchers are nonetheless excited with these initial findings, feeling that a potential diagnostic breakthrough is on the horizon for mesothelioma victims.
The primary difficulty in providing effective treatment for mesothelioma victims is the latent nature of the disease. Mesothelioma can require from 20 to 50 years to become symptomatic, during which time the asbestos cancer develops and metastasizes. Once a case of malignant mesothelioma is detected, it has typically grown to such an extent that it is incurable, yielding an average post-diagnostic survival time of between one and two years.
Currently, there is no early-detection test through which to screen the more than 7.5 million American workers with a history of asbestos exposure for the development of mesothelioma. The development of mesothelioma symptoms most often triggers a series of events that result in histological examination of a tissue biopsy. The mesothelial cancer is incurable at the standard point of diagnosis. While it is not universally believed that an earlier diagnosis of mesothelioma could do anything more to provide curative relief to its sufferers, there is a great deal of ongoing research devoted to uncovering such a test.
There has been a great deal of controversy surrounding the efficacy of an early detection test for mesothelioma. Certain researchers believe that additional time would not have too much of an effect on the treatments used to combat mesothelioma. The disease has thus far proven incurable, suggesting that an earlier diagnosis may simply allow for the appearance of a greater survival rate. While those questioning the effectiveness of early detection via osteopontin blood tests believe that the evidence of a link with mesothelioma is weak, they nonetheless encourage the continuation of such research with the hope that it may eventually lead to a mesothelioma breakthrough.
Osteopontin is a type of protein called a glycoprotein (composed of a carbohydrate and protein) that was initially identified in 1986. Osteopontin is an extracellular structural protein of the organic part of bone, giving it the "osteo" classification. In addition to its link with the development of mesothelioma, osteopontin has been found to occur in higher levels throughout a variety of cancer types, some of which include breast cancer, stomach cancer, ovarian cancer, melanoma and lung cancer.
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[Page updated August 2006]