Australian researchers are warning that a blood test used to help diagnose mesothelioma could indicate the presence of another disease instead.
Mesothelin is a protein that occurs naturally in cells of the mesothelium, the membrane that surrounds and protects internal organs. The recent finding that blood levels of mesothelin are elevated in mesothelioma patients was a breakthrough for the asbestos-linked cancer that can be difficult to diagnose. More than half of the mesothelioma patients tested had significantly elevated serum mesothelin at diagnosis, prompting doctors to begin using serum mesothelin as a diagnostic tool.
But now a new study suggests that serum mesothelin can also be significantly elevated in people with kidney disease and recommends that doctors take that into consideration when looking for mesothelioma. The Australian team set out to determine the relationship between mesothelin concentrations and kidney function, so that doctors can more accurately interpret the results of a mesothelioma blood test.
The cross-sectional study included 144 patients with chronic kidney disease (CKD). The test did not include patients who had had kidney transplants, were on kidney dialysis, or were known to have kidney cancer. The findings showed that serum mesothelin increased with increasing serum creatinine levels, an indicator of the severity of the CKD. There was also a significant correlation between urine mesothelin-to-creatinine levels and mesothelin levels in the blood.
Although they were approaching the test from a different angle, these researchers reached the same conclusion as those who first revealed the serum mesothelin test to be a mesothelioma diagnosis tool: When used as part of a multi-factor diagnostic approach that also considers age, symptoms, biopsy results and history of asbestos exposure, serum mesothelin can be valuable. The new study suggests that renal function should also be on the list of considerations when interpreting the test.
Boudville, N et al, “Mesothelin and kidney function – Analysis of relationship and implications for mesothelioma screening”, February 16, 2011, Lung Cancer. Epub ahead of print.
Induced Cancer Malignant Mesothelioma”, June 29, 2010, Cancer Epidemiology, Biomarkers & Prevention.