Mesothelioma is a rare and aggressive cancer that is difficult to diagnose because symptoms often mimic other diseases such as pulmonary fibrosis or lung cancer. Pathology reports and biopsies help distinguish this cancer from other illnesses, but often patients will have already developed more serious symptoms because the cancer has spread by the time it is detected.
A recent study reported in BMC Cancer showed positive results for a new blood-based assay for the protein marker calretinin. Calretinin is a calcium-binding protein that has been known to be a selective marker for mesothelioma as it can be used to differentiate between lung tumors. This latest study compared calretinin with the more established biomarker mesothelin to see which protein identified mesothelioma at an earlier stage.
This study involved testing two groups: those who have pleural mesothelioma (199 patients), and those with non-malignant asbestos conditions, like asbestosis (control group, 235 patients). Blood serum and plasma were collected from each of the participants to be tested for the presence of calretinin and mesothelin. Age, sample storage time, and mesothelioma subtype were all factors taken into consideration so to not skew results.
Results showed that calretinin was able to identify epithelioid and biphasic mesothelioma 71% of the time, and mesothelin 69%. When used in conjunction with one another, mesothelin was able to correctly identify mesothelioma 71% of the time; calretinin an impressive 97%. The rarer sarcomatoid sub-type of mesothelioma was not able to be identified.
This study concluded that calretinin could be a verified blood marker for malignant mesothelioma, but only for the epithelioid and biphasic sub-types.
Identifying mesothelioma as early as possible is a key component in combating this rare asbestos-caused cancer. With many diagnoses often being too late, scientists and researchers are working on better detection methods in hopes to increase chances of survival.
Georg Johnen, et. al. “Calretinin as a blood-based biomarker for mesothelioma,” BMC Cancer (May 30, 2017). [Link]