A protein called CDLN15 could be a novel diagnostic marker for malignant pleural mesothelioma, allowing doctors to pinpoint asbestos cancer earlier and boost the odds of survival. That is the message from a recently published Japanese study.
Pleural mesothelioma is notoriously difficult to diagnose. It rarely causes any symptoms at all until it is in a late stage. When the symptoms do show up, they are easy to confuse with other illnesses.
Earlier diagnosis of pleural mesothelioma depends on finding things that set it apart from other diseases. This novel diagnostic marker could serve as a red flag for this rare but deadly cancer.
CDLN15 as a Novel Diagnostic Marker
CDLN15 stands for claudin-15. Claudins are a family of proteins that control the flow of molecules in membrane tissue. There are many different claudins.
Pleural mesothelioma grows on the pleural membrane or ‘mesothelium’ around the lungs. Japanese researchers at Fukushima Medical University screened for 25 different claudins in mesothelial tissue.
They discovered that mesothelial cells produce CDLN15. When mesothelial cells turn cancerous, they appear to produce excess CDLN15. CDLN15 was hardly ever present in non-mesothelial tumors. This suggests that it could serve as a novel diagnostic marker for mesothelioma.
Biomarkers are like signposts for particular diseases. There are a few biomarkers that suggest a person might have mesothelioma. But there is no single definitive test.
Having a new mesothelioma biomarker to combine with other known markers could make mesothelioma diagnosis easier and more accurate.
In Search of an Accurate Mesothelioma Diagnosis
An estimated 2,500 Americans receive a diagnosis of mesothelioma every year. For some, that diagnosis comes too late for effective treatment. Many people die of this aggressive cancer within months of diagnosis.
Researchers at top cancer centers are looking for ways to diagnose mesothelioma earlier. Every novel diagnostic marker they find moves them a step closer to that goal.
The Fukushima Medical University researchers examined 42 pleural mesothelioma tissue samples. Eighty-three percent of them overexpressed CDLN15.
“The positive ratio was equal to or greater than other positive markers for MPMs including calretinin (81%), WT-1 (50%), and D2-40 (81%),” reports lead author Masayuki Watanabe.
Just as importantly, this novel diagnostic marker was not common in lung cancer samples. Only four out of fifty lung adenocarcinoma samples were positive for CDLN15. This means that CDLN15 could help doctors distinguish between malignant mesothelioma and lung cancer. This is critical because the two diseases are treated differently.
“In conclusion, CLDN15 can be used in the clinical setting as a positive marker for MPM diagnosis,” writes Dr. Watanabe.
Watanabe, M, et al, “CLDN15 is a novel diagnostic marker for malignant pleural mesothelioma”, June 15, 2021, Scientific Reports, https://www.nature.com/articles/s41598-021-91464-0