Peritoneal mesothelioma, a cancer that starts on the membranes surrounding internal organs, is almost always caused by exposure to asbestos.
But the new study conducted by Duke’s pathology department and published in the Journal of Clinical Pathology notes that peritoneal mesothelioma and Crohn’s (also called Crohn ileitis) share a common characteristic: Inflammation.
In the case of Crohn’s, the inflammation happens in the small intestine, preventing the proper absorption of nutrients and causing a range of gastrointestinal symptoms. The Duke research suggests that people with the type of inflammation present in Crohn’s may also be at higher risk for malignant mesothelioma.
Mesothelioma and Inflammation
Scientists already know something about the relationship between inflammation and mesothelioma.
In 2010, a University of Hawaii study funded by the National Cancer Institute demonstrated tiny fibers of asbestos cause inflammation that ca nturn healthy cells into malignant mesothelioma cells.
That study found that cells killed by asbestos fibers through a process called necrosis release a protein that triggers an inflammatory reaction in the surrounding healthy cells, promoting the growth of mesothelioma tumors. Mesothelioma patients have higher levels of this protein in their blood.
Just last year, the same group of researchers along with colleagues in New York and Italy, found that the inflammation-fighting properties of aspirin slowed tumor growth and improved mesothelioma survival in mice.
Crohn’s and Mesothelioma
This year, with a better understanding of inflammation’s possible role in mesothelioma, the Duke team combed a database of 3,800 mesothelioma cases to look for those with both peritoneal mesothelioma and an inflammatory bowel disease (Crohn’s or ulcerative colitis).
Three patients were identified. All had the classic symptoms of Crohn’s disease and had been definitively diagnosed with Crohn’s for at least three years. Only one of the three peritoneal mesothelioma patients was known to have been exposed to asbestos.
“Chronic inflammation has been associated with the development of malignant mesothelioma in rare instances and these three cases suggest that Crohn’s disease with transmural inflammation may also be a precursor,” writes Kelly J Butnor, MD, a professor in Duke’s Department of Pathology & Laboratory Medicine whose name appears first on the paper. Dr. Butnor specializes in lung and thoracic pathology.
Transmural inflammation, one of the characteristics that separates Crohn’s disease from ulcerative colitis, is inflammation that spans the entire depth of the intestinal wall. The report concludes, “The precise role of Crohn’s disease-related transmural inflammation in the carcinogenesis of peritoneal malignant mesothelioma remains to be determined.”
In the US, as many as 1.6 million people have inflammatory bowel diseases, including Crohn’s. Every year, 2,500 Americans develop malignant mesothelioma. Peritoneal mesothelioma cases account for about a fifth of that number.
Butnor, KJ, et al, “Malignant peritoneal mesothelioma and Crohn disease”, August 2, 2016, Journal of Clinical Pathology