Clapper, Patti, Schweizer and Mason

A recently published report from researchers at Harvard explores the viability of using transcription factor PAX8 as a marker for malignant pleural mesothelioma.  Mesothelioma is a rare form of cancer caused by asbestos in which tumors form in the mesothelium, the protective sac that covers the hearts, lungs, and abdomen. 

The study explored a marker that has been used in detecting ovarian serous neoplasms as they have been shown to have morphologic overlap with malignant mesothelioma.  Mesothelioma generally has a very poor prognosis of less than a year from time of diagnosis.  The hope is to find a sensitive and specific marker so that mesothelioma can be detected at earlier stages, thereby improving overall survival times. 

Researchers were looking to see if PAX8 could reliably distinguish mesothelioma separate from Mullerian tumors, a type of serous ovarian cancer.   PAX8 and the presence of h-caldesmon has been proven to be effective markers in the differential diagnosis of breast and ovarian cancers, and the goal was to determine if it could be as successful in identifying mesothelioma tumors.

Unfortunately, the conclusion of the study was that the presence of staining for PAX8 h-caldesmon was weak and therefore not recommended as being useful in the differential diagnosis of mesothelioma.  Research will continue to search for effective markers.  The full article is published in May edition of The American Journal of Surgical Pathology.