The Importance of Prognostic Factors in Mesothelioma
There is no doubt that malignant pleural mesothelioma (MPM) needs better non-invasive and accurate prognostication (the ability to predict medical outcomes of a treatment or disease) for several reasons, including but not limited to the following: a median survival of 12 months with first line therapy; a median survival of 24 months when treated in a multimodal approach; a staging system currently undergoing a major update, not to mention the diffuse nature of the disease and its variable biology.
Better prognostication in MPM would mean the ability to better differentiate among patients, hopefully at the time of diagnosis. For patients with a poor prognostic, either palliative therapy or no therapy may be appropriate. If prognostic factors indicate that long term survival is possible, aggressive treatment or novel protocols would be justified.
Typically, prognostication in MPM has been approached by studying many variables, usually one at a time and at many centers, all with limited numbers of patients. This is approach is problematic because prognostication cannot function in a vacuum and the majority of these findings remain unsubstantiated in other MPM populations. For example, Although MPM patients tend to be older individuals who are frequently functionally impaired and may have difficulty with aggressive therapy, there is still a significant number of MPM patients with a favorable biology in a multimodal approach, who benefit from intense therapy.
Such variables that can be studied can be purely clinical, such as patient demographics that are frequently combined with standard laboratory values including white blood cell count or platelet count. Other scientists have focused on radiologic parameters by examining CT and PET scans.
Some of the most advanced research being accomplished today uses a molecular pathologic approach, by studying genomics, microRNA, epigenetics or proteomics in order to define single or combinations of candidate prognostic biomarkers from tissue or blood. The future of prognostic biomarkers in MPM will most likely involve a multi-institutional consortium of centers which will harvest tissue, blood and other specimens in a protocol using the same standard operating procedures in order to minimize extraneous differences which could lead to false positive results.
As new research platforms develop, it will be crucial to make sure that an ongoing registry which incorporates solid demographics as well as documentation of specimen archiving be available to the mesothelioma community. At this time the National Mesothelioma Virtual Tissue Bank fulfills that role in the United States, and is adding new sites to ensure that substances and tissues for MPM prognostication will be available for continuing research.
