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.