Just this week, the International Association for the Study of Lung Cancer announced that they will be developing a large international database of mesothelioma patients in an effort to update the current pleural mesothelioma staging system. The agency has joined forces with the International Mesothelioma Interest Group, the organization that developed the staging system that is currently used.
The current pleural mesothelioma staging system, developed in 1995 by the IMIG, is used by the American Joint Committee on Cancer. The American Joint Committee on Cancer is internationally recognized as the official organization for creating and disseminating cancer classification systems. The current staging system, known widely as the TNM staging system, evaluates the relationship between Tumor size, lymph Node, and Metastasis and applies only to tumors affecting the pleura.
In November 2012, authors of a study published in the IASLC’s Journal of Thoracic Oncology voiced concern “that the system is derived from analysis of small, retrospective surgical series; it can be difficult to apply to clinical staging; and uses descriptors for lymph node involvement, which may not be relevant to malignant pleural mesothelioma.”
As the study authors see it, the current system “appropriately distinguishes among T and N categories and overall stages but also highlights areas for potential revision.” According to the authors, the current T descriptors are qualitative and most appropriately used for pathological staging. The authors also state that there is confusion about the difference between N1 and N2 disease, and that further study of the extent of lymph node involvement in mesothelioma may lead to improvements in factor of classification.
As with all cancers, an accurate staging is essential when doctors are determining the extent of the disease and weighing potential mesothelioma treatment options. For example, a localized cancer would be classified as Stage 1, which means that the tumor is able to be removed through surgery. The stages grow to higher levels once the cancer spreads to other parts of the body. The higher the stage, the more advanced the mesothelioma.
Mesothelioma is a rare form of cancer caused by exposure to asbestos. Most mesothelioma patients were exposed to asbestos on the job, though the exact source of exposure is often difficult to trace since the disease may take up to fifty years after exposure to develop.