Most cases of mesothelioma involve cancer and are not diagnosed until the cancer has reached a later stage. During the late stages of cancer, the malignant mesothelioma has metastasized meaning it has spread to different areas of the body. This unfortunately means that the cancer is unresectable or unable to be treated with surgery alone.
In the early stage of cancer, surgery is sometimes able to remove all of the tumors or any diseased tissue. Once the cancer invades surrounding tissue, enters the bloodstream or enters the lymphatic system, surgery alone is not aggressive enough as a treatment. In those cases, the malignant mesothelioma is called unresectable
Surgery for Mesothelioma
Patients who are diagnosed with benign mesothelioma can typically have their tumors removed with surgery. Resectable mesothelioma means that all visible tumors can be removed surgically. Benign mesothelioma involves tumors that are not cancer and therefore do not invade other healthy tissues nor spread to other parts of the body. Unfortunately, most cases of mesothelioma are malignant meaning the tumors are cancerous and will spread.
One of the most recent methods of cancer staging used for mesothelioma is called TNM Staging.
- T = Tumor Stages
- N = Node Stages
- M = Metastasis Stages
Within each of these categories are levels that identify the degree of tumor mass spreading in the pleura (T); the degree to which the cancer has spread to the lymph nodes (N); and the stage of metastasis or spreading to other organs (M). The metastasis staging takes into account the tumor and node stages assigned. Once the T, N and M staging is completed, an overall stage number is assigned which is the familiar I, II, III or IV with Stage IV indicating the worst prognosis and the most limited number of treatment options.
This refinement of the staging process enables doctors to make a better determination as to what treatment options make sense based on the characteristics of the mesothelioma.
If malignant mesothelioma is caught in Stage I before it has metastasized, a doctor may be able to remove all visible tumors surgically. These are cases of resectable mesothelioma.
Even in Stage I, mesothelioma may not always be resectable. A doctor will have to consider the risks of surgery for the individual patient. Some patients may not be healthy enough to undergo surgery. It is also important to consider whether the cancer may have metastasized but the tumors are not yet visible in other parts of the body. If there is a likelihood this is true, the patient and doctor may decide to forgo surgery. Even when surgery is chosen as a treatment option, the doctors usually decide to follow up cases of surgical mesothelioma removal with chemotherapy or radiation treatment.
In later stages of mesothelioma, surgery may be used but primarily to help alleviate symptoms associated with the disease. These cases are not considered resectable mesothelioma because the surgery is used for palliative reasons only. A poor prognosis is given based on factors like a high leukocyte count, thrombocytisis or a nonepithelial histology. When surgery is not an option, the goals of treatments become increasing the lifespan and improving the quality of life for the surviving months of years. Chemotherapy is frequently the chosen treatment option and there has been some success using the high-tech drugs. In addition, multimodality treatments combining chemotherapy and radiation have also improved survival rates.1
Options for Unresectable Mesothelioma
Mesothelioma has virtually no symptoms in its early stages, and the few existing symptoms are often dismissed as signs of a common ailment. Thus, most cases of mesothelioma are not caught until the later stages when they have become unresectable. There are still treatment options available for unresectable mesothelioma.
In fact, mesothelioma treatments are often personalized meaning biomarkers are analyzed to try and predict which therapies will be most effective. Non-surgical non-radiation treatments include anti-folates, immunotherapy and gene therapy combinations. It is hoped that one day medical researchers will develop targeted treatment agents that will work specifically on a patient’s mesothelioma. In the meantime, unresectable mesothelioma is treated with a combination of chemotherapy drugs including pemetrexed and cisplatin or gemcitabine and a platinum compound to name just a couple.2
Only an experienced medical professional will be able to accurately diagnose mesothelioma and determine the best method of treatment. It is an extremely complex process.
Depending on the stage of mesothelioma, a doctor may recommend chemotherapy and/or radiation treatment. These treatments will not cure mesothelioma. They work to reduce tumor size and slow the growth of cancerous cells. Unfortunately the latency period for mesothelioma can be as long as 20 to 40 years. The current research is not only trying to develop the best treatments for various stages of mesothelioma, but is also working on ways to predict who is most likely to develop the disease.3 Chemotherapy and radiation can help extend the prognosis of unresectable mesothelioma while relieving symptoms.
References
1 STERMAN, D. H. and ALBELDA, S. M. (2005), Advances in the diagnosis, evaluation, and management of malignant pleural mesothelioma. Respirology, 10: 266–283. doi: 10.1111/j.1440-1843.2005.00714.x
2 Kelly R. J., Sharon E. and Hassan R. (Sep 2011) Chemotherapy and targeted therapies for unresectable malignant mesothelioma. Lung Cancer. v73:3, 256-63.
3 Ray, M. and Kindler H. L. (Sept 2009) Malignant pleural mesothelioma: an update on biomarkers and treatment. Chest. v136:3, 888-96.
