That is the theory behind recently published mesothelioma research. After analyzing nearly 200 malignant mesothelioma cases, a team of Welsh pathologists determined that subtle differences in mesothelioma cells can have a measurable impact on survival.
The news was best for patients with a particular variety of epithelioid mesothelioma, the most common subtype of the asbestos cancer.
Subtypes of Pleural Mesothelioma
Pleural mesothelioma is one of three types of mesothelioma. It occurs on the membrane that surrounds the lungs and can spread to the lungs and other organs. It is very difficult to treat and there is no cure.
Pleural mesothelioma is divided into three major subtypes based on certain microscopic features of the tumor cells. Most mesothelioma patients (50 to 70 percent) have the epithelioid subtype but about 10 to 20 percent have sarcomatoid, which features spindle-shaped cells and is very aggressive.
The third mesothelioma subtype, biphasic, includes a mix of the two varieties of mesothelioma cells and accounts for about 20 to 35 percent of mesothelioma cases.
Breaking the Subtypes Down Further
But doctors at the University Hospital of Wales were interested in even more subtle differences that occur within the major subtypes and how these differences might impact mesothelioma survival and treatment response.
Their study included 191 cases of malignant pleural mesothelioma. Only cases with good follow-up data were included. For each mesothelioma case, the research team identified not only its subtype but also it’s phenotype within that subtype.
Epithelioid mesothelioma was divided into six phenotypes including myxoid, microcystic, tubulopapillary, solid epithelioid, micropapillary, and pleomorphic.
“Myxoid variant malignant pleural epithelioid mesothelioma was observed to have a favourable overall survival compared with pleomorphic form,” writes author Fouad Sami Alchami, MD, and colleagues in the Journal of Clinical Pathology. “Pleomorphic phenotype had the worst overall survival.”
The team concluded that these morphological phenotypes have a direct bearing on mesothelioma survival and should be included in pathology reports to help both mesothelioma patients and their doctors better understand their disease and determine their prognosis.
Alchami, FS, et al, “Myxoid variant epithelioid pleural mesothelioma defines a favourable prognosis group: an analysis of 191 patients with pleural malignant mesothelioma”, October 18, 2016, Journal of Clinical Pathology