There are three types of mesothelioma cells: epithelial, sarcomatoid and biphasic. The most commonly encountered type, epithelial mesothelioma, responds best to treatment, particularly when the tumor has been detected early. It is responsible for up to 70% of all diagnosed mesothelioma cases. Therefore, epithelial mesothelioma is associated with a more optimistic prognosis, as well as with extended life expectancy. The patient can opt for more aggressive treatment options or for a multimodal treatment approach combining surgery, radiation therapy, and chemotherapy, as well as alternative treatments available in the clinical trial. Survival can be prolonged by up to 200 days or even several years if mesothelioma has been detected in its incipient stages.

Sarcomatoid mesothelioma represents the rarest form of the disease, accounting for 10-20% of the diagnosed cases. This type of cancerous cell is also the most difficult to treat, as it is very aggressive and does not generally respond to treatment as effectively as epithelial or biphasic cells. Moreover, the accurate diagnosis of sarcomatoid mesothelioma is quite problematic due to the existence of three distinct subtypes of cells: transitional, lymphohistiocytoid and desmoplastic. Standard treatment is not very efficient in curing sarcomatoid mesothelioma and surgery in particular entails high risks for the patient’s health, especially when the disease has entered its advanced stages. Because sarcomatoid cells are very resistant, chemotherapy is not very successful either. However, a combination of selenite, a recently discovered drug, and doxorubicin has been demonstrated to be quite effective in combating this type of mesothelioma. The average prognosis for sarcomatoid mesothelioma is less than 6 months. Nevertheless, life expectancy can be prolonged by up to several years in the following circumstances: when cancer has been diagnosed in its early phases and attended to with appropriate treatment, if the subtype of the sarcomatoid cells is lymphohistiocytoid, as well as when the patient does not have any other severe health issues besides mesothelioma.

When the malign tumor is comprised of both epithelial and sarcomatoid cells, the biphasic type is diagnosed. Biphasic cells are involved in between 20 and 35 percent of all cases of diagnosed mesothelioma. Treatment options, as well as prognosis, depend on the dominant cell type. Consequently, if the number of epithelial cells within the tumor is larger, mesothelioma will entail a better response to treatment and, implicitly, an extended life expectancy. However, if the tumor contains a majority of sarcomatoid cells, treatment options will be limited and mesothelioma will be more resistant. Prognosis is also less likely to improve with the prevalence of this type of cells.