What Are the Primary Cell Types of Mesothelioma?

[MUSIC PLAYING] The two main cell types, meaning the types of cells the mesothelium could be made up of, when we look at it under the microscope, are epithelial and sarcomatoid. And these are jargon-like terms, but they become important in terms of the prognosis of the patient and how we treat the disease. So the epithelial cell type is a little more common, and the patients with that disease have a better prognosis. The sarcomatoid cell type is a little more difficult to treat, and that disease behaves a little differently. It tends to progress locally, meaning it doesn't tend to metastasize or go to other places, but it can go through the chest wall and cause pain or go under the diaphragm and affect the abdomen. Now if somebody has more than 90% of either of those cell types, we consider their disease that cell type. If they have more than 10% of both, we call it mixed or biphasic. And generally speaking, we tend to divide groups when we look at information about patients with mesothelioma as epithelial and non-epithelial, with the non-epithelial including sarcomatoid, mixed subtype, and a few other very rare ones. Even though patients with non-epithelial disease do have, overall, a worse prognosis, that doesn't impair long-term survival. I published a paper about 11 years ago showing that patients with non-epithelial disease can still live three years or more. People shouldn't take the prognosis associated with their cell type as a hard and fast rule about how long they're going to live. [MUSIC PLAYING]