What Is Sarcomatoid Mesothelioma?

[MUSIC PLAYING] Sarcomatoid mesothelioma is the other more rare subtype in contrast to epithelial. If somebody has more than 90% sarcomatoid, we consider that sarcomatoid. If somebody has some component of both epithelial and sarcomatoid in a volume greater than 10%, we call that mixed or biphasic type. Sarcomatoid mesothelioma tends to be a little more locally progressive. Sometimes it will go through the chest wall or the diaphragm, which is the muscle that separates the chest and the abdomen, or through the pericardium, the sac around the heart. It is less common for that type to go to other organs, or even the lymph nodes. That said, it's a little less responsive to chemotherapy. But from what we see from more recent data, it may be more responsive to immunotherapy. And we have additional treatment options for those patients. [MUSIC PLAYING]