Treating Mesothelioma

I saw a commercial the other day with this lady who lost her husband to Mesothelioma and because of that she came out with book or guide to help others in her situation. From what I have learned they have various mesothelioma treatments, like with many other Cancers, but the truth being told many people die from this, it's like pancreatic Cancer there are few survivors. These forms of Cancer are very serious and deadly the survival rate is really low. I don't understand why though. Why are the survival rates for these Cancers so low versus other forms of Cancer?