You can learn more about the typical symptoms and conventional treatments here.
There are a host of non-conventional treatment options discussed at the Mesothelioma Cancer Alliance and include acupuncture, herbal and nutritional supplements, lymph drainage therapy, and homeopathy, just to mention a few.
Another alternative treatment option discussed by the American Cancer Institute is Gerson Therapy. This therapy involves coffee enemas, supplements, juicing, and a special diet that is claimed to cleanse the body, boost the immune system, and stimulate metabolism. You can read about Gerson Therapy here
Just as there is no guarantee that conventional treatments will cure mesothelioma cancer, there is no guarantee that natural or alternatives therapies will cure the disease.