Sen. John McCain's tumor is one of the most aggressive forms of brain cancer, and his family and doctors are deliberating next treatment options. Here are some things to know:AGGRESSIVE CANCERMcCain's doctors at the Mayo Clinic said they managed to remove all the tumor that was visible on brain scans. But this kind of tumor, formally known as a glioblastoma multiforme, is aggressive and sneaky. According to the American Brain Tumor Association, an estimated 12,390 new cases are expected to be diagnosed this year. The treatment, called CAR-T cell therapy, has been used for blood cancers, but its value for solid tumors like brain tumors is unknown.

Source: ABC News July 20, 2017 03:00 UTC