My prayers for your brother as well.
Have faith. My 87 year old father was told that he had non-hodgkins lymphoma about 8 weeks ago - long story short the doctors ran tons of tests - including a double bone marrow pull from both hips (can you say painful?). When my parents went in after all of the tests had been looked at, expecting the worst, they were told that his cancer was gone! WTF!? The doc assured them that he did indeed have cancer but now there were no signs of it! More over the tumor, from which they took the biopsy, was gone!