One thing oleander excels at, in addition to fighting leukemia and just about all forms of cancer, is raising white blood cell counts. See for example what happened in this double blind placebo controlled trial:
Herbal Supplement for HIV/AIDS is Successful in Clinical Trial
You can see the entire oleander series of articles at:
http://www.tbyil.com/articles.htm
Curcumin is another excellent supplement for brain cancers as it is great at fighting brain cancers and is also a powerful natural anti-inflammatory.
Other items to consider - N-Actyl Cisteine (critical for glutathione production), inositol/IP6 (powerful tumor fighter) and a powerful mushroom supplement such as Garden of Life's Immune Defense.
All of the above are compatible with Budwig-Cellect, which has has some excellent results itself.