Good critical thinking wonderingoak. All I know is that it's best to take apricot seeds. I guess the best thing would be speak with someone who had cancer and survived whilst taking b17 (although this doesn't actually mean b17 was the cure). Medical opinions would be great too. Found the book here
Amazon.co.uk: World Without Cancer: The Story of Vitamin B17: Books: G. Edward Griffin
Positive comments there but again, not from Doctors.