Apricot kernels, amygdalin, vitamin B17, laetrile... you have to do some research and decide for yourself, google a lot and be critical of what you read, but I just wanted to tell you what I found out when I did the same:
Amygdalin = B17 is not a vitamin, it is a poison. It was given the name of a vitamin so it would seem more legitimate.
Laetrile is a substance which is supposed to be a non-toxic format of amygdalin. Sometimes amygdalin, made from crushed apricot kernels, is sold as laetrile (Mexican laetrile I understand). You also get amygdalin from bitter almonds.
Studies have found amygdalin to be ineffective against cancer. There has been no controlled clinical trials. You will find statements that say that this result is a conspiracy by medical companies who don't want people to have an inexpensive medicine against cancer. I don't believe in this theory. Cancer cells have been killed in lab environment because amygdalin releases cyanide, which is a poison.
Cytostats are also, of course, poison. But when raw apricot kernels, amygdalin, or laetrile are taken orally, it is very difficult to say how much toxicity you are getting in your body, the dose can be lethal, or at least cyanide poisoning. Eating 20 apricot kernels at a time can be lethal according to some reports. I would not dare to try.
BUT PLEASE NOTE: These apricot kernels are raw and they should not be confused with the health store snack variety of apricot kernels which look much like regular almonds. HOWEVER, there were reports of cyanide poisonings also from some bitter apricot kernel snacks bought from health food stores in the 1990's. Then again, I also found an article that claimed that usually the snack variety of apricot kernels is not toxic. To be on the safe side, I don't eat any kind of apricot kernels and don't keep them in the house so that kids won't eat them.
A good page explaining the same: http://www.cancerhelp.org.uk/help/default.asp?page=21859
My husband has cancer. This is our humble opinion after some research, you will find other opinions I am sure.
All the best, Mousey