I was not previously aware of vitamin B17 and after doing cursory research I believe calling it a vitamin is misleading. IF I were suffering aggressive metastasized cancer with a poor prognosis, I may try nearly anything for treatment up to and including assisted suicide. Chemotherapy is literally controlled poisoning where the largest resilient mass sometimes survives, usually with long term consequences for your wellness. Regarding cancer, I generally believe the following to be true:

1. Cancer cells are present in every human body in some small, usually distributed quantity. 

2. The human body has a unique and very effective mechanism featuring your own immune system for finding and disposing of damaged and destructive cells and foreign bodies called autophagy. This mechanism is effectively dormant in modern humans because of constant, habitual feeding.

3. When unregulated cancerous growth is found, your oncologist will first ask you to make changes to your diet, largely to control blood glucose levels because cancer needs massive amounts of glucose to survive and grow, this need explains the aggressive angiogenesis tumors show invariably. 

4. While autophagy is not an effective strategy for treating established tumors, it is an effective mechanism for prevention, and while regulating blood glucose is not a guarantee that malignant tumors will fail to form and grow, it does make growth slower and more difficult for the cancer generally. 

5. For some degree of protection against various metabolic disease including, arguably, cancer, I recommend a period of fasting for at least 48 hours once a month, and one meal every 24 hours for body mass maintenance.

The compounds found in amygdalin, are found in some seeds. I think it is important to note here that most plants have evolved mechanisms to prevent consumption of their seeds, and these mechanisms are energy expensive for the plant being considered. My opinion is that this compound amounts to self proctored chemotherapy, a treatment option that is professionally recommended and managed carefully with appropriate monitoring in cases where other options have been exhausted. While I do think that careful application of plant produced medicinal compounds can be effective, isolation and concentration of even the most basic necessary compounds is patently toxic to our biology, just consider the havoc unregulated glucose can wreak on every cell in your body. Be careful my friend. Thank you for giving me the opportunity to voice my opinion. 🫂