Since you mentioned cancer, Pio, I recently read an article by Dr. James Howenstine who said, "...One of these Hungarian researchers speculated that by the time a patient developed allergies and joint and muscle inflammation 75% of the bile production was lost. When a serious illness like cancer arrived up to 90% of bile production was probably lacking."
Anyway, you are correct - we all have a right to choose our own destiny, though that would imply we have free will.