I am not a vegan/whatever/animal activist, but maybe we should allow terminally-ill or death-row volunteers for this kind of experiment... With good money for the family, and I think some people would like to help mankind in the end. It is better than dying without accomplishing anything in life.
So, you have at most one year with an inoperable tumor, and you will not travel because you want to be close to your family. Would you be a volunteer for this research, for 500 thousand dollars? (monkeys are cheaper, but you are the real deal)