20-Year Prospect
The sad thing about this job is that we even need it in the first place; unfortunately, it doesn't look to be going anywhere any time soon. That said, as long as the fight against cancer is being fought, there will be positions open for the warriors who wage it.
After all, if there's one field almost guaranteed to have a constant flow of funding, it's cancer research (number two: toilet improvements). What will change is the technology being used. Biotechnology, especially the kind developed to eradicate cancer, is advancing at breakneck speed. Be sure to buckle up.