Pubmed is the database you'd typically want to look at for medical and natural sciences. You can configure email alerts for specific keywords there, though it's been ages that I've done that.
- Usually research goes in vitro (in a petri dish) -> in animals -> in humans. An article can claim that they've found the cure for cancer, if its just in vitro it doesnt mean much. The medicine needs to go to the right place, it should not have too bad side effects,...a very small percentage of medicine that works in vitro makes it to human testing. - even if it works in humans it might not be feasible to manufacture it. We have got medicine that costs over 3 million USD per dose, obviously there is a cost when the manufacturer just scraps the project even if it works perfectly.