It seems like an almost impossible dream — a cancer vaccine that would protect healthy people at high risk of cancer. Any incipient malignant cells would be obliterated by the immune system. It would be no different from the way vaccines protect against infectious diseases.
However, unlike vaccines for infectious diseases, the promise of cancer vaccines has only dangled in front of researchers, despite their arduous efforts. Now, though, many hope that some success may be nearing in the quest to immunize people against cancer.
The first vaccine involves people with a frightening chance of developing pancreatic cancer, one of the most difficult cancers to treat once it is underway. Other vaccine studies involve people at high risk of colon and breast cancer.