One of the immune system’s basic jobs is to tell “self” from “non-self.” Our cells carry markers that the immune system uses to recognize them as being part of us. Cells that don’t carry those markers—like bacteria and other pathogens—therefore don’t belong.
Cancer cells, however, fall into a gray area. They’re non-self, yet they also bear markers that connote self-ness—one of the reasons the immune system has a hard time “seeing” and reacting to cancer.
Can we focus the immune system’s spotlight on cancer cells? The provisional answer is yes. Research on cancer immunotherapy—treatments that spur an immune response against cancer cells—has boomed in recent years. (The journal Science recognized cancer immunotherapy as its Breakthrough of the Year in 2013.)
The news that your child has cancer always comes as a shock, but for one cancer, acute lymphoblastic leukemia (ALL), parents can take comfort in the fact that doctors are really good at treating it. The cure rate for ALL has, over the last 40 years, climbed to nearly 90 percent.
Less comforting is the fact that some 10 to 20 percent of children who initially respond well to treatment suffer a relapse within five years. And right now, the drugs at our disposal aren’t very good at turning a relapse back into a remission.