Gregory Beatty, M.D., Ph.D., assistant professor at the University of Pennsylvania Perelman School of Medicine, discusses challenges of using immunotherapy to treat gastrointestinal (GI) cancers.
The majority of the immune system is located in the gut, Beatty says, and every single day, it encounters many pathogens and has to decide to fight them or not. Because of this, it might be difficult to spark the immune system when a foreign body, like cancer, is located there.
However, there are some subsets of GI cancers whose tumors have DNA mismatch repair — which ultimately leads to microsatellite instability – that look more like an invader, thus activating the immune response. This group of patients has seen astounding results with the use of checkpoint inhibitors.
