“We were whatever the thing is right between delighted and surprised — but mostly delighted.”
The classic treatments for cancer include chemotherapy, radiation, and surgery. These can be very effective, but doctors at Mount Sinai Hospital in New York led by Linda Hammerich, Ph.D., and Joshua Brody, M.D., explored a much more radical approach and saw that their boldness paid off. Their new cancer treatment trains the body to fight its own tumors, and as they reported Monday in Nature Medicine, it’s led to significant remissions in several human patients.
The doctors have described the treatment as turning the tumors into “cancer vaccine factories,” which train the patients’ immune system to detect and fight the tumors themselves. They tested it on 11 patients with indolent non-Hodgkin’s lymphomas, an incurable type of cancer that originates in white blood cells. Unlike preventative vaccines, this one is therapeutic, which means it doesn’t prevent cancer but treats it.
“We were whatever the thing is right between delighted and surprised — but mostly delighted,” the study’s lead author Joshua Brody, M.D., director of the Lymphoma Immunotherapy Program at Mount Sinai, tells Inverse.
Recruiting the Immune “Army”
The new therapy works by recruiting dendritic cells, a type of immune cell, into a cancerous tumor by injecting it with molecules designed to stimulate the immune system. Dendritic cells are the ones that will corral the rest of the immune system into killing a tumor.
“Dendritic cells are a very big deal, but a weirdly neglected big deal,” says Brody. He likens the immune system to an army, in which T cells — cells produced as part of the body’s immune response — are the soldiers, and dendritic cells are the generals. To harness the potential of the whole army, Brody’s team had to figure out how to provide the dendritic cells with the information they needed to send the T cells to attack tumors.
Once the dendritic cells are introduced into the tumors, they’ve been recruited into the fight. Then, the patients receive low-dose radiotherapy, which kills enough tumor cells to release antigens, proteins that the immune system can recognize and fight. Antigens are produced by most infectious diseases, triggering our bodies to produce antibodies to fight back. Usually, tumors go more or less undetected by our immune systems, since they’re just mutated versions of our own cells. But by priming the tumors with the dendritic cells, damaged tumor cells will produce antigens that the body can learn to attack.
|Read on: How a Cancer 'Vaccine' Trains the Body's Army to Fight Its Own|