In clinical trials, the success stories across the country have been stunning: a 70-year-old with melanoma given six months to live two years ago who is now healthy and cancer-free; eight of nine patients whose severe lymphoma was brought into remission, with three having their cancer disappear. Though not consistently reproducible, these results are so encouraging that research is moving quickly—in 2011, the National Cancer Institute announced funding for a network of clinical trials into immunological approaches.
Cancer can be such a difficult disease to treat because of its ability to trick the immune system as its cells grow and spread, either exhausting immune components or producing chemicals that cause them to overlook the cancer as harmless. Dr. Joseph Leach of Minnesota Oncology, director of oncology research at Virginia Piper Cancer Institute, refers to this as cancer’s “cloaking device.”
The new breakthrough focuses on immune components called T-cells, which researchers have discovered have built-in “brakes” that normally prevent them from attacking healthy tissues and organs in our bodies—a quality that cancer cells exploit. Previous attempts to combat cancer with the immune system had focused on boosting its power, adding ammunition in a biological arms race. Now the idea is to take off these “brakes” with respect to cancer and allow the immune system to do its job, while not shutting them down completely, which can cause autoimmune problems.
“The basic idea is getting the immune system to recognize that cancer is foreign, and then eliminating it,” says Leach. “It’s the holy grail of cancer treatment, and it’s seemed like a dead end for many years.”
Leach also makes an important distinction: Many previous cancer treatments have attacked the invasion through radiation and chemicals, and while these techniques have prolonged many lives and grown incredibly sophisticated, cancer has a tendency to “figure it out,” he says, and to mutate in self-defense to survive and proliferate.
“With these new therapies, the hope is that the cancer can’t mutate around the immune system,” Leach says. “Because even if it mutates, it’s still going to be a foreign cell, and the treatment will be more durable.”
These treatments aren’t yet standard practice, and research into direct applications for specific cancer types is in early stages. The search for across-the-board treatments, and perhaps cures, will hinge on research into the different makeup of each type of cancer.
“These are just the first generations,” adds Leach. “These are the stone-age tools—there are so many ways that we will be able to augment the immune system.”
Along the way, immune therapies also will open the door for potential combinations with targeted drugs, as doctors better understand the relationship between immunity and cancer. “There’s a ton of work that needs to be done yet,” Leach says. “But we’ve never been so hopeful that we’ll crack some of the fundamental mysteries. This is a new age. This is the way we’ll treat cancer in the future, and someday we’ll look back and laugh at the way we used to.”
