Issue link: https://viewer.e-digitaledition.com/i/41583
INTEGRATING THE IMMUNE SYSTEM INTO THE Cancer-Fighting Arsenal THE RELATIONSHIP BETWEEN THE IMMUNE SYSTEM AND CANCER IS A COMPLEX, MULTILAYERED ONE THAT RESEARCHERS ARE STILL UNRAVELING. WHAT HAS BECOME CLEAR, HOWEVER, IS THAT THE IMMUNE SYSTEM COULD BE A POTENT WEAPON IN THE FIGHT AGAINST CANCER IF IT CAN BE HARNESSED AND DIRECTED TO KILL THE DISEASE. "WE KNOW THERE IS a concept called immune surveillance, in which the immune system identifies and kills small, subclinical cancers in all patients before they become clinically apparent; this is a normal process that occurs in everyone," says Tyler Curiel, M.D., M.P.H., medical oncologist and immunologist at the University of Texas Health Science Center at San Antonio's Cancer Therapy & Research Center. "Individuals with immune defects in certain types of immunity are at a higher risk for cancers. The question has been, if the body has this natural defense against cancer, why is it so hard to harness the immune system to help kill cancer?" An article published in the journal Science in March 2011 discusses the greater understanding researchers have gradually achieved of the relationship between cancer and the immune system, which is laying the groundwork for therapies that may one day be able to bring the full power of the immune system to bear against one of humanity's greatest scourges. Exploring Immunoediting The authors of the Science article — three scientists working with the Cancer Research Institute — noted several recent advances in cancer treatment that are rooted in immunology, including a dendritic cell vaccine for prostate cancer that received approval from the U.S. Food and Drug Administration in 2009, as well as the approvals of Herceptin for breast cancer and Rituxan for non-Hodgkin's lymphoma more than a decade ago. They also highlighted the development of new therapies that combine chemotherapy, radiation therapy and immunotherapy. The overriding concept, however, that emerged as the authors reviewed 40 years of breakthroughs in the relationship between cancer and the immune system was that of immunoediting, which describes the immune system's role in both guarding against and fostering cancer. "Our understanding of immune processes has come from "Immune-based therapy can also be used in cancer prevention. While vaccines are a long way off from human use, the potential they've demonstrated with mice raises the possibility that people may one day be able to be vaccinated to prevent cancer. Over time, immunotherapy will also serve as an adjunct to surgery and as a good salvage therapy for patients with metastatic cancers." — Tyler Curiel, M.D., M.P.H., medical oncologist and immunologist at the University of Texas Health Science Center at San Antonio's Cancer Therapy & Research Center looking at immunity for infectious disease, but there is a fundamental difference between an immune defense against cancer and an immune defense against an infection that originates outside the body," Dr. Curiel says. "Cancers are problems of rapidly develop- ing cells that originate inside the body. It is much easier for the immune system to develop a response against a foreign invader. Cancers are fundamentally different because those cells — no matter how malignant or mutated — are part of the body, and the immune sys- tem has not evolved to attack the body, only invaders. The immune system has a diffi- cult time telling that a cancer shouldn't be there — that's been an underappreciated aspect of developing immu- notherapies for cancer."