Can the Body’s Immune System Fight Cancer?
The timing of treatments and combination of therapies is the focus of new research for cancer, described as the leading veterinary “health event” that accounts for 20 to 25 percent of hospital accruals. David Vail, DVM, DACVIM, discussed novel therapies at last month’s ACVIM conference, such as therapies that stimulate a pet’s immune system to identify and wipe-out tumors using radiation and vaccines. Vail, an oncology professor at the Animal Cancer Center (ACC), was involved in the first trial completed by the newly-formed 14-member Comparative Oncology Trials Consortium last month. News about the first trial, which was funded by the National Cancer Institute, will be published in the next issue of NEWStat.
Although cancer vaccines have been used for some time, professionals now recognize the benefit to combined therapy. “At one time we thought that chemotherapy and radiation were immunosuppressive, but that is not the case,” Vail said. “Depending on the timing, it can stimulate the immune system.”
Three ongoing trials at the ACC at Colorado State University are testing administration of radiation or chemotherapy with amputation for osteosarcoma, radiation combined with an immune stimulant and an anti-cancer vaccine for lung cancer as well as oral malignant melanoma. Veterinary professionals can refer patients for the studies, he added.
Previous rodent studies show that radiation and vaccines given simultaneously cure many more mice than using one or the other, Vail said. Researchers know that the combined treatments change the surface of a tumor, which alerts the body’s immune system to a foreign body, Vail said. “The body recognizes markers or debris from the cell,” which are not present until it is irradiated or treated with chemotherapy, Vail explained. Researchers are trying to determine what timing is best for the combined therapies.