Individualized vaccines created from a patient’s own cancer tumor may help boost the immune system’s response to the illness, according to a study conducted at Dartmouth-Hitchcock Medical Center. Early trials of the innovative new treatment option suggest that patient survival can be greatly improved through such vaccinations.
For the study, researchers (led by Richard Barth Jr, chief of general surgery at Dartmouth-Hitchcock) used dendritic cells culled from a patient’s blood to develop a personalized vaccine. Dendritic cells are an integral part of the immune system that seek out hostile antigens. By programming these dendritic cells to target a patient’s unique cancer cell manifestation, the result is an induced immune response to tumors.
As witnessed in the study, the injection of such a vaccine resulted in an effective anti-tumor response in a majority of patients.
The study included 26 patients who had tumors that had spread from the colon to the liver. All patients were surgically treated to remove the tumors. However, metastasized colon tumors are notorious for spawning regrowth following surgery. In an attempt to reduce the chances for the cancer to return, Barth and associates injected the vaccine into patients one month after surgery.
Study representatives report that 60 percent of all patients who received a vaccination displayed a favorable T-cell immune response to their tumors. Of those with a favorable response, 63 percent were alive and free of any signs of cancer after five years of treatment.
In comparison, only 18 percent of patients who did not respond to the immunization were alive and free of cancer during the same time period.
The study shows for the first time that dendritic vaccines may be useful in the treatment of cancer. Previous research efforts have attempted to show that such vaccines may be helpful in fighting larger tumor deposits. While previously unsuccessful, the vaccines may be used in conjunction with surgery to improve a patient’s chances for survival.
Additional studies are required before the efficacy and effectiveness of the treatment option can be validated. According to Barth, “This study isn’t definitive enough for us to say that everyone with colon cancer that spreads to the liver should get the vaccine. A next possible step would be to compare this vaccine with just dendritic cells which have not been pulsed with tumor antigens as a control.”
Findings of the study were published in the November issue of Clinical Cancer Research.