Timing Crucial for Prostate Cancer Therapy
Reported March 21, 2005
(Ivanhoe Newswire) — Prostate cancer vaccines are most effective when administered right after hormone therapy, according to a new study. Lead study author, Charles Drake, M.D., Ph.D., from Johns Hopkins Kimmel Cancer Center along with colleagues from the University of Connecticut tested a prostate cancer vaccine on mice that were specially bred to develop the disease. Results show when the vaccine was given right after hormonal therapy, it helped reactivate the immune system T-cells, which attacked the cancer tumors. T-cells multiplied three-times as much in the mice who received the vaccine immediately following hormone therapy compared to mice that did not receive hormone therapy, according to the study. Researchers believe after hormone therapy initially gets rid of cancer cells, the cancer returns in numbers small enough for the immune system to fight when stimulated by the vaccine. Dr. Drake concludes, If our findings are confirmed, we believe human vaccines stand a better chance of getting T-cells to respond after most of the tumor is destroyed by hormone therapy. The strategy thereafter would be to continue activating the immune system with repeated vaccines and delay the time until a patient needs more hormone therapy, other treatments, or lives old enough to die from other causes.
SOURCE: Cancer Cell, 2005;7:239-248