Can antihistamines be used to fight cancer?

the Oncology Nurse Advisor take:

New research suggests that antihistamines—medications primarily designed to alleviate allergy symptoms—could play a role in combatting cancer. A research team based at Virginia Commonwealth University recently published findings in The Journal of Leukocyte Biology that seem to indicate that antihistamines can be used to hinder cancer development.



The study authors, led by Daniel H. Conrad, PhD, examined two groups of mice. One group of mice had cancerous tumors, and the other group demonstrated a strong allergic reaction after being purposefully infested with a rodent intestinal helminth. The researchers then treated the allergic group by injection with myeloid-derived suppressor cells and were subsequently treated with one of two antihistamines (cetirizine or cimetidine). The tumorous group was also similarly injected and treated with cetirizine (only). When the results were examined, it was discovered that in the allergic group of mice, effects of the myeloid-derived suppressor cells were reversed by the administered antihistamines. In the tumor group, the antihistamine (cetirizine) reserved the myeloid-derived suppressor cell effect and also reversed the increased tumor growth that is a result of those cells.




The researchers went on to examine blood from human patients with and without allergies, and they discovered that those with allergies has elevated levels of myeloid-derived suppressor cells in their blood. 



This research is promising and demonstrates a link between histamine and myeloid-derived suppressor cells, and thereby implies an anti-cancer property of antihistamines, but study authors acknowledge that the time has not yet arrived to administer antihistamines solely for cancer prevention.