Immunotherapy aims to cure cancer by turning the immune system into an ally against cancer cells. For many years, scientists have focused on many ways of improving immunotherapy to make it more effective. But now, a new study claims that using over-the-counter antihistamines can improve outcomes for cancer patients under immunotherapy.
Over-the-Counter Drug vs. Cancer
The study published in the journal Cancer Cell, reports that high levels of histamines and one of its receptors are associated with tumor resistance to immunotherapy drugs in cancer patients.
According to The Scientist, the study shows that patients who took antihistamines responded better to immune checkpoint inhibitors, immunotherapy drugs that allow T-cells to kill cancer cells, than those who did not take antihistamines.
Study co-first author YiXiao said that they found that histamine receptor 1 (HRH1) show a strong association with poor clinical outcome in hot tumors. In the study, doctors measure plasma histamine levels of the patients to decide whether a dose of antihistamine could benefit them.
They decided to look at how 40 common medications, like antibiotics and steroids, would affect the efficacy of checkpoint inhibitors. When they reviewed the electronic health records of patients, they found that patients under immunotherapy taking H1-antihistamines have significantly improved outcomes.
How Does Antihistamines Improve Cancer Outcomes?
Express.co.uk explains that antihistamines are medicines that relieve allergy symptoms that cause by insect bites or stings, food, and plants. They are bought from pharmacies wherein some of them are available to even without a doctor’s prescription.
The National Health Services said that antihistamines work by blocking the histamine in the body, which is released when something harmful enters the system. Histamine causes blood vessels to expand and skin to swell to protect the body.
Yi Xiao said that they found that HRH1 is strongly associated with poor clinical outcomes, and almost all cancer cells they tested secreted histamines compared to normal cells. Using antihistamines, they were able to suppress its effect on the tumor, like how it affects the body during an allergic reaction.