Jan. 8 (UPI) -- Melanoma patients who take a drug designed prevent heart attacks and lower blood pressure might live longer, according to researchers at Penn State.
In the study, published recently in the journal OncoImmunology, researchers found that the skin cancer patients who received immunotherapy and took a specific type of beta blocker lived longer than patients who only received immunotherapy. An experiment with mice saw the same results, researchers said.
"The type of beta blocker we found to be effective against melanoma -- pan beta blockers -- was actually the least prescribed," Dr. Todd Schell, a professor of microbiology and immunology at Penn State College of Medicine, said in a release. "Most patients are either prescribed beta 1 selective blockers or are not taking beta blockers at all. This means there's a large population of patients who may be eligible to take pan beta blockers while being treated with immunotherapy. And because beta blockers are already FDA approved, it's something we know is safe and can be very quickly implemented in patient care."
Melanoma, the most dangerous form of skin cancer, kills an estimated 10,130 people in the United States annually, according to the Skin Foundation. The cancer is curable if caught early, but if it spreads to other parts of the body it becomes harder to treat and can be fatal.
Researchers analyzed data from 195 metastatic melanoma patients treated with immunotherapy between 2000 and 2015, of which 62 were also taking beta blockers. They compared survival between those taking beta 1-selective blockers, those taking pan beta blockers and those taking no beta blockers.
Five years after immunotherapy and pan beta, about 70 percent of patients were still alive. That compared with 25 percent of those taking beta 1-selective blockers or no beta blockers at all.
In an experiment with mice, done to gain further understanding of the study results, researchers found that the propranolol significantly delayed tumor growth and increased survival.
"These new immunotherapies are great, but they don't work for everyone," said Dr. Joseph Drabick, a physician and professor of medicine at Penn State College of Medicine. "So how can we make these treatments better? We saw that for patients taking pan beta blockers, there was a dramatic improvement in survival, and we were able to duplicate these findings in mice and see the exact same phenomenon."
In metastatic cancer -- or cancer that has spread to other parts of the body -- some forms of immunotherapy that boost the immune system have a success rate of less than 35 percent.
Because physiological stress prevents the immune system from fighting tumors effectively, researchers wanted to know whether lowering stress with beta blockers would improve outcomes in the patients.
"Beta blockers slow your heart rhythm, but they can also affect immune cells and improve immune function," Schell said. "We wanted to see if there would be a correlation between the beta blockers patients were taking for another condition and their response to immunotherapy. For metastatic melanoma, there are currently three different types of immunotherapy approved for use, and we specifically looked at that population of people."
Researchers are planning on a clinical trial on the role of beta blockers in treating cancer.
"The benefit of this is that beta blockers already have a long history of safety in people, and they're cheap and generic," Drabick said. "And now they have the potential to augment some of these newer immunotherapy drugs to help people with cancer."