“A 22% reduction is not trivial, so I think there’s a story here,” added Townsend, who had no role in the study.
The study also found that the longer you use the medications, the more likely you are to experience a benefit.
For every year that the patients took the drugs, the risk of developing colon cancer in the three years following a clear colonoscopy was lowered by 5%.
But Townsend emphasized that studies like this generate more questions than answers.
The population of people who take medications to lower their blood pressure are often older and have other risk factors for cancer.
As people age, their chances of developing high blood pressure go up dramatically — as do their chances of developing cancer.
“You’ve got a population that is primed to develop the problem in the first place,” Townsend said.
Since the study looked at people in the real world, there are risk factors and variables that naturally affect the results.
“Is it the person, or is it the medication?” Townsend wondered.
And prior research has shown the opposite effect — that medications for high blood pressure could cause cancer, instead of preventing it.
“Since 1976 or so, this issue of cancer in patients on blood pressure medicines has been in the literature repeatedly,” Townsend explained.
Based on how these blood pressure medications work, there is some reason to believe they could prevent cancer.
For cancers to grow, they have to develop new blood vessels, and blood pressure medications may block the formation of these new vessels.
“It’s possible that these medications really cut off the blood supply of these tumors and prevent them from growing,” said Dr. Andrew Chan, a colon cancer specialist and professor at Harvard Medical School. He was not involved in the study.
However, the study cannot show a direct cause-and-effect relationship. And Chan added, “one study is not enough to sway clinical practice, and you really need to verify that you have similar associations in other studies.”
WebMD News from HealthDay
SOURCES: Wai K. Leung, M.D., clinical professor, medicine, University of Hong Kong; Andrew Chan, M.D., M.P.H., professor, medicine, Harvard Medical School, Boston; Raymond R. Townsend, M.D., director, Hypertension Program, Hospital of the University of Pennsylvania, and professor, medicine, Hospital of the University of Pennsylvania;Hypertension, July 6, 2020, online
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