BEIJING, Aug.6 (Xinhuanet) -- Women taking blood pressure drug for ten years or longer are associated with twice the risk of breast cancer, according to a new study in the JAMA Internal Medicine on Monday.
The study said that the odds of developing ductal or lobular breast cancer increased by about two and a half times in women on long-term taking calcium channel blockers, which are used as medications to decrease blood pressure in patients with hypertension.
The study included 905 women aged 55 to 74 who were diagnosed with ductal breast cancer between 2000 and 2008, 1,055 women diagnosed with lobular breast cancer and 891 women without cancer who served as a comparison group.
Close to 40 percent of participants in each group took medication for high blood pressure.
Current users of calcium channel blockers included 85 women with ductal breast cancer, 91 with lobular breast cancer and 70 without cancer.
Twenty-five women with ductal breast cancer and 26 with lobular breast cancer had been using the drugs for 10 years or longer, compared to 11 cancer-free women. That worked out to a 2.4- to 2.6-fold higher risk of cancer with long-term use of calcium channel blockers.
"We don't really think these results should change any current clinical practice," Dr. Christopher Li, who led the study at the Fred Hutchinson Cancer Research Center in Seattle, said, adding that the most important thing is to have people manage their hypertension the best they can.
Li suggested that women who get their blood pressure under control using calcium channel blockers should not stop taking them, or be too concerned about any extra risk of breast cancer.