Known as calcium channels blockers, in particular, are associated with a significantly increased risk
Researchers have found that women taking channel blockers calcium to treat high blood pressure for more than 10 years are 2.5 times more likely to develop breast cancer than those who do not use blood pressure medication, or using other types.
"While the results are intriguing, it is necessary to wait until we have confirmatory studies before making any recommendations," said study researcher Dr. Christopher Li, an epidemiologist and researcher on breast cancer at the Fred Hutchinson Cancer Research Center in Seattle.
"People should not fail in any way, to take their medication," says Dr. Li.
The study involved 1,900 women with breast cancer and about 850 women without cancer who served as controls. The researchers found a link between an increased risk of breast cancer and other blood pressure medications such as beta blockers or diuretics, as can be read at the Fred Hutchinson Cancer Research Center News Release
Previous studies have yielded mixed results because, or did not have a sufficient number of participants, or not investigated the long-term use of antihypertensive drugs.
The study shows a probability, but not found a cause-effect relationship between this type of medication and breast cancer.
The next step in the current research would be to study more groups of people taking blood pressure medications and try to understand the underlying mechanism by which channel blockers calcium can affect the risk of cancer, said researchers.