Researchers to test link between common blood pressure pills and breast cancer

Curtin University researchers will examine if the long-term use of a popular blood pressure medication increased the risk of breast cancer in almost 200,000 women as part of a new project supported by the Federal Government.

The new research, awarded an NHMRC Clinical Trials and Cohort Studies Grant, will investigate the link between the long-term use of calcium channel blockers and the risk of breast cancer by examining three internationally renowned Australian and Dutch longitudinal cohorts using state-of-the-art analytical techniques, which have not been used in this area before.

Lead researcher Professor Rachael Moorin, from the Curtin School of Population Health, said the relationship between calcium channel blockers—used widely in Australia as a first-line therapy for high blood pressure—and breast cancer was hotly debated with mixed research across the globe.

"An American study found 58 percent of women with early-stage breast cancer were prescribed a blood pressure-reducing medication and this link has achieved mixed results from research relating to North American, United Kingdom, Nordic and Taiwanese women," Professor Moorin said.

"This study will investigate if taking calcium channel blockers increases the risk of breast cancer in Australian women for the first time. The use of calcium channel blockers may increase the risk of cancer because of their role in changing intracellular calcium levels and breast tissue may be particularly susceptible to the adverse effects of changing intracellular calcium due to its secretary role."

Professor Moorin said the study, which would take about three years to complete, had potentially significant implications for Australian women.

"With an estimated 48 women diagnosed each day, breast cancer was the most commonly diagnosed cancer in Australia in 2019 and the most common in women, with one in seven Australian women diagnosed with breast cancer by the age of 85," Professor Moorin said.

"The incidence of breast cancer is rising with 19,535 new cases diagnosed in Australia in 2019, a 19 percent increase compared with 2013. Breast cancer is second only to lung cancer as the most common cause of death from cancer in Australian women.

"Many women will also have cardiovascular disease such as hypertension or high blood pressure, which occurs in about 30 percent of women aged 45–54 rising to about 45 percent in those aged 75 and over."

The study will examine the Australian Longitudinal Study on Women's Health, the 45 and Up Study data from the Department of Human Services database and The Rotterdam Study from The Netherlands.

Provided by Curtin University