A study from UCLA suggests that breast cancer survivors who take the blood pressure drugs known as ACE inhibitors have an increased risk of their breast cancer recurring. The study found a 56% increased risk of recurrence, but no increase in death rate.

While the study is only a preliminary one, women concerned about its findings can talk to their doctor about prescribing a substitute blood pressure medication. There are so many classes of blood pressure drugs currently available that finding a substitute shouldn't be difficult.

The study also found that women who took a different class of blood pressure medicine, beta blockers, had a reduced risk of breast cancer recurrence. But the number of women in the study taking beta blockers was too small for this difference to be statistically significant.

Common ACE (angiotensin converting enzyme) inhibitors include Benazepril (Lotensin), Captopril, Enalapril (Vasotec), Fosinopril, Lisinopril (Prinivil, Zestril), Moexipril (Univasc), Perindopril (Aceon), Quinapril (Accupril), Ramipril (Altace) and Trandolapril (Mavik).

The study looked at medical records of 1,779 women with early-stage breast cancer who had been treated by doctors from a northern California HMO, the LACE cohort. The women were followed for eight years after their treatment.

In addition to finding that women who took ACE inhibitors had a higher risk of their breast cancer recurring, the study also found that women who took a different class of blood pressure medicine, beta blockers, had a reduced risk of breast cancer recurrence. But the number of women in the study taking beta blockers was too small for this difference to be statistically significant.

Women in the study who took both blood pressure medications together had an intermediate risk of breast cancer recurrence.

Two studies from 2010 had previously suggested that beta blockers may lower cancer spread and recurrence. One study of 400 women in England and Germany found that those who took beta blockers had a lower rate of breast cancer recurrence. The other study was in mice and also found that beta blockers lowered the rate at which cancer spread.

The studies suggesting that ACE inhibitors raise cancer risk and beta blockers lower it are all considered preliminary. Studies are currently underway in Denmark and Canada that are evaluating the effects of ACE inhibitors and beta blockers on much larger groups of breast cancer patients.

An article on The UCLA study was published online April 10, 2011 by the journal Breast Cancer Research and Treatment and will also appear in a future print edition of the journal.