Bisphosphonates do not reduce risk of breast cancer
Two randomized controlled studies have shown that bisphosphonates (drugs used to treat osteoporosis) do not decrease the incidence of breast cancer. Bisphosponates are administered to increase bone density for patients who suffer from osteoporosis. It was considered that the bisphosponates had anti-tumor and anti-metastatic properties based on few observational studies published earlier. The earlier publications suggested that bisphosphonates may protect women from breast cancer.
In the recent two randomized studies, FIT: Fracture Intervention trail and HORIZON – PFT: Health outcome and reduced incidence with Zoledronic acid once yearly Fracture trial test, the bisphosphonates alendronate and zoledronic acid were used for the drug therapy for osteoporosis. In the study the breast cancer incidence was compared between the treatment group and the control group. In case of the FIT, nearly 6459 women aged between 55 and 81 were randomly assigned between alendronate and placebo and followed up for an average of 3.8 years. In HORIZON- PFT nearly 7765 women in the age group of 65 to 89 years were randomly assigned to receive intravenous zoledronic acid or placebo. The study period ranged to nearly 2.8 years. These studies showed that there was no significant difference in the incidence of breast cancer between the treatment arm and the placebo arm.
In case of Fracture Intervention Trail also known as FIT, the breast cancer rate was nearly 1.5 percent in the placebo group when compared to the 1.8 percent in the alendronate group. In the HORIZON –PFT, the rate was 0.8 percent in the placebo as against 0.9 percent in case of the Zoledronic acid group. Dr. Joseph S. Ross, M.D., a JAMA Internal Medicine associate editor opines that this study shows that there is a lot of difference between observational studies and randomized clinical trials and points out the fact that new therapies are to be structured from the results of these randomized controlled trials.
Tuesday, August 26, 2014