US breast cancer rates saw a dramatic decline in 2003, just one year after millions of women stopped using hormone replacement therapy (HRT), a new study found. The new analysis released shows the number of overall US breast cancer cases dropped 7% from 2002 to 2003, a year after an American Cancer Society study found links between the use of HRT and the disease. The decline in breast cancer cases in older women sensitive to the hormone estrogen was even greater, at 12%, the researchers said. “Something went right in 2003 and it seems that it was the decrease in the use of hormone therapy,” said Peter Radvin, a professor at MD Anderson Cancer Center and co-author of the study, in a statement. A study published in September linked the drop in breast cancer rates in 2003 to a reduction in the use of Wyeth’s Premarin, an estrogen replacement product, which was once the top prescribed US pharmaceutical. Wyeth spokeswoman Candace Steele told in an e-mailed statement that “It is simply inappropriate to make any speculative statements based on the MD Anderson Cancer Center analysis. Even the researchers state they cannot give the definitive cause. Clearly more studies are warranted.”