From 1999 to 2005, breast cancer incidence rates in the U.S. decreased by about 2% per year. The decrease was seen only in women aged 50 and older. One theory is that this decrease was partially due to the reduced use of hormone replacement therapy (HRT) by women after the results of a large study called the Women’s Health Initiative were published in 2002. These results suggested a connection between HRT and increased breast cancer risk.
UPDATE October 2014: The Komen Group has come under more scrutiny as only about 20% of the money it raises goes toward actual "research" while the lion's share (40%) goes toward "public education". It is not clear what "public education" comprises. Some charities have been known to call fundraising activities (handing out pamphlets and asking for money) as "educational" activities, even though they are really more directed toward fundraising. It is not clear whether this is what the Komen Group is calling "education". Are there really people out there today who don't know about breast cancer at this point? The other criticism is that the CEO of the Komen group (who got into hot water over the Planned Parenthood tiff) makes over a half-million dollars a year as head of the group.
Charity, as they say, begins at home.