That news appears in the ACS' biannual report on breast cancer in the U.S.
According to the report, breast cancer deaths declined by 2.2% annually from 1990 to 2004, partly due to earlier detection and advances in treatment.
But there are racial gaps in those figures, the report also shows.
Breast Cancer Race Gap
The ACS reports that breast cancer deaths dropped 2.4% per year from 1990 to 2004 in white and Hispanic women, compared with 1.6% annually in African-American women.
The precise reasons for those racial patterns aren't clear. Genetics may play a role, but other factors including income and access to medical care are also important.
"Unfortunately, not all women are benefiting at the same level," says Eyre, noting that by 2004, breast cancer death rates were 36% higher in African-American women than in white women.
The ACS estimates that about 40,460 U.S. women will die of breast cancer in 2007 -- and that about 2.4 million women living in the U.S. have a history of breast cancer.
Latest Breast Cancer Statistics
In the new report, the ACS predicts that an estimated 178,480 new cases of invasive breast cancer will be diagnosed this year among U.S. women.
Invasive cancer has spread from its starting point into surrounding breast tissue. Most breast cancers are invasive.
The ACS also estimates that 62,030 new cases of in situ breast cancer (cancer that hasn't spread beyond its starting point to other breast tissue) will be diagnosed in 2007.
Breast cancer is far more common among women than men. The ACS predicts that in 2007, about 2,030 cases of breast cancer will be diagnosed in men, accounting for about 1% of all breast cancers.
The ACS estimates that 450 men will die of breast cancer in the U.S. this year.
Breast Cancer Rarer?
Breast cancer is U.S. women's most common cancer (except for skin cancers), but it may be becoming rarer than in the past.
Don't race past that word "may." Undetected breast cancers due to missed mammograms may be contributing to the trend.
The ACS reports a 3.5% drop per year in breast cancer cases from 2001 to 2004.
That decline follows a sharp rise in breast cancer cases from 1980 to 1987 that slowed until 2001 and then headed down.
Why the turnaround? The ACS notes two possible reasons.
Reason No. 2: Mammography rates are down. Some women may have breast cancer and not know it. That would make breast cancer rates look lower than they really are.
Mammography isn't a perfect test, but it's the best way to screen women for breast cancer.
Breast Cancer Perspective
A woman living in the U.S. has a 12.3% (1 in 8) lifetime risk of developing breast cancer, states the ACS report.
But remember, that's a general number about a woman's odds of developing breast cancer at some point in her life -- not this year, or even this decade.
Breast cancer becomes more common with age, but it can also strike before menopause, so the ACS encourages women to learn what's normal for their breasts and to get lumps checked by a doctor.
Most lumps aren't breast cancer. But don't assume that a lump is no big deal. Check with your doctor to find out -- and remember, if it is breast cancer, the sooner it's detected, the better your chances may be of survival.
(Do you get regular mammograms? Take the poll on WebMD's Women’s Health: Friends Talking message board.)