In 2011, according to the Susan G. Komen for the Cure organization, it is estimated that among U.S. women, there will be 230,480 new cases of invasive breast cancer, which includes new cases of primary breast cancer among survivors.
There will be 57,650 new cases of in situ breast cancer, which includes ductal carcinoma in situ (DCIS) and lobular carcinoma in situ (LCIS), of those, about 85 percent were DCIS).
DCIS is a non-invasive breast cancer and LCIS is a risk factor that increases the risk of invasive breast cancer.
There will be 39,520 breast cancer deaths.
The incidence of breast cancer declined in the early 2000s. Although mammography screening rates fell somewhat over this same time period, studies show these changes were not likely related to the decline in breast cancer rates.
The decline appears to be related to the drop in use of postmenopausal hormones that occurred after the Women's Health Initiative study showed their use increased risk of breast cancer and heart disease. Since 2003, the incidence of breast cancer has remained stable.
As mammography screening rates have increased, more cases of breast cancer are found at earlier stages, when they are more easily and successfully treated.
During the 1980s and 1990s, diagnoses of early-stage breast cancer, including ductal carcinoma in situ (DCIS), and conditions such as lobular carcinoma in situ (LCIS) increased greatly. Since the late 1990s, these rates have remained steady.
At the same time, diagnoses of advanced stage (metastatic) breast cancer have remained stable or dropped slightly.
Breast cancer is the most common cancer in women worldwide.
It is estimated that more than 1.6 million new cases of breast cancer occurred among women worldwide in 2010.
Rates of breast cancer around the world vary a great deal. In general, developed countries have higher rates than developing countries.
Although not all of the factors that make up this difference are not known, lifestyle and reproductive factors likely play a large role. Low screening rates and incomplete reporting can make rates of breast cancer in developing countries look lower than they truly.
White women have the highest incidence, while American Indian and Alaskan Native women have the lowest rates.
Breast cancer is the most common cancer among African American women. It is also the second leading cause of cancer death among African American women, exceeded only by lung cancer.
In 2011, an estimated 26,840 new cases of breast cancer and 6,040 deaths are expected to occur among African American women.
Breast cancer incidence in African American women is lower than in Caucasian women. Breast cancer mortality, however, is 39 percent higher.
Although breast cancer survival in African American women has increased in recent decades, survival rates remain lower than among Caucasian women.
From 1999-2006, the five-year relative survival rate for breast cancer among African American women was 78 percent compared to 90 percent among Caucasian women. There are many possible reasons for this difference in survival.