Until recently, breast cancer was diagnosed less often in black women than white women, yet despite this, the death rate for breast cancer has been higher in black women. Now, the racial gap in diagnosis has closed, but the death gap has widened, according to a report from the American Cancer Society.
The ACS report suggests that black and white women are being diagnosed with breast cancer at the same rate, as diagnoses have grown more common in black women while those in white women have leveled off. In 2012, the black and white rates equalized at around 135 cases per 100,000 women, the researchers found. In 2002, the white rate was 132 and the black rate was 124.
There are several reasons why white women have had higher rates of breast cancer. They tend to wait longer in life to have children, and earlier childbirth is thought to lower the risk of developing breast cancer later.
But while the white rate for breast cancer diagnoses has leveled off, the black rate has continued to creep up. Greater availability of breast cancer screening in some parts of the country may be one factor. But the leading theory is that it may be due to the greater incidence of obesity in black women. Being obese is tied to a higher risk of developing breast cancer.
Breast cancer deaths rates have been falling for both black and white women, most likely due to earlier diagnosis and better treatment. But the white death rate has been lower than the black death rate for a long time, and it has been falling at a steeper rate. Over a decade, the white breast cancer death rate fell from about 25 to 21 per 100,000, while the black death rate dropped from about 34 to 29 per 100,000.
This translates to a 38% difference between white and black death rate in 2003, and a 42% difference in 2012. One reason is that more black women are diagnosed with breast cancer at a later stage and with a more aggressive form of cancer.
The article was published online in CA: A Cancer Journal for Clinicians.