Breast Cancer Death Rates Continue to Decline, but at Slower Pace

Breast cancer death rates are continuing to decline as they have for decades, but recent statistics show that this decrease has become less profound in recent years and that incidence rates are increasing. These numbers are detailed in Breast Cancer Statistics, 2019-2020, the latest edition of the American Cancer Society’s biennial update of breast cancer statistics in the United States, published in CA: A Cancer Journal for Clinicians.

Outside of skin cancers, breast cancer is the most commonly diagnosed cancer in U.S. women, ranking second to lung cancer in causing female cancer death. It is estimated that 268,600 new cases of invasive breast cancer will be diagnosed this year in U.S. women, with a projected 41,760 breast cancer deaths predicted to occur in women as well.

Decline in Breast Cancer Death Rates

The breast cancer death rate declined by 40% from 1989 to 2017, which is due in part to improvements in screening, awareness, and treatment. This decline in breast cancer mortality led to 375,900 avoided deaths from the disease in 2017.

Though this death rate continues to decrease, it is doing so at a slower rate in recent years. From 1998 to 2011, breast cancer mortality in women dropped by 1.9%, but only decreased by 1.3% from 2011 to 2017. This trend is largely observed in white women, with the black-white discrepancy in breast cancer mortality widening over the last 30 years but remaining stable since 2011. From 2013 to 2017, the breast cancer death rate in black women is 40% higher than in white women, despite the incidence rate in this community being slightly lower. This gap is most profound in black women under the age of 50, who have a death rate double that of their white counterparts.

From 2013-2017, the breast cancer death rate decreased by 2.1% each year in Hispanics/Latinas, 1.5% each year in blacks, 1.0% each year in whites, 0.8% each year in Asians/Pacific Islanders, and was stable in American Indians/Alaska Natives. These statistics also indicate that these mortality rates are now stabilized for black women in Wisconsin and Colorado and for white women in Texas, Nebraska, and Virginia.

Increase in Incidence Rates

Despite the consistent decline in breast cancer death rates, the incidence rate has been slowly increasing by 0.3% every year since 2004. This increase coincides with the rise in local stage and hormone receptor-positive (HR+) disease in women. Increased rates of HR+ breast cancer is likely due to the greater number of women with excess body weight and declining fertility rates, being that these two factors are strongly associated with this type of cancer. Despite this trend, incidence rates of hormone receptor-negative breast cancer (associated with poorer survival rates) have decreased.

From 2016 to 2017, breast cancer surpassed lung cancer as the leading cause of cancer death in black women in six states, as well as in white women in Utah. The death tolls for breast and lung cancer in black women were comparable in four other states as well.

“We can’t say for sure what the reasons are for the slowing of the decline in breast cancer mortality,” said the report’s lead author, Carol DeSantis, MPH. “It could be due in part to the slight increase in incidence since 2004, as well as a sign that optimal breast cancer treatment has become more widespread, particularly among white women. However, more can and should be done to ensure that all women have access to quality care to help eliminate disparities and further reduce breast cancer mortality.”