Headlines & Helpful Information, Research
By: Sean Tuffnell
Last month the American Cancer Society released the annual
update to its “Cancer
Facts and Figures,” which is one of the main sources for cancer
data. News of its release mostly
centered on the fact that cancer incidence and mortality rates in the U.S. in
general are declining thanks in part to steady declines in smoking, as well as
advances in treatment and early detection.
This is all great news.
Yet some casual observers of the report noticed something that may seem
confusing. Early detection and effective
treatment have improved the mortality rate for breast cancer by 40 percent between
1989 and 2016 (the most recent year for which data is available due to the
significant lag required to collect and analyze it properly), yet the estimated
number of breast cancer deaths (based on national mortality data between
2002-2016) has increased to more than 42,000 in 2019. How can that be?
The simple answer is that while the mortality rate and the
actual number of deaths are both important numbers, they are used to answer two
different questions. The number of
deaths show us how far we still have to go to discover and deliver the cures,
while the mortality rate tells us whether we are making progress and which populations
are not benefiting as much from that progress, requiring focused efforts.
We expect the number of cases of breast cancer to increase
over time because the population in the U.S. is growing. The more people there are, the more cancers
there will be. Our population is also
living longer. Since your risk of breast
cancer increases as you get older, we expect to have more breast cancers over
time. Without significant breakthroughs
in treatment or improvements in access to quality care, we could expect the
actual number of deaths to remain consistent or grow with the growth in
population and overall incidence.
That’s why Susan G. Komen is focused on the estimated number
of deaths per year in the U.S., which increased from approximately 41,000 to
more than 42,000 since last year’s report. Focusing on the actual number forces us to
look past the good news of the decline in death rates to the underlying
challenges of metastatic breast cancer and the racial/ethnic disparities that
That’s why in 2016 we announced a Bold Goal to cut that
number in half by 2026. We can reduce
the current number of deaths by focusing on research breakthroughs that will
lead to better treatments for aggressive and metastatic breast cancer;
detecting recurrence earlier; and working to overcome the many barriers that
prevent women from getting the care they need.
And while it may take some time to take effect and to show up in the
data, which are always several years behind current activities, we have begun
to lay the foundation for this progress – investing 70 percent of our 2018
research funding in grants that address metastatic breast cancer and treatment
resistance, and launching a focused effort to improve death rates among
African-American women in the communities where the disparity between the rates
of African-American women and their white neighbors is the greatest.
But how do we know where to target those efforts? That’s where death rates are informative. Death rates are adjusted for both age and
size of the population and can, therefore, be used to compare deaths over time
and among different populations. For
example, it is estimated that this year in Washington, D.C. there will be 100
breast cancer deaths, while in California there will be 4,560 deaths. Just looking at the raw numbers, California
has the higher number of breast cancer deaths.
Yet the raw numbers don’t take into account the number of people who
live there or the age and race/ethnicity of the women in the different
To better understand the burden of breast cancer in each
area we look at the number of deaths per 100,000 people, called the death rate
(or mortality rate). When we do this, the
ACS report shows there were 28.3 deaths per 100,000 people in Washington, D.C.
compared to just 19.8 deaths per 100,000 in California. By looking at the death rates we can see
women who live in Washington, D.C. have higher mortality (and thus, lower
survival) than women in California. That
said, there are certainly specific communities and racial/ethnic populations in
California that have higher death rates than the statewide number, and which
therefore require special attention.
Overall breast cancer death rates increased slowly by 0.4
percent per year from 1975 to 1989, but since have decreased rapidly, by almost
2 percent per year for a total decline of 40 percent through 2016. This decline in mortality is due to improved
breast cancer treatment and early detection (after mammography was shown to be
an effective screening tool in the late 1980s, the self-reported use of
mammography in the U.S. quickly increased from 29 percent of women 40 years and
older in 1987 to 70 percent by 2000).
While we should be excited about the improvement in death
rates, the numbers also show that not all women have benefited equally. There is a striking difference in mortality
trends between African-American and white women beginning in the early
1980s. Currently, African-American women
are, on average, about 40 percent more likely to die from breast cancer than
their white counterparts. This disparity
is due to a combination of factors, including the timing and quality of care received
and the fact that African-American women are more likely to be diagnosed
younger, with a more aggressive form of the disease. It is also influenced by other health
factors, such as obesity, as well as the ability to complete treatment, as
We know no single organization can do this – it takes
everyone, working together. But we are committed to building on our role as
leaders, conveners and collaborators to save lives. To do less is unacceptable.
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