As October is Breast Cancer Awareness Month, it is an appropriate time to ask what sort of progress we are making against this disease in Georgia. For help with this question, we turn to data from the Georgia Department of Public Health. Specifically, we look to the Office of Health Indicators for Planning’s Online Analytical Statistical Information (aka OASIS), which allows us to track health trends and identify areas of greatest need for our state. The OASIS system has thirty years of mortality data for breast cancer, stretching back to 1994.
Figure 1 below presents the statewide death rate (per 100,000 females) for breast cancer from 1994 to 2023.
Figure 1: Female Breast Cancer Death Rates in Georgia, 1994-2003
As this graph above shows, the death rate dropped sharply around the turn of the millennium and then appears to have ticked back up some over the last decade. Though the overall trend has been a gradual improvement, the increase in recent years might cause some alarm.
Thankfully, this graph does not tell the whole story– and likely not even the correct story. As we have noted in previous blog posts[1], a nationwide demographic trend, Georgia included, has been overall aging of the population. And chronic diseases like cancers are much more prevalent among older populations. Figure 2 addresses this point by showing mortality rates for different age groups.
Figure 2: Female Breast Cancer Death Rates in Georgia by Age Group, 1994-2003
Figure 2 above demonstrates several points. First, there are significant disparities in death rates between different age cohorts– rates are low among young women (ages 20-29), then increase with older age groups. And while there is no discernable time trend for the oldest cohort (age 75 and over), there has been significant improvement in mortality rates among women ages 45-59 and ages 60-74. Indeed, the rate for women ages 45-59 has been cut roughly in half over the last three decades.
Recognizing that the risk factors are quite different for different age groups and that we have growing proportions of the population in those older age groups, we need to make use of an age-adjusted rate instead of the raw rate.[2] Figure 3 (below) presents the statewide age-adjusted death rate for the same period as covered in Figure 1 above.
Figure 3: Age-Adjusted Female Breast Cancer Death Rates in Georgia, 1994-2003
So now, when age factors are taken into consideration, we see that breast cancer death rates have been on a steeper and much steadier decline than suggested by the raw rate, The slope of the trend line in Figure 1 is -.05, (meaning about 1.5 fewer deaths per 100,000 now than three decades ago. Yet the slope of the trend line in Figure 3 is -.29 (indicating about 8.7 fewer deaths per 100,000 now as compared with 1994).
But the news is not all good. Figure 4 presents age-adjusted death rates in Georgia by race.
Figure 4: Age-Adjusted Female Breast Cancer Death Rates in Georgia by Race, 1994-2003
As Figure 3 above shows, a significant gap has persisted between Black and white females over the last three decades. Though breast cancer death rates have declined significantly for both groups over this period, this decline has only led to a present-day situation wherein the mortality rate among Black females has dropped to where the breast cancer mortality rate was for white females nearly three decades ago.
Notes:
[1] See, in particular our series on Atlanta’s aging workforce beginning with this post: https://33n.atlantaregional.com/data-diversions/the-aging-workforce-a-fresh-look-episode-1
[2] The OASIS definitions page defines age-adjusted rates as “A weighted average of the age-specific rates, where the weights are the proportions of persons in the corresponding age groups of a standard population.” For a more detailed explanation of how an age-adjusted rate is calculated, including a walk-through of the steps involved, see this explanation at the National Cancer Institute website: https://seer.cancer.gov/seerstat/tutorials/aarates/definition.html