Deaths Involving Both Alzheimer’s and Cancer Decline Slightly Yet Grow in Number Among Older Americans

When Alzheimer’s disease and cancer appear together on a death certificate, they mark one of medicine’s most complex intersections: a brain steadily losing its memory and a body fighting malignancy, all in a patient typically past the age of 65. A new national analysis of more than two decades of U.S. mortality data has now mapped, in unprecedented demographic and geographic detail, how often these two leading killers are recorded on the same death certificate, and the picture it paints is more nuanced than a simple rise or fall. Between 1999 and 2023, the age-adjusted rate of deaths involving both conditions declined modestly, even as the raw annual count of such deaths climbed by roughly 31 percent, from 4,764 to 6,240.

The study, published in the open-access journal Nursing Open, drew on de-identified aggregate mortality records from the Centers for Disease Control and Prevention’s Wide-ranging Online Data for Epidemiologic Research platform, known as CDC WONDER. The researchers defined a case as any death among a U.S. resident aged 65 or older in which both Alzheimer’s disease, coded G30 in the International Classification of Diseases tenth revision, and a malignant neoplasm, coded C00 through C97, appeared anywhere on the same certificate, whether as the underlying cause or a contributing factor. Over the full 25-year window, 143,052 such deaths were identified. Because either condition could occupy any position on the certificate, the case definition captures deaths in which both diseases were recorded, not a cohort of people known to be living with both diagnoses, and the authors are careful to stress that the resulting rates describe population-level patterns rather than individual mortality risk or survival.

To translate raw counts into comparable trends, the team calculated age-adjusted mortality rates standardized to the year 2000 U.S. standard population and modeled temporal patterns with joinpoint regression, a statistical technique that fits a series of connected straight lines on a logarithmic scale and pinpoints the years where the trend changes direction. Annual percent changes describe each segment, while average annual percent changes summarize the whole period. Across the entire study span, the age-adjusted rate fell from 13.96 to 12.05 deaths per 100,000 older adults, a statistically significant average annual decline of 0.73 percent. Yet the joinpoint analysis revealed that this gentle long-term slope conceals a striking rollercoaster: rates rose through the mid-2000s, dropped sharply between roughly 2006 and 2014, climbed again from 2014 to 2021, and then turned downward in the final two years, a dip the authors treat cautiously because it overlaps with the COVID-19 pandemic.

That recurring arc, an early rise, a steep middle-period decline, and a rebound after 2014, appeared in nearly every subgroup examined, from men and women to every age band and census region. Among women, who accounted for 79,117 deaths, the rate rose 1.69 percent annually from 1999 to 2006, plunged 4.33 percent per year through 2014, then surged 3.11 percent annually through 2021. Men, with 63,935 deaths, followed an almost identical choreography, and only men showed a statistically significant full-period decline, at 1.17 percent per year, compared with a non-significant 0.55 percent among women. The consistency of the pattern across sexes and ages suggests that forces operating at the population level, such as shifts in diagnostic practice, death-certificate reporting habits, and the composition of the aging population, may have shaped the recorded rates as much as any change in the underlying biology.

Age left the deepest imprint on the data. Adults aged 85 and older accounted for 82,538 of the deaths, and their crude mortality rate, roughly 57 to 59 per 100,000, dwarfed the 12 to 16 per 100,000 seen among those aged 75 to 84 and the mere 1.5 to 2 per 100,000 among those aged 65 to 74. Only the 75-to-84 group showed a statistically significant long-term decline, at 1.26 percent per year. The authors note that frailty, multimorbidity, and diminished physiological reserve are plausible contributors to the extreme rates in the oldest group, and that biological pathways involving inflammation, DNA repair, and mitochondrial function have been investigated in relation to both neurodegeneration and cancer, but they emphasize that their ecological design cannot measure or confirm any of these mechanisms.

Geography told an equally layered story. The South recorded the most deaths, 48,389, followed by the West with 36,533, the Midwest with 35,260, and the Northeast with 22,870. Yet the Northeast posted the steepest significant decline in its age-adjusted rate, falling from 12.45 to 8.64 per 100,000, an average annual drop of 1.46 percent, while the Midwest also declined significantly. The South’s rate fell as well, though not significantly, and the West bucked the national direction entirely, its rate inching upward from 13.94 to 14.70 per 100,000 with a non-significant average annual change of 0.40 percent. At the state level, cumulative death counts were highest in California, Texas, Ohio, Florida, and Pennsylvania, while point estimates of trend were most negative in New Hampshire, Maryland, Illinois, and Massachusetts and most positive in Oklahoma and Oregon, findings the investigators label exploratory because no adjustment for multiple comparisons was made.

Race and ethnicity produced some of the study’s most consequential contrasts. Non-Hispanic White individuals accounted for 122,214 deaths, and their rate declined only modestly and non-significantly, from 14.21 to 12.85 per 100,000. Non-Hispanic Black individuals, who began the period with the highest rate at 16.35 per 100,000, experienced a significant decline of 1.69 percent per year, converging numerically with the White rate by the study’s end. Hispanic individuals moved in the opposite direction, with a significant average annual increase of 2.58 percent, from a very low baseline of 5.93 per 100,000 in 1999, when only 75 such deaths were recorded, to 9.77 per 100,000 in 2023. The authors caution that the enormous percentage growth in death counts among Hispanic and non-Hispanic Other populations partly reflects those tiny baselines, and that a change from bridged-race to single-race classification in 2021 complicates comparisons, though an overlap analysis for 2018 through 2020 found differences below 1.3 percent for the largest groups.

Urbanization added a final geographic dimension. Restricted to 1999 through 2020 by the available data, the analysis found that nonmetropolitan counties carried consistently higher rates than metropolitan ones, 15.52 versus 13.55 per 100,000 at the start and 14.77 versus 12.70 at the end, though neither area showed a statistically significant full-period trend and no formal between-group comparison was performed. A sensitivity analysis excluding the pandemic years confirmed the overall picture: the pre-pandemic decline of 0.78 percent per year closely matched the full-period estimate, and the significant rise among Hispanic populations persisted, slightly attenuated. The authors interpret these overlapping-period comparisons as consistency checks, not as measurements of COVID-19’s causal impact.

The study’s limitations are substantial and candidly acknowledged. Death certificates are known to underreport Alzheimer’s disease, particularly among older adults burdened with multiple competing conditions, so the true frequency of dual involvement is almost certainly higher than the recorded rates suggest. Without clinical data on cognition, cancer stage, treatment, or comorbidity, the analysis cannot distinguish changes in disease occurrence from changes in certification practice, and it cannot estimate survival among people living with both diagnoses. Socioeconomic conditions, healthcare access, and environmental exposures were not measured, making explanations for the demographic and geographic patterns hypotheses rather than conclusions. What the study does establish is a clear signal for clinicians and health systems: as populations age, a growing number of older adults will face cognitive decline and cancer simultaneously, and coordinated geriatric, oncological, and neurological care, with attention to cognitive assessment, treatment burden, medication management, caregiver support, and goals of care, will become increasingly essential. The authors argue that linking mortality records with individual-level clinical and social data is the necessary next step, so that the patterns now visible on death certificates can be translated into better care for the vulnerable population they represent.

Subject of Research: Population-level mortality trends for deaths with both Alzheimer's disease and cancer recorded on U.S. death certificates among adults aged 65 and older, 1999–2023

Article Title: Trends in Population‐Level Mortality Rates for Deaths With Both Alzheimer's Disease and Cancer Recorded on Death Certificates Among U.S. Adults Aged ≥ 65 Years, 1999–2023

Article References: Zhang, X., Xiong, Y.-J., Lv, T., & Chen, Y. (2026). Trends in Population‐Level Mortality Rates for Deaths With Both Alzheimer's Disease and Cancer Recorded on Death Certificates Among U.S. Adults Aged ≥ 65 Years, 1999–2023. Nursing Open, 13(10), Article e70897. https://doi.org/10.1002/nop2.70897

Image Credits: AI Generated

DOI: 10.1002/nop2.70897

Keywords: Alzheimer's disease, cancer, mortality trends, death certificates, CDC WONDER, older adults, joinpoint regression, health disparities, multimorbidity, epidemiology, geriatrics, United States