Risk of Alzheimer's disease or dementia following a cancer diagnosis.
<h4>Objective</h4>We evaluated dementia and Alzheimer's disease (AD) risks after a cancer diagnosis in a population-based prospective cohort, the Adult Changes in Thought (ACT) study.<h4>Methods</h4>We followed community-dwelling people aged ≥65 years without dementia at...
| Main Authors: | , , , , , |
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| Format: | Article |
| Language: | English |
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Public Library of Science (PLoS)
2017-01-01
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| Series: | PLoS ONE |
| Online Access: | https://journals.plos.org/plosone/article/file?id=10.1371/journal.pone.0179857&type=printable |
| _version_ | 1826578782674223104 |
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| author | Erin J Aiello Bowles Rod L Walker Melissa L Anderson Sascha Dublin Paul K Crane Eric B Larson |
| author_facet | Erin J Aiello Bowles Rod L Walker Melissa L Anderson Sascha Dublin Paul K Crane Eric B Larson |
| author_sort | Erin J Aiello Bowles |
| collection | DOAJ |
| description | <h4>Objective</h4>We evaluated dementia and Alzheimer's disease (AD) risks after a cancer diagnosis in a population-based prospective cohort, the Adult Changes in Thought (ACT) study.<h4>Methods</h4>We followed community-dwelling people aged ≥65 years without dementia at study entry for incident dementia and AD from 1994-2015. We linked study data with cancer registry data and categorized cancer diagnoses as prevalent (diagnosed before ACT study enrollment) or incident (diagnosed during follow-up). We used Cox regression to estimate cause-specific hazard ratios (HRs) with 95% confidence intervals (CIs) for dementia or AD risk comparing people with a cancer diagnosis to people without cancer. We conducted sensitivity analyses restricted to people surviving beyond age 80, and stratified by cancer stage, type, and whether the cancer was smoking-related.<h4>Results</h4>Among 4,357 people, 756 (17.4%) had prevalent cancer; 583 (13.4%) developed incident cancer, 1,091 (25.0%) developed dementia, and 877 (20.1%) developed AD over a median 6.4 years (34,482 total person-years) of follow-up. Among complete cases (no missing covariates) with at least one follow-up assessment, adjusted HRs for dementia following prevalent and incident cancer diagnoses were 0.92 (95%CI: 0.76, 1.11) and 0.87 (95%CI: 0.64, 1.04), compared to no cancer history. HRs for AD were 0.95 (95%CI: 0.77, 1.17) for prevalent cancer and 0.73 (95%CI: 0.55, 0.96) for incident cancer. In sensitivity analyses, prevalent late-stage cancers were associated with reduced risks of dementia (HR = 0.51, 95%CI: 0.30, 0.89) and AD (HR = 0.50, 95%CI: 0.27, 0.94). When limited to people who survived beyond age 80, incident cancers were still associated with reduced AD risk (HR = 0.69, 95%CI: 0.51, 0.92).<h4>Conclusions</h4>Our results do not support an inverse association between prevalent cancer diagnoses, which were primarily early-stage, less aggressive cancers, and risk of dementia or AD. A reduced risk of AD following an incident cancer diagnosis is biologically plausible but may reflect selective mortality. |
| first_indexed | 2024-12-19T19:54:38Z |
| format | Article |
| id | doaj.art-d08f47b367fb40768e079ef33d846d2c |
| institution | Directory Open Access Journal |
| issn | 1932-6203 |
| language | English |
| last_indexed | 2025-03-14T14:07:51Z |
| publishDate | 2017-01-01 |
| publisher | Public Library of Science (PLoS) |
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| series | PLoS ONE |
| spelling | doaj.art-d08f47b367fb40768e079ef33d846d2c2025-02-27T05:38:35ZengPublic Library of Science (PLoS)PLoS ONE1932-62032017-01-01126e017985710.1371/journal.pone.0179857Risk of Alzheimer's disease or dementia following a cancer diagnosis.Erin J Aiello BowlesRod L WalkerMelissa L AndersonSascha DublinPaul K CraneEric B Larson<h4>Objective</h4>We evaluated dementia and Alzheimer's disease (AD) risks after a cancer diagnosis in a population-based prospective cohort, the Adult Changes in Thought (ACT) study.<h4>Methods</h4>We followed community-dwelling people aged ≥65 years without dementia at study entry for incident dementia and AD from 1994-2015. We linked study data with cancer registry data and categorized cancer diagnoses as prevalent (diagnosed before ACT study enrollment) or incident (diagnosed during follow-up). We used Cox regression to estimate cause-specific hazard ratios (HRs) with 95% confidence intervals (CIs) for dementia or AD risk comparing people with a cancer diagnosis to people without cancer. We conducted sensitivity analyses restricted to people surviving beyond age 80, and stratified by cancer stage, type, and whether the cancer was smoking-related.<h4>Results</h4>Among 4,357 people, 756 (17.4%) had prevalent cancer; 583 (13.4%) developed incident cancer, 1,091 (25.0%) developed dementia, and 877 (20.1%) developed AD over a median 6.4 years (34,482 total person-years) of follow-up. Among complete cases (no missing covariates) with at least one follow-up assessment, adjusted HRs for dementia following prevalent and incident cancer diagnoses were 0.92 (95%CI: 0.76, 1.11) and 0.87 (95%CI: 0.64, 1.04), compared to no cancer history. HRs for AD were 0.95 (95%CI: 0.77, 1.17) for prevalent cancer and 0.73 (95%CI: 0.55, 0.96) for incident cancer. In sensitivity analyses, prevalent late-stage cancers were associated with reduced risks of dementia (HR = 0.51, 95%CI: 0.30, 0.89) and AD (HR = 0.50, 95%CI: 0.27, 0.94). When limited to people who survived beyond age 80, incident cancers were still associated with reduced AD risk (HR = 0.69, 95%CI: 0.51, 0.92).<h4>Conclusions</h4>Our results do not support an inverse association between prevalent cancer diagnoses, which were primarily early-stage, less aggressive cancers, and risk of dementia or AD. A reduced risk of AD following an incident cancer diagnosis is biologically plausible but may reflect selective mortality.https://journals.plos.org/plosone/article/file?id=10.1371/journal.pone.0179857&type=printable |
| spellingShingle | Erin J Aiello Bowles Rod L Walker Melissa L Anderson Sascha Dublin Paul K Crane Eric B Larson Risk of Alzheimer's disease or dementia following a cancer diagnosis. PLoS ONE |
| title | Risk of Alzheimer's disease or dementia following a cancer diagnosis. |
| title_full | Risk of Alzheimer's disease or dementia following a cancer diagnosis. |
| title_fullStr | Risk of Alzheimer's disease or dementia following a cancer diagnosis. |
| title_full_unstemmed | Risk of Alzheimer's disease or dementia following a cancer diagnosis. |
| title_short | Risk of Alzheimer's disease or dementia following a cancer diagnosis. |
| title_sort | risk of alzheimer s disease or dementia following a cancer diagnosis |
| url | https://journals.plos.org/plosone/article/file?id=10.1371/journal.pone.0179857&type=printable |
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