Cancer as a Risk Factor for Long-Term Cognitive Deficits and Dementia

• Published in: JNCI : Journal of the National Cancer Institute Vol. 97; no. 11; pp. 854 - 856
• Main Authors: Heflin, Lara H., Meyerowitz, Beth E., Hall, Per, Lichtenstein, Paul, Johansson, Boo, Pedersen, Nancy L., Gatz, Margaret
• Format: Journal Article
• Language: English
• Published: Cary, NC Oxford University Press 01.06.2005; Oxford Publishing Limited (England)
• Subjects: Adult and adolescent clinical studies; Aged; Biological and medical sciences; Cancer; Cognition - drug effects; Cognition - radiation effects; Cognition Disorders - chemically induced; Cognition Disorders - epidemiology; Cognition Disorders - etiology; Comparative analysis; Dementia; Dementia - chemically induced; Dementia - epidemiology; Dementia - etiology; Humans; Incidence; Medical Record Linkage; Medical sciences; Medicin och hälsovetenskap; Neoplasms - complications; Odds Ratio; Organic mental disorders. Neuropsychology; Prevalence; Psychology. Psychoanalysis. Psychiatry; Psychopathology. Psychiatry; Registries; Risk Assessment; Risk Factors; Sweden - epidemiology; Tumors; Sweden; Europe; Human; Cancerology; Cognitive disorder; Risk factor; Malignant tumor; Epidemiology; Long term; Elderly; Public health; Dementia; Twin
• ISSN: 0027-8874; 1460-2105; 1460-2105
• DOI: 10.1093/jnci/dji137

Previous studies have shown that cancer survivors frequently experience short-term cognitive deficits, but it is unknown how long these deficits last or whether they worsen over time. Using a co-twin control design, the cognitive function of 702 cancer survivors aged 65 years and older was compared with that of their cancer-free twins. Dementia rates were also compared in 486 of the twin pairs discordant for cancer. Cancer survivors overall, as well as individuals who had survived cancer for 5 or more years before cognitive testing, were more likely than their co-twins to have cognitive dysfunction (odds ratio [OR] = 2.10, 95% confidence interval [CI] = 1.36 to 3.24; P<.001; and OR = 2.71, 95% CI = 1.47 to 5.01; P<.001, respectively). Cancer survivors were also twice as likely to be diagnosed with dementia as their co-twins, but this odds ratio did not reach statistical significance (OR = 2.0, 95% CI = 0.86 to 4.67; P = .10). These results suggest that cancer patients are at increased risk for long-term cognitive dysfunction compared with individuals who have never had cancer, even after controlling for the influence of genetic factors and rearing environment.