Background: Alzheimer's disease (AD) and cancer increase their frequency with age and can be considered main negative consequences of senescence. Few previous studies reported a lower incidence of cancers in persons with Alzheimer's disease (AD) and lower incidence of AD in persons with cancers. This result needs to be confirmed in different sets and with different study designs since it might be due to confounding due to underreporting and/or shortening of life expectancy of persons with cancer or AD. Methods: This was a prospective/retrospective cohort study. Persons living in the geographical area of the local health authority (ASL) of Milano 1 (Mi1) of 60 or more year from 2004 to 2009 with a first diagnosis of AD or cancer were recruited in their specific diagnostic cohort. Diagnoses were retrieved from the ASL Mi1 informative health system. Based on the person-years of observation during the time period from 2004 to 2009 we calculated the incidences of AD in the cohort of cancers and the incidence of cancers in the AD cohort in the period preceding and following the index diagnosis. The incidence of AD and cancers were calculated also for the general population of ASL Mi1 and observed cases in the two cohorts with respect to those expected from the general population were compared. Separate comparisons were made for the period preceding and following the diagnosis of AD or Cancer, for AD occurrence in smoking and non smoking related cancers and for persons surviving or dying during the period 2004-2009. Results: In the whole population of ASL Mi1 we registered 21451 (12225 men) newly diagnosed cancers and 2832 AD (947 men) giving respectively a crude incidence rate per 10000 p-y of 175.1 and of 22.1. The cohort of persons with AD contributed a total of 15063.0 p-y of observation and the corresponding figure for the cancer cohort was 101317.9 p-y. In 161 cases cancer and AD were diagnosed to the same person with AD preceding cancer in 68 cases. In persons with cancer 246 cases of AD were expected from the incidence observed in the whole population of 60 years or older; the risk of AD occurrence, relative to that of the general population of the same age and gender was therefore significantly reduced (observed/expected = 0.65 95% Confidence Interval [CI] 0.56-0.76). The corresponding figure for the cohort of AD were 241.2 cancer expected with a relative risk (RR) of 0, 57 (95% CI 0.49-0.67). No significant differences in the estimates were observed for the follow-up periods preceding and following the diagnosis, for smoking related cancers or for members of the cohort not surviving for the entire period of follow-up. Conclusion(s): Cancer and AD are negative manifestation of senescence and have an inverse relationship of occurrence. This result might be interpreted as a confirmation for the theory of pleiotropic genes for aging and senescence.
Cancer and Alzheimer Disease: an inverse relationship of occurrence. Results from a population Italian study
Musicco M;Prinelli F;Adorni F
2012
Abstract
Background: Alzheimer's disease (AD) and cancer increase their frequency with age and can be considered main negative consequences of senescence. Few previous studies reported a lower incidence of cancers in persons with Alzheimer's disease (AD) and lower incidence of AD in persons with cancers. This result needs to be confirmed in different sets and with different study designs since it might be due to confounding due to underreporting and/or shortening of life expectancy of persons with cancer or AD. Methods: This was a prospective/retrospective cohort study. Persons living in the geographical area of the local health authority (ASL) of Milano 1 (Mi1) of 60 or more year from 2004 to 2009 with a first diagnosis of AD or cancer were recruited in their specific diagnostic cohort. Diagnoses were retrieved from the ASL Mi1 informative health system. Based on the person-years of observation during the time period from 2004 to 2009 we calculated the incidences of AD in the cohort of cancers and the incidence of cancers in the AD cohort in the period preceding and following the index diagnosis. The incidence of AD and cancers were calculated also for the general population of ASL Mi1 and observed cases in the two cohorts with respect to those expected from the general population were compared. Separate comparisons were made for the period preceding and following the diagnosis of AD or Cancer, for AD occurrence in smoking and non smoking related cancers and for persons surviving or dying during the period 2004-2009. Results: In the whole population of ASL Mi1 we registered 21451 (12225 men) newly diagnosed cancers and 2832 AD (947 men) giving respectively a crude incidence rate per 10000 p-y of 175.1 and of 22.1. The cohort of persons with AD contributed a total of 15063.0 p-y of observation and the corresponding figure for the cancer cohort was 101317.9 p-y. In 161 cases cancer and AD were diagnosed to the same person with AD preceding cancer in 68 cases. In persons with cancer 246 cases of AD were expected from the incidence observed in the whole population of 60 years or older; the risk of AD occurrence, relative to that of the general population of the same age and gender was therefore significantly reduced (observed/expected = 0.65 95% Confidence Interval [CI] 0.56-0.76). The corresponding figure for the cohort of AD were 241.2 cancer expected with a relative risk (RR) of 0, 57 (95% CI 0.49-0.67). No significant differences in the estimates were observed for the follow-up periods preceding and following the diagnosis, for smoking related cancers or for members of the cohort not surviving for the entire period of follow-up. Conclusion(s): Cancer and AD are negative manifestation of senescence and have an inverse relationship of occurrence. This result might be interpreted as a confirmation for the theory of pleiotropic genes for aging and senescence.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
