Investigating the association between cancer and dementia risk: a longitudinal cohort study

Androgen deprivation therapy for prostate cancer and neurocognitive disorders: a systematic review and meta-analysis

BACKGROUND

Prostate cancer is a prevalent disease that urgently needs to address its treatment-related complications. By examining existing evidence on the association between Androgen Deprivation Therapy (ADT) and dementia, this study contributes to the understanding of potential risks. We sought to analyze the currently available evidence regarding the risk of dementia, Alzheimer's disease (AD), vascular dementia, and Parkinson's disease (PD) in patients undergoing ADT.

METHODS

A systematic search of PubMed, EMBASE, Scopus, and Google Scholar was performed to identify studies published from the databases' inception to April 2023. Studies were identified through systematic review to facilitate comparisons between studies with and without some degree of controls for biases affecting distinctions between ADT receivers and non-ADT receivers. This review identified 305 studies, with 28 meeting the inclusion criteria. Heterogeneity was assessed using Higgins I2%. Variables with an I2 over 50% were considered heterogeneous and analyzed using a Random-Effects model. Otherwise, a Fixed-Effects model was employed.

RESULTS

A total of 28 studies were included for analysis. Out of these, only 1 study did not report the number of patients. From the remaining 27 studies, there were a total of 2,543,483 patients, including 900,994 with prostate cancer who received ADT, 1,262,905 with prostate cancer who did not receive ADT, and 334,682 patients without prostate cancer who did not receive ADT. This analysis revealed significantly increased Hazard Ratios (HR) of 1.20 [1.11, 1.29], p < 0.00001 for dementia, HR 1.26 [1.10, 1.43], p = 0.0007 for Alzheimer's Disease, HR 1.66 [1.40, 1.97], p < 0.00001 for depression, and HR 1.57 [1.31, 1.88], p < 0.00001 for Parkinson's Disease. The risk of vascular dementia was HR 1.30 [0.97, 1.73], p < 0.00001.

CONCLUSION

Based on the analysis of the currently available evidence, it suggests that ADT significantly increases the risk of dementia, AD, PD, and depression.

Risk of Dementia in Different Types of Cancer Survivors: A Nationwide Cohort Study

OBJECTIVES

The association between specific types of malignancies and the subsequent risk of dementia remains unknown.

DESIGN

A retrospective population-based cohort study based on data from Taiwan National Health Insurance Research Database.

SETTING AND PARTICIPANTS

We recruited 32,250 patients who survived malignancies and 322,500 controls between 1998 and 2011 and followed them up until the end of 2013.

MEASUREMENTS

Diagnoses of dementia (including Alzheimer's disease (AD), vascular dementia (VaD), and unspecified dementia) was made during the follow-up period. Cox regression analyses were performed after adjusting for potential confounders. A sensitivity analysis was conducted to exclude patients with prodromal dementia.

RESULTS

Cancer survivors were more likely to develop AD (hazard ratio [HR]: 1.68, 95% confidence interval [CI]: 1.38-2.06), unspecified dementia (HR: 1.19, 95% CI: 1.07-1.32), and any dementia (HR: 1.26, 95% CI: 1.16-1.37) compared with controls after adjusting for potential confounders. Importantly, cancers of the digestive and genitourinary organs seem to be associated with AD, unspecified dementia, and any dementia, whereas only malignant neoplasms of the brain are more likely to develop into VaD. Sensitivity analyses after exclusion of the first three or five years of observation and after exclusion of case enrollment before 2009 or 2007 showed consistent findings.

CONCLUSION

Cancer survivors are at higher risk of subsequent dementia. Different types of cancer survivors may contribute to variable risks of specific dementias. Further studies are necessary to investigate the underlying mechanisms in cancer survivors and patients with dementia.

Exploring the Roles of Key Mediators IKBKE and HSPA1A in Alzheimer's Disease and Hepatocellular Carcinoma through Bioinformatics Analysis

Recent studies have hinted at a potential link between Alzheimer's Disease (AD) and cancer. Thus, our study focused on finding genes common to AD and Liver Hepatocellular Carcinoma (LIHC), assessing their promise as diagnostic indicators and guiding future treatment approaches for both conditions. Our research utilized a broad methodology, including differential gene expression analysis, Weighted Gene Co-expression Network Analysis (WGCNA), gene enrichment analysis, Receiver Operating Characteristic (ROC) curves, and Kaplan-Meier plots, supplemented with immunohistochemistry data from the Human Protein Atlas (HPA) and machine learning techniques, to identify critical genes and significant pathways shared between AD and LIHC. Through differential gene expression analysis, WGCNA, and machine learning methods, we identified nine key genes associated with AD, which served as entry points for LIHC analysis. Subsequent analyses revealed IKBKE and HSPA1A as shared pivotal genes in patients with AD and LIHC, suggesting these genes as potential targets for intervention in both conditions. Our study indicates that IKBKE and HSPA1A could influence the onset and progression of AD and LIHC by modulating the infiltration levels of immune cells. This lays a foundation for future research into targeted therapies based on their shared mechanisms.

Towards a Clearer Causal Question Underlying the Association Between Cancer and Dementia

BACKGROUND

Several observational studies have described an inverse association between cancer diagnosis and subsequent dementia risk. Multiple biologic mechanisms and potential biases have been proposed in attempts to explain this association. One proposed explanation is the opposite expression of Pin1 in cancer and dementia, and we use this explanation and potential drug target to illustrate the required assumptions and potential sources of bias for inferring an effect of Pin1 on dementia risk from analyses measuring cancer diagnosis as a proxy for Pin1 expression.

METHODS

We used data from the Rotterdam Study, a population-based cohort. We estimate the association between cancer diagnosis (as a proxy for Pin1) and subsequent dementia diagnosis using two different proxy methods and with confounding and censoring for death addressed with inverse probability weights. We estimate and compare the complements of a weighted Kaplan-Meier survival estimator at 20 years of follow-up.

RESULTS

Out of 3634 participants, 899 (25%) were diagnosed with cancer, of whom 53 (6%) had dementia, and 567 (63%) died. Among those without cancer, 15% (411) were diagnosed with dementia, and 667 (24%) died over follow-up. Depending on the confounding and selection bias control, and the way in which cancer was used as a time-varying proxy exposure, the risk ratio for dementia diagnosis ranged from 0.71 (95% confidence interval [CI] = 0.49, 0.95) to 1.1 (95% CI = 0.79, 1.3).

CONCLUSION

Being explicit about the underlying mechanism of interest is key to maximizing what we can learn from this cancer-dementia association given available or readily collected data, and to defining, detecting, and preventing potential biases.

Association of Cancer History with Lifetime Risk of Dementia and Alzheimer's Disease

Background

The literature presents conflicting results regarding the potential protective effect of prevalent cancer on the development of dementia and Alzheimer's disease (AD).

Objective

Association between cancer and subsequent risk of dementia and/or AD was reported previously, but survival bias has been of concern. Here, we aimed to calculate the lifetime risk of dementia and AD and evaluate the association of cancer history with these two conditions.

Methods

In this retrospective analysis, we included 292,654 participants aged 60+ y during the follow-up and free of dementia at baseline, within the UK Biobank cohort. Lifetime risks of dementia and AD were estimated in individuals with and without cancer history, and different durations of cancer exposure and cancer types.

Results

During a median of 12.5 follow-up years, 5,044 new dementia and 2,141 AD cases were reported. Lifetime risks of dementia and AD were lower in cancer survivors compared to those without cancer, and this effect was more pronounced in participants with cancer history exposure≥5 years. Similar relationship was observed in individual cancer types, except for breast cancer.

Conclusions

Results suggested an inverse association between cancer history and lifetime risk of dementia and AD, which may be modified by different cancer types and cancer exposure time.

Inverse correlation between Alzheimer's disease and cancer from the perspective of hypoxia

Sporadic Alzheimer's disease and cancer remain epidemiologically inversely related, and exploring the reverse pathogenesis is important for our understanding of both. Cognitive dysfunctions in Alzheimer's disease (AD) might result from the depletion of adaptive reserves in the brain. Energy storage in the brain is limited and is dynamically regulated by neurovascular and neurometabolic coupling. The research on neurodegenerative diseases has been dominated by the neurocentric view that neuronal defects cause the diseases. However, the proposal of the 2-hit vascular hypothesis in AD led us to focus on alterations in the vasculature, especially hypoperfusion. Chronic hypoxia is a feature shared by AD and cancer. It is interesting how contradicting chronic hypoxia's effects on both cancer and AD are. In this article, we discuss the potential links between the 2 diseases' etiology, from comparable upstream circumstances to diametrically opposed downstream effects. We suggest opposing potential mechanisms, including upregulation and downregulation of hypoxia-inducible factor-1α, the Warburg and reverse-Warburg effects, lactate-mediated intracellular acidic and alkaline conditions, and VDAC1-mediated apoptosis and antiapoptosis, and search for regulators that may be identified as the crossroads between cancer and AD.

Alzheimer's Disease and Different Types of Cancer Likelihood: Unveiling Disparities and Potential Protective Effects in a Korean Cohort Study

The link between Alzheimer's disease and cancer risk is a concern in public health. However, research has yielded limited and sometimes contrasting results, suggesting the need for more validation. We analyzed a large cohort to examine the long-term association between Alzheimer's disease (AD) and the risk of developing cancer. In total, 24,664 AD patients and 98,656 control participants were selected from the National Health Insurance Cohort database of Korea, spanning from 2002 to 2019. Propensity score matching and overlap-weighted adjustment techniques were used to balance the standardized differences between the AD and control groups. The Cox proportional hazards model was applied to calculate hazard ratios (HRs) with 95% confidence intervals (CIs) for various cancers, considering relevant covariates. Results indicated that patients with AD had a significantly lower likelihood of overall malignancy (HR 0.63; 95% CI, 0.59-0.68) and each of the 10 site-specific cancers compared to the control group. Among these, pancreatic cancer (HR, 0.50) exhibited the strongest inverse association, followed by hepatic (HR, 0.60), gastric (HR, 0.63), kidney (HR, 0.63), lung (HR, 0.64), thyroid (HR, 0.65), colorectal (HR, 0.67), gallbladder and biliary duct (HR, 0.73), hematologic malignancy (HR, 0.73), and bladder cancers (HR, 0.76). This protective effect against certain organ-specific cancers persisted over the 16-year follow-up period, except for in kidney cancer and hematologic malignancies. The protective effect against specific cancer types (gastric, colorectal, lung, hepatic, and pancreatic) was more prominent in individuals aged 60 years and older, regardless of their sex. However, there were some variations in the specific types of cancer observed between males and females. In summary, Korean patients with AD had a lower risk of cancer, especially in individuals 60 years and older, during the 16-year follow-up period.

EGFR is a potential dual molecular target for cancer and Alzheimer's disease

Many researchers are attempting to identify drugs that can be repurposed as effective therapies for Alzheimer's disease (AD). Several recent studies have highlighted epidermal growth factor receptor (EGFR) inhibitors approved for use as anti-cancer drugs as potential candidates for repurposing as AD therapeutics. In cancer, EGFR inhibitors target cell proliferation and angiogenesis, and studies in AD mouse models have shown that EGFR inhibitors can attenuate amyloid-beta (Aβ) pathology and improve cognitive function. In this review, we discuss the different functions of EGFR in cancer and AD and the potential of EGFR as a dual molecular target for AD diseases. In addition, we describe the effects of anti-cancer EGFR tyrosine kinase inhibitors (TKIs) on AD pathology and their prospects as therapeutic interventions for AD. By summarizing the physiological functions of EGFR in cancer and AD, this review emphasizes the significance of EGFR as an important molecular target for these diseases.

Ranking the risk factors for Alzheimer's disease; findings from the UK Biobank study

Background

The cause of the most common form of dementia, sporadic Alzheimer's disease (AD), remains unknown. This may reflect insufficiently powered studies to date for this multi-factorial disorder. The UK Biobank dataset presents a unique opportunity to rank known risk factors and determine novel variables.

Methods

A custom machine learning approach for high dimensionality data was applied to explore prospectively associations between AD in a sub-cohort of 156,209 UK Biobank participants aged 60-70 including more than 2,090 who were subsequently diagnosed with AD.

Results

After the possession of the APOE4 allele, the next highest ranked risk factors were other genetic variants within the TOMM40-APOE-APOC1 locus. When stratified by their apolipoprotein epsilon 4 (APOE4) carrier status, the most prominent risk factors in carriers were AST:ALT ratio, the "number of treatments/ medications" taken as well as "time spent in hospital" while protection was conferred by "Sleeplessness/Insomnia". In non-APOE carriers, lower socioeconomic status and fewer years of education were highly ranked but effect sizes were small relative to APOE4 carriers.

Conclusions

Possession of the APOE4 allele was confirmed as the most important risk factor in AD. Other TOMM40-APOE-APOC1 locus variants further moderate the risk of AD in APOE4 carriers. Liver pathology is a novel risk factor in APOE4 carriers while "Sleeplessness/Insomnia" is protective in AD irrespective of APOE4 status. Other factors such as "Number of treatments/ medications" suggest that multimorbidity is an important risk factor for AD. Future treatments aimed at co-morbidities, including liver disease, may concomitantly lower the risk of sporadic AD.

Sting and p53 DNA repair pathways are compromised in Alzheimer's disease

Alzheimer's disease (AD) is the most common cause of dementia. A common finding in AD is DNA damage. Double-strand DNA breaks (DSBs) are particularly hazardous to neurons because their post-mitotic state forces neurons to rely on error-prone and potentially mutagenic mechanisms to repair DNA breaks. However, it remains unclear whether DNA damage results from increased DNA damage or failure of DNA repair. Oligomerization of the tumor suppressor protein p53 is an essential part of DSB repair, and p53 phosphorylated on S15 is an indicator of DNA damage. We report that the monomer:dimer ratio of phosphorylated (S15) p53 is increased by 2.86-fold in temporal lobes of AD patients compared to age-matched controls, indicating that p53 oligomerization is compromised in AD. In vitro oxidation of p53 with 100 nM H2O2 produced a similar shift in the monomer:dimer ratio. A COMET test showed a higher level of DNA degradation in AD consistent with double-strand DNA damage or inhibition of repair. Protein carbonylation was also elevated (190% of control), indicating elevated oxidative stress in AD patients. Levels of the DNA repair support protein 14-3-3σ, γ-H2AX, a phosphorylated histone marking double strand DNA breaks, and phosphorylated ataxia telangiectasia mutated (ATM) protein were all increased. cGAS-STING-interferon signaling was impaired in AD and was accompanied by a depletion of STING protein from Golgi and a failure to elevate interferon despite the presence of DSBs. The results suggest that oxidation of p53 by ROS could inhibit the DDR and decrease its ability to orchestrate DSB repair by altering the oligomerization state of p53. The failure of immune-stimulated DNA repair may contribute to cell loss in AD and suggests new therapeutic targets for AD.

Caregivers with Cancer Patients: Focus on Hispanics

Cancer is a public health concern and causes more than 8 million deaths annually. Cancer triggers include population growth, aging, and variations in the prevalence and distribution of the critical risk factors for cancer. Multiple hallmarks are involved in cancer, including cell proliferation, evading growth suppressors, activating invasion and metastasis, resisting cell death, enabling replicative immortality, reprogramming energy metabolism, and evading immune destruction. Both cancer and dementia are age-related and potentially lethal, impacting survival. With increasing aging populations, cancer and dementia cause a burden on patients, family members, the health care system, and informal/formal caregivers. In the current article, we highlight cancer prevalence with a focus on different ethnic groups, ages, and genders. Our article covers risk factors and genetic causes associated with cancer and types of cancers and comorbidities. We extensively cover the impact of cancer in Hispanics in comparison to that in other ethnic groups. We also discuss the status of caregivers with cancer patients and urgent needs from the state and federal support for caregivers.