Hormone therapy for prostate cancer increases the risk of Alzheimer's disease: a nationwide 4-year 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.

A Comprehensive Review and Androgen Deprivation Therapy and Its Impact on Alzheimer's Disease Risk in Older Men with Prostate Cancer

Prostate cancer (PCa) is one of the most prevalent malignancies affecting males worldwide. Despite reductions in mortality rates due to advances in early identification and treatment methods, PCa remains a major health concern. Recent research has shed light on a possible link between PCa and Alzheimer's disease (AD), which is a significant neurological ailment that affects older males all over the world. Androgen deprivation therapy (ADT), a cornerstone therapeutic method used in conjunction with radiation and palliative care in advanced metastatic PCa cases, is critical for disease management. Evidence reveals a relationship between ADT and cognitive impairment. Hormonal manipulation may cause long-term cognitive problems through processes such as amyloid beta (Aβ) aggregation and neurofibrillary tangles (NFTs). Fluctuations in basal androgen levels can upset the delicate balance of genes that are sensitive to androgen levels, contributing to cognitive impairment. This detailed review dives into the various aspects of PCa aetiology and its relationship with cognitive decline. It investigates the discovery of particular biomarkers, as well as microRNAs (miRNAs), which play important roles in pathogenic progression. The review attempts to identify potential biomarkers associated with ADT-induced cerebral changes, including Aβ oligomer buildup, NFT formation, and tauopathy, which can contribute to early-onset dementia and cognitive impairment. Besides it further aims to provide insights into innovative diagnostic and therapeutic avenues for alleviating PCa and ADT-related cognitive sequelae by unravelling these complicated pathways and molecular mechanisms.

Psychosocial Factors Associated with Cognitive Function in Prostate Cancer Survivors on Hormonal Treatments: A Systematic Review

Hormonal treatments (HT) for prostate cancer (e.g., androgen deprivation therapy) yield clinical and survival benefits, yet adverse cognitive changes may be a side effect. Since psychosocial factors are largely modifiable, interventions targeting these factors may help mitigate these adverse cognitive effects. This systematic review aimed to identify a range of psychosocial factors associated with cognitive function in individuals with prostate cancer undergoing HT and to determine whether these factors mitigate or exacerbate this effect. Applying PRISMA guidelines, a comprehensive search of relevant databases conducted in September 2023 using terms related to prostate cancer, hormone therapy, and cognitive outcomes was undertaken. The search yielded 694 unique abstracts, with 11 studies included for analysis examining the relationship between cognitive function and the following psychosocial factors: psychological distress, fatigue, insomnia, and coping processes. Findings were mixed with only two studies reporting significant associations between cognitive performance with fatigue and depression. Three studies that included measures of perceived cognitive function identified associations with depression, anxiety, fatigue, insomnia, illness threat appraisals, and coping styles. However, no studies found evidence for an association between self-reported and objective measures of cognitive functioning. Evidence regarding the association of interpersonal factors is lacking. Moreover, whether these factors mitigate or exacerbate the effect of HT on cognitive function still needs to be determined. Overall, the research exploring the association between psychosocial factors and cognitive function in prostate cancer survivors undergoing HT is still in its infancy. Further research is required to optimize the implementation of neuropsychological interventions for prostate cancer survivors.

Cognitive Dysfunction in Patients Treated with Androgen Deprivation Therapy: A Multimodality Functional Imaging Study to Evaluate Neuroinflammation

Background

Androgen deprivation therapy (ADT) for prostate cancer is implicated as a possible cause of cognitive impairment (CI). CI in dementia and Alzheimer's disease is associated with neuroinflammation. In this study, we investigated a potential role of neuroinflammation in ADT-related CI.

Methods

Patients with prostate cancer on ADT for ≥3 months were categorized as having ADT-emergent CI or normal cognition (NC) based on self-report at interview. Neuroinflammation was evaluated using positron emission tomography (PET) with the translocator protein (TSPO) radioligand [11C]-PBR28. [11C]-PBR28 uptake in various brain regions was quantified as standardized uptake value (SUVR, normalized to cerebellum) and related to blood oxygen level-dependent functional magnetic resonance imaging (BOLD-fMRI) choice-reaction time task (CRT) activation maps.

Results

Eleven patients underwent PET: four with reported CI (rCI), six with reported NC (rNC), and one status unrecorded. PET did not reveal any between-group differences in SUVR regionally or globally. There was no difference between groups on brain activation to the CRT. Regardless of the reported cognitive status, there was strong correlation between PET-TSPO signal and CRT activation in the hippocampus, amygdala, and medial cortex.

Conclusions

We found no difference in neuroinflammation measured by PET-TSPO between patients with rCI and rNC. However, we speculate that the strong correlation between TSPO uptake and BOLD-fMRI activation in brain regions involved in memory and known to have high androgen-receptor expression mediating plasticity (hippocampus and amygdala) might reflect inflammatory effects of ADT with compensatory upregulated/increased synaptic functions. Further studies of this imaging readout are warranted to investigate ADT-related CI.

A Systematic Review on the Potential Acceleration of Neurocognitive Aging in Older Cancer Survivors

As survival rates increase, more emphasis has gone to possible cognitive sequelae in older cancer patients, which could be explained by accelerated brain aging. In this review, we provide a complete overview of studies investigating neuroimaging, neurocognitive, and neurodegenerative disorders in older cancer survivors (>65 years), based on three databases (Pubmed, Web of Science and Medline). Ninety-six studies were included. Evidence was found for functional and structural brain changes (frontal regions, basal ganglia, gray and white matter), compared to healthy controls. Cognitive decline was mainly found in memory functioning. Anti-hormonal treatments were repeatedly associated with cognitive decline (tamoxifen) and sometimes with an increased risk of Alzheimer's disease (androgen deprivation therapy). Chemotherapy was inconsistently associated with later development of cognitive changes or dementia. Radiotherapy was not associated with cognition in patients with non-central nervous system cancer but can play a role in patients with central nervous system cancer, while neurosurgery seemed to improve their cognition in the short-term. Individual risk factors included cancer subtypes (e.g., brain cancer, hormone-related cancers), treatment (e.g., anti-hormonal therapy, chemotherapy, cranial radiation), genetic predisposition (e.g., APOE, COMT, BDNF), age, comorbidities (e.g., frailty, cognitive reserve), and psychological (e.g., depression, (post-traumatic) distress, sleep, fatigue) and social factors (e.g., loneliness, limited caregiver support, low SES). More research on accelerated aging is required to guide intervention studies.

Emerging Promise of Therapeutic Approaches Targeting Mitochondria in Neurodegenerative Disorders

Mitochondria are critical for homeostasis and metabolism in all cellular eukaryotes. Brain mitochondria are the primary source of fuel that supports many brain functions, including intracellular energy supply, cellular calcium regulation, regulation of limited cellular oxidative capacity, and control of cell death. Much evidence suggests that mitochondria play a central role in neurodegenerative disorders (NDDs) such as Parkinson's disease, Alzheimer's disease, Huntington's disease, and amyotrophic lateral sclerosis. Ongoing studies of NDDs have revealed that mitochondrial pathology is mainly found in inherited or irregular NDDs and is thought to be associated with the pathophysiological cycle of these disorders. Typical mitochondrial disturbances in NDDs include increased free radical production, decreased ATP synthesis, alterations in mitochondrial permeability, and mitochondrial DNA damage. The main objective of this review is to highlight the basic mitochondrial problems that occur in NDDs and discuss the use mitochondrial drugs, especially mitochondrial antioxidants, mitochondrial permeability transition blockade, and mitochondrial gene therapy, for the treatment and control of NDDs.

Increased cytokine gene expression and cognition risk associated with androgen deprivation therapy

BACKGROUND

Androgen deprivation therapy (ADT) is a standard treatment modality for locally advanced, high-risk, and metastatic hormone-sensitive prostate cancer. Long-term ADT treatment likely develops side-effects that include changes in cognition or onset of dementia. However, the molecular understanding of this effect remains elusive. We attempt to establish a link between ADT and changes in cognitive function using patient databases and bioinformatics analyses.

METHODS

Gene expression profiling was performed using RNA sequencing data from Alzheimer patient cohort and compared with the data from advanced-stage prostate cancer patients receiving neoadjuvant antiandrogen therapy. Differentially expressed genes (DEGs) were analyzed using the Ingenuity knowledge database.

RESULTS

A total of 1952 DEGs in the Alzheimer patient cohort and 101 DEGs were identified in ADT treated prostate cancer patients. Comparing both data sets provided a subset of 33 commonly expressed genes involving cytokine-cytokine signaling with an over representation of cytokine-cytokine receptor interaction, inflammatory cytokines, signaling by interleukins together with alterations in the circulating lymphocyte repertoire, adaptive immune responses, regulation of cytokine production, and changes in T-cell subsets. Additionally, lipopolysaccharide, tumor necrosis factor, and toll-like receptors were identified as upstream transcriptional regulators of these pathways. The most commonly expressed genes viz. IL-17A, CCL2, IL-10, IL-6, IL-1RN, LIF/LIFR were further validated by quantitative RT-PCR exhibited higher expression in antiandrogen treated neuronal, glial, and androgen-responsive prostate cancer cells, compared to no-androgen antagonist treatment.

CONCLUSIONS

Our findings suggest that changes in cytokine signaling under the influence of ADT in prostate cancer patients may be linked with cognitive impairment presenting new avenues for diagnostic and therapeutic development in combating brain deficits.

Deciphering the enigmatic crosstalk between prostate cancer and Alzheimer's disease: A current update on molecular mechanisms and combination therapy

Alzheimer's disease (AD) and prostate cancer (PCa) are considered the leading causes of death in elderly people worldwide. Although both these diseases have striking differences in their pathologies, a few underlying mechanisms are similar when cell survival is considered. In the current study, we employed an in-silico approach to decipher the possible role of bacterial proteins in the initiation and progression of AD and PCa. We further analyzed the molecular connections between these two life-threatening diseases. The androgen deprivation therapy used against PCa has been shown to promote castrate resistant PCa as well as AD. In addition, cell signaling pathways, such as Akt, IGF, and Wnt contribute to the progression of both AD and PCa. Besides, various proteins and genes are also common in disease progression. One such similarity is mTOR signaling. mTOR is the common downstream target for many signaling pathways and plays a vital role in both PCa and AD. Targeting mTOR can be a favorable line of treatment for both AD and PCa. However, drug resistance is one of the challenges in effective drug therapy. A few drugs that target mTOR have now become ineffective due to the development of resistance. In that regard, phytochemicals can be a rich source of novel drug candidates as they can act via multiple mechanisms. This review also presents mTOR targeting phytochemicals with promising anti-PCa, anti-AD activities, and approaches to overcome the issues associated with phytochemical-based therapies in clinical trials.

Association between Androgen Deprivation Therapy and Risk of Dementia in Men with Prostate Cancer

The risk of dementia after androgen deprivation therapy (ADT) in patients with advanced prostate cancer (PCa) remains controversial. This study aimed to evaluate the association between ADT and the incidence of dementia in patients with PCa. We identified patients newly diagnosed with PCa in the National Health Insurance Database of Taiwan from 1 January 2002 to 30 June 2016 and in The Health Improvement Network of the United Kingdom (UK) from 1 January 1998 to 31 March 2018. We classified patients with PCa into ADT and ADT-naïve groups. Propensity score (PS) methods were used to minimize the differences in characteristics between the groups. We performed a Cox proportional hazard model to obtain the adjusted hazard ratio (HR) to compare the incidence of dementia between the groups. Our ADT group comprised 8743 and 73,816 patients in Taiwan and the UK, respectively, which were matched 1:1 to ADT-naïve patients by PS. The incidence rates of dementia in the ADT group were 2.74 versus 3.03 per 1000 person-years in the ADT naïve groups in Taiwan, and 2.81 versus 2.79 per 1000 person-years in the UK. There was no statistical difference between ADT and ADT-naïve groups (adjusted HR: 1.12; 95% confidence interval (CI): 0.87-1.43 in Taiwan and adjusted HR: 1.02; 95% CI: 0.85-1.23 in the UK). We found no association between the incidence of dementia and ADT in patients with advanced PCa in either database. Further studies are warranted to evaluate other possible triggers of incident dementia in patients receiving ADT for advanced PCa.

Quantifying observational evidence for risk of dementia following androgen deprivation therapy for prostate cancer: an updated systematic review and meta-analysis

BACKGROUND

Androgen deprivation therapy (ADT) administration was recently reported and might be positively associated with dementia. However, the existing studies showed controversial results. The aim of this study was to evaluate the relationship between ADT and the risk of dementia through a meta-analysis.

METHODS

Original articles published up to March 2020 were retrieved from Embase, Pubmed, the Cochrane library, and Web of Science for studies focusing on associations between ADT for prostate cancer (PCa) and incidence of dementia. A meta-analysis was conducted using a hazard ratio (HR) and 95% confidence interval (CI) as effect measures. Heterogeneity between the studies was examined using I2 statistics. Subgroup analyses, sensitivity analyses, and meta-regression were conducted, and publication bias was assessed by Egger's test.

RESULTS

Thirteen studies were included in this systematic review. Eleven cohort studies involving 339,400 cases and 436,851 controls were included in the main meta-analysis. ADT administration was associated with a 21% increase in dementia risk (pooled HR = 1.21, 95% CI: 1.13-1.30, P < 0.001). Subgroup analyses based on ADT types showed that luteinizing hormone-releasing hormone agonists (HR = 1.14, P < 0.001), bilateral orchiectomy (HR = 1.42, P < 0.001), oral antiandrogens (HR = 1.35, P = 0.138), and combined androgen blockade (HR = 1.22, P = 0.097) were positively related to subsequent risk of dementia, although the differences were not statistically significant with oral antiandrogens and combined androgen blockade.

CONCLUSIONS

The current study indicated that ADT administration, no matter with types of ADT, is associated with the risk of dementia in patients with PCa. Future studies are needed to determine whether ADT causes dementia or is merely associated with increased risk.

The influence of androgen deprivation therapy on hip geometric properties and bone mineral density in Japanese men with prostate cancer and its relationship with the visceral fat accumulation

The influence of androgen deprivation therapy (ADT) for prostate cancer on the hip geometric properties evaluated by dual-energy X-ray absorptiometry (DXA) has not yet been demonstrated. This study aimed to investigate the changes in these properties after 1 year of ADT. A total of 65 Japanese men with prostate cancer who underwent ADT for the first time in our facility were included in the study. The hip geometric parameters and the bone mineral density (BMD) taken before and after 1 year of ADT were retrospectively examined. With ADT, we not only confirmed significant BMD annual changes in the lumbar spine, the femoral neck, and the total hip of -1.65%, -1.91%, and -2.20%, respectively, but we also confirmed significant annual changes in cross-sectional areas, cross-sectional moments of inertia, and section modulus in the narrow femoral neck of -2.55%, -3.50%, and -3.14%, respectively. The annual rate of decrease in the femoral neck BMD was significantly higher in patients with visceral fat obesity than in those without visceral obesity (-1.79% vs. -0.28%). One year of ADT for Japanese men with prostate cancer might decrease the strength of bending and the structural rigidity as well as BMD at the femoral neck.

The depressive effects of androgen deprivation therapy in locally advanced or metastatic prostate cancer: a comparative study

AIM

To investigate association of androgen deprivation therapy (ADT) with depression and the effect of depression on cognitive functions in men with locally advanced or metastatic prostate cancer.

METHODS

A total of 144 patients were evaluated in a prospective, comparative study. Group1 consisted of 72 patients with locally advanced or metastatic prostate cancer who received complete ADT treatment continuously for 12 months and group2 (control group) consisted of 72 patients who underwent radical prostatectomy without any additional treatment. MoCA (The Montreal Cognitive Assessment) and HAM-D (Hamilton depression rating scale) tests were used to assess the effects of ADT on depression and cognitive functions.

RESULTS

According to post-treatment results of MoCA test, patients had lower mean total scores in both the groups. The deficits were especially prominent in the areas of language ability and short-term memory capacity. In the comparison of two groups according to HAM-D tests, the scores were significantly higher in group1 at baseline-6 month, at baseline-12 month and at 6-12 month follow-up period (p = .003, p < .001, p = .023).There was a relationship between depression and deterioration of language and memory functions at 6th (p < .001, p = .002) and 12th months (p < .001, p = .046). Attention function was deteriorated in these patients at 6th (p < .001) and 12th months (p < .001).

CONCLUSIONS

ADT causes increase in depression and the deterioration of cognitive functions. ADT should be given carefully to these older group of patients with concomitant morbidities.

Factors affecting the diagnosis of prostate cancer through 12 quadrant guided prostate biopsy

PURPOSE

Investigate the factors affecting the efficacy of the widely used 12-quadrant prostate biopsy for the diagnosis of prostate cancer.

METHODS

The data of 1846 male patients between 45 and 75 years of age was evaluated. The patients were subdivided into groups according to age, blood prostate-specific antigen (PSA) levels prostate volume (PV), digital rectal examination (DRE) findings, and pathology results. The tumour detection rates in the 12-quadrant biopsies were compared with PV, PSA levels, and DRE results of the grouped patients.

RESULTS

The tumour detection rate decreased with increasing PV in patients 45-75 years of age and with a PSA level ≤ 14.5. No decrease was detected in patients 45-60 years of age or those aged 61-75 years with a PSA ≤ 6.99 and suspicious DRE findings. A decrease in the tumour detection rate with increasing PV was observed in the other three subgroups of patients in this age group, who had a PSA ≤ 6.99, and normal DRE findings but a PV ≤ 40, PV 41-80, or PV ≥ 81.

CONCLUSIONS

Even though there is no statistically significant relationship between PV and the prostate cancer detection rate in patients 45-60 years of age, the cancer detection rate decreased with increasing PV in three of the four subgroups of patients between the ages of 61 and 75 years. Our study results have demonstrated that an individualised approach can play an important role in the diagnosis and treatment of prostate cancer.

Risk of dementia in prostate cancer survivors: A nationwide cohort study in Korea

OBJECTIVES

To investigate the effects of prostate cancer (PC) and various treatment modalities for PC, specifically androgen deprivation therapy (ADT), on the risk of dementia and dementia subtypes in PC survivors.

MATERIAL AND METHODS

A total of 51,252 patients newly diagnosed with PC from 2007 to 2013, who had no prior diagnosis of cancer or dementia, were included and matched with 209,659 non-cancer control. The screening subset was comprised of subjects who participated in a health screening program. We used Cox proportional hazards model to estimate the relative risk of dementia and dementia subtypes according to the primary treatment for the PC.

RESULTS

Compared to non-PC matched controls, PC survivors showed slightly higher risk for dementia and Alzheimer disease (AD) only in the screening cohort. While PC survivors who underwent ADT were higher risk for dementia and AD, patients who underwent surgery were lower risk for dementia and AD, compared to the non-cancer population. Compared to surgery, ADT, surgery + ADT, and active surveillance/watchful waiting showed a significantly elevated risk for dementia.

CONCLUSION

PC survivors had slightly higher risk for dementia compared to non-PC controls, which might be related to the screening effects of PC. The risk for dementia was most prominent among PC patients who underwent ADT, followed by patients who underwent AS/WW, and those who underwent surgery + ADT. This finding suggests that individualized ADT strategies that consider the survival benefit and underlying dementia risk in PC survivors are necessary.

An Updated Review: Androgens and Cognitive Impairment in Older Men

Androgens are some of the most important sex hormones in men, and they maintain important physiological activities in the human body. Cognitive impairment is one of the most common manifestations of aging in the elderly population and an important factor affecting the quality of life of elderly individuals. The levels of sex hormones in elderly people decrease with age, and low levels of androgens in older male individuals have been closely linked to the development of cognitive impairment. Basic studies have shown that androgens have neuroprotective effects and that androgen deficiency impairs cognitive function by increasing oxidative stress and decreasing synaptic plasticity, among other effects. Additionally, clinical studies have also shown that androgen deficiency is closely related to cognitive impairment. This article reviews the relationship between low androgen levels and cognitive impairment, their potential mechanisms, and the effects of testosterone supplementation in improving cognition.

Determination of oxidative stress levels and some antioxidant enzyme activities in prostate cancer

In this study, the antioxidant enzyme activities such as (SOD, GSH, and CAT) and malondialdehyde (MDA) level which is the end product of lipid peroxidation, were determined from the serum samples taken from patients diagnosed with prostate cancer Van Yuzuncu Yıl University Medical Faculty of Educational Research and Training Hospital and İstanbul Bagcilar Education Research Hospital. The SOD, GSH, and CAT activity of patient groups was found significantly lower than the healthy control group in patients with prostate cancer (p < .05). Serum MDA level is found significantly high when compared to control groups. MDA levels increased in patients that suffer prostate cancer disorder. Whereas, firstly antioxidant enzymes activity of SOD, GSH and CAT have been decreased in control groups. Thus, we concluded that the cause of development of prostate cancer may be the result of an imbalance between the antioxidants and oxidative stress. As a result, SOD, CAT, GSH, and MDA may play an important role in the etiopathogenesis of prostate cancer.

Could hemogram parameters be predictors of dementia in elderly patients?

Objective: To study red cell distribution width (RDW), RDW to platelet ratio (RPR) and mean platelet volume to platelet ratio (MPR), novel inflammatory markers of routine hemogram, of patients with or without dementia, according to the grade of the disease established by Fazekas's score in magnetic resonance imaging (MRI). Methods: A total of 1342 cases that undergone cranial MRI study were retrospectively analyzed. Patients without a previous stroke and over 45 years were enrolled in the study. Demographic and laboratory characteristics of the participants were obtained from institutional computerized database. Subcortical and periventricular white matter were evaluated in axial FLAIR images according to Fazekas's grading scale. Univariate and multivariate analysis were performed for assessing the predictors of Fazekas's grading scale. Results: MPR of Fazekas 0, Fazekas 1, Fazekas 2 and Fazekas 3 groups were 3, 3, 4 and 3%, respectively. MPR difference between study groups was not significant (p = .32). RPR of Fazekas 0, Fazekas 1, Fazekas 2 and Fazekas 3 groups were 6, 7, 7 and 7%, respectively. RPR difference between study groups was significant (p < .001). Conclusion: We suggest that increased RDW and RPR values may indicate higher Fazekas's score and dementia in cranial imaging studies. The radiologist should pay particular attention in interpretation of cranial MRI of these patients.

Association Between Androgen Deprivation Therapy Use and Diagnosis of Dementia in Men With Prostate Cancer

Importance

The association between androgen deprivation therapy (ADT) exposure and dementia is uncertain.

Objective

To analyze the association between ADT exposure and diagnosis of Alzheimer disease or dementia among elderly men with prostate cancer.

Design, Setting, and Participants

This retrospective cohort study used data from the National Cancer Institute's Surveillance, Epidemiology, and End Results-Medicare linked database. Participants were 154 089 elderly men newly diagnosed with prostate cancer between 1996 and 2003. The analyses were conducted between November 1, 2018, and December 31, 2018.

Exposure

Androgen deprivation therapy.

Main Outcomes and Measures

Patients receiving ADT within 2 years of prostate cancer diagnosis were identified. Survival analysis was used to determine the association between ADT exposure and diagnosis of Alzheimer disease or dementia in the follow-up period. Propensity score and instrumental variable approaches were used to minimize measured and unmeasured selection bias. The association by dose of ADT was also examined.

Results

Of the 295 733 men diagnosed with prostate cancer between 1996 and 2003, 154 089 met the study criteria. Of these, 62 330 (mean [SD] age, 76.0 [6.0] years) received ADT within 2 years of prostate cancer diagnosis, and 91 759 (mean [SD] age, 74.3 [6.0] years) did not receive ADT. Mean (SD) follow-up was 8.3 (4.7) years. Exposure to ADT, compared with no ADT exposure, was associated with a diagnosis of Alzheimer disease (13.1% vs 9.4%; difference, 3.7%; 95% CI, 3.3%-3.9%; P < .001; hazard ratio [HR], 1.14; 95% CI, 1.10-1.18) and dementia (21.6% vs 15.8%; difference, 5.8%; 95% CI, 5.4%-6.2%; P < .001; HR, 1.20; 95% CI, 1.17-1.24). For 1 to 4 doses of ADT, the HR was 1.19 (95% CI, 1.15-1.24) for Alzheimer disease and 1.19 (95% CI, 1.15-1.23) for dementia. For 5 to 8 doses of ADT, the HR was 1.28 (95% CI, 1.22-1.35) for Alzheimer disease and 1.24 (95% CI, 1.19-1.29) for dementia. For more than 8 doses of ADT, the HR was 1.24 (95% CI, 1.16-1.34) for Alzheimer disease and 1.21 (95% CI, 1.15-1.28) for dementia. The number needed to harm was 18 patients (95% CI, 17-19 patients) and 10 patients (95% CI, 9.5-11 patients) for Alzheimer disease and dementia, respectively.

Conclusions and Relevance

Among elderly patients with prostate cancer, ADT exposure was associated with subsequent diagnosis of Alzheimer disease or dementia over a follow-up period of at least 10 years.

Human Pathway-Based Disease Network

Constructing disease-disease similarity network is important in elucidating the associations between the origin and molecular mechanism of diseases, and in researching disease function and medical research. In this paper, we use a high-quality protein interaction network and a collection of pathway databases to construct a Human Pathway-based Disease Network (HPDN) to explore the relationship between diseases and their intrinsic interactions. We find that the similarity of two diseases has a strong correlation with the number of their shared functional pathways and the interaction between their related gene sets. Comparing HPDN with disease networks based on genes and symptoms respectively, we find the three networks have high overlap rates. Additionally, HPDN can predict new disease-disease correlations, which are supported by Comparative Toxicogenomics Database (CTD) benchmark and large-scale biomedical literature database. The comprehensive, high-quality relations between diseases based on pathways can further be applied to study important matters in systems medicine, for instance, drug repurposing. Based on a dense subgraph in our network, we find two drugs, prednisone and folic acid, may have new indications, which will provide potential directions for the treatments of complex diseases.

Supraphysiologic-dose anabolic-androgenic steroid use: A risk factor for dementia?

Supraphysiologic-dose anabolic-androgenic steroid (AAS) use is associated with physiologic, cognitive, and brain abnormalities similar to those found in people at risk for developing Alzheimer's Disease and its related dementias (AD/ADRD), which are associated with high brain β-amyloid (Aβ) and hyperphosphorylated tau (tau-P) protein levels. Supraphysiologic-dose AAS induces androgen abnormalities and excess oxidative stress, which have been linked to increased and decreased expression or activity of proteins that synthesize and eliminate, respectively, Aβ and tau-P. Aβ and tau-P accumulation may begin soon after initiating supraphysiologic-dose AAS use, which typically occurs in the early 20s, and their accumulation may be accelerated by other psychoactive substance use, which is common among non-medical AAS users. Accordingly, the widespread use of supraphysiologic-dose AAS may increase the numbers of people who develop dementia. Early diagnosis and correction of sex-steroid level abnormalities and excess oxidative stress could attenuate risk for developing AD/ADRD in supraphysiologic-dose AAS users, in people with other substance use disorders, and in people with low sex-steroid levels or excess oxidative stress associated with aging.

Changes in cerebral metabolic activity in men undergoing androgen deprivation therapy for non-metastatic prostate cancer

OBJECTIVE

Androgen deprivation therapy (ADT) is a common treatment option for men with biochemical relapse from prostate cancer. ADT is associated with changes in mood, cognition, and quality of life, and most recently with increased risk for Alzheimer's disease (AD). This study examined changes in brain metabolism using positron emission tomography (PET) in men undergoing intermittent ADT.

METHODS

Nine men with prostate cancer and a rising PSA (biochemical recurrence) without evidence of metastases were treated with intermittent ADT consisting of 9 months of complete androgen blockade achieved with combined leuprolide acetate and flutamide. Patients underwent resting [Fuorine-18] fluorodeoxyglucose PET (18F-FDGPET) at baseline (before treatment) and again after 9 months of ADT.

RESULTS

Whole-brain mapping analysis after 9 months of androgen deprivation compared to pretreatment baseline revealed decreased regional cerebral glucose metabolism in the cerebellum, posterior cingulate, and medial thalamus bilaterally. Associations of brain metabolism with measurements of cognition and mood while on androgen deprivation revealed positive correlations between the posterior cingulate, left inferior parietal lobule (BA40), and left mid temporal gyrus (BA39) and spatial reasoning and a negative correlation between left inferior parietal lobule and verbal memory. Several mood indices were negatively correlated with hypothalamus and brainstem.

CONCLUSION

These findings suggest that complete androgen deprivation may result in changes in regional brain metabolism associated with variation in mood, verbal memory, and spatial performance. Brain regions that were impacted from ADT are similar and overlap with brain regions with metabolic decline found in early AD and diabetes, suggesting possible common mechanisms.

Cancer-related cognitive impairment in breast cancer survivors: An examination of conceptual and statistical cognitive domains using principal component analysis

There is a great deal of variability in the composition of neuropsychological test batteries used in the assessment of cancerrelated cognitive impairment (CRCI). Not only the development of a gold standard approach for CRCI assessment would allow for easier identification of women suffering from CRCI but it would also promote optimal care for survivors. As a first step towards the development of a valid and reliable unified test battery, the objective of this study was to verify whether the theoretical domains commonly used in CRCI assessment are statistically supported, before and after breast cancer treatment. Principal component analyses (PCA) were performed on the results from 23 neuropsychological tests grouped into eight conceptual domains. For baseline data, the Kaiser-Meyer-Olkin was .82 and Bartlett's X2(253, N=95) = 949.48, P<0.001. A five-component solution explained 60.94% of the common variance. For the post-treatment data, the Kaiser-Meyer-Olkin was .83 and Bartlett's X2(253, N=95) = 1007.21, P<0.001 and a five component solution explained 62.03% of the common variance. Although a visual comparison of the theoretical model with those determined via PCA indicated important overlap between conceptual domains and statistical components, significant dissimilarities were also observed.

Hidden heterogeneity in Alzheimer's disease: Insights from genetic association studies and other analyses

Despite evident success in clarifying many important features of Alzheimer's disease (AD) the efficient methods of its prevention and treatment are not yet available. The reasons are likely to be the fact that AD is a multifactorial and heterogeneous health disorder with multiple alternative pathways of disease development and progression. The availability of genetic data on individuals participated in longitudinal studies of aging health and longevity, as well as on participants of cross-sectional case-control studies allow for investigating genetic and non-genetic connections with AD and to link the results of these analyses with research findings obtained in clinical, experimental, and molecular biological studies of this health disorder. The objective of this paper is to perform GWAS of AD in several study populations and investigate possible roles of detected genetic factors in developing AD hallmarks and in other health disorders. The data collected in the Framingham Heart Study (FHS), Cardiovascular Health Study (CHS), Health and Retirement Study (HRS) and Late Onset Alzheimer's Disease Family Study (LOADFS) were used in these analyses. The logistic regression and Cox's regression were used as statistical models in GWAS. The results of analyses confirmed strong associations of genetic variants from well-known genes APOE, TOMM40, PVRL2 (NECTIN2), and APOC1 with AD. Possible roles of these genes in pathological mechanisms resulting in development of hallmarks of AD are described. Many genes whose connection with AD was detected in other studies showed nominally significant associations with this health disorder in our study. The evidence on genetic connections between AD and vulnerability to infection, as well as between AD and other health disorders, such as cancer and type 2 diabetes, were investigated. The progress in uncovering hidden heterogeneity in AD would be substantially facilitated if common mechanisms involved in development of AD, its hallmarks, and AD related chronic conditions were investigated in their mutual connection.

Radical prostatectomy for clinically localized prostate cancer in patients aged 75 years or older: comparison with primary androgen deprivation therapy

OBJECTIVE

To determine whether radical prostatetomy (RP) is suitable for prostate cancer patients with age ≥75 years in comparison to primary androgen deprivation therapy (PADT).

PATIENTS AND METHODS

A cohort study was conducted in clinically localized prostate cancer patients with ≥75 years of age who underwent RP or PADT at six institutions from 2005 to 2013. Patients who had less than 12 months of follow-up, or received neoadjuvant or adjuvant therapy were excluded. We compared clinical characteristics, cancer-specific and overall survivals, and post-treatment complication rates between two groups.

RESULTS

We included 92 and 99 patients in the RP and PADT groups, respectively. In survival analyses, there were no significant differences in cancer-specific and overall survivals (p = .302 and .995, respectively). The incidence of serious adverse events (cardio- or cerebrovascular event, or bone fracture) was higher in the PADT group (p = .001). Multivariable analysis showed that PADT had a worse effect on the serious adverse events (OR 10.12, p = .038).

CONCLUSIONS

In selected elderly patients, RP was safe and effective for treatment of localized prostate cancer, as compared to PADT. Surgical treatment options should be considered in elderly patients with respect to life expectancy, rather than chronological age.

Alzheimer's disease is associated with prostate cancer: a population-based study

Alzheimer’s disease and cancer are increasingly prevalent with advancing age. However, the association between Alzheimer’s disease and prostate cancer remains unclear. The aim of this study was to examine the relationship between prior Alzheimer’s disease and subsequent prostate cancer using a population-based dataset in Taiwan. Data for this study were sourced from the Taiwan Longitudinal Health Insurance Database 2005. This case-control study included 2101 prostate cancer patients as cases and 6303 matched controls. We used conditional logistic regression analyses to calculate the odds ratio (OR) and corresponding 95% confidence interval (CI) for Alzheimer’s disease between prostate cancer patients and controls. We found that of the 8404 sampled patients, 128 (1.5%) had been diagnosed with Alzheimer’s disease prior to the index date. A Chi-squared test showed that there was a significant difference in the prevalences of prior Alzheimer’s disease between prostate cancer patients and controls (2.1% vs. 1.3%, p < 0.001). The conditional logistic regression analysis showed that the OR of prior Alzheimer’s disease for prostate cancer patients was 1.53 (95% CI: 1.06∼2.21) compared to controls. Furthermore, the OR of prior Alzheimer’s disease for prostate cancer patients was 1.52 (95% CI: 1.04∼2.22) compared to controls after adjusting for hypertension, diabetes, coronary heart disease, hyperlipidemia, obesity, prostatitis, gonorrhea or chlamydia infection, testitis or epididymitis, and alcohol abuse/alcohol dependency syndrome. This study revealed an association between prior Alzheimer’s disease and prostate cancer. We suggest that clinicians be alert to the increased risk of prostate cancer when caring for elderly individuals with Alzheimer’s disease.

Prostate-specific antigen decline pattern in advanced prostate cancer receiving androgen deprivation therapy and relationship with prostate-specific antigen progression

INTRODUCTION

The aim of this study is to evaluate prostate-specific antigen decline pattern including prostate-specific antigen kinetics following androgen deprivation therapy on prostate-specific antigen progression in the patients with advanced prostate cancer.

MATERIALS AND METHODS

Ninety-seven advanced prostate cancer patients receiving maximum androgen deprivation therapy were enrolled in case-control study. Baseline prostate-specific antigen, Gleason Score, bone metastase, nadir prostate-specific antigen, time to nadir prostate-specific antigen, declining slope to nadir prostate-specific antigen, estimated baseline prostate-specific antigen half-time, current prostate-specific antigen, post-nadir prostate-specific antigen time, estimated prostate-specific antigen, estimated decline of baseline prostate-specific antigen as quantitative, and ratio were recorded and calculated.

RESULTS

The ratio of prostate-specific antigen progression was significantly lower at the patients who had slower declining slope to prostate-specific antigen, longer time to nadir prostate-specific antigen, and lower estimated decline ratio of baseline prostate-specific antigen (p: .016, p: .020, and p: .026, respectively).

CONCLUSIONS

The shorter time to nadir prostate-specific antigen following androgen deprivation therapy, faster declining slope to nadir prostate-specific antigen and higher estimated decline ratio of baseline prostate-specific antigen are associated with higher risk of disease progression in patients with hormone-sensitive prostate cancer.

Discrepancies on the association between androgen deprivation therapy for prostate cancer and subsequent dementia: meta-analysis and meta-regression

Limited literature exists on the association between androgen deprivation therapy (ADT) for prostate cancer (PCa) and subsequent dementia and the study conclusions are in conflicts with one another. We searched several cohort databases from 1960 to 2017 for observational or prospective studies that reported on an association between ADT for PCa and subsequent dementia. A meta-analysis was performed to cumulatively determine the association between ADT and dementia including Alzheimer's disease using an incidence rate ratio (IRR), crude hazard ratio (HR), and adjusted HR. Seven studies were eligible for the meta-analysis, with the inclusion of a total of 90, 543 prostate cancer patients. The pooled overall IRR, crude HR, and adjusted HR were 1.78 [95% confidence interval (CI): 1.51-2.10)], 1.80 (95% CI: 1.05-3.10), and 1.59 (95% CI: 1.16-2.18), respectively. A meta-regression analysis showed that the crude HR was affected by both follow -up duration and lag time in the univariate model (p = < 0.001). However, IRR and adjusted HR were not affected by these moderators. The overall outcomes of IRR, crude HR, and adjusted HR were found to be balanced in the sensitivity analysis. A positive association was demonstrated between ADT and the subsequent incidence of dementia in this meta-analysis. Methodological difference including follow-up duration and the time lag could be related with the discrepancies.