Inverse comorbidity in multiple sclerosis: Findings in a complete nationwide cohort

Association between multiple sclerosis and prostate cancer risk: A systematic review and meta‑analysis

Prostate cancer (PCa) risk in patients with multiple sclerosis (MS) remains to be elucidated. The present study conducted a meta-analysis to assess the relationship between MS and PCa. PubMed, EMBASE, Web of Science, and Cochrane Library databases were searched to identify studies on the PCa risk in patients with MS up to September 2022. A random effects meta-analyses model was performed to estimate the relative risk (RR) and the 95% confidence intervals (CI). All eight studies involving 210,943 patients with MS were identified and included in the meta-analysis. The present study revealed that there was no significant association between MS and the risk of PCa (RR=0.78, 95% CI: 0.56-1.08, P<0.0001). Subgroup analyses verified this conclusion when stratified by regions. However, after adjusting for potential confounders, the findings suggested conflicting results. The current evidence shows that compared with the population control, patients with MS have no relationship with PCa risk and further large samples and long-term trials are needed to verify these results.

The association between Parkinson's disease and autoimmune diseases: A systematic review and meta-analysis

Parkinson's disease (PD) is a neurodegenerative disorder that frequently occurs in the older population. Previous epidemiological studies have suggested an association between PD and autoimmune diseases (AIDs). However, some studies have shown conflicting results. This study aimed to summarize existing epidemiological studies on the association between PD with AIDs and to conduct a meta-analysis of combinable results. Four electronic databases (PubMed, Embase, Web of Science Core Collection, and MEDLINE) were searched from each database's inception date until December 12, 2022. All studies that explored the relationship between PD and AIDs were included for quantitative analysis and qualitative review. The pooled relative risk with 95% confidence intervals (CIs) was calculated using a random or fixed effects model. A total of 46 observational studies involving 873,643 patients and 13,402,821 controls were included; ultimately, 38 studies were included in the meta-analysis. The risk of PD combined with AIDs was significantly higher (odds ratio [OR]=1.55, 95% CI: 1.33-1.81), and subgroup analysis found no significant differences in risk by study type, gender, age, and race. Regarding the AID types, the results showed an increased risk of PD combined with bullous pemphigoid (OR=2.67, 95% CI: 2.15-3.31), inflammatory bowel disease (OR=1.30, 95% CI: 1.18-1.45), Crohn's disease (OR=1.30, 95% CI: 1.20-1.42), ulcerative colitis (OR=1.31, 95% CI: 1.14-1.50), Sjögren's syndrome (OR=1.61, 95% CI: 1.24-2.09), and Graves' disease (OR=1.45, 95% CI: 1.24-1.70) than controls. However, there appeared to be no significant association between PD and systemic lupus erythematosus (OR=0.82, 95% CI: 0.66-1.03), multiple sclerosis (OR=2.02, 95% CI: 0.87-4.70), rheumatoid arthritis (OR=0.79, 95% CI: 0.61-1.03), or celiac disease (OR=1.16, 95% CI: 0.79-1.69). This study supports the existence of a strong link between AIDs and PD. When PD and AIDs are identified, clinicians need to be aware of the possibility of coexistence. However, there are some limitations of this study, such as the apparent heterogeneity of some of the results and the fact that most of the included study types were retrospective. Therefore, future larger prospective cohort studies are needed to further explore the interaction between PD and AIDs.

Systematic review registration

INPLASY, identifier INPLASY202280088.

Incidence and risk of cancer among Multiple Sclerosis patients: a matched population-based cohort study

BACKGROUND

Studies have not yet found conclusive results on the risk of cancer in patients with Multiple Sclerosis (MS). This study aimed to compare the incidence of all cancers and of specific types of cancer between MS patients and the general population by age and by sex.

METHODS

All prevalent MS patients identified between 2008-2014 in the nationwide French healthcare database (SNDS) and without history of malignancy, were included in a cohort study followed-up until cancer occurrence, date of death or 31 December 2015, whichever came first. MS patients were matched based on sex and year of birth, to non-MS controls from the general population without cancer before index date. Incidence rate was reported per 100,000 person-year (PY) and risk of cancer was estimated by type of cancer, age and sex using a Cox model (Hazard Ratio, HRs and its 95% confidence intervals, 95%CI).

RESULTS

Overall, 576 cancers per 100,000 PY were observed in MS patients versus 424 per 100,000 PY in the control population. The risk of cancer was higher among MS patients than among population controls whether considered overall (HR: 1.36, 95%CI: 1.29-1.43) or for prostate (HR: 2.08, 95%CI: 1.68-2.58), colorectal and anal (HR: 1.35, 95%CI: 1.16-1.58), trachea bronchus and lung (HR: 2.36, 95%CI: 1.96-2.84), and to a lesser extent, breast cancer (HR: 1.12, 95%CI: 1.03-1.23).

CONCLUSION

MS patients were associated with increased risk of cancer compared to population controls.

Focus on the Complex Interconnection between Cancer, Narcolepsy and Other Neurodegenerative Diseases: A Possible Case of Orexin-Dependent Inverse Comorbidity

Simple Summary

This narrative review first describes from several points of view the complex interrelationship between cancer and neurodegeneration, with special attention to the mechanisms that might underlie an inverse relationship between them. In particular, the mechanisms that might induce an imbalance between cell apoptotic and proliferative stimuli are discussed. Second, the review summarizes findings on orexins and their involvement in narcolepsy, neurodegenerative diseases, and cancer, starting from epidemiological data then addressing laboratory findings, animal models, and human clinical observational and interventional investigations. Important research efforts are warranted on these topics, as they might lead to novel therapeutic approaches to both neurodegenerative diseases and cancer.

Abstract

Conditions such as Alzheimer’s (AD) and Parkinson’s diseases (PD) are less prevalent in cancer survivors and, overall, cancer is less prevalent in subjects with these neurodegenerative disorders. This seems to suggest that a propensity towards one type of disease may decrease the risk of the other. In addition to epidemiologic data, there is also evidence of a complex biological interconnection, with genes, proteins, and pathways often showing opposite dysregulation in cancer and neurodegenerative diseases. In this narrative review, we focus on the possible role played by orexin signaling, which is altered in patients with narcolepsy type 1 and in those with AD and PD, and which has been linked to β-amyloid brain levels and inflammation in mouse models and to cancer in cell lines. Taken together, these lines of evidence depict a possible case of inverse comorbidity between cancer and neurodegenerative disorders, with a role played by orexins. These considerations suggest a therapeutic potential of orexin modulation in diverse pathologies such as narcolepsy, neurodegenerative disorders, and cancer.

Increasing cancer risk over calendar year in people with multiple sclerosis: a case-control study

Background

Data on cancer prevalence and incidence in multiple sclerosis (MS) patients are controversial. This study is aimed at estimating cancer risk in MS patients.

Methods

Nested case–control study using data collected between 01/01/1987 and 28/02/2016 from the United Kingdom Clinical Practice Research Datalink. Cancer diagnoses after first MS code (index date) was counted in 10,204 MS patients and 39,448 controls matched by sex, age, general practitioner, and registration year. Cancer rates were compared using multivariable Cox regression models. Ethics approval was not required.

Results

Cancer was reported in 433 (4.41%) MS patients and 2014 (5.31%) controls after index date. Cancer risk was associated with gender (HR for female = 0.88, 95% CI = 0.81–0.96, p = 0.004), age at index date (HR = 1.06, 95% CI = 1.06–1.07, p < 0.001), and index year (HR = 1.01, 95% CI = 1.00–1.02, p = 0.016), but not with MS status (HR = 0.95, 95% CI = 0.86–1.05, p = 0.323). A significant interaction between MS status and index year was found (HR = 1.02, 95% CI = 1.00–1.04, p = 0.022). Cancer risk was positively associated with index year among MS patients (HR = 1.03, 95% CI = 1.01–1.05; p = 0.010), but not controls (HR = 1.01, 95% CI = 0.99–1.02; p = 0.144). MS patients compared to controls had no increased risk for any specific cancer type.

Conclusions

Overall cancer risk was similar in multiple sclerosis patients and matched controls. The frequency of cancer diagnoses has increased over time among MS patients but not in controls.

Electronic supplementary material

The online version of this article (10.1007/s00415-020-10170-5) contains supplementary material, which is available to authorized users.

Comorbidity in Multiple Sclerosis

Comorbidities in patients with multiple sclerosis (MS) has become an area of increasing interest in the recent years. A comorbidity is defined as any additional disease that coexists in an individual with a given index disease and that is not an obvious complication of the index disease. The aim of this review is to describe the current evidence regarding the range of comorbidities in the population with MS reported in different countries and the current knowledge about the influence of comorbidities on the clinical features and therapeutic challenges in MS. Certain comorbidities are more prevalent in people with MS such as depression, anxiety, cerebro- and cardiovascular diseases, and certain autoimmune disorders such as diabetes, thyroid disease, and inflammatory bowel disease. A previous perception of a trend toward a lower overall risk of cancer in patients with MS appears to be challenged, but there is no evidence on any higher occurrence of malignancies in the population with MS. Comorbidities may modify the clinical presentation of MS, and have implications for treatment choice, adherence, and outcome. Several comorbid conditions are associated with increased disability progression, including diabetes, hypertension, and chronic obstructive pulmonary disease. Comorbidities are common in MS from the time of diagnosis and may account for some of the heterogeneity observed in MS, including diagnostic delay, clinical presentation, degree of disability progression, rate of health care utilization, working ability, employment status, and quality of life. Coexisting diseases and polypharmacy increase the complexity of patient management and poses major challenges, particularly with the increasing number of immunosuppressive disease-modifying therapies.

Phenome-wide examination of comorbidity burden and multiple sclerosis disease severity

Objective

We assessed the comorbidity burden associated with multiple sclerosis (MS) severity by performing a phenome-wide association study (PheWAS).

Methods

We conducted a PheWAS in 2 independent cohorts: a discovery (Boston, United States; 1993–2014) and extension cohort (British Columbia, Canada; 1991–2008). We included adults with MS, ≥1 Expanded Disability Status Scale (EDSS) score, and ≥1 International Classification of Diseases (ICD) code other than MS. We calculated the Multiple Sclerosis Severity Score (MSSS) using the EDSS. We mapped ICD codes into PheCodes (phenotypes), using a published system with each PheCode representing a unique medical condition. Association between the MSSS and the presence of each condition was assessed using logistic regression adjusted for covariates.

Results

The discovery and extension cohorts included 3,439 and 4,876 participants, respectively. After Bonferroni correction and covariate adjustments, a higher MSSS was associated with 37 coexisting conditions in the discovery cohort. Subsequently, 16 conditions, including genitourinary, infectious, metabolic, epilepsy, and movement disorders, met the reporting criteria, reaching the Bonferroni threshold of significance with the same direction of effect in the discovery and extension cohort. Notably, benign neoplasm of the skin was inversely associated with the MSSS.

Conclusion

The phenome-wide approach enabled a systematic interrogation of the comorbidity burden and highlighted clinically relevant medical conditions associated with MS severity (beyond MS-specific consequences) and defines a roadmap for comprehensive investigation of comorbidities in chronic neurologic diseases. Further prospective investigation of the bidirectional relationship between disability and comorbidities could inform the individualized patient management.

A global view of comorbidity in multiple sclerosis: a systematic review with a focus on regional differences, methodology, and clinical implications

Multiple sclerosis (MS) is a chronic autoimmune disorder of the central nervous system which is associated with numerous comorbidities. These include cardiovascular disease, psychiatric and neurologic disturbances, restless leg syndrome, migraine, cancer, autoimmune diseases, and metabolic disorders. Comorbid disease is an important consideration for clinicians treating patients with MS; early presentation of comorbidities can obscure or delay MS diagnosis, as well as significantly impacting the disease course. Improved understanding of comorbidities and their emergence in MS populations is important for improving the quality of life and optimizing treatment for patients. Therefore, we evaluated published studies reporting epidemiologic data on comorbidities and their associated impact on disease progression in patients with MS (PwMS). The prevalence of neurologic, cardiovascular, metabolic, and autoimmune comorbidities was elevated in PwMS in general, and furthermore, this adversely affected a broad range of outcomes. Compared with PwMS, cancer rates in people without MS or the general population were lower, which should prompt further studies into the mechanisms of both diseases. Studies were under-represented in many regions owing to the latitudinal gradient of MS and possible underfunding of studies.

A systematic review of morbidities suggestive of the multiple sclerosis prodrome

INTRODUCTION

The identification of a prodromal phase in multiple sclerosis (MS) could have major implications for earlier recognition and management of MS. The authors conducted a systematic review assessing studies of morbidities before, or at, MS onset or diagnosis.Areas covered: Two independent reviewers searched Medline, Embase, Psycinfo and CINAHL from inception to February 8^th, 2019. To be eligible, studies had to be published in English and report the relative occurrence of at least one morbidity or symptom before, or at, MS onset or diagnosis among MS cases in comparison to a control group not known to have MS. Findings were narratively synthesized. Study quality was assessed using the Newcastle-Ottawa scale (NOS, maximum score 9).Expert opinion: Twenty-nine studies were included, which comprised 83,590 MS cases and 396,343 controls. Most were case-control studies (25/29), 8/29 were of high quality (NOS≥8) and 19/29 examined the period before MS symptom onset. Most studies assessing anxiety, depression, migraine and lower cognitive performance found these conditions to be more prevalent before MS onset or diagnosis relative to controls. There was limited evidence to implicate other conditions. Thus, there is evidence that anxiety, depression, migraine and lower cognitive performance form part of the MS prodrome.

Multiple Sclerosis and Cancer: The Ying-Yang Effect of Disease Modifying Therapies

Over the past two decades, the field of multiple sclerosis (MS) has been transformed by the rapidly expanding arsenal of new disease modifying therapies (DMTs). Current DMTs for MS aim to modulate innate and adaptive immune responses toward a less inflammatory phenotype. Since the immune system is also critical for identifying and eliminating malignant cells, immunosuppression from DMTs may predictably increase the risk of cancer development in MS patients. Compared with healthy controls, patients with autoimmune conditions, such as MS, may already have a higher risk of developing certain malignancies and this risk may further be magnified by DMT treatments. For those patients who develop both MS and cancer, these comorbid presentations create a challenge for clinicians on how to therapeutically address management of cancer in the context of MS autoimmunity. As there are currently no accepted guidelines for managing MS patients with prior history of or newly developed malignancy, we undertook this review to evaluate the molecular mechanisms of current DMTs and their potential for instigating and treating cancer in patients living with MS.

Prevalence of asthma in multiple sclerosis: A United States population-based study

BACKGROUND

Multiple sclerosis (MS) and asthma are complex multifactorial diseases which adversely impact daily functioning. However, the prevalence of asthma in those with MS is not clear. The objective of this study is to characterize the prevalence of asthma in those with MS, with considerations for age, gender, and race.

METHODS

We conducted a U.S. population-based, cross-sectional study of electronic health record information for 56.6 million Americans available in the IBM® Explorys EPM: Explore database. We evaluated the prevalence of asthma in MS (N = 141,880) and non-MS (N = 56,416,790) cohorts, stratifying by age, gender, and race (All, White Americans, and African Americans).

RESULTS

The prevalence of asthma was significantly greater among those with MS than the general population across age, gender, and racial subpopulations. Adjusting for age and gender, asthma was three times more common in MS. In the MS cohort, the prevalence of asthma had a U-shaped distribution with respect to age, with the greatest asthma prevalence among the young and the elderly (> 20% prevalence among those <30 or ≥80 years; prevalence range: 15 to 30%); this significantly differed from the fairly uniform distribution observed in the non-MS cohort (prevalence range: 4 to 9%). These patterns were relatively consistent when stratifying by gender and race.

CONCLUSION

Asthma is significantly more common in those with MS than in the general population - particularly in the young and elderly - irrespective of gender and race. The results add to the growing MS comorbidity literature, and emphasizes the need for comorbidity management as a part of comprehensive MS patient care.

Eosinophils in Autoimmune Diseases

Eosinophils are multifunctional granulocytes that contribute to initiation and modulation of inflammation. Their role in asthma and parasitic infections has long been recognized. Growing evidence now reveals a role for eosinophils in autoimmune diseases. In this review, we summarize the function of eosinophils in inflammatory bowel diseases, neuromyelitis optica, bullous pemphigoid, autoimmune myocarditis, primary biliary cirrhosis, eosinophilic granulomatosis with polyangiitis, and other autoimmune diseases. Clinical studies, eosinophil-targeted therapies, and experimental models have contributed to our understanding of the regulation and function of eosinophils in these diseases. By examining the role of eosinophils in autoimmune diseases of different organs, we can identify common pathogenic mechanisms. These include degranulation of cytotoxic granule proteins, induction of antibody-dependent cell-mediated cytotoxicity, release of proteases degrading extracellular matrix, immune modulation through cytokines, antigen presentation, and prothrombotic functions. The association of eosinophilic diseases with autoimmune diseases is also examined, showing a possible increase in autoimmune diseases in patients with eosinophilic esophagitis, hypereosinophilic syndrome, and non-allergic asthma. Finally, we summarize key future research needs.