Risk of cancer among Finnish multiple sclerosis patients

Cancer and multiple sclerosis: 2023 recommendations from the French Multiple Sclerosis Society

BACKGROUND

Epidemiological data reveal that 45% of persons with multiple sclerosis (PwMS) in France are more than 50 years. This population more than 50 is more susceptible to cancer, and this risk may be increased by frequent use of immunosuppressive drugs. Consequently, concerns have arisen about the potential increased risk of cancer in PwMS and how patients should be screened and managed in terms of cancer risk.

OBJECTIVE

To develop evidence-based recommendations to manage the coexistence of cancer and multiple sclerosis (MS).

METHODS

The French Group for Recommendations in MS collected articles from PubMed and university databases covering the period January 1975 through June 2022. The RAND/UCLA method was employed to achieve formal consensus. MS experts comprehensively reviewed the full-text articles and developed the initial recommendations. A group of multidisciplinary health care specialists then validated the final proposal.

RESULTS

Five key questions were addressed, encompassing various topics such as cancer screening before or after initiating a disease-modifying therapy (DMT), appropriate management of MS in the context of cancer, recommended follow-up for cancer in patients receiving a DMT, and the potential reintroduction of a DMT after initial cancer treatment. A strong consensus was reached for all 31 recommendations.

CONCLUSION

These recommendations propose a strategic approach to managing cancer risk in PwMS.

An exploration of causal relationships between nine neurological diseases and the risk of breast cancer: a Mendelian randomization study

BACKGROUND

Some preceding researches have observed that certain neurological disorders, such as Alzheimer's disease and multiple sclerosis, may affect breast cancer risk. However, whether there are causal relationships between these neurological conditions and breast cancer is inconclusive. This study was designed to explore whether neurological disorders affected the risks of breast cancer overall and of the two subtypes (ER+ and ER-).

METHODS

In the course of this study, genome-wide association study (GWAS) data for nine neurological diseases (Alzheimer's disease, multiple sclerosis, Parkinson's disease, myasthenia gravis, generalized epilepsy, intracerebral haemorrhage, cerebral atherosclerosis, brain glioblastoma, and benign meningeal tumour) were collected from the Complex Trait Genetics lab and the MRC Integrative Epidemiology Unit, and single-nucleotide polymorphisms (SNPs) extensively associated with these neurological ailments had been recognized as instrumental variables (IVs). GWAS data on breast cancer were collected from the Breast Cancer Association Consortium (BCAC). Two-sample Mendelian randomization (MR) analyses as well as multivariable MR analyses were performed to determine whether these SNPs contributed to breast cancer risk. Additionally, the accuracy of the results was evaluated using the false discovery rate (FDR) multiple correction method. Both heterogeneity and pleiotropy were evaluated by analyzing sensitivities.

RESULTS

According to the results of two-sample MR analyses, Alzheimer's disease significantly reduced the risks of overall (OR 0.925, 95% CI [0.871-0.982], P = 0.011) and ER+ (OR 0.912, 95% CI [0.853-0.975], P = 0.007) breast cancer, but there was a negative result in ER- breast cancer. However, after multiple FDR corrections, the effect of Alzheimer's disease on overall breast cancer was not statistically significant. In contrast, multiple sclerosis significantly increased ER+ breast cancer risk (OR 1.007, 95% CI [1.003-1.011], P = 0.001). In addition, the multivariable MR analyses showed that Alzheimer's disease significantly reduced the risk of ER+ breast cancer (IVW: OR 0.929, 95% CI [0.864-0.999], P=0.047; MR-Egger: OR 0.916, 95% CI [0.846-0.992], P=0.031); however, multiple sclerosis significantly increased the risk of ER+ breast cancer (IVW: OR 1.008, 95% CI [1.003-1.012], P=4.35×10-4; MR-Egger: OR 1.008, 95% CI [1.003-1.012], P=5.96×10-4). There were no significant associations between the remainder of the neurological diseases and breast cancer.

CONCLUSIONS

This study found the trends towards a decreased risk of ER+ breast cancer in patients with Alzheimer's disease and an increased risk in patients with multiple sclerosis. However, due to the limitations of Mendelian randomization, we cannot determine whether there are definite causal relationships between neurological diseases and breast cancer risk. For conclusive evidences, more prospective randomized controlled trials will be needed in the future.

Cancer risk, disease-modifying therapy, and age in multiple sclerosis: A retrospective population-based cohort study

BACKGROUND

Long-term population-based safety studies are needed to investigate cancer outcomes in people with multiple sclerosis (MS) treated with modern disease-modifying therapy (DMT).

OBJECTIVES

To investigate if exposure to DMT increases the risk of invasive cancer in MS.

METHODS

We used population-based administrative health data from Alberta, Canada between 2008 and 2018. DMT exposure was defined in two ways: first as exposure to any DMT, and second by DMT type (modulating, sequestering, depleting). Study outcome was time to first diagnosis of invasive cancer. Cancer risk was compared to the general population using standardized incidence ratios (SIRs) and to the unexposed MS cases using hazard ratios (HRs).

RESULTS

The analysis included 14,313 MS cases: 5,801 (40.5 %) were exposed to DMT. Median (interquartile range) follow-up was 8.4 (4.3, 10.4) years. Compared to the general population, there was no difference in cancer risk for the overall MS population (SIR: 0.94, 95 % confidence interval [CI]: 0.87, 1.02) or the DMT-exposed MS cases (SIR: 0.89; 95 % CI: 0.75, 1.05). Compared to unexposed MS cases, we found an interaction with age for exposure to any DMT (p = 0.001) and modulating DMT (p = 0.001), indicating that a difference in the risk of cancer associated with DMT depends on age. Cancer risk was not associated with exposure to sequestering DMT (HR: 1.28, 95 % CI: 0.78, 2.08) or depleting DMT (HR: 2.29, 95 % CI: 0.86, 6.14).

CONCLUSIONS

Cancer risk for MS patients was similar to the general population. In the MS population, the age-dependent effect of DMT for cancer risk suggests a higher risk of cancer with age 62 or older and a protective effect at younger age. Further investigation is required to clarify whether the interaction between DMT exposure and age is a causal effect.

Is cancer risk reduced in multiple sclerosis? Results from a tertiary referral center

BACKGROUND

Multiple sclerosis (MS) patients may be protected against cancer because of increased immune surveillance. However, aberrant T/B cell functioning in MS may increase the risk of cancer. We aimed to compare the frequency of cancer among patients with MS with an appropriate control group matched by the variables such as age, gender, tobacco smoking history, body mass index (BMI), and family history of cancer.

METHODS

The MS patients who were registered and followed up at the MS Center in Hacettepe University Hospitals and appropriately matched with controls were included. A self-administered questionnaire with links to the online survey was delivered.

RESULTS

Overall, 1037 responses out of 2074 in MS patients and 506 responses out of 1500 control group were included. Fourteen (1.35%) of MS patients and 18 (3.6%) of the controls were diagnosed with cancer. The odds ratio of having cancer in patients with MS compared to the control group was 0.389 (95% CI = 0.161-0.940, p < 0.05).

DISCUSSION

There was no statistically significant difference in age, gender, tobacco smoking, and BMI between the groups after propensity score matching. The odds of having cancer were lower in our MS patients compared to the controls. The autoimmune changes responsible for the pathogenesis of MS may be responsible for the decrease in cancer risk.

Association between multiple sclerosis and cancer risk: An extensive review/meta and Mendelian randomization analyses

BACKGROUND

Observational investigations examining cancer risk among multiple sclerosis (MS) patients have produced contradictory findings. Herein, we performed an extensive review and meta-analysis to evaluate the correlation and causation between MS and cancer incidence.

METHODS

We systematically screened for published articles examining cancer incidences among MS patients within the Cochrane Library, PubMed, and Embase databases. Next, we employed STATA v.16.0 for data analysis. Following meta-analysis, we performed a two-sample Mendelian randomization (MR) analysis to uncover the underlying mechanism behind the MS-mediated regulation of certain cancers.

RESULTS

Overall, we selected 18 articles encompassing 14 individual cancers incidences and a total of 368,952 patients for meta-analysis. Based on our analysis, there was reduced pancreatic (ES = 0.68; 95% CI: 0.49-0.93; I 2 = 0%) and ovarian cancer (ES = 0.65; 95% CI: 0.53-0.80; I 2 = 86.7%) co-occurrences among MS patients. Meanwhile, the incidences of breast (ES = 1.10; 95% CI: 1.01-1.21; I 2 = 60.9%) and brain cancers (ES = 1.94; 95% CI: 1.12-3.37; I 2 = 56.1%) were elevated among the same population. However, MR analysis revealed the opposite relation between MS and breast cancer risk (OR = 0.94392; 95% CI: 0.91011-0.97900, P = 0.002). Moreover, it revealed strong incidence of lung cancer (OR = 1.0004; 95% CI: 1.0001-1.0083, P = 0.001) among MS patients, as evidenced by the inverse variance weighting estimator. Lastly, MR found that other forms of cancers were not significantly related to MS.

CONCLUSIONS

Using meta-analysis, we demonstrated that MS patients exhibited enhanced pancreatic and ovarian cancer risk, and diminished breast and brain cancer risk. However, using MR analysis, we discovered an inverse relation between MS and breast cancer risk, and additionally saw an uptick in lung cancer co-occurrence among MS patients.

Risk of cervical pre-cancer and cancer in women with multiple sclerosis exposed to high efficacy disease modifying therapies

There is a growing need to better understand the risk of malignancy in the multiple sclerosis (MS) population, particularly given the relatively recent and widespread introduction of immunomodulating disease modifying therapies (DMTs). Multiple sclerosis disproportionately affects women, and the risk of gynecological malignancies, specifically cervical pre-cancer and cancer, are of particular concern. The causal relationship between persistent human papillomavirus (HPV) infection and cervical cancer has been definitively established. To date, there is limited data on the effect of MS DMTs on the risk of persistent HPV infection and subsequent progression to cervical pre-cancer and cancer. This review evaluates the risk of cervical pre-cancer and cancer in women with MS, including the risk conferred by DMTs. We examine additional factors, specific to the MS population, that alter the risk of developing cervical cancer including participation in HPV vaccination and cervical screening programs.

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.

Prognostic impact of autoimmune disease in oral cavity squamous cell carcinoma

BACKGROUND AND OBJECTIVES

Recent literature has highlighted the role of the host in the prognosis of oral squamous cell carcinoma (OSCC). In this study, we retrospectively examined the impact of autoimmune (AI) disorders as an aspect of the host status on survival outcomes in OSCC patients.

METHODS

From a departmental database of OSCC patients (n = 1369), 123 patients with an AI disorder were identified. AI and no-AI groups were compared for survival outcomes.

RESULTS

There were no significant differences in survival between groups for overall survival, disease-specific survival, local, regional, and distant recurrence-free probabilities. However, survival and recurrence-free probabilities were poorer in the AI group versus the no AI group.

CONCLUSION

Patients with AI disease trended towards worse outcomes. This suggests immune dysregulation in these patients may impact oncologic outcomes.

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.

Peripheral blood values as predictors of autoimmune status in oral cavity squamous cell carcinoma

BACKGROUND

Recent literature has highlighted the role of the host in prognosis in oral squamous cell carcinoma (OSCC). Autoimmune (AI) disease represents a macroscopic depiction of host status. The goal of this study was to predict an AI "status" and to analyze the utility of this "status" as a prognostic indicator in OSCC.

METHODS

From a departmental database of OSCC patients (n = 1377), 125 patients with an AI disorder were identified. PBL values were obtained and standardized for analysis. A LASSO regression model was used to determine the best predictors of AI status and an AI score was developed. The score was then analyzed across various survival endpoints.

RESULTS

When AI score was divided into a binary variable, patients in the highest quartile had a significantly worse overall survival (OS), local recurrence-free (LRFP) and distant recurrence-free probability (DRFP). Survival curves showed significant differences for OS, DSS, LRFP, and DRFP.

CONCLUSIONS

AI diseases are immune dysregulations that could play a role in prognosis. Therefore, development of an AI score is necessary to depict host status in a ubiquitous manner. AI score as a binary variable may be more utilitarian in a clinical setting, compared to the continuous score. This novel tool needs validation and integration into more tumor and host characteristics. This investigation showed utility of such a score, similar to PBL data in OSCC prognosis. Future studies should incorporate other relevant variables known to affect outcome and implement a more comprehensive predictive model.

Incidence of cancer in multiple sclerosis before and after the treatment era- a registry- based cohort study

BACKGROUND

Whether disease-modifying therapies (DMTs) influence cancer in multiple sclerosis (MS) is uncertain.

OBJECTIVES

Assess incidence of cancer diagnosis among Norwegian MS patients compared to the general population in 1953 to 1995 and 1996 to 2017-reflecting era before and after introduction of DMTs.

METHODS

We performed a nationwide cohort study comprising 6949 MS patients and 37,922 controls, matched on age, sex and county. The cohort was linked to Norwegian Cancer Registry, Cause of Death Registry and National Educational database. We used Poisson regression to calculate incidence rate ratio (IRR) of cancer.

RESULTS

During 1953-1995 MS patients had similar cancer frequency compared to controls (IRR: 1.11 (95% Confidence Intervals (CI): 0.90-1.37)), although MS patients had increased frequency of cancer in endocrine glands (IRR: 2.51 (1.27-4.93). During 1996-2017 we identified significant increased frequency of cancer among MS patients compared to controls (IRR: 1.38 (95% CI: 1.28-1.52): in brain (IRR: 1.97 (1.41-2.78)), meninges (IRR: 2.44 (1.54-3.77)), respiratory organs (IRR: 1.96 (1.49-2.63)). The excess cancer diagnosis was most frequent among MS patients ≥ 60 years of age (HR 1.30 (1.15-1.47)).

CONCLUSION

Incidence of cancer among MS patients compared to controls was higher in 1996 to 2017, corresponding in time to the introduction of DMT for MS. This was observed more frequently among MS patients older than 60 years of age.

Autoimmune disease and oral squamous cell carcinoma: A systematic review

BACKGROUND

Oral cancer is typically related to environmental carcinogen exposure including tobacco and alcohol. Other less investigated risk factors may be related to a suppressed or dysregulated immune state, and in oral cancer, various levels of immune dysregulation have been found to affect survival and recurrence rates. The rationale for this systematic review was to investigate the possible role that a growing chronic host condition like an autoimmune disease may play in this disease.

METHODS

A systematic search of the literature was carried out using four electronic databases in order to identify original research of any analytic study design type that investigated the relationship between autoimmune disease and oral cancer. Out of 1,947 identified records, 24 observational studies were included for qualitative synthesis.

RESULTS

The studies varied in end points ranging from overall survival (OS), standardized incidence ratio (SIR), and hazard ratio (HR). Due to the heterogenous sampling of studies even within the same study design group, a meta-analysis was not employed. The current state of the literature is varied and heterogenous in both study design and endpoints.

CONCLUSION

Major limitations existed introducing significant bias especially in determining cancer risk such as lack of information surrounding known etiologic risk factors such as alcohol and tobacco consumption. Despite these limitations, a signal was seen between autoimmune disease and oral cancer outcomes and risk. Future studies investigating the relationship between autoimmune disease and oral cancer in a more focused and quantitative manner are therefore needed.

Potential risk of disease modifying therapies on neoplasm development and coadjutant factors in multiple sclerosis outpatients

Neoplasm development in Multiple Sclerosis (MS) patients treated with disease-modifying therapies (DMTs) has been widely discussed. The aim of this work is to determine neoplasm frequency, relationship with the prescription pattern of DMTs, and influence of the patients’ baseline characteristics. Data from 250 MS outpatients were collected during the period 1981–2019 from the medical records of the Neurology Service of the HUPM (Hospital Universitario Puerta del Mar)—in Southern Spain—and analysed using Cox models. Neoplasm prevalence was 24%, mainly located on the skin, with cancer prevalence as expected for MS (6.8%). Latency period from MS onset to neoplasm diagnosis was 10.4 ± 6.9 years (median 9.30 [0.9–30.5]). During the observation period β-IFN (70.4% of patients), glatiramer acetate (30.4%), natalizumab (16.8%), fingolimod (24.8%), dimethyl fumarate (24.0%), alemtuzumab (6.0%), and teriflunomide (4.8%) were administered as monotherapy. Change of pattern in step therapy was significantly different in cancer patients vs unaffected individuals (p = 0.011) (29.4% did not receive DMTs [p = 0.000]). Extended Cox model: Smoking (HR = 3.938, CI 95% 1.392–11.140, p = 0.010), being female (HR = 2.006, 1.070–3.760, p = 0.030), and age at MS diagnosis (AGE-DG) (HR = 1.036, 1.012–1.061, p = 0.004) were risk factors for neoplasm development. Secondary progressive MS (SPMS) phenotype (HR = 0.179, 0.042–0.764, p = 0.020) and treatment-time with IFN (HR = 0.923, 0.873–0.977, p = 0.006) or DMF (HR = 0.725, 0.507–1.036, p = 0.077) were protective factors. Tobacco and IFN lost their negative/positive influence as survival time increased. Cox PH model: Tobacco/AGE-DG interaction was a risk factor for cancer (HR = 1.099, 1.001–1.208, p = 0.049), followed by FLM treatment-time (HR = 1.219, 0.979–1.517). In conclusion, smoking, female sex, and AGE-DG were risk factors, and SPMS and IFN treatment-time were protective factors for neoplasm development; smoking/AGE-DG interaction was the main cancer risk factor.

Lung cancer risk in patients with multiple sclerosis: a Mendelian randomization analysis

BACKGROUND

The relationship of multiple sclerosis (MS) with lung cancer is under debate. Conventional observational studies have reported conflicting findings, but such studies are susceptible to confounding and reverse causation. With a Mendelian Randomization approach, we were able to evaluate the causality between MS and lung cancer.

METHODS

According to published genome-wide association studies (GWASs), we obtained 35 MS-related single-nucleotide polymorphisms, which were used as instrumental variables in our study. Summary data of individual-level genetic information were obtained from the International Lung Cancer Consortium (ILCCO), with a total of 15,861 controls and 11,348 cases; the latter is composed of patients with lung adenocarcinoma and squamous cell lung cancer. The inverse variance-weighted method was applied to estimate the causation between MS and lung cancer. To further evaluate the pleiotropy, the MR-Egger and Weighted median methods were implemented.

RESULTS

The results of MR analysis suggested a causal effect of MS on lung cancer incidence, with evidence of an increased risk for overall lung cancer [odds ratio (OR): 1.0648; 95% confidence interval (CI): 1.0163-1.1156; p = 0.0082]. However, subgroup analyses showed no significant causal relationships between MS and lung adenocarcinoma (OR = 1.0716; 95% CI 0.9840-1.1671, p = 0.1119) and squamous cell lung cancer (OR = 1.0284; 95% CI 0.9575-1.1045, p = 0.4424). In addition, no pleiotropy was found in our study.

CONCLUSION

Our study indicated that MS is a causal risk factor in the development of lung cancer. Further work is needed to elucidate the potential mechanisms.

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.

Risk of cancer in multiple sclerosis (MS): A systematic review and meta-analysis

OBJECTIVE

To assess the pooled risk of cancer in patients with multiple sclerosis.

METHODS

We searched PubMed, Scopus, EMBASE, Web of Science, Ovid, google scholar and gray literature (references of studies, conference abstracts) which were published up to September 2019. The search strategy included the MeSH and text words as ((cancer) OR tumor) OR neoplasm) OR "malignant neoplasm) OR "benign neoplasm) AND (Multiple Sclerosis OR Sclerosis, Multiple) OR Sclerosis, Disseminated) OR Disseminated Sclerosis) OR MS (Multiple Sclerosis)) OR Multiple Sclerosis, Acute Fulminating).

RESULTS

The first literature search revealed 18,996 articles. After deletion of duplicate articles, finally, 264 articles remained. Excluding non-relevant articles, resulted in including 5 articles which met inclusion criteria. The RR estimated between 0.7 and 1.67 in included articles. The pooled RR estimated as 0.83 (95% CI:0.73-0.96) (I² = 90%, P < 0.001). Two studies provided prevalence of different cancers. The pooled prevalence of breast cancer in two studies was 2% (95%CI:2%-2%) (I² = 0%). The pooled prevalence of digestive system cancer in two studies was 2% (95%CI:1%-2%) (I² = 0%). The pooled prevalence of skin cancer in two studies was 1% (95%CI:0%-1%) (I² = 0).

CONCLUSION

The result of this systematic review showed that the risk of cancer in patients with MS is less than the general population.

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.