Risk of non-melanoma skin cancer in myasthenia patients treated with azathioprine

Clinical Characteristics and Outcomes of Generalized Myasthenia Gravis in Malaysia: A Single-Center Experience

BACKGROUND AND PURPOSE

Myasthenia gravis (MG) is clinically heterogeneous and can be classified into subgroups according to the clinical presentation, antibody status, age at onset, and thymic abnormalities. This study aimed to determine the clinical characteristics and outcomes of generalized MG (GMG) patients based on these subgroups.

METHODS

Medical records of MG patients from 1976 to 2023 were reviewed retrospectively. Patients with pure ocular MG were excluded. Data on demographic, clinical characteristics, laboratory features, and outcomes were analyzed.

RESULTS

This study included 120 GMG patients. There was a slight preponderance of female patients over male patients (male:female ratio=1:1.3), with the age at onset exhibiting a bimodal distribution. Female patients peaked at a lower age (21-30 years) whereas male patients peaked at a higher age (61-70 years). Most (92%, 105 of 114) patients had positive anti-acetylcholine receptor antibodies. Five patients were also tested for anti-muscle-specific tyrosine kinase antibodies, with two showing positivity. Thymectomy was performed in 62 (52%) patients, of which 30 had thymoma, 16 had thymic hyperplasia, 7 had an involuted thymus, and 6 had a normal thymus. There were significantly more female patients (68% vs. 45%, p=0.011) with early-onset disease (<50 years old) and thymic hyperplasia (33% vs. 0%, p<0.025). Most (71%) of the patients had a good outcome based on the Myasthenia Gravis Foundation of America postintervention status. GMG patients with early-onset disease had a significantly better outcome than patients with a late onset in univariate (58% vs. 37%, p=0.041) and multivariate (odds ratio=4.68, 95% confidence interval=1.17-18.64, p=0.029) analyses.

CONCLUSIONS

Female patients with early-onset MG and thymic hyperplasia had significantly better outcomes, but only early-onset disease was independently associated with a good outcome. These findings are comparable with those of other studies.

Group I pharmaceuticals of IARC and associated cancer risks: systematic review and meta-analysis

We aimed to summarize the cancer risk among patients with indication of group I pharmaceuticals as stated in monographs presented by the International Agency for Research on Cancer working groups. Following the PRISMA guidelines, a comprehensive literature search was conducted using the PubMed database. Pharmaceuticals with few studies on cancer risk were identified in systematic reviews; those with two or more studies were subjected to meta-analysis. For the meta-analysis, a random-effects model was used to calculate the summary relative risks (SRRs) and 95% confidence intervals (95% CIs). Heterogeneity across studies was presented using the Higgins I square value from Cochran's Q test. Among the 12 group I pharmaceuticals selected, three involved a single study [etoposide, thiotepa, and mustargen + oncovin + procarbazine + prednisone (MOPP)], seven had two or more studies [busulfan, cyclosporine, azathioprine, cyclophosphamide, methoxsalen + ultraviolet (UV) radiation therapy, melphalan, and chlorambucil], and two did not have any studies [etoposide + bleomycin + cisplatin and treosulfan]. Cyclosporine and azathioprine reported increased skin cancer risk (SRR = 1.32, 95% CI 1.07-1.62; SRR = 1.56, 95% CI 1.25-1.93) compared to non-use. Cyclophosphamide increased bladder and hematologic cancer risk (SRR = 2.87, 95% CI 1.32-6.23; SRR = 2.43, 95% CI 1.65-3.58). Busulfan increased hematologic cancer risk (SRR = 6.71, 95% CI 2.49-18.08); melphalan was associated with hematologic cancer (SRR = 4.43, 95% CI 1.30-15.15). In the systematic review, methoxsalen + UV and MOPP were associated with an increased risk of skin and lung cancer, respectively. Our results can enhance persistent surveillance of group I pharmaceutical use, establish novel clinical strategies for patients with indications, and provide evidence for re-categorizing current group I pharmaceuticals into other groups.

Immunotherapy for keratinocyte cancers. Part I: Immune-related epidemiology, risk factors, pathogenesis, and immunotherapy management of keratinocyte cancers

The important role of the immune system in the surveillance and control of keratinocyte cancers (KCs), namely squamous and basal cell carcinomas, is increasingly appreciated, as new immunotherapies have recently become available. As the field of immunotherapy is rapidly evolving, this review synthesizes key concepts and highlights important cellular components within the immune system responsible for attacking KCs. We review the most current data on the epidemiology, risk factors, and immunotherapy management for KCs. Patients will seek advice from dermatologists to help explain why immunotherapies work for KCs and whether they might be appropriate for different clinical scenarios. Collaboration with medical colleagues across different disciplines to evaluate KCs for response to immunotherapy and early recognition of immune-related adverse events will help to optimize patient outcomes.

Current management of myasthenia gravis in Belgium: a single-center experience

INTRODUCTION

As new treatments are becoming available for patients with myasthenia gravis (MG), it is worth reflecting on the actual status of MG treatment to determine which patients would most likely benefit from the new treatments.

METHODS

We reviewed the clinical files of all MG patients seen at the Department of Neurology of the Antwerp University Hospital during the years 2019, 2020 and 2021.

RESULTS

163 patients were included. Age at diagnosis varied from the first to the eighth decades, with a peak of incidence from 60 to 70 years for both genders, and an additional peak from 20 to 30 years in women. Diplopia and ptosis were by far the most common onset symptom. At maximum disease severity, 24% of the patients still had purely ocular symptoms and 4% needed mechanical ventilation. 97% of the patients received a treatment with pyridostigmine and 68% with corticosteroids, often in combination with immunosuppressants. More than half reported side effects. At the latest visit, 50% of the patients were symptom-free. Also, half of the symptomatic patients were fulltime at work or retired with no or mild limitations in daily living. The remaining patients were working part-time, on sick leave, or retired with severe limitations.

DISCUSSION AND CONCLUSION

The majority of MG patients are doing well with currently available treatments, but often at the cost of side effects in the short and in the long term. A significant group is in need of better treatments.

Myasthenia gravis in clinical practice

BACKGROUND

Myasthenia gravis is largely a treatable disease, but it can result in significant morbidity and even mortality, which can usually be avoided, or at least mitigated, with timely diagnosis and appropriate treatment of the disease. Objective: this review aims to summarize the main practical aspects of the diagnostic approach, treatment and care of myasthenic patients.

METHODS

The authors performed a non-systematic critical review summarizing the main practical aspects of myasthenia gravis.

RESULTS

Most patients with myasthenia have autoantibodies targeted at acetylcholine receptors or, less commonly, muscle-specific kinase - MuSK. Electrophysiology plays an important role in the diagnosis of neuromuscular junction dysfunction. The central clinical manifestation of myasthenia gravis is fatigable muscle weakness, which can affect eye, bulbar, respiratory, and limb muscles. With rare exceptions, patients have a good response to symptomatic treatment, but corticosteroids and/or immunosuppressants are usually also necessary to obtain good control of the manifestations of the disease.

CONCLUSION

Knowledge of the peculiar aspects of their clinical and electrophysiological presentations is important for the diagnosis. Likewise, specific treatment and response time to each drug are crucial for proper care.

Cancer occurrence following azathioprine treatment in myasthenia gravis patients: A systematic review and meta-analysis

Treatments of myasthenia gravis (MG) usually include immunosuppressants such as glucocorticoids, tacrolimus, and azathioprine (AZA). In clinical practice, azathioprine therapy is thought to have a potential risk for developing secondary malignancies in myasthenia gravis patients. However, published data on the long-term safety of azathioprine in myasthenia gravis patients are limited and not consistent among studies. To explore cancer occurrence following azathioprine therapy in myasthenia gravis patients in the long term, we searched Medline, EMBASE, and the Cochrane Library for terms related to azathioprine, myasthenia gravis and cancer occurrence. Two investigators independently extracted trial data. A pooled estimate was calculated from fixed-effects meta-analysis. Our analysis included 1650 azathioprine-treated patients and 2481 non-azathioprine-treated patients. All five studies showed some concerns regarding the risk of bias. In a meta-analysis of 5 studies, we observed no significantly elevated risk of cancer occurrence among individuals with prior myasthenia gravis diagnosis who received long-term azathioprine treatment (OR 1.09; 95% CI 0.86-1.38, p = 0.46). Prospective studies are needed to observe the safety of azathioprine.

Cancer in myasthenia gravis subtypes in relation to immunosuppressive treatment and acetylcholine receptor antibodies: A Swedish nationwide register study

BACKGROUND AND PURPOSE

The potentially increased risk of extrathymic cancers in myasthenia gravis (MG) remains uncertain. We present the occurrence of extrathymic cancer diagnoses in different MG subgroups.

METHODS

We conducted a nationwide Swedish register-based cohort study, including patients who had their first MG diagnosis or first prescription of acetylcholine esterase inhibitors between the years 2006 and 2018. Timing and subtypes of cancer diagnosis in relation to MG as well as corticosteroid-sparing immunosuppressants (CSISs) were identified from national patient, cancer and drug registers.

RESULTS

In the study population of 2812 MG patients, 92 had juvenile MG (3%), 632 had early-onset MG (23%), 1968 had late-onset MG (LOMG; 70%) and 120 patients had thymoma-associated MG (TAMG; 4%). Extrathymic cancers were observed in 630 patients (22.4%). Skin cancer and cancer in the male genital organs were most common (N = 138, respectively), followed by cancers in the female genital organs (N = 103), digestive organs (N = 90) and breast (N = 80). Patients with TAMG (29.2%) and LOMG (28.4%) had the highest occurrence of extrathymic cancer. Cancer frequency was comparable between acetylcholine receptor antibody seropositive and seronegative patients. Two or more CSIS prescriptions significantly increased the frequency of cancer, especially cancers in the digestive organs (p = 0.0026), male genital organs (p = 0.0037) and skin (p < 0.0001).

CONCLUSIONS

Most extrathymic cancer types in MG were observed in TAMG and LOMG patients, and there was a clear correlation between CSIS exposure and cancer risk. This study sheds light on extrathymic cancers also in non-thymoma MG.

Use of Immunomodulating Drugs and Risk of Cutaneous Melanoma: A Nationwide Nested Case-Control Study

Purpose

Cutaneous melanoma is among the fastest growing malignancies in Norway and ultraviolet radiation (UVR) exposure is the primary environmental risk factor. Immunomodulating drugs can increase skin photosensitivity and suppress immune responses, and by such mechanisms influence melanoma risk. We, therefore, aimed to examine the associations between use of immunomodulating drugs and melanoma risk, at a nationwide population level.

Patients and Methods

In the Cancer Registry of Norway, we identified all cases aged 18-85 with a first primary cutaneous melanoma diagnosed in 2007-2015 (n=12,106). These were matched to population controls from the Norwegian National Registry 1:10 (n=118,564), on sex and year of birth using risk set sampling. Information on prescribed drugs (2004-2015) was obtained by linkage to the Norwegian Prescription Database (NorPD). Conditional logistic regression was used to estimate rate ratios (RRs) and 95% confidence intervals (CIs) for associations between use of immunomodulating drugs (immunosuppressants and corticosteroids) and melanoma risk, adjusted for ambient UVR and other drug use.

Results

Compared with ≤1 prescription, use of ≥8 prescriptions of immunosuppressants was associated with increased risk of melanoma (RR 1.50, 95% CI 1.27, 1.77). Similar associations were found for subgroups of immunosuppressants: drugs typically prescribed to organ transplant recipients (OTRs) (RR 2.02, 95% CI 1.35, 3.03) and methotrexate (RR 1.27, 95% CI 1.04, 1.55). Similar results were found for high levels of cumulative doses and across all histological subtypes. Use of corticosteroids was not associated with melanoma risk.

Conclusion

We found a positive association between use of immunosuppressants and melanoma risk, with the highest risk seen for drugs prescribed to OTRs. Knowledge about this risk increase is important for physicians and users of these drugs, for intensified surveillance, awareness and cautious sun exposure.

Use of hydrochlorothiazide and risk of skin cancer: a nationwide Taiwanese case-control study

Background

The antihypertensive agent hydrochlorothiazide has been associated with increased risks of non-melanoma skin cancer (NMSC) and possibly some melanoma subtypes. Previous studies were, however, conducted in predominantly Caucasian populations. We therefore examined the association between hydrochlorothiazide and skin cancer risk in an Asian population.

Methods

By using Taiwan’s National Health Insurance Research Database (NHIRD), we conducted three separate case–control studies of lip cancer, non-lip non-melanoma skin cancer and melanoma. Cases (n = 29,082) with a first-ever skin cancer diagnoses (2008–2015) were matched 1:10 to population controls. We estimated odds ratios (ORs) associating hydrochlorothiazide use with skin cancer risk by using conditional logistic regression.

Results

Hydrochlorothiazide use showed no overall association with any of the three outcomes: ORs for high cumulative use of HCTZ (≥50,000 mg) were 0.86 (95% CI 0.09–7.81) for lip cancer, 1.16 (95% CI 0.98–1.37) for non-lip NMSC and 1.07 (95% CI 0.65–1.76) for melanoma. There was some evidence of a dose–response pattern for non-lip NMSC, with an OR of 1.66 (95% CI 0.82–3.33) for 100,000–149,999 mg of HCTZ. The null findings were robust across subgroup and sensitivity analyses.

Conclusion

Use of HCTZ appears safe in terms of skin cancer risk in an Asian population.

Metastatic Merkel cell carcinoma and myasthenia gravis: contraindication for therapy with immune checkpoint inhibitors?

Background

PD-1/PD-L1 inhibitors are promising approaches for advanced Merkel cell carcinoma (MCC). Nevertheless, these inhibitors bear a high risk for induction of immune-related adverse events (irAEs), particularly flares of preexisting autoimmune diseases. Neurological irAEs of PD-1/PD-L1 inhibitors are possibly underestimated and potentially fatal toxicities. Additionally, exacerbations of preexisting myasthenia gravis (MG) with a high MG-specific-related mortality have been reported.

Case presentation

A 61-year-old woman with a history of MG since 2005 was treated with azathioprine and pyridostigmine after thymectomy. In March 2016, she was diagnosed with MCC. Six months later the tumor had progressed to stage IV and metastases were detected in lymph nodes and the pancreas. The immunosuppressive therapy was therefore changed to mycophenolatmofetil (MMF) and an immune checkpoint blockade with the PD-1 inhibitor pembrolizumab was initiated in November 2016. Due to MMF-induced liver toxicity, MMF was switched to cyclosporine A (CsA) with normalized liver transaminases six weeks later. After six cycles of pembrolizumab the patient achieved a partial response. Follow up analysis sixty-five weeks later revealed a long-lasting tumor response with a partial remission of pancreatic and inguinal metastases and no flare of MG.

Conclusions

Patients with a preexisting MG can be considered for treatment with immune checkpoint inhibitors if they have a life-threatening cancer and if other effective, long-lasting treatment options are not available. The risks and benefits of therapy should be weighed in a multidisciplinary setting and should be discussed thoroughly with the patient. Exacerbation of underlying MG can be potentially life-threatening and requires close monitoring in collaboration with neuromuscular specialists.

Myasthenia gravis

Myasthenia gravis (MG) is an autoimmune disease caused by antibodies against the acetylcholine receptor (AChR), muscle-specific kinase (MuSK) or other AChR-related proteins in the postsynaptic muscle membrane. Localized or general muscle weakness is the predominant symptom and is induced by the antibodies. Patients are grouped according to the presence of antibodies, symptoms, age at onset and thymus pathology. Diagnosis is straightforward in most patients with typical symptoms and a positive antibody test, although a detailed clinical and neurophysiological examination is important in antibody-negative patients. MG therapy should be ambitious and aim for clinical remission or only mild symptoms with near-normal function and quality of life. Treatment should be based on MG subgroup and includes symptomatic treatment using acetylcholinesterase inhibitors, thymectomy and immunotherapy. Intravenous immunoglobulin and plasma exchange are fast-acting treatments used for disease exacerbations, and intensive care is necessary during exacerbations with respiratory failure. Comorbidity is frequent, particularly in elderly patients. Active physical training should be encouraged.

Myasthenia Gravis and Lambert-Eaton Myasthenic Syndrome

PURPOSE OF REVIEW

This article discusses the pathogenesis, diagnosis, and management of autoimmune myasthenia gravis (MG) and Lambert-Eaton myasthenic syndrome (LEMS).

RECENT FINDINGS

Recognition of new antigenic targets and improved diagnostic methods promise to improve the diagnosis of MG, although the clinical phenotypes associated with newer antibodies have not yet been defined. Future therapies might specifically target the aberrant immune response. The apparent increase in the prevalence of MG is not fully explained. Results of a long-awaited trial of thymectomy support the practice of performing a thymectomy under specific conditions.

SUMMARY

The current treatment options are so effective in most patients with MG or LEMS that in patients with refractory disease the diagnosis should be reconsidered. The management of MG is individualized, and familiarity with mechanisms, adverse effects, and strategies to manage these commonly used treatments improves outcome. Patient education is important. LEMS, frequently associated with an underlying small cell lung cancer, is uncommon, and the mainstay of treatment is symptomatic in most patients.

Management of actinic keratosis at specific body sites in patients at high risk of carcinoma lesions: expert consensus from the AKTeam™ of expert clinicians

Actinic keratoses (AK) arise on sun-exposed regions of the skin. If left untreated, AK may progress to invasive squamous cell carcinoma (SCC), although the rate of progression is low. A practical treatment algorithm for the treatment of AK in standard situations has been published by the AKTeam^™ expert panel. However, management of particular situations of AK with increasing/higher carcinoma risk or AK progressing into carcinomas with increased aggressiveness due to their anatomical location (risky areas), or in patients with an increased risk of SCC requires further discussion. These include AK on the dorsal hands, forearms, legs, periorbital region, eyelids, ears, or lips, and organ transplant recipients, patients undergoing treatment with carcinogenic agents and patients with chronic lymphocytic leukaemia. The main objective was to propose therapeutic strategies for the treatment of AK located in risky areas and in patients with more invasive/aggressive lesions and a higher risk of progression to SCC. A systematic review of the literature was initially performed, and results were discussed by the experts to propose best management practices in specific situations. Finally, adapted management strategies for AK occurring in risky areas and in high-risk patients are presented, taking into account the experts' own clinical experience and current guidelines. In most of these 'at-risk' situations, patients can be treated according to the AKTeam^™ treatment algorithm. Difficult-to-treat lesions should be treated more aggressively due to their higher risk of transformation. For patients with skin that is highly susceptible to actinic damage, monitoring and sun protection strategies are mandatory, and patients should undergo more regular follow-up. Further assessment of newer therapies in clinical trials is necessary to determine optimal treatment conditions. This expert consensus provides guidance for the management of AK in risky body sites and in patients with an increasing/higher risk for SCCs.

Spectrum of Immune-Related Conditions Associated with Risk of Keratinocyte Cancers among Elderly Adults in the United States

Background: Elevated keratinocyte carcinoma risk is present with several immune-related conditions, e.g., solid organ transplantation and non-Hodgkin lymphoma. Because many immune-related conditions are rare, their relationships with keratinocyte carcinoma have not been studied.Methods: We used Medicare claims to identify cutaneous squamous cell carcinoma (SCC) and basal cell carcinoma (BCC) cases in 2012, and controls matched on sex and age. All subjects were aged 65 to 95 years, of white race, and had attended ≥1 dermatologist visit in 2010-2011. Immune-related conditions were identified during 1999-2011 using Medicare claims. Associations were estimated with logistic regression, with statistical significance determined after Bonferroni correction for multiple comparisons.Results: We included 258,683 SCC and 304,903 BCC cases. Of 47 immune-related conditions, 21 and 9 were associated with increased SCC and BCC risk, respectively. We identified strongly elevated keratinocyte carcinoma risk with solid organ transplantation (SCC OR = 5.35; BCC OR = 1.94) and non-Hodgkin lymphoma (SCC OR = 1.62; BCC OR = 1.25). We identified associations with common conditions, e.g., rheumatoid arthritis [SCC OR = 1.06, 95% confidence interval (95% CI), 1.04-1.09] and Crohn's disease (SCC OR = 1.33, 95% CI, 1.27-1.39; BCC OR = 1.10, 95% CI, 1.05-1.15), and rare or poorly characterized conditions, e.g., granulomatosis with polyangiitis (SCC OR = 1.88; 95% CI, 1.61-2.19), autoimmune hepatitis (SCC OR = 1.81; 95% CI, 1.52-2.16), and deficiency of humoral immunity (SCC OR = 1.51, 95% CI, 1.41-1.61; BCC OR = 1.22, 95% CI, 1.14-1.31). Most conditions were more positively associated with SCC than BCC. Associations were generally consistent regardless of prior keratinocyte carcinoma history.Conclusions: Many immune-related conditions are associated with elevated keratinocyte carcinoma risk and appear more tightly linked to SCC.Impact: Immunosuppression or immunosuppressive treatment may increase keratinocyte carcinoma risk, particularly SCC. Cancer Epidemiol Biomarkers Prev; 26(7); 998-1007. ©2017 AACR.

Effect of rituximab on malignancy risk in patients with ANCA-associated vasculitis

OBJECTIVES

Patients with antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) treated with cyclophosphamide have an increased malignancy risk compared with the general population. We investigated whether treatment with rituximab instead of cyclophosphamide has decreased the malignancy risk in patients with AAV.

METHODS

The study included patients with AAV treated at a tertiary vasculitis referral centre between 2000 and 2014. The malignancy incidence in these patients was compared with the incidence in the general population by calculating standardised incidence ratios (SIRs), adjusted for sex, age and calendar year. Malignancy incidence was compared between rituximab-treated and cyclophosphamide-treated patients.

RESULTS

Of the 323 included patients, 33 developed a total of 45 malignancies during a mean follow-up of 5.6 years. This represented a 1.89-fold increased (95% CI 1.38 to 2.53) malignancy risk, and a non-significantly increased risk if non-melanoma skin cancer was excluded (SIR, 1.09; 95% CI 0.67 to 1.69). The risk of non-melanoma skin cancer was 4.58-fold increased (95% CI 2.96 to 6.76). Cyclophosphamide-treated patients had an increased malignancy risk compared with the general population (SIR, 3.10; 95% CI 2.06 to 4.48). In contrast, rituximab-treated patients had a malignancy risk similar to the general population (SIR, 0.67; 95% CI 0.08 to 2.43). The malignancy risk in cyclophosphamide-treated patients was 4.61-fold higher (95% CI 1.16 to 39.98) than in rituximab-treated patients.

CONCLUSIONS

The malignancy risk in patients with AAV was lower in rituximab-treated patients than in cyclophosphamide-treated patients. Notably, rituximab treatment was not associated with an increased malignancy risk compared with the general population. Rituximab could therefore be a safe alternative to cyclophosphamide in the treatment of AAV.

Nonmelanoma skin cancer risk awareness in azathioprine-treated myasthenia gravis patients

OBJECTIVES

Increased rates of NMSC (nonmelanoma skin cancer) have recently been reported in people with MG (myasthenia gravis) receiving azathioprine treatment. Guidelines on azathioprine for patients with dermatological and gastrointestinal disorders stress the importance of NMSC risk awareness and prevention. The aim of this study is to assess whether MG patients are being informed of this risk.

METHODS

Clinical records of patients with MG attending a university hospital neurology clinic were reviewed. Data on patient demographics, clinical presentation, diagnostic tests, azathioprine treatment, development of NMSC, and counseling regarding NMSC risk were recorded.

RESULTS

Sixty-nine MG cases were identified, median age 58 years (range 20-90). Forty-two (60.9%) had received azathioprine at some point with a mean cumulative dose of 235.5 g (range 9.1-972.8 g). Skin cancer risk and prevention advice provision was documented in 3 (7.1%) azathioprine-treated patients. Five patients developed histologically confirmed NMSC of whom all were treated with azathioprine (incidence rate of 24.9 per 1000, 16 times higher than expected). Documented advice on other safety issues such as regular blood test monitoring was found in 33 (78.8%) azathioprine-treated cases.

CONCLUSIONS

Preventative measures such as daily sunscreen use have been shown to reduce the incidence of NMSC in the general population. The results of this study demonstrate a very low rate of advice provision about NMSC risk in azathioprine-treated MG patients and the need for increased awareness among treating neurologists and patients.

Myasthenia gravis and risks for comorbidity

Myasthenia gravis (MG) is an autoimmune disorder leading to skeletal muscle weakness and fatigability. MG subgroups are defined according to pathogenetic autoantibody (against acetylcholine receptor, muscle-specific tyrosine kinase or lipoprotein receptor-related protein 4), thymus pathology and clinical manifestations. MG patients have an increased risk for concordant autoimmune disease, in particular with early onset MG. Most common comorbidities are thyroid disease, systemic lupus erythematosus and rheumatoid arthritis. Cardiomyositis and subclinical heart dysfunction have been described in patients with thymoma MG and late onset MG but represent no major threat. A thymic lymphoepithelioma implies an increased risk for another cancer. Autoimmune MG represents no distinct cancer risk factor, although lymphomas and a few other cancer types have been reported with slightly increased frequency. Severe MG-related muscle weakness means a risk for respiratory failure and respiratory tract infection. Drug MG treatment can lead to side-effects. Thymectomy is regarded as a safe procedure both short and long term. Non-MG-related comorbidity represents a diagnostic and therapeutic challenge, especially in elderly patients. Diagnostic accuracy and optimal follow-up is necessary to identify and treat all types of coexisting disease in MG.