Brain tumors in patients with myotonic dystrophy: a population-based study

[Dystrophia myotonica Type 1 associated with glioblastoma: a case report]

This case involved a 65-year-old woman, who had been suffered from weakness in both legs for 10 years. She had not been diagnosed of dystrophia myotonica type 1 (DM1) despite her son's diagnosis of DM and her distinct facial features and gait anomaly. During her son's recent clinical visit, she was finally suspected of having DM. She was sent to our institution, where a distinct muscle atrophy and grip myotonia were observed and a genetical examination was performed. The sequencing data confirmed her diagnosis of DM1 due to the distinct 230-900 CTG repeats found in the dystrophia myotonica protein kinase gene 3' untranslated region. A brain MRI revealed an abnormal lesion with irregular ring-enhancement at the right temporal lobe. Because of the steady growth of the lesion during one month observation, a surgical intervention was performed in our institution. The histopathological examination gave a diagnosis of glioblastoma multiforme (GBM). The clinical management of the patient required special cares during the perioperative periods due to the distinct pathological manifestation of DM. The risk of developing cancer in DM patients has been estimated about twice as much as general population. Since GBM developed in the DM patient is rarely reported, we present this rare case with a few insights: the difficulties of the clinical management of DM patients under the perioperative stress; the pathological contribution of DM to the malignant transformation of the glial cells.

Cerebral involvement and related aspects in myotonic dystrophy type 2

Myotonic dystrophy type 2 (DM2) is an autosomal dominant multisystemic disorder caused by CCTG repeats expansion in the first intron of the CNBP gene. In this review we focus on the brain involvement in DM2, including its pathogenic mechanisms, microstructural, macrostructural and functional brain changes, as well as the effects of all these impairments on patients' everyday life. We also try to understand how brain abnormalities in DM2 should be adequately measured and potentially treated. The most important pathogenetic mechanisms in DM2 are RNA gain-of-function and repeat-associated non-ATG (RAN) translation. One of the main neuroimaging findings in DM2 is the presence of diffuse periventricular white matter hyperintensity lesions (WMHLs). Brain atrophy has been described in DM2 patients, but it is not clear if it is mostly caused by a decrease of the white or gray matter volume. The most commonly reported specific cognitive symptoms in DM2 are dysexecutive syndrome, visuospatial and memory impairments. Fatigue, sleep-related disorders and pain are also frequent in DM2. The majority of key symptoms and signs in DM2 has a great influence on patients' daily lives, their psychological status, economic situation and quality of life.

Cancer phenotype in myotonic dystrophy patients: Results from a meta-analysis

INTRODUCTION

Recent studies have provided evidence that patients with myotonic dystrophy (DM) are at excess risk of cancer. However, inconsistencies regarding affected anatomic sites persist.

METHODS

We performed a meta-analysis of cancer risk in DM, searching among studies published between January 1, 1990 and December 31, 2016. Eligible studies were full reports of DM cohorts with site-specific risks.

RESULTS

The analysis included 5 studies, comprising 2,779 patients. Risk estimates for cancers of the endometrium and cutaneous melanoma were reported in all studies. The pooled standardized incidence ratio (pSIRs) for endometrial cancer was 7.48 (95% confidence interval [CI] 4.72-11.8) and for cutaneous melanoma was 2.45 (95% CI 1.31-4.58). Among cancers reported in 4 of 5 studies, elevated risks were observed for thyroid (pSIR = 8.52, 95% CI 3.62-20.1), ovarian (pSIR = 5.56, 95% CI 2.99-10.3), testicular (pSIR = 5.95, 95% CI 2.34-15.1), and colorectal (pSIR = 2.2, 95% CI 1.39-3.49) cancers.

DISCUSSION

Our data refine the DM cancer phenotype, which may guide patient clinical management and inform plans for molecular investigations to understand DM-related carcinogenesis. Muscle Nerve 58: 517-522, 2018.

Systematic thyroid screening in myotonic dystrophy: link between thyroid volume and insulin resistance

Background

Myotonic dystrophy (DM1), a neuromuscular disease related to DMPK gene mutations, is associated to endocrine disorders and cancer. A routine endocrine work-up, including thyroid ultrasound (US), was conducted in 115 genetically-proven DM1 patients in a neuromuscular reference center. The aim of this study was to determine the prevalence and the causes of US thyroid abnormalities in DM1.

Results

In the whole population (age 45.1 ± 12.2 years, 61.7% female), palpable nodules or goiters were present in 29.2%. The percentage of US goiter (thyroid volume > 18 mL) and US nodules were, respectively, 38.3 and 60.9%. Sixteen of the 115 patients had a thyroidectomy, after 22 fine-needle aspiration cytology guided by thyroid imaging reporting and data system (TIRADS) classification. Six micro- (1/6 pT3) and 3 macro-papillary thyroid carcinoma (PTCs) (2/3 intermediate risk) were diagnosed (7.9% of 115). Thyroid US led to the diagnosis of 4 multifocal and 2 unifocal (including 1 macro-PTC) non-palpable PTCs. Ultrasound thyroid volume was positively correlated to body mass index (BMI) (p = 0.015) and parity (p = 0.036), and was inversely correlated to TSH (p < 0.001) and vitamin D levels (p = 0.023). The BMI, the frequencies of glucose intolerance and PTC were significantly higher in UsGoiter versus non-UsGoiter groups.

Conclusion

In this systematically screened DM1 cohort, the frequency of UsGoiter, mainly associated to BMI, was about 40%, US nodules 60%, thyroidectomies 13–14%, and PTCs 8%, two-thirds of them being micro-PTCs with good prognosis. Therefore, a systematic screening remains debatable. A targeted US screening in case of clinical abnormality or high BMI seems more appropriate.

Electronic supplementary material

The online version of this article (10.1186/s13023-019-1019-3) contains supplementary material, which is available to authorized users.

Cancer Risk in Myotonic Dystrophy Type I: Evidence of a Role for Disease Severity

Background

Myotonic dystrophy type 1 (DM1) is an inherited trinucleotide repeat disorder in which specific cancers have been implicated as part of the disease phenotype. This study aimed to assess whether cancer risk in DM1 patients is modified by disease severity.

Methods

Using the United Kingdom Clinical Practice Research Datalink (primary care electronic medical records), we identified a cohort of 927 DM1 and a matched cohort of 13 085 DM1-free individuals between January 1, 1988 and February 29, 2016. We used Cox regression models to calculate the hazard ratios (HRs) and 95% confidence intervals (CIs) of organ-specific cancer risks. Analyses were stratified by age at DM1 diagnosis as a surrogate for disease severity. Statistical tests were two-sided.

Results

Patients with classic DM1 (age at diagnosis: 11-40 years) were at elevated risk of cancer overall (HR = 1.81; 95% CI = 1.12 to 2.93); cancers of the thyroid (HR = 15.93; 95% CI = 2.45 to 103.64), uterus (HR = 26.76; 95% CI = 2.32 to 309.26), and cutaneous melanoma (HR = 5.98; 95% CI = 1.24 to 28.79) accounted for the excess. In late-onset DM1 patients (age at diagnosis >40 years), a reduced overall cancer risk was observed (HR = 0.53; 95% CI = 0.32 to 0.85), possibly driven by the deficit in hematological malignancies (DM1 = 0 cases, DM1-free = 54 cases; P = .02). The difference between the observed HR for classic and late-onset DM1 was statistically significant (P < .001).

Conclusions

The observed difference in relative cancer risk between classic and late-onset DM1 patients compared with their DM1-free counterparts provides the first evidence that disease severity modifies DM1-related cancer susceptibility. This novel finding may guide clinical management and scientific investigations for the underlying molecular mechanisms in DM-related carcinogenesis.

Survival patterns and cancer determinants in families with myotonic dystrophy type 1

BACKGROUND AND PURPOSE

Research indicates that patients with myotonic dystrophy type 1 (DM1) are at increased risk of cancer and early death. Family data may provide insights given DM1 phenotypic heterogeneity, the broad range of non-muscular manifestations and the usual delays in the diagnosis of DM1.

METHOD

Family history data were collected from 397 genetically and/or clinically confirmed DM1 patients (respondents) enrolled in the US or UK myotonic dystrophy registries. Standardized mortality ratios were calculated for DM1 first-degree relatives (parents, siblings and offspring) by their reported DM1 status (affected, unaffected or unknown). For cancer-related analyses, mixed effects logistic regression models were used to evaluate factors associated with cancer development in DM1 families, including familial clustering.

RESULTS

A total of 467 deaths and 337 cancers were reported amongst 1737 first-degree DM1 relatives. Mortality risk amongst relatives reported as DM1-unaffected was comparable to that of the general population [standardized mortality ratio (SMR) 0.82, P = 0.06], whilst significantly higher mortality risks were noted in DM1-affected relatives (SMR = 2.47, P < 0.0001) and in those whose DM1 status was unknown (SMR = 1.60, P < 0.0001). In cancer risk analyses, risk was higher amongst families in which the DM1 respondent had cancer (odds ratio 1.95, P = 0.0001). Unknown DM1 status in the siblings (odds ratio 2.59, P = 0.004) was associated with higher cancer risk.

CONCLUSION

There is an increased risk of death, and probably cancer, in relatives with DM1 and in those whose DM1 status is unknown. This suggests a need to perform a careful history and physical examination, supplemented by genetic testing, to identify family members at risk for DM1 and who might benefit from disease-specific clinical care and surveillance.

Health economic evaluation of a serum-based blood test for brain tumour diagnosis: exploration of two clinical scenarios

OBJECTIVES

To determine the potential costs and health benefits of a serum-based spectroscopic triage tool for brain tumours, which could be developed to reduce diagnostic delays in the current clinical pathway.

DESIGN

A model-based health pre-trial economic assessment. Decision tree models were constructed based on simplified diagnostic pathways. Models were populated with parameters identified from rapid reviews of the literature and clinical expert opinion.

SETTING

Explored as a test in both primary and secondary care (neuroimaging) in the UK health service, as well as application to the USA.

PARTICIPANTS

Calculations based on an initial cohort of 10 000 patients. In primary care, it is estimated that the volume of tests would approach 75 000 per annum. The volume of tests in secondary care is estimated at 53 000 per annum.

MAIN OUTCOME MEASURES

The primary outcome measure was quality-adjusted life-years (QALY), which were employed to derive incremental cost-effectiveness ratios (ICER) in a cost-effectiveness analysis.

RESULTS

Results indicate that using a blood-based spectroscopic test in both scenarios has the potential to be highly cost-effective in a health technology assessment agency decision-making process, as ICERs were well below standard threshold values of £20 000-£30 000 per QALY. This test may be cost-effective in both scenarios with test sensitivities and specificities as low as 80%; however, the price of the test would need to be lower (less than approximately £40).

CONCLUSION

Use of this test as triage tool in primary care has the potential to be both more effective and cost saving for the health service. In secondary care, this test would also be deemed more effective than the current diagnostic pathway.

Risk of skin cancer among patients with myotonic dystrophy type 1 based on primary care physician data from the U.K. Clinical Practice Research Datalink

Myotonic dystrophy type 1 (DM1) is an inherited multisystem neuromuscular disorder caused by a CTG trinucleotide repeat expansion in the DMPK gene. Recent evidence documents that DM1 patients have an increased risk of certain cancers, but whether skin cancer risks are elevated is unclear. Using the U.K. Clinical Practice Research Datalink (CPRD), we identified 1,061 DM1 patients and 15,119 DM1-free individuals matched on gender, birth year (±2 years), attending practice and registration year (±1 year). We calculated the hazard ratios (HRs) and 95% confidence intervals (CIs) for the association of DM1 diagnosis with skin cancer risk using Cox proportional hazards models, for all skin cancers combined and by histological subtype. Follow-up started at the latest of the age at practice registration, DM1 diagnosis/control selection or January 1st 1988, and ended at the earliest of the age at first skin cancer diagnosis, death, transfer out of the practice, last date of data collection or the end of the CPRD record (October 31, 2016). During a median follow-up of 3.6 years, 35 DM1 patients and 108 matched DM1-free individuals developed a skin cancer. DM1 patients had an increased risk of skin cancer overall (HR = 5.44, 95% CI = 3.33-8.89, p < 0.0001), and basal cell carcinoma (BCC) (HR = 5.78, 95% CI = 3.36-9.92, p < 0.0001). Risks did not differ by gender, or age at DM1 diagnosis (p-heterogeneity > 0.5). Our data confirm suggested associations between DM1 and skin neoplasms with the highest risk seen for BCC. Patients are advised to minimize ultraviolet light exposure and seek medical advice for suspicious lesions.

Imaging of the thymus in myotonic dystrophy type 1

The occurrence of thymoma in myotonic dystrophy type 1 (DM1) has been occasionally reported, and an increased risk of tumors has been observed. We performed imaging of the thymus in 22 patients carrying DMPK expansion. Clinical examination and routine instrumental exams were performed at the same time. We observed no thymic abnormalities in 13 subjects, thymic hyperplasia in eight patients, and an invasive thymoma in one case. Subjects with thymic abnormalities did not show peculiarities as regards clinical and electrophysiological features. We observed thymoma in one patient with an expansion in the higher range. Abnormalities of the thymus including hyperplasia and thymoma can be present in DM1, but do not seem to play a major role in DM1 pathogenesis. Further studies are needed to understand if some RNA splicing factors involved in DM1 and influenced by CTG expansion size could have a role in thymocytes proliferation.

Pigmentation phenotype, photosensitivity and skin neoplasms in patients with myotonic dystrophy

BACKGROUND AND PURPOSE

Recent studies have suggested a possible excess risk of skin neoplasms in patients with myotonic dystrophy (DM). Risk factors related to this observation have not been defined.

METHOD

Information regarding personal history of skin tumors, pigmentation phenotype, and skin reaction to sun exposure were collected from 266 DM patients who were enrolled in the US National Institutes of Health National Registry of Myotonic Dystrophy and Facioscapulohumeral Muscular Dystrophy Patients and Family Members.

RESULTS

Seventy-seven subjects reported having skin tumors that were either benign (n = 31), malignant (n = 32) or both (n = 14). Female gender [odds ratio (OR) = 2.27, 95% confidence interval (CI) 1.02-5.05, P = 0.04], older age (OR = 1.10, 95% CI 1.05-1.16, P < 0.001) and DM1 subtype (OR = 3.42, 95% CI 1.27-9.26, P = 0.02) were associated with a malignant skin tumor. The associations between malignant skin tumors and known risk factors [light eye color (OR = 1.62, 95% CI 0.78-3.39, P = 0.20), light skin complexion (OR = 1.31, 95% CI 0.63-2.73, P = 0.48) and moderate/extensive face freckles (OR = 1.47, 95% CI 0.50-4.34, P = 0.49)] were modest. Strong, but not statistically significant, associations were noted with sunburn reactions when exposed to sunlight (OR = 4.28, 95% CI 0.91-19.95, P = 0.06, and OR = 2.19, 95% CI 0.67-7.09, P = 0.19, for sunburn with and without blistering, respectively).

CONCLUSIONS

Although our study was limited by small sample size, the risk factors for malignant skin tumors in DM strongly resemble the general population. It is recommended that DM patients adhere to sun exposure protective behavior.

Myotonic Dystrophies: State of the Art of New Therapeutic Developments for the CNS

Myotonic dystrophies are multisystemic diseases characterized not only by muscle and heart dysfunction but also by CNS alteration. They are now recognized as brain diseases affecting newborns and children for myotonic dystrophy type 1 and adults for both myotonic dystrophy type 1 and type 2. In the past two decades, much progress has been made in understanding the mechanisms underlying the DM symptoms allowing development of new molecular therapeutic tools with the ultimate aim of curing the disease. This review describes the state of the art for the characterization of CNS related symptoms, the development of molecular strategies to target the CNS as well as the available tools for screening and testing new possible treatments.