The effect of everolimus on renal angiomyolipoma in pediatric patients with tuberous sclerosis being treated for subependymal giant cell astrocytoma

Tuberous Sclerosis Complex and the kidneys: what nephrologists need to know

Tuberous sclerosis complex (TSC) is an autosomal dominant disease characterized by the development of hamartomas in the central nervous system, heart, skin, lungs, and kidneys and other manifestations including seizures, cortical tubers, radial migration lines, autism and cognitive disability. The disease is associated with pathogenic variants in the TSC1 or TSC2 genes, resulting in the hyperactivation of the mTOR pathway, a key regulator of cell growth and metabolism. Consequently, the hyperactivation of the mTOR pathway leads to abnormal tissue proliferation and the development of solid tumors. Kidney involvement in TSC is characterized by the development of cystic lesions, renal cell carcinoma and renal angiomyolipomas, which may progress and cause pain, bleeding, and loss of kidney function. Over the past years, there has been a notable shift in the therapeutic approach to TSC, particularly in addressing renal manifestations. mTOR inhibitors have emerged as the primary therapeutic option, whereas surgical interventions like nephrectomy and embolization being reserved primarily for complications unresponsive to clinical treatment, such as severe renal hemorrhage. This review focuses on the main clinical characteristics of TSC, the mechanisms underlying kidney involvement, the recent advances in therapy for kidney lesions, and the future perspectives.

Clinical practice recommendations for kidney involvement in tuberous sclerosis complex: a consensus statement by the ERKNet Working Group for Autosomal Dominant Structural Kidney Disorders and the ERA Genes & Kidney Working Group

Tuberous sclerosis complex (TSC) is an autosomal dominant disorder characterized by the presence of proliferative lesions throughout the body. Management of TSC is challenging because patients have a multifaceted systemic illness with prominent neurological and developmental impact as well as potentially severe kidney, heart and lung phenotypes; however, every organ system can be involved. Adequate care for patients with TSC requires a coordinated effort involving a multidisciplinary team of clinicians and support staff. This clinical practice recommendation was developed by nephrologists, urologists, paediatric radiologists, interventional radiologists, geneticists, pathologists, and patient and family group representatives, with a focus on TSC-associated kidney manifestations. Careful monitoring of kidney function and assessment of kidney structural lesions by imaging enable early interventions that can preserve kidney function through targeted approaches. Here, we summarize the current evidence and present recommendations for the multidisciplinary management of kidney involvement in TSC.

Sirolimus can promote the disappearance of renal angiomyolipoma associated with tuberous sclerosis complex: a prospective cohort study

BACKGROUND

Renal angiomyolipoma (RAML) is the most common kidney lesion in patients with tuberous sclerosis complex (TSC), affecting about 80% of patients. It is a benign tumor that grows over time, usually bilaterally, and can easily lead to kidney complications such as acute hemorrhage. Herein, we investigated the efficacy and safety of sirolimus in children with TSC-associated RAML and explored the factors affecting tumor disappearance under sirolimus treatment through subgroup analysis.

METHODS

A prospective cohort study was conducted. Sirolimus was initiated at 1 mg/(m2 × day), and dose adjustments were made by a 2-week titration period to attain a trough blood concentration of 5-10 ng/mL. The disappearance of RAML in children after sirolimus treatment was observed, and Cox regression was used to screen the factors affecting tumor disappearance.

RESULTS

One hundred and twenty-six patients who met the criteria were analyzed. After 3 months, 6 months, 12 months, and 24 months of follow-up, tumors disappeared in 18 (14.3%), 30 (23.8%), 39 (31.0%), and 42 (33.3%) children, respectively. Tumors disappeared in 50 (39.7%) children by the last visit of each individual, and 30 (60%) of them occurred within 6 months. The multivariate Cox regression analysis showed that patients with a smaller maximum tumor diameter at baseline had a higher tumor disappearance rate. Thirty-six (29%) patients had stomatitis during the entire treatment period, and no serious adverse reactions were observed.

CONCLUSIONS

Sirolimus could promote the disappearance of TSC-related RAML. The disappearance rate was correlated with the maximum diameter at baseline, and the smaller the tumor was, the higher the disappearance rate. It is well tolerated in the treatment of RAML associated with TSC.

Clinical Practice Guidelines for tuberous sclerosis complex-associated renal angiomyolipoma by the Japanese Urological Association: Summary of the update

New clinical issues have been raised through an interval of 7 years from the previous version (2016). In this study, we update the "Clinical Practice Guidelines for tuberous sclerosis complex-associated renal angiomyolipoma" as a 2023 version under guidance by the Japanese Urological Association. The present guidelines were cooperatively prepared by the Japanese Urological Association and Japanese Society of Tuberous Sclerosis Complex; committee members belonging to one of the two societies or specializing in the treatment of this disease were selected to prepare the guidelines in accordance with the "Guidance for preparing treatment guidelines" published by Minds (2020 version). The "Introduction" consisted of four sections, "Background Questions (BQ)" consisted of four sections, "Clinical Questions (CQ)" consisted of three sections, and "Future Questions (FQ)" consisted of three sections (total: 14 sections). Concerning CQ, an agreement was confirmed through voting by the committee members based on the direction and strength of recommendation, accuracy of evidence, and recommendation comments. The present guidelines were updated based on the current evidence. We hope that the guidelines will provide guiding principles for the treatment of tuberous sclerosis complex-associated renal angiomyolipoma to many urologists, becoming a foundation for subsequent updating.

Recent Advances in Renal Tumors with TSC/mTOR Pathway Abnormalities in Patients with Tuberous Sclerosis Complex and in the Sporadic Setting

A spectrum of renal tumors associated with frequent TSC/mTOR (tuberous sclerosis complex/mechanistic target of rapamycin) pathway gene alterations (in both the germline and sporadic settings) have recently been described. These include renal cell carcinoma with fibromyomatous stroma (RCC FMS), eosinophilic solid and cystic renal cell carcinoma (ESC RCC), eosinophilic vacuolated tumor (EVT), and low-grade oncocytic tumor (LOT). Most of these entities have characteristic morphologic and immunohistochemical features that enable their recognition without the need for molecular studies. In this report, we summarize recent advances and discuss their evolving complexity.

Rapamycin and rapalogs for tuberous sclerosis complex

BACKGROUND

Potential benefits of rapamycin or rapalogs for treating people with tuberous sclerosis complex (TSC) have been shown. Currently everolimus (a rapalog) is only approved for TSC-associated renal angiomyolipoma and subependymal giant cell astrocytoma (SEGA), but not other manifestations of TSC. A systematic review needs to establish evidence for rapamycin or rapalogs for various manifestations in TSC. This is an updated review.

OBJECTIVES

To determine the effectiveness of rapamycin or rapalogs in people with TSC for decreasing tumour size and other manifestations and to assess the safety of rapamycin or rapalogs in relation to their adverse effects.

SEARCH METHODS

We identified relevant studies from the Cochrane-Central-Register-of-Controlled-Trials (CENTRAL), Ovid MEDLINE and ongoing trials registries with no language restrictions. We searched conference proceedings and abstract books of conferences. Date of the last searches: 15 July 2022.

SELECTION CRITERIA

Randomised controlled trials (RCTs) or quasi-RCTs of rapamycin or rapalogs in people with TSC.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted data and assessed the risk of bias of each study; a third review author verified the extracted data and risk of bias decisions. We assessed the certainty of the evidence using GRADE.

MAIN RESULTS

The current update added seven RCTs, bringing the total number to 10 RCTs (with 1008 participants aged 3 months to 65 years; 484 males). All TSC diagnoses were by consensus criteria as a minimum. In parallel studies, 645 participants received active interventions and 340 placebo. Evidence is low-to-high certainty and study quality is mixed; mostly a low risk of bias across domains, but one study had a high risk of performance bias (lack of blinding) and three studies had a high risk of attrition bias. Manufacturers of the investigational products supported eight studies. Systemic administration Six studies (703 participants) administered everolimus (rapalog) orally. More participants in the intervention arm reduced renal angiomyolipoma size by 50% (risk ratio (RR) 24.69, 95% confidence interval (CI) 3.51 to 173.41; P = 0.001; 2 studies, 162 participants, high-certainty evidence). In the intervention arm, more participants in the intervention arm reduced SEGA tumour size by 50% (RR 27.85, 95% CI 1.74 to 444.82; P = 0.02; 1 study; 117 participants; moderate-certainty evidence) ,and reported more skin responses (RR 5.78, 95% CI 2.30 to 14.52; P = 0.0002; 2 studies; 224 participants; high-certainty evidence). In one 18-week study (366 participants), the intervention led to 25% fewer seizures (RR 1.63, 95% CI 1.27 to 2.09; P = 0.0001) or 50% fewer seizures (RR 2.28, 95% CI 1.44 to 3.60; P = 0.0004); but there was no difference in numbers being seizure-free (RR 5.30, 95% CI 0.69 to 40.57; P = 0.11) (moderate-certainty evidence). One study (42 participants) showed no difference in neurocognitive, neuropsychiatry, behavioural, sensory and motor development (low-certainty evidence). Total adverse events (AEs) did not differ between groups (RR 1.09, 95% CI 0.97 to 1.22; P = 0.16; 5 studies; 680 participants; high-certainty evidence). However, the intervention group experienced more AEs resulting in withdrawal, interruption of treatment, or reduced dose (RR 2.61, 95% CI 1.58 to 4.33; P = 0.0002; 4 studies; 633 participants; high-certainty evidence and also reported more severe AEs (RR 2.35, 95% CI 0.99 to 5.58; P = 0.05; 2 studies; 413 participants; high-certainty evidence). Topical (skin) administration Four studies (305 participants) administered rapamycin topically. More participants in the intervention arm showed a response to skin lesions (RR 2.72, 95% CI 1.76 to 4.18; P < 0.00001; 2 studies; 187 participants; high-certainty evidence) and more participants in the placebo arm reported a deterioration of skin lesions (RR 0.27, 95% CI 0.15 to 0.49; 1 study; 164 participants; high-certainty evidence). More participants in the intervention arm responded to facial angiofibroma at one to three months (RR 28.74, 95% CI 1.78 to 463.19; P = 0.02) and three to six months (RR 39.39, 95% CI 2.48 to 626.00; P = 0.009; low-certainty evidence). Similar results were noted for cephalic plaques at one to three months (RR 10.93, 95% CI 0.64 to 186.08; P = 0.10) and three to six months (RR 7.38, 95% CI 1.01 to 53.83; P = 0.05; low-certainty evidence). More participants on placebo showed a deterioration of skin lesions (RR 0.27, 95% CI 0.15 to 0.49; P < 0.0001; 1 study; 164 participants; moderate-certainty evidence). The intervention arm reported a higher general improvement score (MD -1.01, 95% CI -1.68 to -0.34; P < 0.0001), but no difference specifically in the adult subgroup (MD -0.75, 95% CI -1.58 to 0.08; P = 0.08; 1 study; 36 participants; moderate-certainty evidence). Participants in the intervention arm reported higher satisfaction than with placebo (MD -0.92, 95% CI -1.79 to -0.05; P = 0.04; 1 study; 36 participants; low-certainty evidence), although again with no difference among adults (MD -0.25, 95% CI -1.52 to 1.02; P = 0.70; 1 study; 18 participants; low-certainty evidence). Groups did not differ in change in quality of life at six months (MD 0.30, 95% CI -1.01 to 1.61; P = 0.65; 1 study; 62 participants; low-certainty evidence). Treatment led to a higher risk of any AE compared to placebo (RR 1.72, 95% CI 1.10, 2.67; P = 0.02; 3 studies; 277 participants; moderate-certainty evidence); but no difference between groups in severe AEs (RR 0.78, 95% CI 0.19 to 3.15; P = 0.73; 1 study; 179 participants; moderate-certainty evidence).

AUTHORS' CONCLUSIONS

Oral everolimus reduces the size of SEGA and renal angiomyolipoma by 50%, reduces seizure frequency by 25% and 50% and implements beneficial effects on skin lesions with no difference in the total number of AEs compared to placebo; however, more participants in the treatment group required a dose reduction, interruption or withdrawal and marginally more experienced serious AEs compared to placebo. Topical rapamycin increases the response to skin lesions and facial angiofibroma, an improvement score, satisfaction and the risk of any AE, but not severe adverse events. With caution regarding the risk of severe AEs, this review supports oral everolimus for renal angiomyolipoma, SEGA, seizure, and skin lesions, and topical rapamycin for facial angiofibroma.

MicroRNA Expression Profile in TSC Cell Lines and the Impact of mTOR Inhibitor

The aim of this study was to assess the potential implication of microRNA on tuberous sclerosis (TSC) pathogenesis by performing microRNA profiling on cell lines silencing TSC1 or TSC2 genes using qPCR panels, before and after incubation with rapamycin. Significant differences in expression were observed between samples before and after rapamycin treatment in nineteen miRNAs in TSC1, five miRNAs in TSC2 and seven miRNAs in controls. Of miRNAs dysregulated before rapamycin treatment, three normalized after treatment in the TSC1 group (miR-21-3p, miR-433-3p, let-7g-3p) and one normalized in the TSC2 group (miR-1224-3p). Of the miRNAs dysregulated before rapamycin treatment in the TSC1 and TSC2 groups, two did not normalize after treatment (miR-33a-3p, miR-29a-3p). The results of the possible targets indicated that there are four common genes with seed regions susceptible to regulation by those miRNAs: ZBTB20, PHACTR2, PLXNC1 and ATP1B4. Our data show no changes in mRNA expression of these targets after rapamycin treatment. In conclusion, results of our study indicate the involvement of miRNA dysregulation in the pathogenesis of TSC. Some of the miRNA might be used as markers of treatment efficacy and autonomic miRNA as a target for future therapy.

Focal cortical dysplasia pathology: diagnostic difficulty, classification, and utility for pathogenesis

OBJECTIVE

In the histopathological examination of treatment-resistant epilepsy, focal cortical dysplasia (FCD) is the most common diagnosis in the pediatric group. FCD is classified histopathologically according to the International League Against Epilepsy (ILAE) classification. In the last decade since the ILAE classification has been released, molecular genetic studies have revealed mTOR pathway–related mutations as a major etiology. The objective of this study was to determine the incidence of FCD in treatment-resistant epilepsy patients, explore histomorphological and immunohistochemical features, examine clinicopathological correlation, demonstrate mTOR pathway activation using a pS6 antibody immunohistochemically, and try to introduce a candidate for possible targeted therapies.

METHODS

Paraffin blocks and slides of tissue from patients with treatment-resistant epilepsy were reexamined retrospectively. Histopathological subtypes of FCD were determined according to the ILAE classification. NeuN and neurofilament H (NF-H) staining were performed, and additionally a pS6 antibody was used to demonstrate mTOR pathway activation.

RESULTS

In 32 cases diagnosed with FCD, or 17.5% of 183 surgical epilepsy materials, there were no significant differences in the statistical analysis of clinical variables between the ILAE FCD subtypes. Recommended antibody NeuN revealed microcolumnar alignment in the FCD type Ia and IIIa groups and the loss of lamination in the type Ib group. Another recommended antibody, NF-H, was not found to be useful in discriminating between normal and dysmorphic neurons. pS6 expression, showing mTOR pathway activation, was observed in dysmorphic neurons and balloon cells in all FCD type II cases.

CONCLUSIONS

Significant pS6 expression in FCD type II represents the genomic nature of the disease noted in the literature. Nevertheless, the known MTOR gene and mTOR pathway–related mutations remain behind proportionally to explain the mTOR pathway activation in all FCD type II cases. Clinicopathologically and genetically integrated classification and usage of mTOR pathway inhibitors in treatment are expected as a recent evolution.

Perivascular epithelioid cell tumor of the lung: A case report and literature review

The perivascular epithelioid cell tumor (PEComa) is a rare tumor of interstitial origin characterized by several immunological and muscle cell markers. The clear cell sugar tumor (CCST) of the lung is a type of PEComa defined by thin cell walls and high levels of glycogen in the cytoplasm. We herein reported the case of a 48‐year‐old male with a recurrence of lung CCST. The preoperative diagnosis of the lung mass was performed by percutaneous needle biopsy. During the thoracoscopic resection, multiple adhesions in the thoracic cavity were described. The tumor invaded the chest wall, and the boundaries between the tumor and surrounding normal tissues were unclear. The mediastinal lymph nodes were significantly enlarged. No relevant gene mutations were detected. After concomitant chemoradiotherapy, the patient's condition was stable. We also conducted a literature review and discussed the overall findings.

mTOR Inhibitor Treatment in Patients with Tuberous Sclerosis Complex Is Associated with Specific Changes in microRNA Serum Profile

The aim of this study was to determine the serum profiles of miRNAs in patients with tuberous sclerosis (TSC) upon sirolimus treatment and compare them with those previously treated with everolimus in a similarly designed experiment. Serum microRNA profiling was performed in ten TSC patients before sirolimus therapy and again after 3–6 months using qPCR panels (Exiqon). Of 752 tested miRNAs, 28 showed significant differences in expression between TSC patients before and after sirolimus treatment. Of these, 11 miRNAs were dysregulated in the same directions as in the sirolimus groupcompared with the previously described everolimus group, miR-142-3p, miR-29c-3p, miR-150-5p, miR-425-5p, miR-376a-3p, miR-376a-3p, miR-532-3p, and miR-136-5p were upregulated, while miR-15b-3p, miR-100-5p, and miR-185-5p were downregulated. The most significant changes of expression, with fold changes exceeding 1.25 for both treatments, were noted for miR-136-5p, miR-376a-3p, and miR-150-5p. The results of a pathway analysis of the possible target genes for these miRNAs indicated the involvement of the Ras and MAPK signaling pathway. Upregulation of miR-136, miR-376a-3p, and miR-150-5p was noted in TSC patients treated with mTOR inhibitors, indicating a role in the downregulation of the mTOR pathway. Further studies are needed to determine the relationship between upregulated microRNAs and treatment efficacy.

Perfect match: mTOR inhibitors and tuberous sclerosis complex

Tuberous sclerosis complex (TSC) is an autosomal dominant syndrome that presents with diverse and complex clinical features and involves multiple human systems. TSC-related neurological abnormalities and organ dysfunction greatly affect the quality of life and can even result in death in patients with TSC. It is widely accepted that most TSC-related clinical manifestations are associated with hyperactivation of the mammalian target of rapamycin (mTOR) pathway caused by loss‑of‑function mutations in TSC1 or TSC2. Remarkable progress in basic and translational research has led to encouraging clinical advances. Although mTOR inhibitors (rapamycin/everolimus) demonstrate great potential in TSC management, two major concerns hamper their generalized application. One is the frequent manifestation of adverse events, such as stomatitis, infections, and menstrual disorders; and the other is the poor response in certain patients. Thus, indicators are required to effectively predict the efficacy of mTOR inhibitors. Herein, we have summarized the current utilization of mTOR inhibitors in the treatment of TSC and focused on their efficacy and safety, in an attempt to provide a reference to guide the treatment of TSC.

Hyperactivation of mammalian target of rapamycin (mTOR) is essential in the pathogenesis of tuberous sclerosis complex (TSC) and can serve as a therapeutic target.

mTOR inhibitors have shown considerable success in multiple clinical trials for the treatment of TSC, including neurological, pulmonary, cardiac, renal, and cutaneous phenotypes.

mTOR inhibitors are associated with adverse events, which should be considered during the management of TSC.

Indicators to predict mTOR inhibitor efficacy are required to select patients who are likely to benefit from such therapy.

Everolimus for the treatment of epithelioid hemangioma: a case report

Epithelioid hemangioma is a rare benign vascular tumor manifested as slow-growing subcutaneous or dermal nodules. A previously therapeutic strategy involved surgical excision and sclerotherapy. However, no standard treatment has been established. Here, we reported an atypical case of epithelioid hemangioma that had a locally aggressive behavior and was successfully treated with everolimus, a rapamycin analog used for cancer therapy. A 1-year-old boy presented with an ulcerated lump in the left palmar region. The imaging test results, confirmed through histopathologic examination, suggested a diagnosis of epithelioid hemangioma. Targeted therapy with everolimus was administered orally because of a minimal response to initial transarterial sclerotherapy. The patient achieved a satisfactory response with a significantly reduced lesion size and improved hand function after a 2-year follow-up. This finding showed that patients with locally aggressive forms of epithelioid hemangioma may significantly benefit from everolimus as a potential targeted therapy.

Renal tumors in tuberous sclerosis complex

Tuberous sclerosis complex (TSC) is a multisystem hereditary disorder characterized by the growth of benign tumors (hamartomas) in multiple organs, including the kidneys. Renal angiomyolipomas (AML) are a major diagnostic feature of TSC and are present in the majority of patients by adulthood. However, AML are usually asymptomatic during childhood when neurological and developmental manifestations are the main source of morbidity. Kidney manifestations of TSC have historically been the main cause of morbidity and mortality of adults with TSC. The recognition that the complications of TSC are caused by dysregulation of the mammalian target of rapamycin (mTOR) pathway has led to an enormous progress in the management of patients with TSC in the last two decades, the establishment of diagnostic guidelines, and trials which have shown the therapeutic benefit of mTOR inhibitors. Kidney surveillance of children with TSC now provides the opportunity for timely interventions to reduce the impact of TSC in adulthood. In this review, we discuss the current management of kidney tumors associated with TSC, including the diagnosis, surveillance, and treatment options for these lesions. We also present outcome data from international registries demonstrating the effectiveness of the current management strategies. With clear management guidelines and efficient treatment of kidney tumors, we envisage that the long-term outcomes of patients with TSC will further improve in the future.

Rare inherited kidney diseases: an evolving field in Nephrology

There are more than 150 different rare genetic kidney diseases. They can be classified according to diagnostic findings as (i) disorders of growth and structure, (ii) glomerular diseases, (iii) tubular, and (iv) metabolic diseases. In recent years, there has been a shift of paradigm in this field. Molecular testing has become more accessible, our understanding of the underlying pathophysiologic mechanisms of these diseases has evolved, and new therapeutic strategies have become more available. Therefore, the role of nephrologists has progressively shifted from a mere spectator to an active player, part of a multidisciplinary team in the diagnosis and treatment of these disorders. This article provides an overview of the recent advances in rare hereditary kidney disorders by discussing the genetic aspects, clinical manifestations, diagnostic, and therapeutic approaches of some of these disorders, named familial focal and segmental glomerulosclerosis, tuberous sclerosis complex, Fabry nephropathy, and MYH-9 related disorder.

The paradox of autophagy in Tuberous Sclerosis Complex

Tuberous sclerosis complex (TSC) is an autosomal dominant genetic disorder caused by germline mutations in TSC1 or TSC2 genes, which leads to the hyperactivation of the mTORC1 pathway, an important negative regulator of autophagy. This leads to the development of hamartomas in multiple organs. The variability in symptoms presents a challenge for the development of completely effective treatments for TSC. One option is the treatment with mTORC1 inhibitors, which are targeted to block cell growth and restore autophagy. However, the therapeutic effect of rapamycin seems to be more efficient in the early stages of hamartoma development, an effect that seems to be associated with the paradoxical role of autophagy in tumor establishment. Under normal conditions, autophagy is directly inhibited by mTORC1. In situations of bioenergetics stress, mTORC1 releases the Ulk1 complex and initiates the autophagy process. In this way, autophagy promotes the survival of established tumors by supplying metabolic precursors during nutrient deprivation; paradoxically, excessive autophagy has been associated with cell death in some situations. In spite of its paradoxical role, autophagy is an alternative therapeutic strategy that could be explored in TSC. This review compiles the findings related to autophagy and the new therapeutic strategies targeting this pathway in TSC.

The metformin in tuberous sclerosis (MiTS) study: A randomised double-blind placebo-controlled trial

BACKGROUND

Tuberous Sclerosis Complex (TSC) is a genetic disorder characterised by the development of benign tumours secondary to loss of inhibitory regulation of the mTOR (mechanistic Target of Rapamycin) intracellular growth pathway. Metformin inhibits the mTOR pathway. We investigated whether metformin would reduce growth of hamartomas associated with tuberous sclerosis complex.

METHODS

In this multicentre randomized, double-blind, placebo-controlled trial, patients with a clinical diagnosis of tuberous sclerosis, aged over 10 years and with at least one renal angiomyolipoma of greater than 1 cm in diameter were enrolled. Participants were randomly allocated (1:1) by a secure website to receive metformin or placebo for 12 months. The primary outcome was percentage volume change of renal angiomyolipomas (AML) at 12 months compared to baseline. Secondary outcomes were percentage change at 12 months from baseline in volume of cerebral Subependymal Giant Cell Astrocytomas (SEGA); appearance of facial and ungual hamartomas; frequency of epileptic seizures; and adaptive behaviour. The trial is registered with The International Standard Randomised Controlled Trial Number (ISRCTN), number 92545532, and the European Union Drug Regulating Authorities Clinical Trials (EUDRACT), number 2011-001319-30.

FINDINGS

Between 1 November 2012 and 30 September 2015 72 patients were screened and 55 were randomly assigned to metformin (28) or placebo (27). Four participants withdrew between randomisation and starting treatment. All 51 patients who started therapy completed the trial and were assessed for outcome at 12 months. The median percentage change in angiomyolipoma (AML) volume was +7.6% (IQR -1.8% to +42.6%) for the placebo group and +8.9% (IQR 1.3% to 19.5%) for the metformin group (p = 0.28). Twenty-seven patients had SEGAs: 13 received placebo and 14 metformin. The median percentage change in SEGA volume was +3.0% (IQR -22.8% to +27.7%) for the placebo group and - 20.8% (IQR - 47.1% to - 5.0%) for the metformin group (p = 0.03). Twenty-one patients were assessed for seizure frequency: 9 received placebo and 12 received metformin. In the metformin group, a mean reduction of 43.7% from baseline in seizures was observed and in the placebo group a 3.1% mean reduction was observed, with a difference in response of 40.6% (95% CI -3.1% to +84.2%, p = 0.03). There were no significant differences between metformin and placebo groups for the other secondary outcomes. There were no deaths. Three serious adverse events (SAEs) occurred during the trial (all patients on metformin).

INTERPRETATION

Metformin did not reduce AML volume. Metformin did reduce SEGA volume and seizure frequency compared with placebo. There may be a role for metformin in slowing or reversing growth of some life-threatening hamartomas in TSC and for reducing seizure frequency. Further study is justified.

FUNDING

This study was funded by the National Institute for Health and Research (NIHR) through the The Research for Patient Benefit Programme (RfPB).

Fate of Pediatric Renal Angiomyolipoma During mTOR Inhibitor Treatment in Tuberous Sclerosis Complex

OBJECTIVE

To evaluate the clinical and radiographic follow-up of renal angiomyolipoma (AML) in pediatric patients with tuberous sclerosis complex (TSC) on mTOR inhibitors.

METHODS

We performed retrospective chart review of children who were diagnosed with TSC between 2000 and 2019 and prescribed everolimus at age ≤18 years. Treatment assessment was performed in patients who were medically-compliant by serum drug trough levels and who had at least a baseline and one subsequent renal imaging study.

RESULTS

Nineteen patients were analyzed. Average age of everolimus initiation was 9 years, and indication was neurologic in 17 (90%). Fourteen patients (73.6%) had AML with average size of 1.9 (0.4-5) cm. Medication was discontinued due to side effects in 3 (16%) patients. Treatment assessment was analyzed for 15 patients with median medication exposure 5.1 (0.8-8.5) years. Among 13 with AML, the dominant lesion decreased in size in 9 (69%) and stayed stable in 4 (31%). Greatest absolute size decrease was seen for lesions ≥2 cm. No new AML lesions formed during treatment.

CONCLUSION

Although not currently approved for this indication, everolimus appears to be well-tolerated with similar efficacy for pediatric AML as in adult AML. Use may be most warranted in children with AML ≥2 cm.

A Review of Investigations for Patients With Tuberous Sclerosis Complex Who Were Referred to the Tuberous Sclerosis Clinic at The Hospital for Sick Children: Identifying Gaps in Surveillance

OBJECTIVE

As a newly established tuberous sclerosis clinic (TSC) clinic at The Hospital for Sick Children, we reviewed our referrals to determine if children with TSC received appropriate surveillance as advised by the 2012 International Tuberous Sclerosis Complex Consensus Recommendations.

METHODS

We completed a retrospective review of all patients seen in the TSC clinic from January 2016 to December 2017 to determine if children referred to the clinic had appropriate surveillance as suggested by the Tuberous Sclerosis Complex Consensus Recommendations.

RESULTS

Ninety patients were seen in the TSC clinic. The median age at first visit was 9.9 years, and 47 were males. Seventy-six percent had undergone genetic testing before the initial clinic visit; however, genetic counseling was completed in only 66%. Brain magnetic resonance imaging was completed in 94%, abdominal imaging was completed in 91%, and an echocardiography and electrocardiography in 88% and 83%, respectively. In addition, dermatology and ophthalmology evaluations were completed in 78% and 91%, respectively. Assessment of TSC-associated neuropsychiatric disorders (TAND) was only completed in 4% of the patients.

CONCLUSIONS

Systems surveillance was completed in the majority before the first TSC clinic visit. However, TSC-associated neuropsychiatric disorder screening was completed in few cases. This suggests that referring physicians may not be familiar with the neuropsychiatric manifestations of TSC and that there may be underdiagnosed or undertreated illness. Future emphasis should be placed on educating all practitioners to assess and treat tuberous sclerosis complex-associated neuropsychiatric disorder in tuberous sclerosis complex.

The UK guidelines for management and surveillance of Tuberous Sclerosis Complex

BACKGROUND

The severity of Tuberous Sclerosis Complex (TSC) can vary among affected individuals. Complications of TSC can be life threatening, with significant impact on patients' quality of life. Management may vary dependent on treating physician, local and national policies, and funding. There are no current UK guidelines. We conducted a Delphi consensus process to reach agreed guidance for the management of patients with TSC in the UK.

METHODS

We performed a literature search and reviewed the 2012/13 international guideline for TSC management. Based on these, a Delphi questionnaire was formed. We invited 86 clinicians and medical researchers to complete an online survey in two rounds. All the people surveyed were based in the UK. Clinicians were identified through the regional TSC clinics, and researchers were identified through publications. In round one, 55 questions were asked. In round two, 18 questions were asked in order to obtain consensus on the outstanding points that had been contentious in round one. The data was analysed by a core committee and subcommittees, which consisted of UK experts in different aspects of TSC. The Tuberous Sclerosis Association was consulted.

RESULTS

About 51 TSC experts took part in this survey. Two rounds were required to achieve consensus. The responders were neurologists, nephrologists, psychiatrist, psychologists, oncologists, general paediatricians, dermatologist, urologists, radiologists, clinical geneticists, neurosurgeons, respiratory and neurodisability clinicians.

CONCLUSIONS

These new UK guidelines for the management and surveillance of TSC patients provide consensus guidance for delivery of best clinical care to individuals with TSC in the UK.

Continuous low-dose everolimus shrinkage tuberous sclerosis complex-associated renal angiomyolipoma: a 48-month follow-up study

Tuberous sclerosis complex (TSC) is a rare disease that causes multisystem benign neoplasm, induced by dysregulation of the mammalian target of the rapamycin pathway (mTOR). This study aimed to examine the effects of continuous low-dose everolimus, a potent and selective inhibitor of mTOR, on the treatment of TSC-associated renal angiomyolipoma (AML). Between July 2013 and August 2017, 11 patients with TSC-AML were enrolled for an everolimus therapy protocol. An oral everolimus dose starting at 2.5 mg daily was gradually increased to 5.0 mg daily. All patients were evaluated using MRI or CT scanning at baseline, 12, 24, 36 and 48 months after the start of treatment for measuring changes of renal AML mass volume. Everolimus therapy resulted in significant shrinkage of TSC-AML volume after 48 months follow-up. Serum levels of everolimus were subdivided into group I (<8 ng/mL, n=6) and group II (>8 ng/mL, n=5). The volume reduction rates were 10.6%-65.2% in group I and 42.5%-70.6% in group II. To evaluate the response to treatment, three of six (50%) were responders in group I, and all the patients in group II (5/5, 100%) were responders. The differences in AML volume reduction between the groups were statistically significant at 12 months (p=0.011), 24 months (p=0006), 36 months (p=0.014) and 48 months (p=0.05). These results suggest that continuous low-dose everolimus therapy (2.5-5 mg daily) might be effective in shrinking TSC-AML volume and minimizes adverse effects and subsequent reducing medical costs.

Establishment of a Regional Interdisciplinary Medical System for Managing Patients with Tuberous Sclerosis Complex (TSC)

Tuberous sclerosis complex (TSC) is an autosomal dominant inherited disease characterized by lesions that involve multiple organs. Interdisciplinary management at individual facilities needs to be coordinated to treat multiple organ systems. We hypothesized that the number of patients, opportunities for patients to undergo examinations, and opportunities for patients to be treated would increase after establishment of a TSC board (TB) in our hospital. From August 1979 to August 2017, 76 patients were studied. We established the TB in our hospital in 2014. We divided the patients into the pre-TB group and post-TB group. Patients consisted of 33 females and 43 males (mean age, 18.7 years; median age, 15 years). The follow-up period was 2 to 457 months (mean, 51.6 months; median, 24.5 months). Twenty-four patients were in the pre-TB group, and 52 were in the post-TB group. Regular follow-up (p < 0.001), younger age (p = 0.002), opportunities for patients to undergo examinations, opportunities for patients to receive neurological treatment (p < 0.001), and mammalian target of rapamycin (mTOR) inhibitor usage (p = 0.041) were significantly higher in the post-TB group. The radial relationship around the axis of TSC coordinators may be the key to interdisciplinary management of TSC.

Renal progression factors in young patients with tuberous sclerosis complex: a retrospective cohort study

BACKGROUND

Renal pathology in tuberous sclerosis complex (TSC) is characterized by the growth of angiomyolipoma and renal cysts, and in rare cases renal cell carcinoma. Other consequences of renal involvement in TSC, including hypertension, proteinuria, and hyperfiltration, are not well studied. We aimed to analyze the early manifestations of the renal TSC phenotype in a young TSC cohort and to explore common, modifiable risk factors.

METHODS

In this retrospective cohort study, TSC patients attending the TSC clinics of two tertiary hospitals were included. Data on demographics, history, genotype, kidney function, hematuria, proteinuria, blood pressure, and renal imaging were collected.

RESULTS

Eighty patients were included, with a median age of 0.8 years (0.0-63.0) at first presentation, and a median follow-up time of 10.2 (0.4-41.0) years. Mutation analysis was available in 64 patients (80%). Renal lesions (cysts or angiomyolipoma) were observed in 55/73 (75%). Thirty-two percent (19/60) were hypertensive, 8/51 (16%) had proteinuria, and 18/71 (25%) had hyperfiltration (median eGFR 154 ml/min/m²). Six (7.5%) patients had developed end stage renal disease at the last follow-up. No association was found between hyperfiltration, hypertension, or proteinuria and CKD ≥ 3. Cox regression showed a significant positive association between the presence of a renal intervention and CKD ≥ 3 (Hazard-Ratio 3.91, P < 0.05).

CONCLUSIONS

Besides renal cysts and angiomyolipoma, the modifiable progression factors hypertension, proteinuria, and hyperfiltration occur frequently and early in TSC patients. This represents a preventive treatment target.

Renal manifestation of tuberous sclerosis complex

Tuberous sclerosis complex (TSC) is a tumor predisposition syndrome with significant renal cystic and solid tumor disease. It commonly causes several types of cystic disease and benign tumors (angiomyolipomata) in the kidneys that can both lead to significant premature loss of glomerular filtration rate. The main risks of angiomyolipomata, severe bleeding, loss of renal function, and pulmonary lymphangioleiomyomatosis, can be ameliorated by active surveillance and preemptive therapy with mTOR inhibitors. The cystogenic mechanism may involve primary cilia, but also appears to also involve a majority of normal tubular cells and may be driven by a minority of cells with mutations inactivating both their TSC1 or TSC2 genes. Malignant tumors are rare.

mTOR Signaling and Neural Stem Cells: The Tuberous Sclerosis Complex Model

The mechanistic target of rapamycin (mTOR), a serine-threonine kinase, plays a pivotal role in regulating cell growth and proliferation. Notably, a great deal of evidence indicates that mTOR signaling is also crucial in controlling proliferation and differentiation of several stem cell compartments. Consequently, dysregulation of the mTOR pathway is often associated with a variety of disease, such as cancer and metabolic and genetic disorders. For instance, hyperactivation of mTORC1 in neural stem cells (NSCs) is associated with the insurgence of neurological manifestation characterizing tuberous sclerosis complex (TSC). In this review, we survey the recent contributions of TSC physiopathology studies to understand the role of mTOR signaling in both neurogenesis and tumorigenesis and discuss how these new insights can contribute to developing new therapeutic strategies for neurological diseases and cancer.