Urea Cycle Dysregulation Generates Clinically Relevant Genomic and Biochemical Signatures.

The urea cycle (UC) is the main pathway by which mammals dispose of waste nitrogen. We find that specific alterations in the expression of most UC enzymes occur in many tumors, leading to a general metabolic hallmark termed "UC dysregulation" (UCD). UCD elicits nitrogen diversion toward carbamoyl-phosphate synthetase2, aspartate transcarbamylase, and dihydrooratase (CAD) activation and enhances pyrimidine synthesis, resulting in detectable changes in nitrogen metabolites in both patient tumors and their bio-fluids. The accompanying excess of pyrimidine versus purine nucleotides results in a genomic signature consisting of transversion mutations at the DNA, RNA, and protein levels. This mutational bias is associated with increased numbers of hydrophobic tumor antigens and a better response to immune checkpoint inhibitors independent of mutational load. Taken together, our findings demonstrate that UCD is a common feature of tumors that profoundly affects carcinogenesis, mutagenesis, and immunotherapy response.

De novo loss-of-function KCNMA1 variants are associated with a new multiple malformation syndrome and a broad spectrum of developmental and neurological phenotypes.

KCNMA1 encodes the large-conductance Ca2+- and voltage-activated K+ (BK) potassium channel α-subunit, and pathogenic gain-of-function variants in this gene have been associated with a dominant form of generalized epilepsy and paroxysmal dyskinesia. Here, we genetically and functionally characterize eight novel loss-of-function (LoF) variants of KCNMA1. Genome or exome sequencing and the participation in the international Matchmaker Exchange effort allowed for the identification of novel KCNMA1 variants. Patch clamping was used to assess functionality of mutant BK channels. The KCNMA1 variants p.(Ser351Tyr), p.(Gly356Arg), p.(Gly375Arg), p.(Asn449fs) and p.(Ile663Val) abolished the BK current, whereas p.(Cys413Tyr) and p.(Pro805Leu) reduced the BK current amplitude and shifted the activation curves toward positive potentials. The p.(Asp984Asn) variant reduced the current amplitude without affecting kinetics. A phenotypic analysis of the patients carrying the recurrent p.(Gly375Arg) de novo missense LoF variant revealed a novel syndromic neurodevelopmental disorder associated with severe developmental delay, visceral and cardiac malformations, connective tissue presentations with arterial involvement, bone dysplasia and characteristic dysmorphic features. Patients with other LoF variants presented with neurological and developmental symptoms including developmental delay, intellectual disability, ataxia, axial hypotonia, cerebral atrophy and speech delay/apraxia/dysarthria. Therefore, LoF KCNMA1 variants are associated with a new syndrome characterized by a broad spectrum of neurological phenotypes and developmental disorders. LoF variants of KCNMA1 cause a new syndrome distinctly different from gain-of-function variants in the same gene.

The nucleotide prodrug CERC-913 improves mtDNA content in primary hepatocytes from DGUOK-deficient rats.

Loss-of-function mutations in the deoxyguanosine kinase (DGUOK) gene result in a mitochondrial DNA (mtDNA) depletion syndrome. DGUOK plays an important role in converting deoxyribonucleosides to deoxyribonucleoside monophosphates via the salvage pathway for mtDNA synthesis. DGUOK deficiency manifests predominantly in the liver; the most common cause of death is liver failure within the first year of life and no therapeutic options are currently available. in vitro supplementation with deoxyguanosine or deoxyguanosine monophosphate (dGMP) were reported to rescue mtDNA depletion in DGUOK-deficient, patient-derived fibroblasts and myoblasts. CERC-913, a novel ProTide prodrug of dGMP, was designed to bypass defective DGUOK while improving permeability and stability relative to nucleoside monophosphates. To evaluate CERC-913 for its ability to rescue mtDNA depletion, we developed a primary hepatocyte culture model using liver tissue from DGUOK-deficient rats. DGUOK knockout rat hepatocyte cultures exhibit severely reduced mtDNA copy number (~10%) relative to wild type by qPCR and mtDNA content remains stable for up to 8 days in culture. CERC-913 increased mtDNA content in DGUOK-deficient hepatocytes up to 2.4-fold after 4 days of treatment in a dose-dependent fashion, which was significantly more effective than dGMP at similar concentrations. These early results suggest primary hepatocyte culture is a useful model for the study of mtDNA depletion syndromes and that CERC-913 treatment can improve mtDNA content in this model.

Diversion of aspartate in ASS1-deficient tumours fosters de novo pyrimidine synthesis.

Cancer cells hijack and remodel existing metabolic pathways for their benefit. Argininosuccinate synthase (ASS1) is a urea cycle enzyme that is essential in the conversion of nitrogen from ammonia and aspartate to urea. A decrease in nitrogen flux through ASS1 in the liver causes the urea cycle disorder citrullinaemia. In contrast to the well-studied consequences of loss of ASS1 activity on ureagenesis, the purpose of its somatic silencing in multiple cancers is largely unknown. Here we show that decreased activity of ASS1 in cancers supports proliferation by facilitating pyrimidine synthesis via CAD (carbamoyl-phosphate synthase 2, aspartate transcarbamylase, and dihydroorotase complex) activation. Our studies were initiated by delineating the consequences of loss of ASS1 activity in humans with two types of citrullinaemia. We find that in citrullinaemia type I (CTLN I), which is caused by deficiency of ASS1, there is increased pyrimidine synthesis and proliferation compared with citrullinaemia type II (CTLN II), in which there is decreased substrate availability for ASS1 caused by deficiency of the aspartate transporter citrin. Building on these results, we demonstrate that ASS1 deficiency in cancer increases cytosolic aspartate levels, which increases CAD activation by upregulating its substrate availability and by increasing its phosphorylation by S6K1 through the mammalian target of rapamycin (mTOR) pathway. Decreasing CAD activity by blocking citrin, the mTOR signalling, or pyrimidine synthesis decreases proliferation and thus may serve as a therapeutic strategy in multiple cancers where ASS1 is downregulated. Our results demonstrate that ASS1 downregulation is a novel mechanism supporting cancerous proliferation, and they provide a metabolic link between the urea cycle enzymes and pyrimidine synthesis.

Clinical heterogeneity of mitochondrial NAD kinase deficiency caused by a NADK2 start loss variant.

Mitochondrial NAD kinase deficiency (NADK2D, OMIM #615787) is a rare autosomal recessive disorder of NADPH biosynthesis that can cause hyperlysinemia and dienoyl-CoA reductase deficiency (DECRD, OMIM #616034). NADK2 deficiency has been reported in only three unrelated patients. Two had severe, unremitting disease; one died at 4 months and the other at 5 years of age. The third was a 10 year old female with CNS anomalies, ataxia, and incoordination. In two cases mutations in NADK2 have been demonstrated. Here, we report the fourth known case, a 15 year old female with normal intelligence and a mild clinical and biochemical phenotype presumably without DECRD. Her clinical symptoms, which are now stable, became evident at the age of 9 with the onset of decreased visual acuity, bilateral optic atrophy, nystagmus, episodic lower extremity weakness, peripheral neuropathy, and gait abnormalities. Plasma amino acid levels were within normal limits except for mean lysine and proline levels that were 3.7 and 2.5 times the upper limits of normal. Whole exome sequencing (WES) revealed homozygosity for a g.36241900 A>G p. Met1Val start loss mutation in the primary NADK2 transcript (NM_001085411.1) encoding the 442 amino acid isoform. This presumed hypomorphic mutation has not been previously reported and is absent from the v1000GP, EVS, and ExAC databases. Our patient's normal intelligence and stable disease expands the clinical heterogeneity and the prognosis associated with NADK2 deficiency. Our findings also clarify the mechanism underlying NADK2 deficiency and suggest that this disease should be ruled out in cases of hyperlysinemia, especially those with visual loss, and neurological phenotypes.

Necrotizing Enterocolitis Is Not Associated With Sequence Variants in Antioxidant Response Genes in Premature Infants.

Reactive oxygen species mediate intestinal injury in necrotizing enterocolitis (NEC), and yet the contribution of antioxidant response (ARE) gene polymorphisms to NEC risk remains unknown. Premature infants recruited in a multicenter study were genotyped for 6 ARE variants. Among 637 infants, 52 had NEC, and 22 developed surgical NEC. Gestational age <28 weeks (P < 0.02) and African American race (P = 0.03) were associated with NEC. The NFE2L2 (rs6721961), SOD2 (rs4880), GSTP1 (rs1695), NQO1 (rs1800566), GCLC (rs17883901), and HMOX1 (rs2071747) variants were not associated with medical or surgical NEC. This study does not support a role for common deleterious ARE variants in NEC.

Antioxidant response genes sequence variants and BPD susceptibility in VLBW infants.

BACKGROUND: Lung injury resulting from oxidative stress contributes to bronchopulmonary dysplasia (BPD) pathogenesis. Nuclear factor erythroid-2 related factor-2 (NFE2L2) regulates cytoprotective responses to oxidative stress by inducing enzymes containing antioxidant response elements (ARE). We hypothesized that ARE genetic variants will modulate susceptibility or severity of BPD in very-low-birth-weight (VLBW) infants. METHODS: Blood samples obtained from VLBW infants were used for genotyping variants in the SOD2, NFE2L2, GCLC, GSTP1, HMOX1, and NQO1 genes. SNPs were genotyped utilizing TaqMan probes (Applied Biosystems (ABI), Grand Island, NY), and data were analyzed using the ABI HT7900. Genetic dominance and recessive models were tested to determine associations between SNPs and BPD. RESULTS: In our cohort (n = 659), 284 infants had BPD; 135 of whom developed severe BPD. Presence of the hypomorphic NQO1 SNP (rs1800566) in a homozygous state was associated with increased BPD, while presence of the NFE2L2 SNP (rs6721961) was associated with decreased severe BPD in the entire cohort and in Caucasian infants. In regression models that adjusted for epidemiological confounders, the NQO1 and the NFE2L2 SNPs were associated with BPD and severe BPD, respectively. CONCLUSION: Genetic variants in NFE2L2-ARE axis may contribute to the variance in liability to BPD observed in preterm infants. These results require confirmation in independent cohorts.

Reduced mitochondrial DNA content and heterozygous nuclear gene mutations in patients with acute liver failure.

OBJECTIVES: Historically, mitochondrial disorders have been associated with predominantly multisystem or neurological symptoms. If present, hepatic complications were thought to be a late feature. Recently, mutations in at least 4 nuclear genes have been identified in infants presenting with rapidly progressive hepatic failure, which may be precipitated by infection or drugs. We aimed to determine whether hepatic mitochondrial DNA (mtDNA) depletion is associated with apparently isolated hepatic failure in individuals with acute liver failure (ALF) of known or unknown etiologies undergoing liver transplant (LT). In addition, we wished to establish whether there was an excess of mutations in gene known to cause hepatic mtDNA depletion. METHODS: Using previously established methods, we demonstrated that end-stage liver disease from known causes did not lead to hepatic mtDNA depletion. RESULTS: Using thresholds derived from receiver-operator curve analysis, 66% of cases with ALF had probable or definite mtDNA depletion, including 34% with definite mtDNA depletion. There was a small but significant increase in the proportion of patients undergoing LT for ALF with heterozygous mutations known to lead to mtDNA depletion and hepatic failure compared with controls (P = 0.001). CONCLUSIONS: Liver disease severe enough to require LT does not cause secondary mtDNA depletion; however, the majority of patients undergoing LT for ALF had reduced mtDNA content, which fell within the range seen in patients with classic mtDNA depletion. A subset of patients with ALF has mutations in genes known to lead to mtDNA depletion and hepatic failure. Together, these results suggest defective mtDNA maintenance is associated with ALF.

Is Computed-Tomography-Based Body Composition a Reliable Predictor of Chemotherapy-Related Toxicity in Pancreatic Cancer Patients?

BACKGROUND: Malnutrition, loss of weight and of skeletal muscle mass are frequent in pancreatic cancer patients, a majority of which will undergo chemotherapy over the course of their disease. Available data suggest a negative prognostic role of these changes in body composition on disease outcomes; however, it is unclear whether tolerance to chemotherapeutic treatment is similarly and/or negatively affected. We aimed to explore this association by retrospectively assessing changes in body composition and chemotherapy-related toxicity in a cohort of advanced pancreatic cancer patients. METHODS: Body composition was evaluated through clinical parameters and through radiological assessment of muscle mass, skeletal muscle area, skeletal muscle index and skeletal muscle density; and an assessment of fat distribution by subcutaneous adipose tissue and visceral adipose tissue. We performed descriptive statistics, pre/post chemotherapy comparisons and uni- and multivariate analyses to assess the relation between changes in body composition and toxicity. RESULTS: Toxicity risk increased with an increase of skeletal muscle index (OR: 1.03) and body mass index (OR: 1.07), whereas it decreased with an increase in skeletal muscle density (OR: 0.96). Multivariate analyses confirmed a reduction in the risk of toxicity only with an increase in skeletal muscle density (OR: 0.96). CONCLUSIONS: This study suggests that the retrospective analysis of changes in body composition is unlikely to be useful to predict toxicity to gemcitabine-nab-paclitaxel.

Recessive deoxyguanosine kinase deficiency causes juvenile onset mitochondrial myopathy.

Deoxyguanosine kinase (DGUOK) (MIM#601465) deficiency was originally described as the cause of an infantile onset hepatocerebral mitochondrial disease [1]. The classic features of this disorder include significant hepatic failure with nystagmus and hypotonia. Mitochondrial DNA studies reveal significant mitochondrial DNA depletion in the affected tissues. Subsequently it has been shown that the same mutations in this gene may present with isolated acute liver failure without cerebral involvement. In this paper we studied the mitochondrial DNA depletion in cells from a patient presenting with mitochondrial myopathy caused by a novel mutation in DGUOK. Subsequently we developed the method to diagnose this condition using MyoD induced fibroblasts to study the muscle specific phenotype. In addition, supplementation of MyoD induced fibroblasts with dAMP and dGMP resulted in a restoration of mtDNA quantity.

The Screening and COnsensus Based on Practices and Evidence (SCOPE) Program Results of a Survey on Daily Practice Patterns for Patients with Metastatic Colorectal Cancer-A Swiss Perspective in the Context of an International Viewpoint.

In Switzerland, physicians do not have national guidelines for metastatic colorectal cancer (mCRC) patient care and utilize international versions for management recommendations. Moreover, information about adherence to these guidelines and real-world practice patterns in Switzerland or other countries is lacking. The Screening and COnsensus based on Practices and Evidence (SCOPE) program were designed by an international expert panel of gastrointestinal oncologists to gather real-world insights in the current clinical setting to manage patients with mCRC who have received prior treatment. We sought to understand general practice patterns, the influence of molecular diagnostics (e.g., testing for KRAS, NRAS, BRAF, and MSI), tumor sidedness, and patient-centric factors on treatment selection utilizing in-person surveys and three hypothetical patient case scenarios. Here, we describe and evaluate the Swiss data from the SCOPE program within the context of an international viewpoint and discuss the findings of our analysis. In general, we find that the real-world clinical decisions of Swiss physicians (SWI) closely follow international (INT) recommendations and guidelines, largely paralleling their regional and international counterparts in using the two approved treatments in the third- and fourth-line settings, namely trifluridine-tipiracil and regorafenib. Finally, our data suggest a tendency toward the use of trifluridine-tipiracil (SWI: 79%; INT: 66%) over regorafenib (SWI: 18%; INT: 18%) as the preferred third-line treatment choice in mCRC patients regardless of KRAS status.

Combined Targeting of Pathogenetic Mechanisms in Pancreatic Neuroendocrine Tumors Elicits Synergistic Antitumor Effects.

Pancreatic neuroendocrine neoplasms (PanNENs) are the second most common malignancy of the pancreas. Surgery remains the only curative treatment for localized disease. For patients with inoperable advanced or metastatic disease, few targeted therapies are available, but their efficacy is unpredictable and variable. Exploiting prior knowledge on pathogenetic processes involved in PanNEN tumorigenesis, we tested buparlisib (PI3K inhibitor) and ribociclib (CDK4/6 inhibitor), as single agents or in combination, in different preclinical models. First, we used cell lines representative of well-differentiated (INS-1E, NT-3) and poorly differentiated (BON-1) PanNENs. The combination of buparlisib with ribociclib reduced the proliferation of 2D and 3D spheroid cultures more potently than the individual drugs. Buparlisib, but not ribociclib, induced apoptosis. The anti-proliferative activity of the drugs correlated with downstream target inhibition at mRNA and protein levels. We then tested the drugs on primary islet microtissues from a genetic PanNET animal model (Men1-defective mice) and from wild-type mice: the drug combination was effective against the former without altering islet cell physiology. Finally, we treated PanNET patient-derived islet-like 3D tumoroids: the combination of buparlisib with ribociclib was effective in three out of four samples. Combined targeting of PI3K and CDK4/6 is a promising strategy for PanNENs spanning various molecular and histo-pathological features.

Making a definitive diagnosis: successful clinical application of whole exome sequencing in a child with intractable inflammatory bowel disease.

PURPOSE: We report a male child who presented at 15 months with perianal abscesses and proctitis, progressing to transmural pancolitis with colocutaneous fistulae, consistent with a Crohn disease-like illness. The age and severity of the presentation suggested an underlying immune defect; however, despite comprehensive clinical evaluation, we were unable to arrive at a definitive diagnosis, thereby restricting clinical management. METHODS: We sought to identify the causative mutation(s) through exome sequencing to provide the necessary additional information required for clinical management. RESULTS: After sequencing, we identified 16,124 variants. Subsequent analysis identified a novel, hemizygous missense mutation in the X-linked inhibitor of apoptosis gene, substituting a tyrosine for a highly conserved and functionally important cysteine. X-linked inhibitor of apoptosis was not previously associated with Crohn disease but has a central role in the proinflammatory response and bacterial sensing through the NOD signaling pathway. The mutation was confirmed by Sanger sequencing in a licensed clinical laboratory. Functional assays demonstrated an increased susceptibility to activation-induced cell death and defective responsiveness to NOD2 ligands, consistent with loss of normal X-linked inhibitor of apoptosis protein function in apoptosis and NOD2 signaling. CONCLUSIONS: Based on this medical history, genetic and functional data, the child was diagnosed as having an X-linked inhibitor of apoptosis deficiency. Based on this finding, an allogeneic hematopoietic progenitor cell transplant was performed to prevent the development of life-threatening hemophagocytic lymphohistiocytosis, in concordance with the recommended treatment for X-linked inhibitor of apoptosis deficiency. At >42 days posttransplant, the child was able to eat and drink, and there has been no recurrence of gastrointestinal disease, suggesting this mutation also drove the gastrointestinal disease. This report describes the identification of a novel cause of inflammatory bowel disease. Equally importantly, it demonstrates the power of exome sequencing to render a molecular diagnosis in an individual patient in the setting of a novel disease, after all standard diagnoses were exhausted, and illustrates how this technology can be used in a clinical setting.

Mixed response and mechanisms of resistance to larotrectinib in metastatic carcinoma ex pleomorphic adenoma of the parotid harboring an NTRK2 fusion: A case report.

INTRODUCTION: Standardized systemic treatment options are lacking for carcinoma ex pleomorphic adenoma, which is a rare and aggressive tumor primarily found in salivary glands.Here we report the case of a 63-year-old male with carcinoma ex pleomorphic adenoma of the left parotid and parapharyngeal space harboring a neurotrophic receptor tyrosine kinase (NTRK) 2 fusion who was treated with a small molecule inhibitor that targets the tropomyosin receptor kinase (TRK) proteins. To the best of our knowledge, no similar case has been described in the literature so far. PATIENT CONCERNS: After multiple surgical resections and radiotherapy for localized cancer disease over several years, our patient again developed an increasing swelling and pain around the left ear and numbness of the left half of the face. DIAGNOSIS: Magnetic resonance imaging and positron emission tomography/computed tomography scans showed tumor recurrence in the left parotid, below the left ear, and in the parapharyngeal space, as well as metastases of the lungs and cervical lymph nodes. As data on the efficacy of systemic therapies for inoperable carcinoma ex pleomorphic adenoma are scarce, we performed a next-generation sequencing that revealed the presence of a hitherto unknown NTRK2 fusion. INTERVENTIONS: Treatment with the TRK inhibitor larotrectinib was initiated, which induced rapid symptom improvement. However, part of the tumor had to be removed shortly afterwards due to local progression. Molecular testing did not demonstrate any alterations accounting for resistance to larotrectinib, with maintenance of the NTRK2 fusion. OUTCOMES: Three months later, imaging confirmed mixed response. While the reason for this remains unknown, the patient is in good condition and continues to receive larotrectinib. CONCLUSION: It remains unclear why our patient showed mixed response to larotrectinib and further studies are needed to explore other possible mechanisms of resistance.

Advanced Gastric Cancer: Current Treatment Landscape and a Future Outlook for Sequential and Personalized Guide: Swiss Expert Statement Article.

BACKGROUND: Gastric cancer is a leading cause of cancer-related deaths worldwide. Several treatment possibilities have been investigated, but only a few show clinically meaningful results. SUMMARY: Systemic treatment options for advanced gastric cancer (aGC) have evolved over the recent years, implementing the growing molecular knowledge of this heterogeneous disease. Molecular profiling (at least for HER-2-expression, microsatellite instability status, Epstein-Barr virus expression, and programmed death ligand-1 expression/combined positive score [CPS]) is recommended for all therapy-fit patients prior to the start of a systemic treatment and is crucial for decisions on treatment strategy and drug selection. Various examples like the application of trastuzumab in the HER-2-positive subgroup underline the benefits of this approach starting from the first-line setting. A combination of platinum and fluoropyrimidine remains the first-line chemotherapy backbone in the treatment of advanced gastric cancer. Triplet combinations adding taxanes to the doublet regimen are reserved for certain scenarios. Unfortunately, almost all patients who receive first-line treatment (with or without anti-HER-2 blockade) progress and <70% are eligible for a second-line therapy. The addition of monoclonal antibodies has substantially improved outcomes in this setting. As such, ramucirumab has led to significant and clinically meaningful advancements in the second-line treatment. Furthermore, immuno-oncology with checkpoint inhibition and immune stimulation has evolved in the field of aGC. Recent first-line data show a significant survival benefit in aGC patients with a CPS ≥ 5 under immunochemotherapy. Nonetheless, the impact of immunotherapy combinations and immunochemotherapy remains an area of investigation. Key Message: In this review, we highlight recent improvements in the treatment landscape of advanced gastric cancer, the heterogeneity of this disease, and possible personalized targets.

The mitochondrial carrier Citrin plays a role in regulating cellular energy during carcinogenesis.

Citrin, encoded by SLC25A13 gene, is an inner mitochondrial transporter that is part of the malate-aspartate shuttle, which regulates the NAD+/NADH ratio between the cytosol and mitochondria. Citrullinemia type II (CTLN-II) is an inherited disorder caused by germline mutations in SLC25A13, manifesting clinically in growth failure that can be alleviated by dietary restriction of carbohydrates. The association of citrin with glycolysis and NAD+/NADH ratio led us to hypothesize that it may play a role in carcinogenesis. Indeed, we find that citrin is upregulated in multiple cancer types and is essential for supplementing NAD+ for glycolysis and NADH for oxidative phosphorylation. Consequently, citrin deficiency associates with autophagy, whereas its overexpression in cancer cells increases energy production and cancer invasion. Furthermore, based on the human deleterious mutations in citrin, we found a potential inhibitor of citrin that restricts cancerous phenotypes in cells. Collectively, our findings suggest that targeting citrin may be of benefit for cancer therapy.

Spinal segmental stabilisation exercises for chronic low back pain: programme adherence and its influence on clinical outcome.

Exercise rehabilitation is one of the few evidence-based treatments for chronic non-specific low back pain (cLBP), but individual success is notoriously variable and may depend on the patient's adherence to the prescribed exercise regime. This prospective study examined factors associated with adherence and the relationship between adherence and outcome after a programme of physiotherapeutic spine stabilisation exercises. A total of 32/37 patients with cLBP completed the study (mean age, 44.0 (SD = 12.3) years; 11/32 (34%) male). Adherence to the 9-week programme was documented as: percent attendance at therapy, percent adherence to daily home exercises (patient diary) and percent commitment to rehabilitation (Sports Injury Rehabilitation Adherence Scale (SIRAS)). The average of these three measures formed a multidimensional adherence index (MAI). Psychological disturbance, fear-avoidance beliefs, catastrophising, exercise self-efficacy and health locus of control were measured by questionnaire; disability in everyday activities was scored with the Roland-Morris disability scale and back pain intensity with a 0-10 graphic rating scale. Overall, adherence to therapy was very good (average MAI score, 85%; median (IQR), 89 (15)%). The only psychological/beliefs variable showing a unique significant association with MAI was exercise self-efficacy (Rho = 0.36, P = 0.045). Pain intensity and self-rated disability decreased significantly after therapy (each P < 0.01). Adherence to home exercises showed a moderate, positive correlation with the reduction in average pain (Rho = 0.54, P = 0.003) and disability (Rho = 0.38, P = 0.036); higher MAI scores were associated with greater reductions in average pain (Rho = 0.48, P = 0.008) and a (n.s.) tendency for greater reductions in disability (Rho = 0.32, P = 0.07) Neither attendance at therapy nor SIRAS were significantly related to any of the outcomes. The benefits of rehabilitation depended to a large extent on the patient's exercise behaviour outside of the formal physiotherapy sessions. Hence, more effort should be invested in finding ways to improve patients' motivation to take responsibility for the success of their own therapy, perhaps by increasing exercise self-efficacy. Whether the "adherence-outcome" interaction was mediated by improvements in function related to the specific exercises, or by a more "global" effect of the programme, remains to be examined.

Metastatic Mixed Adenoneuroendocrine Carcinoma of the Colon with Response to Immunotherapy with Pembrolizumab: A Case Report.

Mixed adenoneuroendocrine carcinoma (MANEC) is a rare, aggressive tumor arising from different localizations along the gastrointestinal tract with generally poor prognosis. We present the case of a 51-year-old female patient with histopathologically confirmed diagnosis of a MANEC of the descending colon. At presentation, the tumor had already spread to the liver causing extensive hepatic metastases. Immunohistochemical examination showed 5%-10% of tumor cells to express the programmed cell death receptor ligand 1 and FoundationOne testing revealed a high mutational tumor burden with 149 Muts/Mb. The patient responded very well clinically and radiologically to anti-programmed death 1 receptor monoclonal antibody pembrolizumab therapy after having undergone 3 previous systemic treatment regimens as well as selective internal radiation therapy of her hepatic metastases. Clinical improvement was evident after the first infusion already and is ongoing for 10 months so far with very little side effects including initial and short lived skin irritation as well as muscle pain. To our knowledge, this is the first published case where a MANEC was successfully treated with immunotherapy targeting the programmed death 1 receptor.

Severe Neonatal RYR1 Myopathy With Pathological Features of Congenital Muscular Dystrophy.

The phenotypes associated with pathogenic variants in the ryanodine receptor 1 gene (RYR1, OMIM# 180901) have greatly expanded over the last few decades as genetic testing for RYR1 variants has become more common. Initially described in association with malignant hyperthermia, pathogenic variants in RYR1 are typically associated with core pathology in muscle biopsies (central core disease or multiminicore disease) and symptomatic myopathies with symptoms ranging from mild weakness to perinatal lethality. We describe a 2-week-old male patient with multiple congenital dysmorphisms, severe perinatal weakness, and subsequent demise, whose histopathology on autopsy was consistent with congenital muscular dystrophy. Immunohistochemical analysis of dystrophy-associated proteins was normal. Rapid exome sequencing revealed a novel heterozygous nonsense variant (p.Trp661Ter) in RYR1, as well as a previously described RYR1 pathogenic variant associated with congenital myopathy (p.Phe4976Leu). This highlights the potential for RYR1 pathogenic variants to produce pathological findings most consistent with congenital muscular dystrophy.

Cetuximab monotherapy and cetuximab plus capecitabine as first-line treatment in older patients with RAS- and BRAF wild-type metastatic colorectal cancer. Results of the multicenter phase II trial SAKK 41/10.

INTRODUCTION: While the anti-VEGF antibody bevacizumab was studied repeatedly as part of low-intensity regimens in less fit elderly patients with metastatic colorectal cancer (mCRC), anti-EGFR antibodies as upfront treatment modality have been scarcely investigated. MATERIAL AND METHODS: In SAKK 41/10, the benefit of cetuximab, either alone or in combination with capecitabine, was evaluated in vulnerable elderly patients with RAS/BRAF-wild-type mCRC. RESULTS AND DISCUSSION: The trial was stopped prematurely due to slow accrual after the inclusion of 24 patients (11 in the monotherapy arm, 13 in the combination arm). Median patient age was 80 years (range 71-89), median CIRS-G score 7 (range 2-13), and median IADL score 7 (range 3-8). At week 12, 6 of 11 patients (55%) were progression-free in the cetuximab monotherapy arm and 9 of 13 patients (69%) in the combination arm. Response rate was 9% in the monotherapy arm and 38% combination arm. The 6 patients with right-sided primary tumors were not responsive to cetuximab. NGS revealed additional mutations affecting the RAS/RAF/MAP kinase pathway in 5 patients; 4 of these patients showed early disease progression. Cetuximab was generally well tolerated and a trend toward an improvement of symptom-related QoL was observed. In the combination arm, a higher incidence of toxicities and treatment stoppings was observed. In conclusion, trial recruitment - requiring both geriatric as well as molecular eligibility criteria - proved more difficult than expected. Bearing in mind the very small sample size, upfront cetuximab treatment appeared tolerable and showed promising activity in left-sided tumors in both treatment arms.