Characteristics, aetiology and implications for management of multiple primary renal tumours: a systematic review

In a subset of patients with renal tumours, multiple primary lesions may occur. Predisposition to multiple primary renal tumours (MPRT) is a well-recognised feature of some inherited renal cancer syndromes. The diagnosis of MPRT should therefore provoke a thorough assessment for clinical and genetic evidence of disorders associated with predisposition to renal tumourigenesis. To better define the clinical and genetic characteristics of MPRT, a systematic literature review was performed for publications up to 3 April 2024. A total of 7689 patients from 467 articles were identified with MPRT. Compared to all patients with renal cell carcinoma (RCC), patients with MPRT were more likely to be male (71.8% versus 63%) and have an earlier age at diagnosis (<46 years, 32.4% versus 19%). In 61.1% of cases MPRT were synchronous. The proportion of cases with similar histology and the proportion of cases with multiple papillary renal cell carcinoma (RCC) (16.1%) were higher than expected. In total, 14.9% of patients with MPRT had a family history of cancer or were diagnosed with a hereditary RCC associated syndrome with von Hippel-Lindau (VHL) disease being the most common one (69.7%), followed by Birt-Hogg-Dubé (BHD) syndrome (14.2%). Individuals with a known or likely genetic cause were, on average, younger (43.9 years versus 57.1 years). In rare cases intrarenal metastatic RCC can phenocopy MPRT. We review potential genetic causes of MPRT and their implications for management, suggest an approach to genetic testing for individuals presenting with MPRT and considerations in cases in which routine germline genetic testing does not provide a diagnosis.

Frequency of pathogenic germline variants in cancer susceptibility genes in 1336 renal cell carcinoma cases

Renal cell carcinoma (RCC) occurs in a number of cancer predisposition syndromes, but the genetic architecture of susceptibility to RCC is not well defined. We investigated the frequency of pathogenic and likely pathogenic (P/LP) germline variants in cancer susceptibility genes (CSGs) within a large series of unselected RCC participants. Whole-genome sequencing data on 1336 RCC participants and 5834 controls recruited to the UK 100 000 Genomes Project, a nationwide multicentre study, was analyzed to identify rare P/LP short variants (single nucleotide variants and insertions/deletions ranging from 1 to 50 base pairs) and structural variants in 121 CSGs. Among 1336 RCC participants [mean: 61.3 years (±12 SD), range: 13-88 years; 64% male], 85 participants [6.4%; 95% CI (5.1, 7.8)] had one or more P/LP germline variant in a wider range of CSGs than previously recognized. A further 64 intragenic variants in CSGs previously associated with RCC were classified as a variant of uncertain significance (VUS) (24 'hot VUSs') and were considered to be of potential clinical relevance as further evaluation might results in their reclassification. Most patients with P variants in well-established CSGs known to predispose to renal cell carcinoma (RCC-CSGs) were aged <50 years. Burden test analysis for filtered variants in CSGs demonstrated a significant excess of CHEK2 variants in European RCC participants compared with the healthy European controls (P = 0.0019). Approximately, 6% of the patients with RCC unselected for family history have a germline variant requiring additional follow-up analysis. To improve diagnostic yield, we suggest expanding the panel of RCC-CSGs tested to include CHEK2 and all SDHx subunits and raising the eligibility criteria for age-based testing.

Elongin C (ELOC/TCEB1)-associated von Hippel-Lindau disease

Around 95% of patients with clinical features that meet the diagnostic criteria for von Hippel-Lindau disease (VHL) have a detectable inactivating germline variant in VHL. The VHL protein (pVHL) functions as part of the E3 ubiquitin ligase complex comprising pVHL, elongin C, elongin B, cullin 2 and ring box 1 (VCB-CR complex), which plays a key role in oxygen sensing and degradation of hypoxia-inducible factors. To date, only variants in VHL have been shown to cause VHL disease. We undertook trio analysis by whole-exome sequencing in a proband with VHL disease but without a detectable VHL mutation. Molecular studies were also performed on paired DNA extracted from the proband's kidney tumour and blood and bioinformatics analysis of sporadic renal cell carcinoma (RCC) dataset was undertaken. A de novo pathogenic variant in ELOC NM_005648.4(ELOC):c.236A>G (p.Tyr79Cys) gene was identified in the proband. ELOC encodes elongin C, a key component [C] of the VCB-CR complex. The p.Tyr79Cys substitution is a mutational hotspot in sporadic VHL-competent RCC and has previously been shown to mimic the effects of pVHL deficiency on hypoxic signalling. Analysis of an RCC from the proband showed similar findings to that in somatically ELOC-mutated RCC (expression of hypoxia-responsive proteins, no somatic VHL variants and chromosome 8 loss). These findings are consistent with pathogenic ELOC variants being a novel cause for VHL disease and suggest that genetic testing for ELOC variants should be performed in individuals with suspected VHL disease with no detectable VHL variant.

Multilocus Inherited Neoplasia Allele Syndrome (MINAS): an update

Multi-locus Inherited Neoplasia Allele Syndrome (MINAS) refers to individuals with germline pathogenic variants in two or more cancer susceptibility genes(CSGs). With increased use of exome/genome sequencing it would be predicted that detection of MINAS would become more frequent. Here we review recent progress in knowledge of MINAS. A systematic literature search for reports of individuals with germline pathogenic variants in 2 or more of 94 CSGs was performed. In addition, participants with multiple primary tumours who underwent genome sequencing as part of the Rare Disease arm of the UK 100,000 Genomes Project were interrogated to detect additional cases. We identified 385 MINAS cases (211 reported in the last 5 years, 6 from 100,000 genomes participants). Most (287/385) cases contained at least one pathogenic variant in either BRCA1 or BRCA2. 108/385 MINAS cases had multiple primary tumours at presentation and a subset of cases presented unusual multiple tumour phenotypes. We conclude that, as predicted, increasing numbers of individuals with MINAS are being have been reported but, except for individuals with BRCA1/BRCA2 MINAS, individual CSG combinations are generally rare. In many cases it appears that the clinical phenotype is that which would be expected from the effects of the constituent CSG variants acting independently. However, in some instances the presence of unusual tumour phenotypes and/or multiple primary tumours suggests that there may be complex interactions between the relevant MINAS CSGs. Systematic reporting of MINAS cases in a MINAS database (e.g. https://databases.lovd.nl/shared/diseases/04296 ) will facilitate more accurate prognostic predictions for specific CSG combinations.

Seventh BHD international symposium: recent scientific and clinical advancement

The 7th Birt-Hogg-Dubé (BHD) International Symposium convened virtually in October 2021. The meeting attracted more than 200 participants internationally and highlighted recent findings in a variety of areas, including genetic insight and molecular understanding of BHD syndrome, structure and function of the tumor suppressor Folliculin (FLCN), therapeutic and clinical advances as well as patients' experiences living with this malady.

AB0004 THE ASSOCIATION OF THE RARE RS35667974 IFIH1 GENE POLYMORPHISM WITH SIX AUTOIMMUNE DISEASES: STRUCTURAL BIOLOGICAL INSIGHTS

Background:

Genome wide association studies (GWAS) have successfully identified novel autoimmune disease-associated loci, with many of them shared by multiple disease-associated pathways but much of the genetics and pathophysiological mechanisms remain still obscure. Considering that most of the potential causal variants are still unknown, many studies showed that the missense variant rs35667974 at interferon induced with helicase C domain 1 (IFIH1) gene is protective for type 1 diabetes (T1D), psoriasis (PS) and psoriatic arthritis (PsA), while it was found to be also associated with ankylosing spondylitis (AS), Crohn’s disease (CD) and ulcerative colitis (UC). IFIH1 gene encodes a cytoplasmic RNA helicase that recognizes viral RNA and is involved in innate immunity through recognition of viral RNA [1].

Objectives:

To investigate the role of the rare rs35667974 variant of IFIH1 gene, which resides in exon 14 and changes a conserved isoleucine at position #923 to valine in T1D, PS, PsA, AS, CD and UC [2-4] as well as the mechanism that may affect the function in the protein structure.

Methods:

Evolutionary analysis revealed heavily conserved sequence elements among species, indicating structural/functional importance of the mutation at position #923. In silico mutagenesis and three-dimensional (3D) homology modeling was used to localize the polymorphism under study on the IFIH1 protein. The mutant was constructed using molecular modeling with the program Maestro (Schrodinger, LLC) [5]. Molecular mechanics/dynamics studies were applied to validate structural/functional changes caused by the Ile923V substitution. All figures depicting 3D models were generated using the PyMOL molecular-graphics system V.2.2 [6].

Results:

Evolutionary and structural analysis revealed that the position of residue Ile923 is located on a protein loop (921-927) directly interacting with mRNA both to the phosphoribose chain and the base pairs. Mutation of Ile to Val at position #923 will directly affect the said interaction with mRNA [7] (Figure 1). Moreover, it has been reported that pre-mRNA or mRNA levels did not correlate with Ile923Val, suggesting that, Ile923Val did not alter the expression of IFIH1 in a major way [7].

Figure 1.

Structural representation of the interferon-induced helicase C domain-containing protein 1 [Homo sapiens] structure (4GL2 from Protein Data Bank) (in green) bound to the double stranded RNA (in orange-yellow). The location of the mutation (I923V) is highlighted in pink. The proximity of the aminoacid 923 to the nucleotide is apparent.

Conclusion:

This study represents a comprehensive evaluation of the role of the shared rs35667974 variant of autoimmune locus IFIH1, reported to lead to a loss of function phenotype and, as a consequence, reduced levels of IFIH1 protein and activity that protect against autoimmunity. Structural analysis of rare shared genetic susceptibility or protection loci may provide insight to our understanding of the pathophysiology of autoimmune diseases and the research findings may affect the better management of the diseases under study.

References:

[1]Nejentsev S et al. (2009). Science 324:387–389.

[2]Smyth DJ et al. (2006). Nat Genet. 38: 617–619.

[3]Li Y et al. (2010). J Invest Dermatol 130:2768–2772.

[4]Ellinghaus D et al. (2016). Nat Genet 48:510–518.

[5]Schrödinger Release 2017-1: Maestro, Schrödinger, LLC, New York, NY, 2017.

[6]Schrödinger LLC: The PyMOL Molecular Graphics System 2016 version 2.2.

[7]Wu B et al. (2013). Cell 152:276-289[8] Downes K et al. (2010). PLoS One 5:e12646.

Disclosure of Interests:

None declared

Comparison of long-term survivals following hepatectomy for hepatocellular carcinoma according to the time-point of recurrence and treatment modalities for recurrent disease

Objective

Disease recurrence following curatively intended hepatectomy for hepatocellular carcinoma (HCC) limits oncologic outcome. Based on the extent, location and time-point of tumor recurrence, different therapeutic modalities are available to treat recurrent HCC. Therefore, our aim was to investigate the role of these treatments and the time-point of recurrence on long-term survival.

Methods

Clinicopathological data of patients, who underwent hepatectomy for HCC at a major hepatobiliary center in Switzerland between 2012 and 2019, were assessed. Patients suffering tumor recurrence were stratified according to the treatment modalities for recurrent HCC including surgical treatment (repeat hepatectomy or liver transplantation), interventional treatment, and conservative treatment (chemotherapy or best supportive care). Groups were compared regarding to overall survival (OS). Additionally, long-term outcomes were compared between patients with early (≤ 12 months) and late (&gt; 12 months) tumor recurrence.

Results

During the study period, 159 patients underwent hepatectomy for HCC. Median follow-up time was 53 months. After a median time of seven (1-64) months, 74 patients were diagnosed with tumor recurrence (47 %). The majority of patients developed early recurrence (n = 49) and 58 patients had intrahepatic recurrence only. Treatment options were re-resection, liver transplantation, interventional methods, and palliative therapy in 5, 15, 23, and 31 patients, respectively. Surgical treatment was significantly associated with improved OS compared to interventional and conservative treatment (5-year OS: 84% vs. 39% vs. 30%, p &lt; 0.0001). OS was significantly better among patients with late recurrence compared to patients with early recurrence, irrespective of the treatment modality used for the recurrent disease (5-year OS: 70% vs. 38%, p = 0.008).

Conclusion

Repeat hepatectomy or liver transplantation for recurrent HCC following hepatectomy is associated with better long-term survival compared to interventional or conservative therapies, especially for patients with late tumor recurrence. Patients with intrahepatic HCC recurrence should be evaluated according to the extent of tumor burden, liver function, and functional status to identify the best candidates for a surgical treatment.

Parenchymal-sparing hepatectomy for colorectal liver metastases reduces postoperative morbidity while maintaining equivalent oncologic outcomes compared to non-parenchymal-sparing resection

Objective

Modern chemotherapy and repeat hepatectomy allow to tailor the surgical strategies for the treatment of colorectal liver metastases (CRLM). This study addresses the hypothesis that parenchymal-sparing hepatectomy reduces postoperative complications while ensuring similar oncologic outcomes compared to the standardized non-parenchymal-sparing procedures.

Methods

Clinicopathological data of patients who underwent liver resection for CRLM between 2012 and 2019 at a major hepatobiliary center in Switzerland were assessed. Patients were stratified according to the tumor burden score [TBS2 = (maximum tumor diameter in cm)2 + (number of lesions)2)] and were dichotomized in a lower and a higher tumor burden cohort according to the median TBS. Postoperative outcomes, overall survival (OS) and disease-free survival (DFS) of patients following parenchymal-sparing resection (PSR) for CRLM were compared with those of patients undergoing non-PSR.

Results

During the study period, 153 patients underwent liver resection for CRLM with curative intent. PSR was performed in 79 patients with TBS &lt; 4.5, and in 42 patients with TBS ≥ 4.5. In patients with lower tumor burden (TBS &lt; 4.5), PSR was associated with lower complication rate (15.2% vs. 46.2%, p = 0.009), and shorter length of hospital stay (5 vs. 9 days, p = 0.006) in comparison to non-PSR. For TBS &lt; 4.5, PSR resulted in equivalent 5-year OS (48% vs. 39%, p = 0.479) and equivalent 5-year DFS rates (DFS, 44% vs. 29%, p = 0.184) compared to non-PSR. For TBS ≥ 4.5, PSR resulted in lower postoperative complication rate (33.3% vs. 63.2%, p = 0.031), lower length of hospital stay (6 vs. 9 days, p = 0.005), equivalent 5-year OS (29% vs. 22%, p = 0.314), and equivalent 5-year DFS rates (29% vs. 22%, p = 0.896) compared to non-PSR. Among all patients treated with PSR, patients undergoing minimal-invasive hepatectomy had equivalent 5-year OS (42% vs. 37%, p = 0.261) and equivalent 5-year DFS (34% vs. 34%, p = 0.613) rates compared to patients undergoing open hepatectomy.

Conclusion

PSR for CRLM is associated with lower postoperative morbidity, shorter length of hospital stay, and equivalent oncologic outcomes compared to non-PSR independently from tumor burden. Our findings suggest that minimal-invasive PSR should be considered as the preferred method for the treatment of curatively resectable CRLM if allowed by tumor size and location.

Major postoperative complications increase tumor recurrence rate and diminish long-term survival following resection for pancreatic ductal adenocarcinoma

Objective

Major complications have been associated with worse oncologic outcomes following resection for several gastrointestinal malignancies. However, the impact of major postoperative morbidity on the survival of patients undergoing resection for pancreatic ductal adenocarcinoma (PDAC) remains unclear.

Methods

Clinicopathological data of patients who underwent resection for PDAC between 2014 and 2019 in a major swiss hepatopancreatobiliary center were assessed. We evaluated the disease-free (DFS) and overall survival (OS) of patients suffering a major postoperative complication (grade-3 or higher within 90 days according to Clavien-Dindo classification) in comparison to those of patients without any major postoperative adverse events.

Results

During the study period, 186 patients underwent resection for PDAC with curative intent. Pancreatoduodenectomy, distal pancreatectomy, and total pancreatectomy were performed in 66%, 12%, and 22% of patients, respectively. Major 90-day postoperative morbidity and mortality rate were 21.5% and 4.3%, respectively. After excluding patients who died within 90 days, major postoperative morbidity significantly increased the length of hospital stay [median 22 (8-66) days vs. 13 (5-26) days, p &lt; 0.0001] resulting in a delay of returning to intended oncologic treatment and reducing the likelihood of receiving adjuvant chemotherapy (56% vs. 83%, p = 0.001). Postoperative major complications were associated with significantly worse DFS (median DFS 10 vs. 16 months, hazard ratio 1.9, 95% confidence interval 1.91-2.96, p = 0.004) and worse OS (median OS 14 vs. 37 months, hazard ratio 1.7, 95% confidence interval 1.02-2.75, p = 0.04) in multivariate analysis.

Conclusion

Major postoperative complications promote tumor recurrence following resection for PDAC, thus limiting long-term survival. Careful patient selection and optimized complication management may reduce postoperative morbidity, thereby lowering its negative impact on oncologic prognosis.

Endoscopic ultrasound-guided hepaticogastrostomy vs. ERCP for preoperative biliary drainage in patients undergoing pancreatic resection

Objective

Preoperative bile drainage in patients with obstructive jaundice due to pancreatic head malignancy is needed, if pancreatic head resection cannot be performed in a timely fashion. The safety and efficacy of ultrasound-guided hepaticogastrostomy (HGS) as an alternative to the established endoscopic retrograde cholangio-pancreatography (ERCP) with stent placement needs further investigation.

Methods

Clinicopathological data of patients who underwent partial or total pancreaticoduodenectomy between January 2017 and December 2019 in a major swiss hepatopancreatobiliary center were assessed. We compared the HGS with ERCP/stent regarding the kinetics of bilirubin decrease, the procedure-related morbidity, and the postoperative surgical outcomes.

Results

During the study period, 102 patients underwent pancreaticoduodenectomy or total pancreatectomy for pancreatic malignancy. Preoperative bile drainage was performed in 65 patients (20 HGS, 45 ERCP). HGS was associated with a faster (6 vs. 10 days, P = 0.042) and more effective (133 µmol/L vs. 101 µmol/L, P = 0.037) reduction of the serum bilirubin levels. HGS was safe and did not differ from ERCP with stent placement concerning post-interventional complications (P = 0.565), postoperative mortality (P = 0.996) and postoperative morbidity (P = 0.896), including infectious complications (wound infection, P = 0.662/ intra-abdominal abscess, P = 0.587), severe pancreatic fistula (P = 0.587), bile leak (P = 0.131), and postoperative hemorrhage (P = 0.886).

Conclusion

HGS performed in a specialized multidisciplinary hepatopancreatobiliary center is feasible and safe and may result in more accelerated and effective bile drainage compared to the established ERCP. In patients with obstructive jaundice related to pancreatic malignancy unable to undergo adequate bile drainage by ERCP, HGS may be an effective alternative method enabling surgery in a timely manner.

Missense variants in DPYSL5 cause a neurodevelopmental disorder with corpus callosum agenesis and cerebellar abnormalities

The collapsin response mediator protein (CRMP) family proteins are intracellular mediators of neurotrophic factors regulating neurite structure/spine formation and are essential for dendrite patterning and directional axonal pathfinding during brain developmental processes. Among this family, CRMP5/DPYSL5 plays a significant role in neuronal migration, axonal guidance, dendrite outgrowth, and synapse formation by interacting with microtubules. Here, we report the identification of missense mutations in DPYSL5 in nine individuals with brain malformations, including corpus callosum agenesis and/or posterior fossa abnormalities, associated with variable degrees of intellectual disability. A recurrent de novo p.Glu41Lys variant was found in eight unrelated patients, and a p.Gly47Arg variant was identified in one individual from the first family reported with Ritscher-Schinzel syndrome. Functional analyses of the two missense mutations revealed impaired dendritic outgrowth processes in young developing hippocampal primary neuronal cultures. We further demonstrated that these mutations, both located in the same loop on the surface of DPYSL5 monomers and oligomers, reduced the interaction of DPYSL5 with neuronal cytoskeleton-associated proteins MAP2 and βIII-tubulin. Our findings collectively indicate that the p.Glu41Lys and p.Gly47Arg variants impair DPYSL5 function on dendritic outgrowth regulation by preventing the formation of the ternary complex with MAP2 and βIII-tubulin, ultimately leading to abnormal brain development. This study adds DPYSL5 to the list of genes implicated in brain malformation and in neurodevelopmental disorders.

Radiological assessment of response and adverse events associated with novel systemic oncological therapies

The last decade has seen a paradigm shift in medical oncology treatment with the rise of novel systemic agents, principally molecular targeted therapy and immunotherapy. These new groups of anti-cancer treatment have revolutionised the prognostic landscape for certain patient cohorts with advanced disease, and it is hoped that through ongoing extensive clinical research, significant survival benefits may be demonstrated in the majority of tumour types. However, radiological response assessment of these new agents has become more nuanced for radiologists, as the behaviour of both responding and progressing tumour burden can be more diverse than with conventional chemotherapy. Additionally, radiologists need to be aware of adverse events associated with these treatments as some side effects carry a high morbidity/mortality and may manifest radiologically before they become clinically apparent. This review discusses radiological response assessment and adverse events associated with these novel agents, which have become fundamental aspects of systemic oncological therapy.

[Laparoscopic versus open gastrectomy for advanced gastric cancer : Operative and postoperative results]

BACKGROUND

Minimally invasive gastrectomy is increasingly becoming established worldwide as an alternative to open gastrectomy (OG); however, the majority of available articles in the literature refer to Asian populations and early stages of gastric cancer. This makes an international comparison difficult due to a discrepancy in patient populations and tumor biology as well as Asian and western treatment approaches. Little is known, therefore, whether laparoscopic gastrectomy (LG) can be performed in advanced cancer, in particular with respect to laparoscopic D2 lymphadenectomy, with sufficient radicality and safety in this country.

MATERIAL AND METHODS

All gastrectomies performed for the treatment of advanced gastric cancer with clinical UICC stages 2 and 3 between 2005 and 2017 were analyzed. A case match by age, gender and UICC stage was performed to compare the operative and early postoperative results of LG and OG.

RESULTS

A total of 243 patients with advanced gastric cancer were analyzed. Of these 81 patients (33.3%) underwent LG. The operative time for LG was around 74 min longer (279.2 min vs. 353.4 min, OG vs. LG; p < 0.001), the hospital stay after LG was around 4 days shorter (22.9 days vs. 18.4 days, OG vs. LG; p < 0.001). Significantly more lymph nodes were resected by LG (24.1 lymph nodes vs. 28.8 lymph nodes, OG vs. LG; p < 0.001). In terms of morbidity and mortality there were no differences between the groups.

CONCLUSION

The present study showed that minimally invasive gastrectomy can be performed safely and with comparable histopathological results to open surgery, even in advanced gastric cancer in western populations; however, larger case series and evidence from high-quality studies are urgently needed especially to compare short-term and long-term survival.

THU0027 THE ASSOCIATION OF THE RS35677470 DNASE1L3 GENE POLYMORPHISM WITH SLE, RA AND SSC: STRUCTURAL/BIOLOGICAL INSIGHTS

Background:

Genome-wide association studies (GWAS) have identified hundreds of autoimmune diseases-associated loci so far but much of the heritability of these diseases remains unknown. In an attempt to identify potential causal variants, various studies revealed that the missense variant rs35677470 atDNASE1L3is associated with the development of systemic lupus erythematosus (SLE), rheumatoid arthritis (RA) and systemic sclerosis (SSc), thus exhibiting a pleiotropic effect. Deoxyribonuclease I-like 3 (DNase1L3) is a member of human DNase I family, representing a nuclease that cleaves double-stranded DNA during apoptosis and is involved in the development of autoimmune diseases [1].

Objectives:

To investigate the role of the rs35677470 polymorphism atDNASE1L3gene leading to the R206C mutation in SLE, RA and SSc [2-3] and the mechanism that may affect the loss of function in the protein structure.

Methods:

TheDNASE1L3evolution was investigated to define conservation elements in the protein sequence using, BLASTP extended searches [4], TCOFFEE [5] multiple sequence alignments, and MEGAX [6] for phylogenetics analysis. Three-dimensional (3D) homology modeling was used to localize the polymorphism under study. The mutant was constructed by molecular modeling using the structures of homologous DNAses (PDB entries 1atn, 4awn, 3d3w; [7-9]). Molecular mechanics/dynamics studies were applied to validate structural/functional changes caused by the R206C substitution. All figures depicting 3D models were generated using the PyMOL molecular-graphics system V.2.2 (Schrodinger, LLC).

Results:

The evolutionary analysis shows heavily conserved sequence elements among species indicating structural/functional importance. Structural analysis revealed that the rs35677470 SNP codes for a nonconservative amino acid variation, R206C, disrupts the conserved electrostatic network holding protein secondary structure elements to place. Specifically, the R206 to E170 interaction, part of a salt bridge network stabilizing two a-helices, is being interrupted, thereby affecting the molecular architecture (Fig. 1). Indeed, previous studies on the effect of this SNP in Caucasian populations resulting in a lower level of DNAse1L3 activity are consistent with this observation [10].

Figure 1.

Ribbon representation of the DNAse1L3 homology model showing the position of the stabilizing salt bridge network (E170- R206, R208- D219). Insert figure shows the R206C mutation. Positively charged R (in blue), negatively charged D,E (in red) and C (in yellow) are shown. Distances are in Angstroms.

Conclusion:

This study represents a comprehensive evaluation of the shared autoimmune loci ofDNASE1L3(rs35677470), reported to produce an inactive form of DNaseIL3 [10]. The structural analysis, explains the potential role of the produced mutation by modifying the placement of structural elements and consequently introducing disorder in the protein folding and affecting biological function. Altogether, this study contributes to the delineation of the genetic architecture of SLE, RA and SSc.

References:

[1]Sisirak V et al (2016). Cell 166:88–101

[2]Westra HJ et al (2018). Nat Genet. 50:1366-74

[3]Acosta-Herrera M et al. (2018). Ann Rheum Dis. 78:311-19

[4]Altschul SF et al (1997) Nucleic Acids Res. 25:3389-402.

[5]Notredame et al (2000) JMB, 302:205-17

[6]Kumar S et al (2018) Mol. Biol. Evol. 35:1547-9

[7]Kabsch W et al (1990) Nature 347: 37-44

[8]Parciegla et al (2012) Biochemistry 51: 10250

[9]Sasaki K et al (1993) Acta Cryst., A 49: 111-2

[10]Ueki et al (2009) Clinica Chim. Acta 407:20–4

Disclosure of Interests:

None declared

De-novo Upper Gastrointestinal Tract Cancer after Liver Transplantation: A Demographic Report

BACKGROUND

Immunosuppression is essential after liver transplantation (LT). It, however, increases the risk for cancer.

OBJECTIVE

To evaluate the prevalence and outcome of upper gastrointestinal (GI) tract cancer in LT patients and assess the perioperative risk of surgery for the upper GI malignancies post-LT.

METHODS

2855 patients underwent LT at our clinic from 1988 to 2018. 20 patients developed upper GI cancer. Data were retrospectively extracted from our database. Analysis included patients' specific data, tumor histopathology and stage, the treatment given and survival.

RESULTS

23 patients developed upper GI malignancies (2 gastric and 18 esophageal cancers; 3 excluded), translating to a incidence of 26.4 per 100,000 population per year. All patients were male. 80% showed alcohol-induced cirrhosis before LT. Most of the tumors were diagnosed at a stage ≥III. 70% underwent surgery and 78.6% developed postoperative complications. One-year-survival was 50%. Total survival rate was 28.6% with a median follow-up of 10 months (range: 0-184).

CONCLUSION

Upper GI malignancies are more common after LT compared to the general population. Men after LT, due to alcohol-induced liver cirrhosis, are at a higher risk. Upper GI surgery after LT can be safe, but the severe risk for complications and a poor survival require strict indications.

A multicentre assessment of prostate MRI quality and compliance with UK and international standards

AIM

To assess prostate magnetic resonance imaging (MRI) image quality and compliance with technical standards between centres in the South West region of the UK.

MATERIALS AND METHODS

Fifteen imaging sites in the region submitted seven consecutive anonymised MRI studies. These were assessed by two experienced radiologists in consensus. Overall, subjective image quality for T2-weighted imaging (T2W), diffusion weighted imaging (DWI), and dynamic contrast enhancement (DCE) was scored on a five-point Likert scale. Five additional quality parameters were also assessed visually, including image noise, motion, artefact, and distortion. The degree of compliance by each site with 21 published technical standards was also assessed.

RESULTS

Ninety-four MRI examinations were reviewed from across all sites (mean 6.3 scans per site, range 5-7). Mean compliance with technical standards was 63% (range 38-86%). Forty-seven percent of sites did not perform DCE. One site used a 3 T scanner. The percentage of patients with overall quality scores of ≥3 (diagnostically acceptable) were 68% for T2W, 81% for DWI, and 60% for both T2W and DWI. Ninety-three percent of the 45 patients who underwent DCE had diagnostically acceptable studies. By scanner age, the percentage of patients with diagnostically acceptable T2W scores was 53% for scanners ≥7 years and 80% when <7 years (p=0.006). Comparing individual sites, the mean overall quality scores were 2.9 (range 2.2-4.2) for T2W, 3.2 (1.8-4.7) for DWI, and 3.4 (2.5-4.7) for DCE.

CONCLUSION

There is wide variation in compliance with recognised technical standards and image quality across sites. If MRI is to replace biopsy in selected low-risk patients, improvements in image quality may be required.

Hepatotoxicity following systemic therapy for colorectal liver metastases and the impact of chemotherapy-associated liver injury on outcomes after curative liver resection

Patients with colorectal liver metastases (CLM) have remarkably benefited from the advances in medical multimodal treatment and surgical techniques over the last two decades leading to significant improvements in long-term survival. More patients are currently undergoing liver resection following neoadjuvant chemotherapy, which has been increasingly established within the framework of curative-indented treatment strategies. However, the use of several cytotoxic agents has been linked to specific liver injuries that not only impair the ability of liver tissue to regenerate but also decrease long-term survival. One of the most common agents included in modern chemotherapy regimens is oxaliplatin, which is considered to induce a parenchymal damage of the liver primarily involving the sinusoids defined as sinusoidal obstruction syndrome (SOS). Administration of bevacizumab, an inhibitor of vascular endothelial growth factor (VEGF), has been reported to improve response of CLM to chemotherapy in clinical studies, concomitantly protecting the liver from the development of SOS. In this review, we aim to summarize current data on multimodal treatment concepts for CLM, give an in-depth overview of liver damage caused by cytostatic agents focusing on oxaliplatin-induced SOS, and evaluate the role of bevacizumab to improve clinical outcomes of patients with CLM and to protect the liver from the development of SOS.

[The Impact of Tumor Cell Proliferation on Occult Micrometastases, Tumor Recurrence and Patient Outcome Following Resection for Liver Malignancies]

Liver resection is currently considered to be essential part of the curative treatment of primary and secondary liver malignancies. However, long-term survival in these patients is limited by the high incidence of tumor recurrence. Recent clinical and experimental studies have indicated that cellular and molecular mechanisms associated with liver regeneration after partial hepatectomy may have a proliferative effect on occult micrometastases and circulating tumor cells and are thus responsible for recurrent disease. Growth factors and cytokines involved in liver regeneration have also been shown to influence tumour growth and metastasis. However, the underlying mechanisms explaining the interactions between regenerating liver tissue and tumour cell proliferation remain unclear. The development of modern agents specifically targeting these processes may improve disease-free and overall survival rates after oncological hepatectomy.

Polycystic ovary syndrome: insight into pathogenesis and a common association with insulin resistance

Polycystic ovary syndrome (PCOS) is a common condition that typically develops in reproductive-age women. The cardinal clinical and biochemical characteristics of PCOS include reproductive dysfunction and hyperandrogenic features. PCOS is also strongly associated with obesity based on data from epidemiological and genetic studies. Accordingly, PCOS often becomes manifest in those women who carry a genetic predisposition to its development, and who also gain weight. The role of weight gain and obesity in the development of PCOS is mediated at least in part, through worsening of insulin resistance. Compensatory hyperinsulinaemia that develops in this context disrupts ovarian function, with enhanced androgen production and arrest of ovarian follicular development. Insulin resistance also contributes to the strong association of PCOS with adverse metabolic risk, including dysglycaemia, dyslipidaemia and fatty liver. Conversely, modest weight loss of just 5% body weight with improvement in insulin sensitivity, frequently results in clinically meaningful improvements in hyperandrogenic, reproductive and metabolic features. Future developments of novel therapies for obese women with PCOS should focus on promotion of weight loss and improvement in insulin sensitivity. In this context, therapies that complement lifestyle changes such as dietary modification and exercise, particularly during the maintenance phase of weight loss are important. Putative novel targets for therapy in PCOS include human brown adipose tissue.

Clinical Relevance of Donor-Specific IgM Antibodies in HLA Incompatible Renal Transplantation: A Retrospective Single-Center Study

Immunoglobulin G (IgG) antibodies against donor human leukocyte antigens (HLA) are monitored in the pre-and post-transplant period due to their established role in predicting rejection and renal allograft survival. However, the role of immunoglobulin M (IgM) anti-HLA donor-specific antibodies (DSA) is not fully understood, especially in highly-sensitized patients undergoing direct transplantation. We designed this study to determine whether IgM DSA predicts rejection episodes and/or graft failure. Samples from 92 patients who had undergone HLA-antibody incompatible transplants were tested at 5 time points: days -8 (pre-plasmapheresis), 0, 7, 14, and 30 using Luminex microbead assay with ethylenediaminetetraacetic acid containing wash buffer (LABScreen®, One Lambda, Canoga Park, CA). IgM was defined positive if the mean fluorescence values were greater than 2000. Presence of pre- and post-transplant IgM was correlated with early antibody mediated rejection episodes (within 30 days post-transplantation) and graft failure. Statistical analyses were performed using SPSS IBM software. Graft survival estimates were death-censored. The presence of pre-transplant IgM DSA did not predict rejection (p=0.83) or graft failure (p=0.424). The post-transplant IgM DSA levels peaked at day 14 (similar to IgG DSA levels). Presence of IgM DSA post-transplant (de novo and resynthesis) was not associated with rejection (p=0.83). However, post-transplant IgM was associated with graft failure (p=0.037). This study shows additional testing of post-transplant IgM DSA over and above IgG is important as post-transplant IgM DSA is associated with graft failure.

Polycystic ovary syndrome: insight into pathogenesis and a common association with insulin resistance

Polycystic ovary syndrome (PCOS) is a common condition that typically develops in reproductive-age women. The cardinal clinical and biochemical characteristics of PCOS include reproductive dysfunction and hyperandrogenic features. PCOS is also strongly associated with obesity based on data from epidemiological and genetic studies. Accordingly, PCOS often becomes manifest in those women who carry a genetic predisposition to its development, and who also gain weight. The role of weight gain and obesity in the development of PCOS is mediated at least in part, through worsening of insulin resistance. Compensatory hyperinsulinaemia that develops in this context disrupts ovarian function, with enhanced androgen production and arrest of ovarian follicular development. Insulin resistance also contributes to the strong association of PCOS with adverse metabolic risk, including dysglycaemia, dyslipidaemia and fatty liver. Conversely, modest weight loss of just 5% body weight with improvement in insulin sensitivity, frequently results in clinically meaningful improvements in hyperandrogenic, reproductive and metabolic features. Future developments of novel therapies for obese women with PCOS should focus on promotion of weight loss and improvement in insulin sensitivity. In this context, therapies that complement lifestyle changes such as dietary modification and exercise, particularly during the maintenance phase of weight loss are important. Putative novel targets for therapy in PCOS include human brown adipose tissue.