Preoperative CT-based predictive factors for resectability and medium-term overall survival in patients with peritoneal carcinomatosis from colorectal cancer.

AIM: To determine preoperative radiological findings that may correlate with resectability and medium-term overall survival (OS) in patients with peritoneal carcinomatosis (PC) from colorectal cancer (CRC). MATERIALS AND METHODS: The study included 81 consecutive patients with PC scheduled for cytoreductive surgery (CRS) with hyperthermic intraperitoneal chemotherapy (HIPEC). PCI scores from preoperative computed tomography (CT) were compared with Peritoneal Cancer Index (PCI) scores at laparotomy. Odds ratio (OR), a Cox proportional hazards regression model, and Kaplan-Meier survival analyses were performed to evaluate resectability ("open and close procedure" [O&C]) and OS. RESULTS: A radiological PCI score ≥20 (OR; 20.61 p=0.001), involvement of the perihepatic region (OR; 3.63, p=0.047) and extensive small bowel involvement (OR; 9.90, p=0.019) were risk factors for O&C. Involvement of the left abdominal region correlated adversely to OS (HR; 6.86, p<0.001). CONCLUSIONS: The location of PC, in addition to the extent of PC as determined by preoperative CT, predicts resectability and medium-term survival.

Cohort study of corticosteroid use and risk of hospital admission for diverticular disease.

BACKGROUND: Medication has been suggested as a potential risk factor for diverticular disease. The objective of this study was to investigate the association between the intake of corticosteroids, indometacin or aspirin and diverticular disease. METHOD: This was a prospective population-based cohort study of middle-aged women in the Swedish Mammography Cohort. Use of corticosteroids (oral or inhaled), indometacin or aspirin in 1997 was determined from questionnaires. Cases of diverticular disease were identified from the Swedish national registers until the end of 2010. The relative risk (RR) of diverticular disease requiring hospital admission according to the use of medication was estimated using Cox proportional hazards models, adjusted for age, body mass index, physical activity, fibre intake, diabetes, hypertension, alcohol, smoking and education. RESULTS: A total of 36 586 middle-aged women in the Swedish Mammography Cohort were included, of whom 674 (1.8 per cent) were hospitalized with diverticular disease at least once. Some 7.2 per cent of women reported intake of oral corticosteroids and 8.5 per cent use of inhaled corticosteroids. In multivariable analysis, women who reported oral corticosteroid intake had a 37 per cent (RR 1.37, 95 per cent c.i. 1.06 to 1.78; P = 0.012) increased risk of diverticular disease compared with those who reported no intake at all. Use of inhaled corticosteroids was associated with an even more pronounced increase in risk of 71 per cent (RR 1.71, 1.36 to 2.14; P < 0.001). There was a significant dose-response relationship, with the risk increasing with longer duration of inhaled corticosteroids (P for trend < 0.001). Use of indometacin (2.5 per cent of women) or aspirin (44.2 per cent) did not influence the risk. CONCLUSION: There was a significant relationship between corticosteroids (especially inhaled) and diverticular disease requiring hospital admission.

Randomized clinical trial of fluid restriction in colorectal surgery.

BACKGROUND: Perioperative fluid therapy can influence postoperative hospital stay and complications after elective colorectal surgery. This trial was designed to examine whether an extremely restricted perioperative fluid protocol would reduce hospital stay beyond the existing fast-track hospital time of 7 days after surgery. METHODS: Patients were randomized to restricted or standard perioperative intravenous fluid regimens in a single-centre trial. Randomization was stratified for colonic, rectal, open and laparoscopic surgery. Patients were all treated within a fast-track protocol (careful preoperative preparation, optimal analgesia, early oral nutrition and early mobilization). The primary endpoint was length of postoperative hospital stay. The secondary endpoint was complications within 30 days. RESULTS: Seventy-nine patients were randomized to restricted and 82 to standard fluid therapy. Patients in the restricted group received a median of 3050 ml fluid on the day of surgery compared with 5775 ml in the standard group (P < 0·001). There was no difference between groups in primary hospital stay (median 6·0 days in both groups; P = 0·194) or stay including readmission (median 6·0 days in both groups; P = 0·158). The proportion of patients with complications was significantly lower in the restricted group (31 of 79 versus 47 of 82; P = 0·027). Vasopressors were more often required in the restricted group (97 versus 80 per cent; P < 0·001). CONCLUSION: Restricted perioperative intravenous fluid administration does not reduce length of stay in a fast-track protocol.

Defunctioning stoma in rectal cancer surgery - A risk factor for Low Anterior Resection Syndrome?

BACKGROUND: In rectal cancer surgery the formation of a defunctioning stoma is common in order to reduce the consequences of an anastomotic leakage. The role of a defunctioning stoma and time to stoma reversal, in relation to major Low Anterior Resection Syndrome (LARS) in the long-term perspective, is still unclear. The aim of the study was to investigate the association between a defunctioning stoma and long-term bowel function. METHOD: Patients who underwent curative rectal cancer surgery between 2007 and 2013 in Stockholm county, Sweden, who had no history of anastomotic leakage, without a remaining stoma, free of cancer and alive in April 2017 were eligible for the study. The exposures were (i) use of defunctioning stoma at cancer surgery and (ii) time to stoma reversal. Main outcome was major LARS with information retrieved from the LARS score questionnaire. Multivariable logistic regression model was used to calculate odds ratios (OR) primary comparing major LARS to no LARS. RESULTS: A total of 430 patients were included in analysis. The mean follow-up time was 6.7 years after surgery (range 3.4-10.7 years). The use of a defunctioning stoma was associated to major LARS with an adjusted OR of 2.43 (95% CI 1.14-5.20) when compared to no stoma. There were no evident associations between time to stoma reversal and the risk of major LARS. CONCLUSION: This study indicates that the presence of a defunctioning stoma is associated with impaired bowel function in the long-term perspective, while failing to show any clear association to time to stoma reversal.

Prevalence of low anterior resection syndrome and impact on quality of life after rectal cancer surgery: population-based study.

BACKGROUND: The prevalence of major low anterior resection syndrome (LARS) after rectal cancer surgery varies from 17·8 to 56·0 per cent, but data from high-quality studies are sparse. The aim of this study was to determine the prevalence of LARS and its association with quality of life (QoL) in a large, well defined, population-based cohort. METHODS: This was a population-based study that included all patients who had curative rectal cancer surgery with total or partial mesorectal excision in Stockholm County in Sweden between 2007 and 2013. Patients without a remaining stoma, free from cancer and alive in April 2017 were eligible for the study. The LARS score questionnaire, EORTC QLQ-C30 and Cleveland Clinic Florida Fecal Incontinence score were used as outcome measures. Adjusted mean scores (and differences) of EORTC QLQ-C30 for LARS groups were calculated using repeated measures ANCOVA regression models while adjusting for predefined confounders. RESULTS: In total, 481 patients (82·6 per cent response rate) were included in the analysis. Mean follow-up time was 6·7 (range 3·4-11·0) years after surgery. The prevalence of LARS was 77·4 per cent (370 of 478 patients), with 53·1 per cent (254 of 478) experiencing major LARS. Patients with major LARS reported worse on all EORTC QLQ-C30 subscales (except for financial difficulties) than patients without LARS. A higher mean LARS score was associated with a greater impact on bowel-related QoL. CONCLUSION: After anterior resection for rectal cancer, the majority of patients suffer from major LARS with a negative impact on QoL.

ANTECEDENTES: La prevalencia del síndrome de resección anterior baja (Low Anterior Resection Syndrome, LARS) mayor después de cirugía del cáncer de recto varía entre 17,8% y 56,0%, pero los datos procedentes de estudios de alta calidad son escasos. El objetivo de este estudio fue determinar la prevalencia de LARS y su asociación con la calidad de vida (quality of life, QoL) en una gran cohorte poblacional bien definida. MÉTODOS: Este fue un estudio de base poblacional con todos los pacientes que se sometieron a cirugía curativa de cáncer de recto con exéresis total o parcial del mesorrecto en el condado de Estocolmo en Suecia entre 2007-2013. Los pacientes sin estoma definitivo, sin recidiva y vivos en abril de 2017 fueron elegibles para el estudio. El cuestionario de puntuación LARS, el EORTC QLQ-C30 y el sistema de puntuación de incontinencia de la Cleveland Clinic Florida se usaron como medidas de resultado. Las puntuaciones medias ajustadas (y las diferencias) de EORTC QLQ-C30 para grupos LARS se calcularon utilizando modelos de regresión ANCOVA de medidas repetidas ajustando por factores de confusión predefinidos. RESULTADOS: En total, 481 pacientes (tasa de respuesta del 82,6%) se incluyeron en el análisis. El tiempo medio de seguimiento fue de 6,7 años después de la cirugía (rango 3,4-11,0 años). La prevalencia de LARS fue 77,4% (n = 370) y un 53,1% (n = 254) presentó un LARS mayor. Los pacientes con LARS mayor tuvieron peores resultados en todas las subescalas EORTC QLQ-C30 (excepto por dificultades financieras) que los pacientes sin LARS. Una puntuación LARS media más alta se asoció con un mayor impacto en la calidad de vida relacionada con el intestino. CONCLUSIÓN: Después de una resección anterior por cáncer de recto, la mayoría de los pacientes sufren un LARS mayor con un impacto negativo en la calidad de vida.

Identification of novel deletion breakpoints bordered by segmental duplications in the NF1 locus using high resolution array-CGH.

BACKGROUND: Segmental duplications flanking the neurofibromatosis type 1 (NF1) gene locus on 17q11 mediate most gene deletions in NF1 patients. However, the large size of the gene and the complexity of the locus architecture pose difficulties in deletion analysis. We report the construction and application of the first NF1 locus specific microarray, covering 2.24 Mb of 17q11, using a non-redundant approach for array design. The average resolution of analysis for the array is approximately 12 kb per measurement point with an increased average resolution of 6.4 kb for the NF1 gene. METHODS: We performed a comprehensive array-CGH analysis of 161 NF1 derived samples and identified heterozygous deletions of various sizes in 39 cases. The typical deletion was identified in 26 cases, whereas 13 samples showed atypical deletion profiles. RESULTS: The size of the atypical deletions, contained within the segment covered by the array, ranged from 6 kb to 1.6 Mb and their breakpoints could be accurately determined. Moreover, 10 atypical deletions were observed to share a common breakpoint either on the proximal or distal end of the deletion. The deletions identified by array-CGH were independently confirmed using multiplex ligation-dependent probe amplification. Bioinformatic analysis of the entire locus identified 33 segmental duplications. CONCLUSIONS: We show that at least one of these segmental duplications, which borders the proximal breakpoint located within the NF1 intron 1 in five atypical deletions, might represent a novel hot spot for deletions. Our array constitutes a novel and reliable tool offering significantly improved diagnostics for this common disorder.

A large deletion disrupts the exon 3 transcription activation domain of the BRCA2 gene in a breast/ovarian cancer family.

We describe the identification of a large deletion in the BRCA2 gene as the disease-causing mutation in a Swedish breast/ovarian cancer family. The 5068-bp deletion encompassed the 3' region of exon 3, including the 3' splice site and most of intron 3, and it resulted on the mRNA level in an inframe exon 3 skipping. The junction site also included an insertion of 4 bp (CCAT). The mutation (nt504del5068insCCAT) resulted in a genotype absent of the two transcription activation regions localized to exon 3. The breast cancer phenotype associated with the described mutation resembled the phenotype of breast cancer found in both BRCA1 and BRCA2 mutation carriers. This is the first report of a large deletion as the disease-causing mutation in the BRCA2 gene.

Reactivity of cytochromes c and f with mutant forms of spinach plastocyanin.

The reduction of plastocyanin by cytochromes c and f has been investigated with mutants of spinach plastocyanin in which individual, highly conserved surface residues have been modified. These include Leu-12 and Phe-35 in the 'northern' hydrophobic patch and Tyr-83 and Asp-42 in the 'eastern' acidic patch. The differences observed all involved binding rather than the intrinsic rates of electron transfer. The Glu-12 and Ala-12 mutants showed small but significant decreases in binding constant with cytochrome c, even though the cytochrome is not expected to make contact with the northern face of plastocyanin. These results, and small changes in the EPR parameters, suggested that these mutations cause small conformational changes in surface residues on the eastern face of plastocyanin, transmitted through the copper centre. In the case of cytochrome f, the Glu-12 and Ala-12 mutants also bound less strongly, but Leu12Asn showed a marked increase in binding constant, suggesting that cytochrome f can hydrogen bond directly to Asn-12 in the reaction complex. A surprising result was that the kinetics of reduction of Asp42Asn were not significantly different from wild type, despite the loss of a negative charge.

PMM2 mutation spectrum, including 10 novel mutations, in a large CDG type 1A family material with a focus on Scandinavian families.

Carbohydrate-deficient glycoprotein syndrome type IA (CDG IA) is an autosomal recessive disease characterized clinically by severe involvement of the central and peripheral nervous system, and biochemically by complex defects in carbohydrate residues in a number of serum glycoproteins. CDG IA is caused by mutations in the PMM2 gene located in chromosome region 16p13. In this study, 61 CDG type IA patients (122 chromosomes) were screened for mutations in the PMM2 gene using a combination of SSCP and sequence analysis. More than 95% of the mutations could be detected. All of them were missense mutations. Mutations 422G>A and 357C>A were strikingly more common in the material and comprised 58% of mutations detected. Of the 20 mutations found, 10 were not reported previously. Seven mutations, e.g. 26G>A (five alleles) and 548T>C (seven alleles), were found only in Scandinavian families. The most common genotype was 357C>A/422G>A (36%). Three patients were homozygous, 357C>A/357C>A (two cases), and 548T>C/548T>C (one case). No patients homozygous for the most common mutation 422G>A were detected. The different mutations were clustered e.g., in that most were located in exon 5 (five) and exon 8 (six), while no mutation was detected in exon 2. When the frequencies of each mutation were included, exon 5 comprised 61% (65 chromosomes) of the mutations; in Scandinavian patients the frequency of these mutations was 72%. Thus, analysis of exon five in these patients enables both reliable and time-saving first screening in prenatal diagnostic cases. This could be followed by a second step of additional strategies for the detection of other mutations.

The western Swedish BRCA1 founder mutation 3171ins5; a 3.7 cM conserved haplotype of today is a reminiscence of a 1500-year-old mutation.

The most recurrent BRCA1/BRCA2 mutation in Sweden is the BRCA1 mutation 3171ins5. In the western part of Sweden this mutation accounts for as much as 77% of identified mutations in these two genes. Our aim was to analyse in detail the haplotype and founder effects of the 3171ins5 and furthermore attempt to estimate the time of origin of the mutation. In the study we included eighteen apparently unrelated families with hereditary breast and/or ovarian cancer. At least one individual in each family had previously tested positive for the 3171ins5 mutation. Polymorphic microsatellite markers were used for the haplotype analyses. The markers were located within or flanking the BRCA1 gene spanning a region of 17.3 cM. We found several different haplotypes both for disease alleles and for the normal alleles. However, a conserved haplotype of 3.7 cM was observed in the 3171ins5 carriers spanning over four markers located within or very close to the BRCA1 gene. As this haplotype was not present in any of the normal controls it is highly likely that this is a mutation identical by descent, i.e. a true founder. The results from the haplotype analyses were used to estimate the age of the mutation. Estimations based on the P(excess) and linkage disequilibrium gives a first appearance of the mutation sometime around the 6th century, approximately 50 generations ago.

Expression of spinach plastocyanin in E. coli.

An expression vector designed for overexpression of plastocyanin in the periplasmic space of E. coli has been developed. The vector contains the signal peptide sequence of Pseudomonas aeruginosa azurin and the mature sequence of spinach plastocyanin. The precursor is efficiently translocated to the periplasmic space and correctly processed to mature plastocyanin. No detectable amount of plastocyanin was present in the cytoplasmic or in the membrane fraction. A large scale preparation of the recombinant plastocyanin in a 20 litre fermentor yielded approximately 30 mg of pure plastocyanin. The recombinant protein obtained from E. coli shows CD, EPR and optical properties identical to plastocyanin isolated from spinach.

Flash-photolysis studies of the electron transfer from genetically modified spinach plastocyanin to photosystem I.

Plastocyanin (Pc) has been modified by site-directed mutagenesis at two separate electron-transfer (ET) sites: Leu-12-Glu at a hydrophobic patch, and Tyr-83-His at an acidic patch. The reduction potential at pH 7.5 is decreased by 26 mV in Pc(Leu-12-Glu) and increased by 35 mV in Pc(Tyr-83-His). The latter mutant shows a 2-fold slower intracomplex ET to photosystem I (PSI) as expected from the decreased driving force. The affinity for PSI is unaffected for this mutant but is drastically decreased for Pc(Leu-12-Glu). It is concluded that the hydrophobic patch is more important for the ET to PSI.

The structural gene for cytochrome c551 from Pseudomonas aeruginosa. The nucleotide sequence shows a location downstream of the nitrite reductase gene.

The gene coding for Pseudomonas aeruginosa cytochrome c551 has been cloned and its nucleotide sequence determined. Cytochrome c551 is expressed as a 104 amino acid pre-protein from which a signal peptide of 22 amino acids is cleaved off during the translocation across the cytoplasmic membrane. The gene is located just downstream of the gene coding for nitrite reductase on the Pseudomonas aeruginosa chromosome, suggesting that these genes form an operon.

Expression of the blue copper protein azurin from Pseudomonas aeruginosa in Escherichia coli.

The structural gene for the blue copper protein azurin from Pseudomonas aeruginosa has been subcloned in different expression plasmid vectors. The highest yield of expression was obtained when the gene with its native ribosome-binding site was placed downstream of the lac promoter in plasmid pUC18. The protein is exported to the periplasmic space in Escherichia coli and the amount corresponds to 27% of the total protein content in the periplasmic space. The preprotein is cleaved correctly according to N-terminal sequencing of the purified protein. Azurin has been purified in large amounts and is spectroscopically indistinguishable from the protein purified from P. aeruginosa.

Delimitation of a critical tumour suppressor region at distal 1p in neuroblastoma tumours.

We analysed DNA from 68 neuroblastoma tumours for loss of heterozygosity (LOH) on the distal chromosome 1p (1p-LOH) using PCR-based DNA polymorphisms. Fifteen tumours (22%) displayed 1p-LOH. The shortest region of overlap (SRO) for the deletions was defined proximally by marker D1S244 and distally by marker D1S80. The CDC2L1 locus, located on chromosome 1p36, has been put forward as a neuroblastoma tumour suppressor. We analysed coding regions of the CDC2L1 gene in a subset of aggressive neuroblastoma tumours with known allelic loss for different 1p-markers. Single-stranded conformation polymorphism, heteroduplex and sequencing analysis of tumour DNA did not reveal any significant changes in the coding region. Using a DNA sequence polymorphism, we showed, in a primary tumour with an interstitial allelic deletion, that this tumour had both alleles of the CDC2L1 locus retained in the tumour. Thus, we showed that the neuroblastoma tumour suppressor critical region on 1p in our material is defined by loci D1S244 and D1S80 and that the CDC2L1 locus is distal to the critical region.

A founder mutation of the BRCA1 gene in Western Sweden associated with a high incidence of breast and ovarian cancer.

The aim of this study was to describe and characterise a founder mutation of the BRCA1 gene in western Sweden. Of 62 families screened for BRCA mutations, 24 had BRCA1 mutations and two had BRCA2 mutations. Tumours that occurred in family members were histologically reviewed and mutational status was analysed using archival paraffin-embedded tissues. The same BRCA1 mutation, 3171ins5, was found in 16 families who were clustered along the western coast of Sweden. Mutation analysis revealed a maternal linkage in 13 families and a paternal linkage in 3. There was complete agreement between mutation analysis results obtained from blood and archival tissues. The penetrance of breast or ovarian cancer by age 70 years was estimated to be between 59 and 93%. There were no differences in survivals between breast or ovarian cancer patients with the mutation and age-matched controls. Thus, a predominant BRCA1 gene founder mutation associated with a high risk of breast and ovarian cancer has been identified and found to occur in a restricted geographical area, thereby allowing timely and cost-effective mutation screening using blood samples or archival histological material.

Novel germline mutations in Swedish von Hippel-Lindau disease patients.

We have used a combination of different mutation detection systems in analyzing two Swedish families with von Hippel-Lindau disease (VHL). The methods employed were single-stranded conformation polymorphism (SSCP), heteroduplex analysis, and direct sequencing. The families were both shown to carry constitutional mutations in the VHL gene not reported earlier. Both were frameshift mutations (i.e. nt761delC and nt732insAA) predicted to give a premature stop codon. The correlation of mutation data to different clinical features of VHL is discussed.

Analysis of location and integrity of the human PITSLRE (p58(cdc2L1)) genes in neuroblastoma cell genomes.

The family of PITSLRE kinase genes, located in chromosome 1p36, has recently been associated with neuroblastoma tumorigenesis. In order to evaluate the role of these genes as putative tumor suppressor genes, we have analyzed the integrity of the coding region in primary tumors and its location relative to a neuroblastoma consensus deletion. A subset of aggressive neuroblastoma tumors with allelic loss of different parts of chromosome 1p were investigated. Single-strand conformation polymorphism (SSCP), heteroduplex (HD) and sequencing analysis of tumor DNA did not reveal any significant changes in the coding region. In particular, a primary tumor with an interstitial allelic deletion in 1p36 did not reveal concomitant loss of heterozygosity of the PITSLRE gene region when analyzed with a C/T DNA sequence polymorphism in exon 5 of PITSLRE1. FISH analysis on neuroblastoma cell lines with small interstitial deletions and with a balanced translocation in 1p36 revealed that the PITSLRE gene cluster was localized distal to the neuroblastoma consensus deletion. against an involvement of the PITSLRE genes in neuroblastoma tumorigenesis.

Effects on Cell Proliferation, Activator Protein-1 and Genotoxicity by Fecal Water from Patients with Colorectal Adenomas.

BACKGROUND: The free water phase of feces (fecal water) may mediate the effects of diet on colon carcinogenesis. We examined the effects of fecal water from adenoma patients and controls on three parameters in colonocytes believed to be relevant to tumorigenesis, i.e. genotoxicity in intact cells and on isolated DNA, proliferative activity and activator protein-1 (AP-1) activity. METHODS: Genotoxicity in intact colonic cells was assayed using the single-cell gel electrophoresis assay (`comet' assay) and on isolated DNA using double-stranded DNA from the X-174 RF plasmid. Cell proliferation was assessed using the commercially available `alamar blue' proliferation kit and AP-1 activity using cells transiently transfected with an AP-1-luciferase reporter construct. RESULTS: The data showed that lipid extracts of fecal water samples from the adenoma patients had a significantly higher capacity to induce cell proliferation than those from controls, and that this effect could be explained to a large extent by the concentrations of deoxycholic and chenodeoxycholic acids in the fecal water using regression models. No difference between patients and controls was observed for induction of AP-1 activity or induction of DNA strand breaks in intact cells. However, induction of DNA strand breaks in isolated DNA was significantly higher for the fecal waters from patients than for those from controls, which could be explained in part in a regression model by concentrations of lithocholic acid in fecal water and fecapentaene-12 in feces. CONCLUSIONS: Our results support the hypothesis that the biochemistry of fecal waters from adenoma patients and controls differs.