Multidisciplinary treatment of desmoid tumours in Gardner's syndrome due to a large interstitial deletion of chromosome 5q.

BACKGROUND AND AIMS: Classic autosomal-dominant familial adenomatous polyposis (FAP) is clinically defined by the development of hundreds to thousands of colorectal adenomas beginning in childhood and adolescence. A variant of FAP characterized by polyposis in combination with osteomas or soft tissue tumours is called Gardner's syndrome. FAP is caused by germline inactivation of the APC (adenomatous polyposis coli) tumour-suppressor gene located on the long arm of chromosome 5 (5q21-5q22). Cytogenetically visible deletions of chromosome 5q encompassing APC have very rarely been reported. Here, we aimed to phenotypically and genetically characterize a patient with a heterozygous 5q deletion resulting in Gardner's syndrome. METHODS AND RESULTS: A 26-year-old female patient with mild mental handicap and dysmorphic features due to a cytogenetically visible deletion on chromosome 5q (microscopically estimated region 5q14-5q23) presented at our tertiary referral centre because of mild adenomatous polyposis (<500 polyps). Twenty months after prophylactic proctocolectomy with definitive ileostomy, three rapidly growing desmoids were observed. Tumour-associated complications necessitated a multidisciplinary approach including medical treatment, surgery and radiation therapy. The characterization of the deletion by comparative genomic hybridization identified a large 5q deletion expanding over a 20-Mb region (5q21.3-5q23.3) including the APC gene. CONCLUSION: Chromosome deletions must be suspected in patients presenting with FAP together with mental handicap and dysmorphic features. This case also impressively shows that FAP-associated desmoids need multimodal treatment taking into account the patient's individual symptoms, disease progression and tumour location.

MUTYH hotspot mutations in unselected colonoscopy patients.

AIM: Biallelic MutY human homologue (MUTYH) germline mutations predispose to recessively inherited adenomatous polyposis, designated MUTYH-associated polyposis (MAP), and colorectal cancer (CRC). The hotspot mutations p.Y179C and p.G396D account for the majority of pathogenic variants of MUTYH in Caucasians. Our aim was to evaluate the prevalence of MUTYH mutations in a prospective cohort of unselected patients with different colorectal diseases. METHOD: The hotspot mutations p.Y179C and p.G396D were genotyped in 352 consecutive patients undergoing colonoscopy at our tertiary referral centre. Exons 2-14 were sequenced in hotspot mutation carriers to exclude additional variants. RESULTS: Overall, we identified five heterozygous p.Y179C mutations and three heterozygous p.G396D mutations in seven hotspot mutation carriers (risk allele frequencies 0.7% and 0.4%, respectively). Two of these hotspot mutation carriers harboured a heterozygous p.Q338H variant, which is of uncertain clinical significance, on the other allele. Three individuals were biallelic MUTYH variant carriers (p.Y179C/p.G382D: typical MAP; p.Y179C/p.Q338H: atypical MAP with late onset and lower polyp burden; p.G382D/p.Q338H: inflammatory bowel disease), and four subjects were monoallelic mutation carriers. CONCLUSION: MUTYH-associated disease, and hence genetic counselling and MUTYH genetic testing, should be considered in the clinical routine of an endoscopy unit, but the wide range of phenotypes represents a challenge for patient identification. The clinical significance of p.Q338H should be evaluated in future case-control studies because compound heterozygotes for pathogenic mutations and p.Q338H may be at increased risk for mild polyposis or CRC. In addition, MUTYH should be assessed as a potential susceptibility gene for the development of colitis-associated CRC in future.

A randomized multicenter phase II study comparing capecitabine with irinotecan or cisplatin in metastatic adenocarcinoma of the stomach or esophagogastric junction.

BACKGROUND: The combination of irinotecan with 5-fluorouracil demonstrates efficacy with tolerable safety in the first-line treatment of metastatic gastroesophageal cancer (mGC). This randomized phase II trial compared for the first time capecitabine with irinotecan or cisplatin in this setting. PATIENTS AND METHODS: Patients were randomly assigned to receive 3-week cycles of capecitabine 1000 mg/m(2), twice daily for 14 days, with on day 1 either irinotecan 250 mg/m(2) (XI) or cisplatin 80 mg/m(2) (XP). The primary end point was overall response rate (ORR) and secondary end points included progression-free survival (PFS), overall survival (OS) and safety. RESULTS: Of 118 patients recruited, 112 were eligible for safety analysis and 103 for efficacy analysis. In the XI and XP treatment arms, there were no marked differences in ORR, 37.7% versus 42.0%, and median PFS, 4.2 versus 4.8 months, although median OS was longer, 10.2 versus 7.9 months, respectively. Grade 3/4 toxicity was higher in the XP regimen for thrombocytes (18.2% versus 1.8%), nausea (23.6% versus12.3%) and vomiting (16.4% versus 1.8%) and in the XI arm for diarrhea (22.8% versus 7.3%). CONCLUSION: The comparable activity and safety of the XI and XP regimens establish XI as a relevant platinum-free first-line treatment choice for patients with mGC.

Absence of the interstitial cell of Cajal network in mitochondrial neurogastrointestinal encephalomyopathy.

Mitochondrial neurogastrointestinal encephalomyopathy (MNGIE) is a rare autosomal-recessive multisystemic disorder with predominant gastrointestinal involvement, presenting with variable degrees of gut dysmotility up to frank chronic intestinal pseudoobstruction. Despite major advances in understanding its basic molecular pathogenesis in recent years, the distinct mechanisms and pathoanatomical substrate underlying MNGIE-associated gastrointestinal dysmotility are still widely unknown. As yet, though their critical role in proper gastrointestinal transit in terms of spontaneous pacemaker activity and enteric neurotransmission is well established, the population of the interstitial cells of Cajal (ICC) has not been investigated in MNGIE. Therefore, we examined small bowel samples of a well-characterized MNGIE patient by using conventional histology and immunohistochemistry techniques. The ICC network was studied by immunohistochemistry for the tyrosine kinase Kit (CD117), known to reliably detect ICCs, while mucosal mast cells served as an internal and normal small bowel specimen as external controls. At a light microscopic level, no gross structural alteration of the bowel wall composition and its neuromuscular elements was noted. However, a complete absence of Kit immunoreactive cells could be demonstrated in regions where ICCs are normally abundant, while internal and external controls retained strong Kit positivity. In conclusion, our preliminary results provide a first evidence for an alteration of the ICC network in MNGIE, and support the notion that ICC loss might be an early pathogenetic event in MNGIE-associated gut motor dysfunction before significant myopathic and/or neuropathic structural changes occur.

Para-[(123)I]iodo-L-phenylalanine in patients with pancreatic adenocarcinoma: tumour uptake, whole-body kinetics, dosimetry.

UNLABELLED: Recently, p-[(123)I]iodo-L-phenylalanine (IPA) was clinically validated for brain tumour imaging. Preclinical studies demonstrated uptake of IPA into pancreatic adenocarcinoma suggesting its diagnostic application in patients with pancreatic tumours. The aim was to study the tumour uptake of IPA in patients with pancreatic adenocarcinoma and to analyse its biodistribution and dosimetry to assess the radiation dose resulting from its diagnostic use. PATIENTS, METHODS: Seven patients with pancreatic adenocarcinoma underwent whole-body scintigraphies and SPECT up to 24 h after administration of 250 MBq of IPA. Tumour uptake of IPA was assessed visually. Time activity curves and the corresponding residence times were determined for whole-body, kidneys, liver, spleen, lung, heart content, brain, and testes. Mean absorbed doses for various organs and the effective dose were assessed based on the MIRD formalism using OLINDA/EXM. RESULTS: IPA exhibited no accumulation in proven manifestations of pancreatic adenocarcinomas. IPA was exclusively eliminated by the urine and showed a delayed clearance from blood. Residence times were 0.26 +/- 0.09 h for kidneys, 0.38 +/- 0.19 h for liver, 0.15 +/- 0.07 h for spleen, 0.51 +/- 0.20 h for lungs, 0.22 +/- 0.07 h for heart content, 0.11 +/- 0.05 h for brain, 0.014 +/- 0.005 h for testes and 6.4 +/- 2.2 h for the remainder. The highest absorbed doses were determined in the urinary bladder wall and in the kidneys. According to the ICRP 60 the effective dose resulting from 250 MBq IPA was 3.6 +/- 0.7 mSv. CONCLUSION: Para-[(123)I]iodo-L-phenylalanine can be used in diagnostic nuclear medicine with acceptable radiation doses. Besides its proven validity for brain tumour imaging, IPA does not appear to be suitable as tracer for pancreatic cancer.

Characterization of the nuclear import of human MutLalpha.

DNA mismatch repair (MMR) is essential for the maintenance of replication fidelity. Its major task is to recognize mismatches as well as insertion/deletion loops of newly synthesized DNA strands. Although different players of human MMR have been identified, the regulation of essential steps of MMR is poorly understood. Because MMR is initiated in the nucleus, nuclear import might be a mechanism to regulate MMR. Nuclear targeting is accomplished by conserved signal sequences called nuclear localization signals (NLS), which represent clusters of positively charged amino acids (aa). hMLH1 contains two clusters of positively charged amino acids, which are candidate NLS sequences (aa 469-472 and 496-499), while hPMS2 contains one (aa 574-580). To study the effect of these clusters on nuclear import, NLS mutants of hMLH1 and hPMS2 were generated and expressed in 293T cells. The subcellular localization of the mutant constructs was monitored by confocal laser microscopy. We demonstrated that missense mutations of two signal sequences, one in hMLH1 and one in hPMS2, lead to impaired nuclear import, which was especially prominent for mutants of the hMLH1 residues K471 and R472; and hPMS2 residues K577 and R578.

Downregulation of CD44v6 in colorectal carcinomas is associated with hypermethylation of the CD44 promoter region.

Overexpression of the cell adhesion protein CD44v6 has been demonstrated in colorectal cancer and other gastrointestinal tumors. While CD44v6 is upregulated in benign colorectal adenomas and well-differentiated colorectal cancer tissues, downregulation frequently occurs during disease progression. The mechanism of downregulation, however, is unknown. Therefore, we evaluated the methylation status of the CD44 promoter as a mechanism for decreased CD44v6 expression in advanced colorectal carcinomas. We demonstrated by methylation-sensitive restriction enzyme digestion that the CpG islands of the CD44 promoter were methylated in 6/21 (28%) of benign colorectal adenomas. Interestingly, in colorectal carcinomas the frequency of promoter methylation was significantly increased (10/19; 53%) compared to 7/21 (33%) in the corresponding normal mucosa. Methylation seems to be associated with a more advanced cancer stage, but the trend did not reach statistical significance. In colorectal carcinomas with CD44 promoter methylation CD44v6 mRNA was detected by reverse transcription-polymerase chain reaction in 3/10 carcinomas, whereas in tumors without CD44 promoter methylation CD44v6 expression was observed in 8/9 (P

Transient mismatch repair gene transfection for functional analysis of genetic hMLH1 and hMSH2 variants.

BACKGROUND: Germline mutations in the mismatch repair (MMR) genes hMLH1 and hMSH2 can cause hereditary non-polyposis colorectal cancer (HNPCC). However, the functional in vitro analysis of hMLH1 and hMSH2 mutations remains difficult. AIMS: To establish an in vitro method for the functional characterisation of hMLH1 and hMSH2 mutations. METHODS: hMLH1 and hMSH2 wild type (wt) genes and several mutated subclones were transiently transfected in mismatch repair deficient cell lines (HCT-116 and LOVO). Apoptosis, proliferation, and regulation of mRNA expression and protein expression of interacting proteins were analysed by Hoechst staining, AlamarBlue staining, real time polymerase chain reaction, and western blotting, respectively. RESULTS: The protein expression of hMLH1 and hMSH2 mutants was significantly decreased after transfection compared with wild type transfections. The hMLH1 and hMSH2 interacting proteins hPMS2 and hMSH6 became detectable only after transfection of the respective wild type genes. In parallel, hMSH6 mRNA levels were increased in hMSH2 wt transfected cells. However, hPMS2 mRNA levels were independent of the mutation status of its interacting partner hMLH1, indicating a post-transcriptional regulating pathway. In the hMLH1 deficient HCT-116 cell line apoptosis was not affected by transfection of any mismatch repair gene, whereas complementation of hMSH2 deficiency in LOVO cells increased apoptosis. Conversely, proliferative activity of HCT-116 was decreased by complementation with hMLH1wt and unaffected in hMSH2 deficient LOVO cells. CONCLUSION: These data show that the cellular role of the MMR genes and its mutations are assessable in a simple transient transfection system and show the influence of MMR gene regulation on major cell growth regulating mechanisms. This method is applicable for the functional definition of mutations in hMLH1 and hMSH2 genes observed in patients with suspected HNPCC.

Frequency of the Amsterdam criteria in a regional German cohort of patients with colorectal cancer.

Estimates of the colon cancer burden associated with hereditary nonpolyposis colorectal cancer (HNPCC) vary from less than 1 % to more than 5 %. Amsterdam criteria fulfilled within a kindred (classic Amsterdam and Amsterdam II criteria) are widely used to identify patients prone to HNPCC. The present study was initiated to assess the frequency of the Amsterdam criteria within a regional German cohort of 207 patients with a history of colorectal cancer (CRC). Data on individual and family cancer histories were available in 154 patients (73 women, 81 men; mean age at diagnosis 62.4 +/- 13.3 years). A total of 843 first degree relatives have been identified within the kindreds of whom 121 had verified cancers. In 28 of 154 families (18 %), at least one first degree relative of the index patient had CRC. With respect to a typical family history, five kindreds (3.2 %) were likely to suffer from HNPCC on a clinical basis (4 kindreds met the classic Amsterdam criteria and one kindred the Amsterdam II criteria). Testing for microsatellite instability could additionally be performed in 4 of 5 patients who met the Amsterdam criteria and revealed DNA instability in 3 cases. Moreover, a missense mutation of MSH2 (Gly965Asp) was detected in one patient with microsatellite instability. Based on the classic Amsterdam and Amsterdam II criteria approximately 3 % of a regional German cohort of patients with CRC are likely to suffer from HNPCC. However, the final diagnosis of HNPCC can only be established by detection of pathogenic germline mutations within the DNA mismatch repair genes.

Expression and release of IL-18 binding protein in response to IFN-gamma.

IL-18 and IL-18 binding protein (IL-18BP) are two newly described opponents in the cytokine network. Local concentrations of these two players may determine biological functions of IL-18 in the context of inflammation, infection, and cancer. As IL-18 appears to be involved in the pathogenesis of Crohn's disease and may modulate tumor growth, we investigated the IL-18/IL-18BPa system in the human colon carcinoma/epithelial cell line DLD-1. In this study, we report that IFN-gamma induces expression and release of IL-18BPa from DLD-1 cells. mRNA induction and secretion of IL-18BPa immunoreactivity were associated with an activity that significantly impaired release of IFN-gamma by IL-12/IL-18-stimulated PBMC. Inducibility of IL-18BPa by IFN-gamma was also observed in LoVo, Caco-2, and HCT116 human colon carcinoma cell lines and in the human keratinocyte cell line HaCaT. Induction of IL-18BPa in colon carcinoma/epithelial cell lines was suppressed by coincubation with sodium butyrate. IFN-gamma-mediated IL-18BPa and its suppression by sodium butyrate were confirmed in organ cultures of intestinal colonic biopsy specimens. In contrast, sodium butyrate did not modulate expression of IL-18. The present data suggest that IFN-gamma may limit biological functions of IL-18 at sites of colonic immune activation by inducing IL-18BPa production. Down-regulation of IL-18BPa by sodium butyrate suggests that reinforcement of local IL-18 activity may contribute to actions of this short-chain fatty acid in the colonic microenvironment.

A de novo deletion of chromosome 5q causing familial adenomatous polyposis, dysmorphic features, and mild mental retardation.

Familial adenomatous polyposis (FAP) is an autosomal dominant disorder that typically presents with colorectal cancer secondary to extensive adenomatous polyps of the colon. The molecular basis and clinical phenotype of FAP are well known. Recurrent episodes of severe abdominal pain and a positive fecal occult blood test in an 18-yr-old boy with mild mental retardation and slight dysmorphic features of the face, head, and skeletal system led to the diagnosis of FAP. The clinical workup revealed the presence of over 100 sessile colonic polyps but no polyp formation in the upper GI tract, no cancer development, nor other FAP-associated lesions. To find out whether there is an association between mental retardation and FAP we performed a chromosome analysis including comparative genomic hybridization and an indirect genotype analysis with polymorphic markers from the APC gene region. Cytogenetic analysis showed an interstitial deletion of chromosomal region 5q that was confined to the region 5q21-q22 by comparative genomic hybridization. The deletion, spanning about 10 centimorgans, encompassed the complete APC gene and can be considered as causative for FAP. Moreover, molecular genetic analysis with polymorphic markers flanking the APC gene demonstrated a de novo deletion on the paternal chromosome. Cytogenetically detectable deletions on chromosome 5 including the APC gene generally lead to an associated gene deletion syndrome. Individuals who present with mild mental retardation and dysmorphic features should therefore be investigated for chromosomal deletions. If the deletion encompasses the APC gene, these patients are at high risk of developing FAP and associated complications.

Bethesda guidelines: relation to microsatellite instability and MLH1 promoter methylation in patients with colorectal cancer.

BACKGROUND: Microsatellite instability is a hallmark of mismatch repair deficiency in hereditary nonpolyposis colorectal cancer and results from mutations in the mismatch repair genes MLH1 or MSH2 or from gene inactivation associated with DNA methylation. The Bethesda guidelines were established to identify patients with colorectal cancer who should be tested for microsatellite instability. OBJECTIVE: To assess the Bethesda guidelines for detection of microsatellite instability and to determine the role of MLH1 promoter methylation in colorectal cancer. DESIGN: Prospective cohort study. SETTING: Tertiary care referral center in Frankfurt, Germany. PATIENTS: 125 consecutive patients with colorectal cancer. MEASUREMENTS: Patients were assessed according to the Bethesda guidelines, and tumor specimens were analyzed for microsatellite instability. Patients with microsatellite instability were tested for MLH1 promoter methylation and MLH1 and MSH2 germline mutations. RESULTS: Microsatellite instability was detected in 17 of 58 patients who fulfilled and 5 of 67 patients who did not fulfill criteria of the Bethesda guidelines. In 11 of 17 patients with microsatellite instability who fulfilled Bethesda guidelines, an MLH1 (n = 3), MSH2 (n = 7), or combined MLH1 and MSH2 (n = 1) mutation was found. Among the patients with microsatellite instability who did not fulfill Bethesda guidelines, no mutations were observed; MLH1 promoter methylation was observed in 6 of 11 patients with an MLH1 or MSH2 mutation and 5 of 11 patients without an MLH1 or MSH2 mutation. CONCLUSIONS: The Bethesda guidelines are useful for selecting patients for microsatellite instability testing. MLH1 and MSH2 testing should be recommended in all patients with colorectal cancer and microsatellite instability who fulfill at least one Bethesda criterion. MLH1 promoter methylation may accompany rather than initiate carcinogenesis in patients with colorectal cancer who have mismatch repair gene defects.

Randomized, placebo-controlled, double-blind trial with interferon-alpha with and without amantadine sulphate in primary interferon-alpha nonresponders with chronic hepatitis C.

In primary interferon-alpha (IFN-alpha) nonresponders with chronic hepatitis C, retreatment with IFN-alpha has only limited efficacy with sustained response rates below 10%. Therefore, the aims of the present study were to compare the efficacy and safety of IFN-alpha alone or in combination with amantadine sulphate in nonresponders to previous IFN-alpha monotherapy. Fifty-five IFN-alpha nonresponders with chronic hepatitis C (mean age: 46.6 years) received IFN-alpha 6 MIU thrice weekly for 24 weeks followed by 3 MIU thrice weekly for additional 24 weeks. Amantadine sulphate (n=26) or a matched placebo (n=29) was given orally twice daily for 48 weeks. Because of a low initial response rate at week 12 (13/55 patients) and a high breakthrough rate (8/13 patients) after IFN-alpha dose reduction in week 24, a virological end-of-treatment response with undetectable serum HCV-RNA (< 1000 copies/mL) was achieved in only five patients (IFN-alpha/amantadine sulphate, one patient; IFN-alpha/placebo, four patients). After 24 weeks follow-up a sustained virological response was observed in only two patients receiving IFN-alpha and placebo. Health-related quality-of-life analysis showed a substantial improvement of the Profile of Mood States (POMS) scale concerning the subscales fatigue (P < 0.05) and vigor (P < 0.05) in patients receiving combined IFN-alpha/amantadine sulphate treatment compared with those treated with IFN-alpha alone. IFN-alpha/amantadine sulphate combination therapy was well tolerated without any serious adverse events. In conclusion, retreatment with IFN-alpha and amantadine sulphate does not increase the low sustained virological response rates of IFN-alpha therapy in primary IFN-alpha nonresponders with chronic hepatitis C, but may lead to a sustained improvement of health-related quality-of-life.

Activation of a cryptic splice site of PTEN and loss of heterozygosity in benign skin lesions in Cowden disease.

Cowden disease is an autosomal dominant syndrome characterized by facial trichilemmomas, acral keratoses, papillomatous papules, mucosal lesions, and an increased risk for breast and nonmedullary thyroid cancer. Here, we describe a novel PTEN splicing site mutation in a family with classical Cowden disease and we studied benign skin lesions typical for Cowden disease for loss of heterozygosity. We found a PTEN IVS2 + 1G > Alpha 5'-splicing acceptor mutation resulting in activation of a cryptic splice site. Activation of this cryptic splice site is predicted to result in a frameshift with a premature stop codon, thus disrupting the phosphatase core motif of PTEN. Loss of heterozygosity analysis of two trichilemmomas, one fibroma, and three acanthomas of the index patient demonstrated loss of heterozygosity at the PTEN locus in four of these lesions. In conclusion, our data demonstrate that a PTEN splicing site mutation causes activation of a cryptic splice site, which results in aberrant transcripts.

Randomized, double-blind, placebo-controlled trial of interferon alfa2a with and without amantadine as initial treatment for chronic hepatitis C.

Although the antiviral effects of amantadine sulphate (1-aminoadamantan sulphate) have not been characterized for the hepatitis C virus (HCV), previous pilot studies have suggested promising results in patients with chronic hepatitis C. The aim of the present study was to compare the efficacy, safety, and health-related quality of life (HRQOL) of interferon alfa (IFN-alpha) alone or in combination with oral amantadine for treatment of chronic hepatitis C. One hundred nineteen previously untreated patients with chronic hepatitis C were randomly allocated to treatment with IFN-alpha2a at a dose of 6 megaunits 3 times a week subcutaneously for 24 weeks, followed by 3 megaunits thrice weekly for an additional 24 weeks plus amantadine sulphate administered orally 100 mg twice a day for 48 weeks or the same IFN regimen plus a matched placebo. The primary endpoint was undectable serum HCV RNA (<1,000 copies/mL) at week 24 after treatment. At the end of treatment and the 24-week follow-up period serum HCV RNA was undetectable in 20 (34%) and 6 (10%) of the 59 patients treated with the combination IFN-alpha plus amantadine and in 20 (33%) and 13 (22%) of the 60 patients treated with IFN-alpha alone, respectively (P = n.s.). Discontinuation of therapy for adverse events was similar in both treatment groups. Although treatment with IFN-alpha worsened HRQOL, combination with amantadine showed a substantial trend to improve fatigue and vigor. In conclusion, combination therapy IFN-alpha plus amantadine is as effective as IFN-alpha monotherapy in previously untreated patients with chronic hepatitis C.

5'-CpG island methylation of the LKB1/STK11 promoter and allelic loss at chromosome 19p13.3 in sporadic colorectal cancer.

BACKGROUND: In patients with Peutz-Jeghers syndrome (PJS), causative germline mutations in the LKB1/STK11 gene on chromosome 19p13.3 have been identified. Because of the loss of heterozygosity (LOH) at 19p13.3 in hamartomas and the cancer susceptibility of patients with PJS, LKB1/STK11 is suggested to act as a tumour suppressor. However, the frequency of genetic and epigenetic inactivation of LKB1/STK11 in sporadic tumours is unclear. AIMS: To investigate the LKB1/STK11 gene for promoter hypermethylation and allelic loss in tumour specimens of patients with sporadic colorectal cancer. METHODS: DNA from 50 consecutive paraffin embedded sporadic colorectal adenocarcinomas and corresponding normal epithelium was extracted. After bisulphite treatment, specimens were analysed for methylation of the LKB1/STK11 promoter 5'-CpG island by methylation specific polymerase chain reaction (MSP). In addition, tumours were analysed for LOH of chromosome 19p13.3. In tumours exhibiting LOH, LKB1/STK11 was sequenced. RESULTS: MSP was successful in 48 of 50 tumour specimens. Of those, four (8%) demonstrated hypermethylation of the LKB1/STK11 promoter 5'-CpG island. Moreover, LOH at either D19S886 or D19S878 was observed in five of 38 (13%) informative tumours. All five tumours showing LOH at 19p13.3 were advanced and four of five were located in the left sided colon. There was no correlation between LOH and LKB1/STK11 promoter hypermethylation or somatic mutation. CONCLUSIONS: In sporadic colorectal cancer, hypermethylation of the LKB1/STK11 promoter and allelic loss at the STK 11 gene locus are rare events. LOH at 19p13.3 was associated with advanced tumour stage and left sided location but not with LKB1/STK11 promoter hypermethylation or somatic mutation.

Characterisation of patients with primary biliary cirrhosis responding to long term ursodeoxycholic acid treatment.

BACKGROUND: In some patients with primary biliary cirrhosis, ursodeoxycholic acid causes full biochemical normalisation of laboratory data; in others, indexes improve but do not become normal. AIMS: To characterise complete and incomplete responders. METHODS: Seventy patients with primary biliary cirrhosis were treated with ursodeoxycholic acid 10-15 mg/kg/day and followed up for 6-13 years. RESULTS: In 23 patients (33%) with mainly stage I or II disease, cholestasis indexes and aminotransferases normalised within 1-5 years, except for antimitochondrial antibodies. Histological findings improved. Indexes were not normalised in 47 patients (67%) although the improvement of their biochemical functions parallelled the trend in the first group. In these incomplete responders histological findings improved to a lesser extent. The only difference between the two groups before treatment was higher levels of alkaline phosphatase and gamma glutamyl transpeptidase in the incomplete responders. At onset of treatment the discriminant value separating responders from incomplete responders was 660 U/l for alkaline phosphatase and 131 U/l for gamma glutamyl transpeptidase. One year later it was 239 and 27 U/l (overall predictive value for responders 92%, for incomplete responders 81%). There were no differences between the two groups concerning immune status, antimitochondrial antibody subtypes, liver histology, or any other data. HLA-B39, DRB1*08, DQB1*04 dominated in both groups. CONCLUSIONS: In patients with mainly early stages of primary biliary cirrhosis, higher values of alkaline phosphatase and gamma glutamyl transpeptidase are the only biochemical indexes which allow discrimination between patients who will completely or incompletely respond to ursodeoxycholic acid treatment.

Fluorine-18 FDG positron emission tomography for imaging of hepatocellular carcinoma.

OBJECTIVE: The detection of increased fluorine-18 fluorodeoxyglucose (18F-FDG) uptake by positron emission tomography (PET) is based on the enhanced glucose metabolism of tumor cells. Because the detection and staging of hepatocellular carcinoma (HCC) in patients with liver cirrhosis can be difficult, we prospectively evaluated the sensitivity of 18F-FDG PET in 14 consecutive patients with HCC. METHODS: Whole body and regional 18F-FDG PET of the liver were obtained. The results were compared with ultrasonography, contrast-enhanced, helical CT, histological grading, p53 protein expression of HCC, and serum alpha-fetoprotein (AFP) level. RESULTS: In 7 patients PET demonstrated increased tumor 18F-FDG uptake, whereas HCC was not distinguishable from nonmalignant liver tissue in 7 other patients. Hepatic lesions were detected by ultrasonography in all patients, whereas only 11 of 14 HCCs could be identified by CT. In 3 patients extrahepatic spread was demonstrated by 18F-FDG PET. Patients with increased tumor 18F-FDG uptake had significantly larger hepatic lesions and higher serum AFP levels than those with normal 18F-FDG uptake. Lesions could be visualized by 18F-FDG PET in 7 of 8 patients with moderately or poorly differentiated HCC, whereas none of the six well-differentiated tumors was detected. Two patients with strong p53 expression demonstrated increased tumor 18F-FDG uptake and extrahepatic metastases. CONCLUSIONS: The sensitivity of 18F-FDG PET for the imaging of HCC is low. Nevertheless, in patients with moderately or poorly differentiated HCC, tumors >5 cm, or with markedly elevated AFP levels 18F-FDG PET may contribute to an effective noninvasive staging.