How to predict a high rate of inappropriateness for upper endoscopy in an endoscopic centre?

BACKGROUND: Inappropriateness of upper endoscopy (EGD) indication causes decreased diagnostic yield. Our aim of was to identify predictors of appropriateness rate for EGD among endoscopic centres. METHODS: A post-hoc analysis of two multicentre cross-sectional studies, including 6270 and 8252 patients consecutively referred to EGD in 44 (group A) and 55 (group B) endoscopic Italian centres in 2003 and 2007, respectively, was performed. A multiple forward stepwise regression was applied to group A, and independently validated in group B. A <70% threshold was adopted to define inadequate appropriateness rate clustered by centre. RESULTS: discrete variability of clustered appropriateness rates among the 44 group A centres was observed (median: 77%; range: 41-97%), and a <70% appropriateness rate was detected in 11 (25%). Independent predictors of centre appropriateness rate were: percentage of patients referred by general practitioners (GP), rate of urgent examinations, prevalence of relevant diseases, and academic status. For group B, sensitivity, specificity and area under receiver operating characteristic curve of the model in detecting centres with a <70% appropriateness rate were 54%, 93% and 0.72, respectively. CONCLUSIONS: A simple predictive rule, based on rate of patients referred by GPs, rate of urgent examinations, prevalence of relevant diseases and academic status, identified a small subset of centres characterised by a high rate of inappropriateness. These centres may be presumed to obtain the largest benefit from targeted educational programs.

Ultrasound guided fine needle biopsy of early hepatocellular carcinoma complicating liver cirrhosis: a multicentre study.

BACKGROUND: Because hepatic cirrhosis is a major risk factor for hepatocellular carcinoma, recent guidelines by the European Association for the Study of the Liver (EASL) on clinical management of hepatocellular carcinoma recommend periodic ultrasound surveillance of cirrhotic patients with immediate workup for nodules >1 cm; an increase in the frequency of screening is considered sufficient for smaller lesions. AIMS: To determine the actual risk of hepatocellular carcinoma associated with the latter lesions and to assess the role of ultrasound guided-fine needle biopsy in their diagnosis. PATIENTS AND METHODS: Data were analysed for 294 new nodular lesions <20 mm, including 48 that were <10 mm, detected during a prospective multicentre study involving ultrasound surveillance of 4375 patients with hepatic cirrhosis. In the absence of alpha fetoprotein (AFP) levels diagnostic of hepatocellular carcinoma, ultrasound guided-fine needle biopsy was performed (n = 274). AFP and fine needle biopsy diagnoses of malignancies (hepatocellular carcinoma and lymphoma) were considered definitive. Non-malignant fine needle biopsy diagnoses (dysplastic or regenerative nodule) were verified by a second imaging study. Diagnoses of hepatocellular carcinoma based on this study were considered definitive; non-malignant imaging diagnoses were considered definitive after at least one year of clinical and ultrasound follow up. RESULTS: Overall, 258/294 (87.6%) nodules proved to be hepatocellular carcinoma, including 33/48 (68.7%) of those < or =10 mm. Overall typing accuracy of ultrasound guided-fine needle biopsy was 89.4%, and 88.6% for lesions < or =10 mm. CONCLUSIONS: In a screening population, well over half of very small nodules arising in cirrhotic livers may prove to be hepatocellular carcinoma, and approximately 90% of these malignancies can be reliably identified with ultrasound guided-fine needle biopsy.

Genetic testing among high-risk individuals in families with hereditary nonpolyposis colorectal cancer.

Hereditary nonpolyposis colorectal cancer (HNPCC) is frequently associated with constitutional mutations in a class of genes involved in DNA mismatch repair. We identified 32 kindreds, with germline mutations in one of three genes hMSH2, hMLH1 or hMSH6. In this study, we purposed to evaluate how many high-risk individuals in each family underwent genetic testing: moreover, we assessed how many mutation-positive unaffected individuals accepted colonoscopic surveillance and the main findings of the recommended follow-up. Families were identified through a population-based registry, or referred from other centres. Members of the families were invited for an education session with two members of the staff. When a kindred was consistent with HNPCC, neoplastic tissues were examined for microsatellite instability (MSI) and immunohistochemical expression of MSH2, MLH1 and MSH6 proteins. Moreover, constitutional mutations were searched by SSCP or direct sequencing of the whole genomic region. Of the 164 subjects assessed by genetic testing, 89 were gene carriers (66 affected - that is, with HNPCC-related cancer diagnosis - and 23 unaffected) and 75 tested negative. Among the 23 unaffected gene carriers, 18 (78.3%) underwent colonoscopy and four declined. On a total of 292 first degree at risk of cancer, 194 (66.4%) did not undergo genetic testing. The main reasons for this were: (a) difficulty to reach family members at risk, (b) lack of collaboration, (c) lack of interest in preventive medicine or 'fatalistic' attitude towards cancer occurrence. The number of colorectal lesions detected at endoscopy in gene carriers was significantly (P<0.01) higher than in controls (noncarriers). We conclude that a large fraction of high-risk individuals in mutation-positive HNPCC families does not undergo genetic testing, despite the benefits of molecular screening and endoscopic surveillance. This clearly indicates that there are still barriers to genetic testing in HNPCC, and that we are unable to provide adequate protection against cancer development in these families.

Familial microsatellite-stable non-polyposis colorectal cancer: incidence and characteristics in a clinic-based population.

BACKGROUND: About 15%-20% of colorectal cancers (CRCs) are familial. While a fraction of these arise in the context of hereditary syndromes, the causes underlying the majority of familial CRCs are not yet understood. PATIENTS AND METHODS: Family history of cancer, clinical characteristics, and microsatellite instability (MSI) in a series of 100 consecutive CRC patients were evaluated. RESULTS: Eighteen patients had a positive family history of CRC in a first-degree relative. Of these, two had a clinical diagnosis of familial adenomatous polyposis (FAP), and three were diagnosed with hereditary non-polyposis colorectal cancer (HNPCC) following results of MSI analysis. A diagnosis of HNPCC was also established in a fourth patient with early onset CRC, who had a second-degree relative with CRC, and whose tumor was positive for MSI. The remaining 13 familial CRCs did not show MSI in tumor DNA. The mean age at tumor diagnosis in patients with familial microsatellite-stable (MSS) CRC was higher than in HNPCC and FAP patients and similar to that recorded in sporadic cases. The incidence of second primary malignancies was significantly higher in familial MSS CRC probands (n = 4) compared to patients who did not have a diagnosis of FAP or HNPCC and did not have first-degree relatives affected with CRC (n = 6, in a total of 81 probands with these characteristics). CONCLUSIONS: These results define the existence of a subset of familial CRCs characterized by relatively late age at onset, high incidence of second primary tumors, and absence of MSI in tumor DNA.

[Helicobacter pylori and gastric carcinoma]. / Helicobater pylori e carcinoma gastrico.

Among the suspected bacterial causes of cancer, H. pylori is the agent more consistently linked to malignancy. After its discovery in 1983 and the later confirmation as the leading cause of chronic gastritis, several studies were performed to prove an association between H. pylori infection and gastric carcinoma. The epidemiological data have been so strong that in 1994 the International Association for Research on Cancer stated that "there was sufficient evidence" to classify H. pylori as a group I carcinogen in humans. However, the exact mechanisms underlying the link between H. pylori infection and gastric carcinoma remain still to be elucidated. The natural history of H. pylori infection shows that, although roughly half of the world's human population bears the organism, only a minority of individuals develop clinically important outcomes (e.g. peptic ulcer, lymphoproliferative diseases, atrophic gastritis and gastric carcinoma): host's genetic make-up, duration of infection, diet and differences between H. pylori strains have been proposed as factors potentially able to influence the outcomes in different individuals. The damaging agents by which H. pylori could promote gastric carcinogenesis are produced either by the organism or as a consequence of the host inflammatory response to the infection. Gastric mucosal chronic damage may, therefore, lead to changes in the pattern of epithelial cell kinetic (increase in cell proliferation and induction of apoptosis) in gastric glands which may induce DNA injury with irreversible genetic lesions. Finally, a direct association between H. pylori infection and the induction of gastric carcinoma has been recently demonstrated in an animal model, giving further credence to the role of this organism in gastric carcinogenesis.

Severe imbalance of cell proliferation and apoptosis in the left colon and in the rectosigmoid tract in subjects with a history of large adenomas.

BACKGROUND: Alterations in epithelial proliferation and apoptosis in colonic mucosa are associated with an increased risk of colon cancer. It is unclear if these alterations represent a generalised "field defect". AIMS: To analyse segmental patterns of cell proliferation and apoptosis in the colon of subjects with a high and no apparent risk of colon cancer. METHODS: Pancolonoscopy was performed in 15 patients with resected adenomas (> or =1.5 cm) and in nine subjects without an apparent risk of colorectal cancer. Mucosal biopsies were taken from the right colon, left colon, and sigmoid rectum. Crypt cell proliferation and apoptosis were evaluated, respectively, with bromodeoxyuridine immunohistochemistry and terminal deoxyuridine nucleotidyl nick end labelling of DNA strand breaks. Results are expressed as total labelling index (TLI) and labelling index (LI) for each of the five compartments in which colonic crypts were divided (fourth and fifth compartments were evaluated together) for cell proliferation and as apoptotic index (AI) for apoptosis assessment. RESULTS: No significant segmental variations in proliferation were found in either group. Compared with controls, adenoma patients had higher TLIs for the right (p>0.05), left (p<0.005), and sigmoid rectum (p<0.05) segments, and higher left colon LIs for crypt compartments (compartment 1, p<0.01; compartment 2, p<0.005; compartment 3, p<0.001; compartments 4-5, p<0.01). Control AIs were similar in all segments but in the adenoma patients left colon and sigmoid rectum AIs were lower than their right colon indexes (p<0.05, p<0.05) and corresponding values for controls (p<0.01, p<0.05). CONCLUSIONS: The colonic mucosa of patients with past adenomas presents diffuse hyperproliferation and, distally, abnormally distributed proliferating cells and markedly reduced apoptosis. These changes represent a significant risk for malignancies and could account for the high prevalence of left colon tumours.

Mutations of the 'minor' mismatch repair gene MSH6 in typical and atypical hereditary nonpolyposis colorectal cancer.

Mutations of the mismatch repair (MMR) genes MLH1 and MSH2 are associated with hereditary nonpolyposis colorectal cancer (HNPCC), a highly penetrant autosomal dominant condition characterized by hypermutability of short tandemly repeated sequences in tumor DNA. Mutations of another MMR gene, MSH6, seem to be less common than MLH1 and MSH2 defects, and have been mostly observed in atypical HNPCC families, characterized by a weaker tumor family history, higher age at disease onset, and low degrees of microsatellite instability (MSI), predominantly involving mononucleotide runs. We have investigated the MSH6 gene sequence in the peripheral blood of 4 HNPCC and 20 atypical HNPCC probands. Two frameshift mutations within exon 4 were detected in 2 patients. One mutation was found in a proband from a typical HNPCC family, who had developed a colorectal cancer (CRC), a gastric cancer and a rectal adenoma. The CRC and the adenoma showed mild MSI limited to mononucleotide tracts, while the gastric carcinoma was microsatellite stable. The other mutation was detected in an atypical HNPCC proband, whose CRC showed widespread MSI involving both mono- and dinucleotide repeats. The phenotypic variability associated with MSH6 constitutional mutations represents a complicating factor for the optimization of strategies aimed at identifying candidates to MSH6 genetic testing.

Assessment of pathogenicity criteria for constitutional missense mutations of the hereditary nonpolyposis colorectal cancer genes MLH1 and MSH2.

To determine the role played by MLH1 and MSH2 missense variants in cancer susceptibility, we have investigated the following genetic and biological characteristics associated with six MLH1 and four MSH2 missense changes identified in Italian hereditary nonpolyposis colorectal cancer (HNPCC) families: co-segregation with disease phenotype and/or bonafide pathogenetic mutations; presence of the variant in healthy control subjects; evolutionary conservation of the involved aminoacid and type of aminoacid change; and presence/absence of microsatellite instability (MSI) in tumour DNA. Overall, nine variants did not fulfil > or = 2 pathogenicity criteria. MSI was investigated in tumour samples from carriers of nine different missense mutations. Only 3/9 variants were associated with MSI in tumour DNA. In addition, four variants were not present in affected pedigree members, and five variants were observed in the control population. Based upon these results, we conclude that most MLH1 and MSH2 missense changes are unlikely to act as major causative factors in colorectal cancer susceptibility and development.

Risk indicators of organic diseases in uninvestigated dyspepsia: a one-week survey in 246 Italian endoscopy units.

OBJECTIVE: To evaluate the predictive value of demographic and clinical features and of the results of an office-based test for Helicobacter pylori antibodies, in the presence of organic dyspepsia. DESIGN: Over a 1-week period, 2206 consecutive patients first referred for endoscopy in 246 Italian centres were included. METHODS: Demographic and clinical features, endoscopy findings, and histological diagnosis of H. pylori infection were recorded for all patients. IgG antibodies to H. pylori were determined in 2128 cases by a rapid, immunochromatographic method (Flex Sure HP, S.K.D., San Jose, CA). RESULTS: Endoscopic abnormalities were found in 939 patients (42.6%). Histologically assessed H. pylori infection was predictive for duodenal ulcer (odds ratio (OR), 6.79; 95% confidence interval (CI), 4.4-10.5). Being male (OR, 1.97; 95% CI, 1.7-2.3), older than 40 years (OR, 1.81; 95% CI, 1.5-2.2), a smoker (OR, 1.88; 95% CI, 1.6-2.3), and presenting nocturnal awakening (OR, 1.62; 95% CI, 1.3-2.0) were independently associated with secondary dyspepsia. Epigastric (OR, 1.50; 95% CI, 1.2-1.9) and retrosternal pain (OR, 1.39; 95% CI, 1.1 -1.8) severe enough to affect the usual activities were predictive of organic diseases. The results of the Flex Sure HP test correlated poorly with histological findings. CONCLUSIONS: Male gender, older age, cigarette smoking, a family history of peptic ulcer, symptoms severe enough to induce awakening, epigastric/retrosternal pain severe enough to influence the usual activities are all independently (although weakly) associated with organic dyspepsia. H. pylori infection is strongly associated with duodenal ulcer, but the rapid test we used was not sensitive enough to achieve clinical utility.

Importance of changes in epithelial cell turnover during Helicobacter pylori infection in gastric carcinogenesis.

The role of Helicobacter pylori in gastric carcinogenesis is supported almost exclusively by epidemiological data and prospective histopathological studies. From biological and molecular points of view, there is no evidence that H pylori or its cytotoxic products have any mutagenic effects. Nevertheless, this infection is associated with profound changes in the pattern of epithelial cell turnover in gastric glands, though the importance of these changes in gastric carcinogenesis is still controversial. H pylori infection increases cell proliferation and alters the distribution of cycling cells within these glands, but these changes can be reversed by successful eradication of the infection. Apoptosis seems to be increased in gastric epithelial cells during H pylori infection, as shown by in vitro studies. There is some, though no conclusive, evidence that this finding also occurs in H pylori positive subjects. It seems that cagA status influences the effect of H pylori on epithelial apoptosis in infected patients. An association of in vitro H pylori induced apoptosis with changes in the expression of pro- and anti-apoptotic genes is reported in the literature, but further study is necessary to clarify the effect of H pylori infection on the molecular events of the apoptotic pathway.

Epithelial-cell apoptosis and proliferation in Helicobacter pylori-related chronic gastritis.

BACKGROUND: Several studies have shown that Helicobacter pylori infection is associated with enhanced gastric epithelial-cell proliferation, which is thought to be involved in its apparent carcinogenicity. This hyperproliferation is believed to be related to the inflammatory effects of the bacterium. The role of Helicobacter pylori in gastric epithelial apoptosis, however, is less clear. AIM: We attempted to identify the effect of Helicobacter pylori infection on apoptosis in the gastric epithelium and its possible relation to epithelial-cell proliferation and mucosal inflammation. PATIENTS AND METHODS: We studied cell proliferation (via bromodeoxyuridine labelling), apoptosis (using in situ TdT-mediated dUTP-biotin nick end labelling of DNA strand breaks) and mononuclear and polymorphonuclear cell infiltrates (computer-assisted image analysis) in gastric antral biopsies obtained from 37 gastritis patients (20 Helicobacter pylori-positive, 17 Helicobacter pylori-negative). RESULTS: Helicobacter pylori-positives displayed significantly enhanced proliferation within the gastric epithelium that was positively correlated with both acute and chronic inflammatory-cell densities. Apoptotic indexes were similar in both groups and showed no correlation with any of the parameters under consideration. CONCLUSIONS: Enhanced epithelial cell proliferation and an altered distribution of cycling cells within the gastric glands are a common feature of chronic superficial gastritis caused by Helicobacter pylori. In vivo immunohistochemically detected apoptosis of gastric epithelial cells does not seem to be affected by Helicobacter pylori infection. Further study is needed to clarify the effect of this infection on programmed cell death within gastric glands.

Lack of PMS2 gene-truncating mutations in patients with hereditary colorectal cancer.

Hereditary non-polyposis colorectal cancer (HNPCC) is a genetically heterogeneous disease for which PMS2 gene, a member of the human PMS gene family, is believed to have a marginal role. To better define the contribution of PMS2 to hereditary colorectal cancer, we investigated this gene in 22 unrelated Italian patients that, despite a positive family history and/or early onset and development of tumors with microsatellite instability (MSI), did not carry constitutional mutations of MLH1 and MSH2 genes. No mutations with clear-cut pathogenetic significance were detected in the coding regions of PMS2 gene, but only 8 polymorphisms (7 common and 1 rare, 3 silent and 5 missense) and 3 unique molecular variants (2 missense substitutions and one 3-nucleotide deletion) were seen. Lack of PMS2 truncating mutations in our study does not disagree with its supposed marginal involvement in hereditary colorectal cancer, but at the same time points out the need to investigate the phenotypic molecular and clinical characteristics more specifically associated with PMS2 mutations.

MLH1 and MSH2 constitutional mutations in colorectal cancer families not meeting the standard criteria for hereditary nonpolyposis colorectal cancer.

Genetic diagnosis of hereditary nonpolyposis colorectal cancer (HNPCC) may have a significant impact on the clinical management of patients and their at-risk relatives. At present, clinical criteria represent the simplest and most useful method for the identification of HNPCC families and for the selection of candidates for genetic testing. However, reports of mismatch repair (MMR) gene mutations in families not fulfilling the minimal diagnostic criteria point out the necessity to identify additional clinical parameters suggestive of genetic predisposition to colorectal cancer (CRC) related to MMR defects. We thus investigated a series of 32 Italian putative HNPCC individuals selected on the basis of one of the following criteria: 1) family history of CRC and/or other extracolonic tumors; 2) early-onset CRC; and 3) presence of multiple primary malignancies in the same individual. These patients were investigated for the presence of MLH1 and MSH2 mutations by single-strand conformation polymorphism analysis. Pathogenetic truncating mutations were identified in 4 (12.5%) cases, 3 of them involving MSH2 and 1 MLH1. In addition, 2 missense MLH1 variants of uncertain significance were observed. All pathogenetic mutations were associated with early age (<40 years) at onset and proximal CRC location. Our results support the contention that constitutional MMR mutations can also occur in individuals without the classical HNPCC pattern. Moreover, evaluation of the clinical parameters associated with MMR mutations indicates that early onset combined with CRC location in the proximal colon can be definitely considered suggestive of MMR-related hereditary CRC and should be included among the guidelines for referring patients for genetic testing.

Hereditary nonpolyposis colorectal cancer: an approach to the selection of candidates to genetic testing based on clinical and molecular characteristics.

OBJECTIVE: Identification of clinical and molecular characteristics associated with constitutional MLH1 and MSH2 mutations and definition of a stepwise strategy for the selection of colorectal cancer (CRC) patients amenable to MLH1 and MSH2 genetic testing. METHODS: 90 unrelated CRC patients were initially selected on the basis of either familial or early onset occurrence of CRC. They were screened for the presence of constitutional MLH1 and MSH2 mutations and for microsatellite instability (MSI). RESULTS: 16 pathogenetic mutations (9 MLH1 and 7 MSH2) were identified in 41% of Amsterdam hereditary nonpolyposis colorectal cancer (HNPCC) families, 5% of suspected HNPCC families, and 14% of sporadic early-onset CRC patients. The presence of the mutations correlated with MSI, with early age of onset and proximal location of the tumor, and with the presence of some extracolonic tumors of the HNPCC spectrum and/or multiple tumors in the family. CONCLUSIONS: Evaluation of clinical and molecular characteristics is useful for the identification of candidates to MLH1 and MSH2 mutational analysis and allows the application of a rational approach to genetic testing.

Epithelial cell turnover and apoptosis.

The homeostasis of gastric epithelial cells is maintained by the balance between cell proliferation and apoptosis. Alterations of these physiological cellular events in chronic pathological conditions of the stomach. As far as the proliferative pattern is concerned, an increase in the total number of epithelial proliferating cells and an abnormal distribution of the latter are frequently observed in chronic gastritis, gastric atrophy, intestinal metaplasia, gastric dysplasia and gastric cancer. Conversely, apoptosis has been found to be impaired in intestinal metaplasia, gastric dysplasia and cancer. Helicobacter pylori infection is associated with changes in epithelial-cell turnover, though their significance in gastric carcinogenesis is still controversial. An increase in overall epithelial cell proliferation and the upward shift of replicating cells toward the superficial part of the gastric pits are patterns usually observed during Helicobacter pylori infection and these changes can be reversed by successful eradication of the infection. However, it seems that this reversibility will be lost during progression through the steps of gastric carcinogenesis, such as intestinal metaplasia, probably representing the phenotypic expression of the true initiating phase of the carcinogenetic process. The influence of Helicobacter pylori infection on gastric epithelial apoptosis in humans is still controversial, since different results having been obtained by different authors. It seems that cagA status influences the effect of Helicobacter pylori on epithelial apoptosis, so that a different cagA make-up of the studied groups could explain these conflicting results. However, further studies are needed to elucidate this issue in humans.

Characterization of MSH2 and MLH1 mutations in Italian families with hereditary nonpolyposis colorectal cancer.

Mismatch repair genes MSH2 and MLH1 are considered to be the two major genes that are responsible for hereditary nonpolyposis colorectal cancer (HNPCC). Germline heterozygous inactivating mutations of MSH2 and MLH1 have been identified previously in a substantial fraction of individuals who are predisposed genetically to colorectal carcinoma (CRC) and other tumors of the HNPCC spectrum. With the aim of determining the relevance of these two genes in the Italian population, we submitted to mutational analysis a set of 17 HNPCC families, all of which fulfilled the "Amsterdam criteria." A combination of different techniques, including reverse transcription-polymerase chain reaction (RT-PCR) of long fragments and single-strand conformation polymorphism (SSCP) on cDNA and genomic DNA, allowed the identification of ten molecular variants, seven of which are predicted to inactivate mismatch repair function. The mutated predisposing gene was MSH2 in two families and MLH1 in five other families. All of the mutations were characterized by DNA sequencing and appeared to involve different molecular mechanisms, such as short in-frame and out-of-frame deletions, splicing errors, and nonsense mutations. This study also demonstrates that, in the Italian population, a considerable fraction of HNPCC families (at least 41%) is linked to MSH2 and MLH1 mutations.

Hereditary nonpolyposis colorectal cancer: review of clinical, molecular genetics, and counseling aspects.

Lynch syndrome, or hereditary nonpolyposis colon cancer (HNPCC), is an autosomal-dominant disease accounting for approximately 1-5% of all colorectal cancer cases. Due to the lack of pathognomonic morphological or biomolecular markers, HNPCC has traditionally posed unique problems to clinicians and geneticists alike, both in terms of diagnosis and clinical management. Recently, novel insight into the pathogenesis of this syndrome has been provided by the identification of its molecular basis. In HNPCC families, germline mutations in any of four genes encoding proteins of a specialized DNA repair system, the mismatch repair, predispose to cancer development. Mutations in mismatch repair genes lead to an overall increase of the mutation rate and are associated with a phenotype of length instability of microsatellite loci. The present report summarizes the clinicopathological aspects of HNPCC and reviews the most recent molecular and biochemical findings.