Peutz-Jeghers syndrome: intriguing suggestion of gastrointestinal cancer prevention from surveillance.

BACKGROUND: Peutz-Jeghers syndrome is characterized by GI polyps and mucocutaneous pigmentation and carries an increased risk of GI cancer. GI polyps may bleed or cause intussusception. Luminal GI surveillance is recommended, but there are few data detailing outcomes from GI surveillance in Peutz-Jeghers syndrome. OBJECTIVE: This study aimed to assess outcomes from GI surveillance in patients with Peutz-Jeghers syndrome. DESIGN: This study is a retrospective review, using hospital and registry notes and endoscopy and histology reports. SETTING: The investigation was conducted at a tertiary referral center. PATIENTS: All patients with Peutz-Jeghers syndrome who were followed up at St Mark's hospital were included. MAIN OUTCOME MEASURES: The primary outcomes measured were surveillance procedures performed, complications, and long-term outcomes. RESULTS: Sixty-three patients from 48 pedigrees were included; the median age when patients were first seen was 20 years (range, 3-59). Only baseline investigations were performed in 12 patients. The remaining patients were followed up for 683 patient years, a median of 10 years (range, 2-41). Seven hundred seventy-six procedures were performed to assess the GI tract. These led to 5 double-balloon enteroscopies, 1 push enteroscopy, and 71 surgical procedures. Of the surgical procedures, 20 were performed as a result of baseline investigations, 12 arose from investigations of symptoms, and 39 were due to surveillance of asymptomatic patients. No emergency surgical interventions were performed. No luminal GI cancers were diagnosed. Of the 2461 polypectomies performed, 6 polyps contained atypia or dysplasia. Six complications arose from endoscopy or surgical intervention, requiring 5 laparotomies to manage these complications. CONCLUSION: GI surveillance in Peutz-Jeghers syndrome is relatively safe and avoids the need for emergency surgery for small-bowel polyps. The lack of GI cancers may reflect that surveillance and polypectomy have prevented cancer from developing, although the detection of neoplasia or dysplasia is uncommon.

The type of somatic mutation at APC in familial adenomatous polyposis is determined by the site of the germline mutation: a new facet to Knudson's 'two-hit' hypothesis.

APC is often cited as a prime example of a tumor suppressor gene. Truncating germline and somatic mutations (or, infrequently, allelic loss) occur in tumors in FAP (familial adenomatous polyposis). Most sporadic colorectal cancers also have two APC mutations. Clues from attenuated polyposis, missense germline variants with mild disease and the somatic mutation cluster region (codons 1,250-1,450) indicate, however, that APC mutations might not result in simple loss of protein function. We have found that FAP patients with germline APC mutations within a small region (codons 1,194-1,392 at most) mainly show allelic loss in their colorectal adenomas, in contrast to other FAP patients, whose 'second hits' tend to occur by truncating mutations in the mutation cluster region. Our results indicate that different APC mutations provide cells with different selective advantages, with mutations close to codon 1,300 providing the greatest advantage. Allelic loss is selected strongly in cells with one mutation near codon 1,300. A different germline-somatic APC mutation association exists in FAP desmoids. APC is not, therefore, a classical tumor suppressor. Our findings also indicate a new mechanism for disease severity: if a broader spectrum of mutations is selected in tumors, the somatic mutation rate is effectively higher and more tumors grow.

Risk factors predicting intra-abdominal desmoids in familial adenomatous polyposis: a single centre experience.

BACKGROUND: Desmoids are myofibroblastic proliferations occurring in 15% of patients with familial adenomatous polyposis (FAP), 70% being intra-abdominal desmoids (IAD). Since the morbidity and mortality due to desmoids is almost entirely attributable to IAD, we aimed to identify specifically risk factors predicting IAD development in FAP. METHODS: We undertook a retrospective review of our institutional database. Multivariate analysis was performed, and hazard ratios (HR) calculated for variables including female gender, 3' APC mutation, surgical intervention for FAP (colectomy with ileo-rectal anastomosis or restorative proctocolectomy), age at surgery and family history (FH) of desmoids. RESULTS: Of the 558 patients analysed, 49 (9%) developed IAD; 22 (4%) diagnosed intra-operatively and 27 (5%) developing over a median post-operative period of 34 (7-120) months. 75% of IAD had developed before age 40. A 3' APC mutation (HR 5.2, 95% CI 2.1-13.3, P = 0.001), positive FH (HR 2.5, 95% CI 1.4-4.6, P = 0.003) and female gender (HR 1.9, 95% CI 1.0-3.5, P = 0.04) were found to be predictive of IAD development. No significant difference in IAD risk was detected between the type of surgical intervention (P = 0.37) or age at surgery (P = 0.29). CONCLUSIONS: Our analysis confirms 3' APC mutation to be the most significant risk factor for IAD development. The independent association between positive FH and IAD risk suggests the existence of modifier genes, independent of the APC genotype-phenotype correlation. Few of these risk factors can be meaningfully modified. Delaying prophylactic surgery may be appropriate in female patients with a 3' APC mutation and attenuated polyposis.

Comparison of outcomes of ileal pouch-anal anastomosis for familial adenomatous polyposis with and without previous ileorectal anastomosis.

BACKGROUND: It is reported that previous colectomy and ileorectal anastomosis (IRA) has no effect on postoperative complications and functional outcomes of secondary proctectomy and ileal pouch-anal anastomosis (IPAA) in patients with familial adenomatous polyposis (FAP). This retrospective study re-examined the question in a single centre. METHODS: Some 185 patients were grouped by either IPAA as the initial prophylactic surgical procedure (primary IPAA) or IPAA preceded by IRA (secondary IPAA). Data on functional outcomes were available for 104, 83 and 56 patients at years 1, 5 and 10 respectively. RESULTS: The 78 patients who had secondary IPAA were older at the time of operation than the 107 who underwent primary IPAA (35.7 versus 29.2 years; P < 0.001). Six (8 per cent) of the secondary IPAA procedures could not be completed. Otherwise, apart from more wound infections in the secondary IPAA group (9 versus 0.9 per cent in the primary IPAA group; P = 0.012), there were no significant differences in rates of complications, functional outcomes, desmoid disease or pouch failure. CONCLUSION: Conversion from IRA to IPAA may not be possible in patients with FAP. Where conversion is successful, pouch outcomes are similar but wound infections are more frequent.

Disease severity and genetic pathways in attenuated familial adenomatous polyposis vary greatly but depend on the site of the germline mutation.

BACKGROUND: Attenuated familial adenomatous polyposis (AFAP) is associated with germline mutations in the 5', 3', and exon 9 of the adenomatous polyposis coli (APC) gene. These mutations probably encode a limited amount of functional APC protein. METHODS AND RESULTS: We found that colonic polyp number varied greatly among AFAP patients but members of the same family tended to have more similar disease severity. 5' Mutants generally had more polyps than other patients. We analysed somatic APC mutations/loss of heterozygosity (LOH) in 235 tumours from 35 patients (16 families) with a variety of AFAP associated germline mutations. In common with two previous studies of individual kindreds, we found biallelic changes ("third hits") in some polyps. We found that the "third hit" probably initiated tumorigenesis. Somatic mutation spectra were similar in 5' and 3' mutant patients, often resembling classical FAP. In exon 9 mutants, in contrast, "third hits" were more common. Most "third hits" left three 20 amino acid repeats (20AARs) on the germline mutant APC allele, with LOH (or proximal somatic mutation) of the wild-type allele; but some polyps had loss of the germline mutant with mutation leaving one 20AAR on the wild-type allele. CONCLUSIONS: We propose that mutations, such as nt4661insA, that leave three 20AARs are preferentially selected in cis with some AFAP mutations because the residual protein function is near optimal for tumorigenesis. Not all AFAP polyps appear to need "three hits" however. AFAP is phenotypically and genetically heterogeneous. In addition to effects of different germline mutations, modifier genes may be acting on the AFAP phenotype, perhaps influencing the quantity of functional protein produced by the germline mutant allele.

Exclusion of PTEN and 10q22-24 as the susceptibility locus for juvenile polyposis syndrome.

Juvenile polyposis syndrome (JPS; MIM 174900) is an autosomal dominant condition with incomplete penetrance characterized by hamartomatous polyps of the gastrointestinal tract and a risk of gastrointestinal cancer. Gastrointestinal hamartomatous polyps are also present in Cowden syndrome (CS; MIM 158350) and Bannayan-Zonana syndrome (BZS; also called Ruvalcaba-Myhre-Smith syndrome; MIM 153480). The susceptibility locus for both CS and BZS has recently been identified as the novel tumor suppressor gene PTEN, encoding a dual specificity phosphatase, located at 10q23.3. A putative JPS locus, JP1, which most likely functions as a tumor suppressor, had previously been mapped to 10q22-24 in both familial and sporadic juvenile polyps. Given the shared clinical features of gastrointestinal hamartomatous polyps among the three syndromes and the coincident mapping of JP1 to the region of PTEN, we sought to determine whether JPS was allelic to CS and BZS by mutation analysis of PTEN and linkage approaches. Microsatellite markers spanning the CS/BZS locus (D10S219, D10S551, D10S579, and D10S541) were used to compute multipoint lod scores in eight informative families with JPS. Lod scores of < -2.0 were generated for the entire region, thus excluding PTEN and any genes within the flanking 20-cM interval as candidate loci for familial JPS under our statistical models. In addition, analysis of PTEN using a combination of denaturing gradient gel electrophoresis and direct sequencing was unable to identify a germline mutation in 14 families with JPS and 11 sporadic cases. Therefore, at least a proportion of JPS cases are not caused by germline PTEN alteration or by an alternative locus at 10q22-24.

The epidemiology and transmission of Helicobacter pylori infection in children.

How and when Helicobacter pylori infection is acquired is unknown. Faecal-oral and oral-oral transmission have been demonstrated in animal studies of other Helicobacter species, whilst sero-epidemiological studies in adults show a cohort effect suggesting that primary acquisition occurs in childhood. H. pylori can be detected non-invasively using serology or the 13C-urea breath test, and although the accuracy of both methods is well established in adults, further validation studies are needed in children, especially those under 5 years old. In children, the age-specific prevalences of H. pylori, which are low in developed countries and high in developing countries, suggest that in most cases infection is acquired early in life. Prospective studies show that the incidence of H. pylori infection in adults is about 0.4% per year; in children, studies using the 13C-urea breath test demonstrate incidences in developing and developed countries of 36% and 2.7% per year, respectively. Intra-familial clustering of H. pylori and high prevalences in orphanages and institutions for the mentally retarded suggest that person-to-person transmission of H. pylori is important. In addition, H. pylori infection has been associated with poor childhood socio-economic conditions--with overcrowding and close person-to-person contact through bed sharing being the most consistent and significant associations. However, these studies are liable to recall-bias. Since it is still unclear whether H. pylori is transmitted by the faecal-oral or oral-oral routes, it is possible that both routes exist.(ABSTRACT TRUNCATED AT 250 WORDS)

Methodological issues in developing a scale to measure social support.

In recent years there has been considerable research and clinical interest in developing instruments to assess social supports available to individuals. There is, however, a notable deficiency of attempts to evaluate the psychometric properties of these questionnaires. The present article describes efforts made to evaluate the properties of a Social Relationship Scale (SRS) that was developed as part of a prospective study of the psychosocial influences on the health status of a population. Some descriptive scale statistics are also presented.

A review of physical abnormalities in familial adenomatous polyposis.

Familial adenomatous polyposis (FAP) is an autosomal dominant condition wherein multiple polyps may be found in the gastrointestinal tract. Initially referred to as familial polyposis coli, it has become evident that virtually all patients with FAP develop adenomas in the upper gastrointestinal tract and thus the syndrome is now termed familial adenomatous polyposis. The number of associated conditions both malignant and benign has been increasingly recognized. Some of these lesions cause morbidity and mortality in affected individuals whilst others act as important clinical markers for identifying patients not yet expressing the phenotype. These abnormalities can arise from tissues of all three primary embryonic layers and are described in this paper.

A 10-year review of surgery for desmoid disease associated with familial adenomatous polyposis.

BACKGROUND: Desmoid tumours affect 10-25 per cent of patients with familial adenomatous polyposis and represent a major cause of morbidity and mortality. Surgery for intra-abdominal desmoids has traditionally been used as a last resort or to manage obstructive complications. The aim was to review 10 years of desmoid surgery in patients with familial adenomatous polyposis from a single centre. METHODS: Patients who had surgery for desmoid disease between 1994 and 2004 were identified from the Polyposis Registry database and their hospital notes reviewed. RESULTS: Twenty patients had surgery to remove 32 desmoid tumours (16 intra-abdominal, 12 abdominal wall, four extra-abdominal). Complete clearance was achieved in 19 tumours and, of these, clinically significant recurrence occurred in eight. There was no difference in recurrence rates for site or sex. There was no operative mortality. Intra-abdominal desmoid resection was associated with a mean resection of 45.55 (range 10-200) cm of small bowel. One patient required long-term parenteral feeding. Median follow-up was 5 (range 0.6-10) years. During this period, one patient died (metastatic duodenal cancer); there was no mortality from desmoid disease. CONCLUSION: Surgery for intra-abdominal desmoids in selected patients is less hazardous than previously reported. Surgery for abdominal wall and extra-abdominal tumours is safe. However, disease recurrence remains a major problem.

Osteomesopycnosis.

Osteomesopycnosis is a rare osteosclerotic bone disorder limited to the axial skeleton. The disease has diagnostic radiographic findings. Fewer than 20 cases have been published in the literature. We present the first Australian case of this disease.

Analysis of the proteinases of representative Trichomonas vaginalis isolates.

Isoelectric focusing and sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) with acrylamide copolymerized with gelatin (substrate-SDS-PAGE) were combined to evaluate the proteinases of both long-term-grown and fresh isolates of Trichomonas vaginalis. This two-dimensional substrate-SDS-PAGE resolved as many as 23 distinct proteinase activities in several isolates, and proteinases had relative molecular masses between 23 and 110 kilodaltons (kDa). Isoelectric points (pI) of proteinases ranged from 5.7 to 7.0. Overall, the various representative proteinase profiles were similar among those of long-term-grown and fresh isolates, although heterogeneity existed among several cysteine proteinase activities. Pattern changes were detected in fresh isolates passaged over several weeks, showing the ability of proteinases to be differentially expressed and to undergo phase variation. The two-dimensional proteinase patterns were very reproducible for isolates analyzed over a certain period of time before expression of some proteinases varied. The heterogeneity and differential expression of certain proteinases were not coordinated with phenotypic variation of already characterized immunogens and adhesins. Data suggesting that a 43-kDa proteinase resided on the parasite surface were obtained on the basis of removal of activity following pronase or proteinase K treatment of live organisms. Finally, immunized experimental animals produced antibody to many T. vaginalis proteinases, which indicates the immunogenic nature of trichomonad proteinases.

Relatedness of structures of a major immunogen in Trichomonas vaginalis isolates.

Solubilization of live Trichomonas vaginalis organisms with detergent caused the release of cysteine proteinases in the detergent extract which were inhibitable with N-alpha-p-tosyl-L-lysine chloromethyl ketone. The detergent extracts of all isolates tested possessed similar cysteine proteinase activities. These parasite proteinases rapidly degraded a prominent immunogen whose surface disposition undergoes phenotypic variation in some isolates. The relatedness of the forms of this immunogen among all isolates tested was confirmed by identical immunoblot patterns of autolysed immunogen, and data suggest the presence of repeating units or at least equidistant sites for proteinase cleavage within the immunogen molecule.

Antibody in sera of patients infected with Trichomonas vaginalis is to trichomonad proteinases.

BACKGROUND: A recent report demonstrated the immunogenic character of the cysteine proteinases of Trichomonas vaginalis. It was of interest, therefore, to examine for the presence of serum anti-proteinase antibody among patients with trichomoniasis. METHODS: An immunoprecipitation assay was used involving protein A-bearing Staphylococcus aureus first coated with the IgG fraction of goat anti-human Ig and then mixed with individual sera of patients to bind human antibody. These antibody-coated bacteria were then added to detergent extracts of T vaginalis. Bound immune complexes on S aureus were washed and solubilised for electrophoretic analysis on acrylamide copolymerised with gelatin for detection of proteinase activity. RESULTS: Sera from patients (50/50), but none from sera of normal, uninfected women, possessed IgG to numerous trichomonad cysteine proteinases. The presence of this serum anti-proteinase antibody disappeared after drug treatment and cure of patients of the T vaginalis infection. CONCLUSIONS: The commonality of the anti-proteinase antibody in the sera of patients with trichomoniasis provided evidence for the expression of the same repertoire of parasite proteinases during infection. These observations have important implications for the in vivo relevance of the proteinases and indicate that strategies to use a specific serum antibody response for diagnosis of this infection may be possible.

Vaginal antibody of patients with trichomoniasis is to a prominent surface immunogen of Trichomonas vaginalis.

Twenty vaginal washes (VWs) and ten vaginal mucus (VM) samples from patients with trichomoniasis were examined for the presence of antibody to surface protein immunogens of Trichomonas vaginalis. Fourteen of 20 VWs (70%) and 8 of 10 VM (80%) had immunoglobulin G (IgG) antibody (Ab) that reacted in an immunoprecipitation (IP) assay with one iodinated Trichomonas vaginalis surface protein immunogen with a relative molecular mass of 230,000 daltons (230-kDa) (P230). No similar IP of any iodinated protein was observed when detergent extract was first depleted of P230 with monoclonal antibody (MAb), indicating a highly specific VW IgG response of patients to P230. VWs were also obtained from 10 patients from one to four weeks after treatment. These VWs had the same, or in one case a greater, level of IgG to P230. Under no circumstances was Ab to P230 or any other trichomonad protein detected in VWs or VM from normal, uninfected women. Flow cytofluorometry with VW Ab yielded heterogeneous fluorescent and non-fluorescent populations of trichomonads, reaffirming the restricted Ab response to one or a few epitopes on P230 in the vagina of patients. Under identical conditions, the MAb gave totally fluorescent parasite populations of some isolates, and the MAb again demonstrated variable epitope accessibility to Ab binding (Infect Immun 1987;55:1037). Finally, the MAb or VW Ab was never cytolytic for immunoreactive (fluorescent) parasites, even in the presence of complement. This study identifies the most important trichomonad surface immunogen on the basis of the vaginal Ab response, and data underscore the significance of immune evasion strategies of this sexually transmitted disease agent.

The vagina of women infected with Trichomonas vaginalis has numerous proteinases and antibody to trichomonad proteinases.

BACKGROUND: Patients with trichomoniasis have serum antibody to numerous T. vaginalis cysteine proteinases, indicating that the proteinases are expressed in vivo. It was important, therefore, to examine for the presence of soluble trichomonad proteinases and/or antibody to the proteinases in the vagina of infected women. METHODS: Vaginal washes (VWs) from 20 women were examined for the presence of proteinases by electrophoresis using acrylamide co-polymerised with gelatin as the indicator system. Antibody to proteinases in VWs was detected by an immunoprecipitation assay involving protein A-bearing Staphylococcus aureus first coated with anti-human immunoglobulin G (IgG) antibody, which was then added to VWs. For VWs having soluble proteinases, the bacteria were used to determine whether immune complexes between antibody and proteinases were present. VWs without soluble proteinases were incubated with the anti-human IgG treated bacteria before adding to detergent extracts of T. vaginalis. Individual isolates from the patients examined in this study were also analysed by one- and two-dimensional electrophoresis for their proteinase content. Finally, VWs were from patients without any history of other sexually transmitted diseases (STDs) as well as from individuals having numerous other STDs, including yeast, group B streptococcus, chlamydia, and syphilis. RESULTS: Approximately one-third of patients had soluble proteinases in the VWs; the remaining two-thirds (70%) of patients and normal women had no detectable proteinases in VWs. Half of the patients without soluble proteinases had IgG which, when bound to S. aureus, immunoprecipitated many proteinases from a detergent extract of T. vaginalis. All soluble proteinases and those precipitated from trichomonal extracts were inhibited by inhibitors of cysteine proteinases. Finally, patients having trichomoniasis in addition to numerous other STD agents, including yeast, group B streptococcus, chlamydia, and syphilis did not have soluble proteinases in VWs. Equally noteworthy, some patients with soluble proteinases in VWs did not have other detectable STD agents. CONCLUSIONS: Proteinases were detected in the vagina of some patients with trichomoniasis, and in most cases the proteinases were complexed with IgG, which was precipitated by S. aureus. Patients without soluble proteinases in VWs also had antibody specifically to trichomonad proteinases, again demonstrating both the expression and immunogenic nature of the proteinases in vivo. The absence of soluble proteinases in normal women and in patients having other STD agents as well as the presence of proteinases in VWs of patients without other detectable STD pathogens reinforced the idea that the proteinases were of T. vaginalis parasite origin. The findings of this study indicate that proteinases may be important to the T. vaginalis-host interrelationship.

The establishment of a polyposis register.

Guidelines are presented for the establishment of a regional or national register of patients with familial adenomatous polyposis. The detailed recommendations are based on the work in committees of the "Leeds Castle Polyposis Group" and the "EuroFAP". The aims of national and regional polyposis registers are discussed, and the stages of development of a register are reviewed: Ascertainment of probands, construction of pedigrees, identification of family members at risk, and screening of members at risk. The problem of data confidentiality is discussed.

Variants at the secretory phospholipase A2 (PLA2G2A) locus: analysis of associations with familial adenomatous polyposis and sporadic colorectal tumours.

The Min mouse is a model for human familial adenomatous polyposis (FAP), an autosomal dominant disease characterised by multiple adenomatous gastrointestinal polyps. The severity of the Min phenotype is modified by a locus (Mom1) on mouse chromosome 4, at a position syntenic with human chromosome 1p35-p36. The secretory phospholipase A2 (Pla2s) gene is a candidate for this modifier locus and there is evidence that a locus on human chromosome 1p35-p36 acts to modify the severity of human duodenal FAP. We have analysed the human secretory phospholipase A2 locus (PLA2G2A) for variants that could directly influence the FAP phenotype. We found no PLA2G2A variants predicted to result in functional variation in the phospholipase A2 protein. Two PLA2G2A polymorphisms were, however, discovered, one a 'silent' base change in exon 3 and another in a noncoding region. Three other variants (possible mutations) were found in non-coding regions. In 70 FAP patients from 20 families, no associations were found between the severity of duodenal polyposis and any PLA2G2A variant. One allele at the exon 3 polymorphic site did, however, occur more often then expected in patients with relatively severe colonic FAP. Although of borderline statistical significance, this association, if genuine, is likely to result from linkage disequilibrium between the PLA2G2A alleles studied and undetected genetic variation at a closely linked locus. The frequency of the alleles at both polymorphic sites has also been determined in the germ line of patients with sporadic colorectal adenomas and carcinomas and in random controls, but no differences were found among these groups. Our results suggest that PLA2G2A variants do not influence inherited or sporadic colonic tumours. A linked locus may be a modifier of human FAP, but does not influence the risk of colorectal tumours in the general population.

Desmoid tumours complicating familial adenomatous polyposis.

BACKGROUND: Desmoid tumours are one of the most important and intriguing extracolonic manifestations of familial adenomatous polyposis (FAP). They have been studied only in small numbers of patients. METHODS: Patients with FAP who also had desmoid tumour were identified from a polyposis registry database and their hospital notes were reviewed. RESULTS: There were 166 desmoids in 88 patients (median age 32 (interquartile range 22-38) years; 51 (58 per cent) female); 83 tumours (50 per cent) were within the abdomen and 80 (48 per cent) were in the abdominal wall. All but 16 individuals (18 per cent) had already undergone abdominal surgery, which was significantly more recent in women (P = 0.01, Mann-Whitney U test). Intra-abdominal desmoids caused small bowel and ureteric obstruction and resulted in ten deaths; survival was significantly poorer than in patients with abdominal wall desmoid alone (chi2 = 3. 93, 1 d.f., P = 0.047, log rank test), and eight of 22 patients who underwent resection of intra-abdominal desmoid died in the perioperative period. CONCLUSION: Abdominal wall desmoids caused no deaths or significant morbidity; although recurrence was common after excision, the treatment was safe. Intra-abdominal desmoids can cause serious complications and treatment is often unsuccessful; in particular, surgery for desmoids at this site is hazardous.