Management of duodenal adenomatosis in FAP: single centre experience.

Duodenal and ampullary carcinoma in familial adenomatosis (FAP) is the third leading cause of FAP related deaths. Management of this condition is a challenging. The aim of this study was to evaluate the role of multiple targeted endoscopic biopsies and macroscopic appearance as the major determinants for surgical intervention. A secondary aim was to assess histological heterogeneity through comparing endoscopic biopsies and describe the clinical outcomes of our cohort after intervention. We reviewed our FAP surveillance database of 67 patients, between January 1999--June 2011 undergoing upper GI surveillance and where indicated, subsequent surgical intervention. Among 67 patients, 11 underwent surgical resection. Pancreas-preserving duodenectomy was performed in four patients (five procedures), and Whipple's operation in seven patients. The average size of polyps was 43 mm (range 17-65 mm), and the average number of targeted endoscopic biopsies per lesion was 7.5 (range 5-10). Two cases of high-grade (severe) dysplasia were diagnosed on endoscopic biopsies each understaged compared with the subsequent surgical specimen. All carcinomas identified have been resectable with no evidence of local spread or distant metastasis. There was one postoperative death, but no cancer related deaths. We identified both cancers at an early stage and there were no missed or late diagnoses. There have been no recurrences of carcinoma in a more than 7 years follow-up. Due to the heterogeneous nature of these lesions, comprehensive macroscopic assessment should be complemented with multiple targeted biopsies to improve the chance of early detection of advanced lesions.

Investigating the potential role of genetic and epigenetic variation of DNA methyltransferase genes in hyperplastic polyposis syndrome.

BACKGROUND: Hyperplastic Polyposis Syndrome (HPS) is a condition associated with multiple serrated polyps, and an increased risk of colorectal cancer (CRC). At least half of CRCs arising in HPS show a CpG island methylator phenotype (CIMP), potentially linked to aberrant DNA methyltransferase (DNMT) activity. CIMP is associated with methylation of tumor suppressor genes including regulators of DNA mismatch repair (such as MLH1, MGMT), and negative regulators of Wnt signaling (such as WIF1). In this study, we investigated the potential for interaction of genetic and epigenetic variation in DNMT genes, in the aetiology of HPS. METHODS: We utilized high resolution melting (HRM) analysis to screen 45 cases with HPS for novel sequence variants in DNMT1, DNMT3A, DNMT3B, and DNMT3L. 21 polyps from 13 patients were screened for BRAF and KRAS mutations, with assessment of promoter methylation in the DNMT1, DNMT3A, DNMT3B, DNMT3L MLH1, MGMT, and WIF1 gene promoters. RESULTS: No pathologic germline mutations were observed in any DNA-methyltransferase gene. However, the T allele of rs62106244 (intron 10 of DNMT1 gene) was over-represented in cases with HPS (p<0.01) compared with population controls. The DNMT1, DNMT3A and DNMT3B promoters were unmethylated in all instances. Interestingly, the DNMT3L promoter showed low levels of methylation in polyps and normal colonic mucosa relative to matched disease free cells with methylation level negatively correlated to expression level in normal colonic tissue. DNMT3L promoter hypomethylation was more often found in polyps harbouring KRAS mutations (p = 0.0053). BRAF mutations were common (11 out of 21 polyps), whilst KRAS mutations were identified in 4 of 21 polyps. CONCLUSIONS: Genetic or epigenetic alterations in DNMT genes do not appear to be associated with HPS, but further investigation of genetic variation at rs62106244 is justified given the high frequency of the minor allele in this case series.

Linkage to chromosome 2q32.2-q33.3 in familial serrated neoplasia (Jass syndrome).

Causative genetic variants have to date been identified for only a small proportion of familial colorectal cancer (CRC). While conditions such as Familial Adenomatous Polyposis and Lynch syndrome have well defined genetic causes, the search for variants underlying the remainder of familial CRC is plagued by genetic heterogeneity. The recent identification of families with a heritable predisposition to malignancies arising through the serrated pathway (familial serrated neoplasia or Jass syndrome) provides an opportunity to study a subset of familial CRC in which heterogeneity may be greatly reduced. A genome-wide linkage screen was performed on a large family displaying a dominantly-inherited predisposition to serrated neoplasia genotyped using the Affymetrix GeneChip Human Mapping 10 K SNP Array. Parametric and nonparametric analyses were performed and resulting regions of interest, as well as previously reported CRC susceptibility loci at 3q22, 7q31 and 9q22, were followed up by finemapping in 10 serrated neoplasia families. Genome-wide linkage analysis revealed regions of interest at 2p25.2-p25.1, 2q24.3-q37.1 and 8p21.2-q12.1. Finemapping linkage and haplotype analyses identified 2q32.2-q33.3 as the region most likely to harbour linkage, with heterogeneity logarithm of the odds (HLOD) 2.09 and nonparametric linkage (NPL) score 2.36 (P = 0.004). Five primary candidate genes (CFLAR, CASP10, CASP8, FZD7 and BMPR2) were sequenced and no segregating variants identified. There was no evidence of linkage to previously reported loci on chromosomes 3, 7 and 9.

Risk factors for colorectal cancer in patients with multiple serrated polyps: a cross-sectional case series from genetics clinics.

BACKGROUND: Patients with multiple serrated polyps are at an increased risk for developing colorectal cancer (CRC). Recent reports have linked cigarette smoking with the subset of CRC that develops from serrated polyps. The aim of this work therefore was to investigate the association between smoking and the risk of CRC in high-risk genetics clinic patients presenting with multiple serrated polyps. METHODS AND FINDINGS: We identified 151 Caucasian individuals with multiple serrated polyps including at least 5 outside the rectum, and classified patients into non-smokers, current or former smokers at the time of initial diagnosis of polyposis. Cases were individuals with multiple serrated polyps who presented with CRC. Controls were individuals with multiple serrated polyps and no CRC. Multivariate logistic regression was performed to estimate associations between smoking and CRC with adjustment for age at first presentation, sex and co-existing traditional adenomas, a feature that has been consistently linked with CRC risk in patients with multiple serrated polyps. CRC was present in 56 (37%) individuals at presentation. Patients with at least one adenoma were 4 times more likely to present with CRC compared with patients without adenomas (OR = 4.09; 95%CI 1.27 to 13.14; P = 0.02). For females, the odds of CRC decreased by 90% in current smokers as compared to never smokers (OR = 0.10; 95%CI 0.02 to 0.47; P = 0.004) after adjusting for age and adenomas. For males, there was no relationship between current smoking and CRC. There was no statistical evidence of an association between former smoking and CRC for both sexes. CONCLUSION: A decreased odds for CRC was identified in females with multiple serrated polyps who currently smoke, independent of age and the presence of a traditional adenoma. Investigations into the biological basis for these observations could lead to non-smoking-related therapies being developed to decrease the risk of CRC and colectomy in these patients.

Phenotypic diversity in patients with multiple serrated polyps: a genetics clinic study.

OBJECTIVE: Hyperplastic polyposis is a colonic polyposis condition of unknown aetiology. The purpose of this study was to examine the spectrum of phenotypic variation in patients with multiple serrated polyps as a basis for gene discovery. METHODS: One hundred and twenty-six patients with multiple (> or = 5) serrated polyps were recruited to the study. Polyp counts were extracted from histology and colonoscopy reports. Ethnicity was self-reported. Family history of cancer data were derived from pedigrees. Ascertainment status was classified as either index case or identified by screening. RESULTS: The average reported polyp count was 39. Patients with highest polyp numbers were more likely to be male (P = 0.02). Colorectal cancer (CRC) was identified in 49 of 119 patients (41%) and 28% of these patients had multiple CRC. Young onset patients had higher polyp numbers (P = 0.03) and were more likely to have their CRC in the distal colon (P = 0.02). CRC was significantly associated with the presence of adenomas (P = 0.03). Patients were divided into moderate polyposis (5-79 serrated polyps) and dense polyposis (80 or more) categories. The dense polyposis category was associated with a lack of family history for CRC (P = 0.034) and male gender (P = 0.014), independent of ascertainment status and recruitment site. CONCLUSION: Multiple serrated polyps were associated with an increased personal risk of CRC. A subset of patients with the highest polyp numbers was more likely to be male and to have no family history of CRC. This result suggests heterogeneous modes of inheritance and has implications for studies investigating the genetic basis of multiple serrated polyps.

Analysis of families with Lynch syndrome complicated by advanced serrated neoplasia: the importance of pathology review and pedigree analysis.

The identification of Lynch syndrome has been greatly assisted by the advent of tumour immunohistochemistry (IHC) for mismatch repair (MMR) proteins, and by the recognition of the role of acquired somatic BRAF mutation in sporadic MMR-deficient colorectal cancer (CRC). However, somatic BRAF mutation may also be present in the tumours in families with a predisposition to develop serrated polyps in the colorectum. In a subgroup of affected members in these families, CRCs emerge which demonstrate clear evidence of MMR deficiency with absent MLH1 staining and high-level microsatellite instability (MSI). This may result in these families being erroneously classified as Lynch syndrome, or conversely, an individual is considered "sporadic" due to the presence of a somatic BRAF mutation in a tumour. In this report, we describe two Lynch syndrome families who demonstrated several such inconsistencies. In one family, IHC deficiency of both MSH2 and MLH1 was demonstrated in tumours from different affected family members, presenting a confusing diagnostic picture. In the second family, MLH1 loss was observed in the lesions of both MLH1 mutation carriers and those who showed normal MLH1 germline sequence. Both families had Lynch syndrome complicated by an independently segregating serrated neoplasia phenotype, suggesting that in families such as these, tumour and germline studies of several key members, rather than of a single proband, are indicated to clarify the spectrum of risk.

Hepatosplenic T-cell lymphoma following infliximab therapy for Crohn's disease.

Tumour necrosis factor inhibitors have revolutionised the management of Crohn's disease, but reports of a possible association between concomitant infliximab and immunomodulator therapy and hepatosplenic T-cell lymphoma (a rare form of aggressive non-Hodgkin's lymphoma) have emerged. We describe the first case in Australia of hepatosplenic T-cell lymphoma in a patient who had been treated with infliximab and immunomodulators for Crohn's disease.