Localization of the gene for familial adenomatous polyposis on chromosome 5

Genetics of primary macronodular adrenal hyperplasia

Recent advances in molecular genetics investigations of primary macronodular adrenal hyperplasia (PMAH) have been providing new insights for the research on this issue. The cAMP-dependent pathway is physiologically triggered by ACTH and its receptor, MC2-R, in adrenocortical cells. Different mechanisms of this cascade may be altered in some functioning adrenal cortical disorders. Activating somatic mutations of the GNAS gene (known as gsp oncogene) which encodes the stimulatory G protein alpha-subunit (Gsα) have been found in a small number of adrenocortical secreting adenomas and rarely in PMAH. Lately, ARMC5 was linked to the cyclic AMP signaling pathway, which could be implicated in all of mechanisms of cortisol-secreting by macronodules adrenal hyperplasia and the molecular defects in: G protein aberrant receptors; MC2R; GNAS; PRKAR1A; PDE11A; PDE8B. Around 50 % of patient's relatives with PMAH and 30 % of apparently sporadic hypercortisolism carried ARMC5 mutations. Therefore, PMAH is genetically determined more frequently than previously believed. This review summarizes the most important molecular mechanisms involved in PMAH.

Recent progress in Lynch syndrome and other familial colorectal cancer syndromes

The current understanding of familial colorectal cancer was limited to descriptions of affected pedigrees until the early 1990s. A series of landscape-altering discoveries revealed that there were distinct forms of familial cancer, and most were related to genes previously not known to be involved in human disease. This review largely focuses on advances in our understanding of Lynch syndrome because of the unique relationship of this disease to defective DNA mismatch repair and the clinical implications this has for diagnostics, prevention, and therapy. Recent advances have occurred in our understanding of the epidemiology of this disease, and the advent of broad genetic panels has altered the approach to germline and somatic diagnoses for all of the familial colorectal cancer syndromes. Important advances have been made toward a more complete mechanistic understanding of the pathogenesis of neoplasia in the setting of Lynch syndrome, and these advances have important implications for prevention. Finally, paradigm-shifting approaches to treatment of Lynch-syndrome and related tumors have occurred through the development of immune checkpoint therapies for hypermutated cancers. CA Cancer J Clin 2018;68:217-231. © 2018 American Cancer Society.

Genetic Events Responsible for Colorectal Tumorigenesis: Achievements and Challenges

Colorectal carcinogenesis is a multistep process that is accompanied by accumulation of changes in proto-oncogenes and tumor-suppressor genes. APC/MCC, RAS, DCC, p53 mutations and/or allelic losses, hyperexpression of c-MYC and RB genes, as well as other genomic alterations appear at characteristic stages of tumor development and are observed in most neoplasms. However, consideration of each of these abnormalities leaves many unanswered questions. The striking data on recurrent amplification of the RB tumor-suppressor gene as well as suppressive activities of protein kinase C and activated RAS genes, at least in some colon carcinoma cell lines, suggest the unusual effects of some signalling pathways in colonic epithelial cells. The results obtained to date indicate that distinct sets of genetic changes may underlie the development of colorectal tumors.

Onco-Suppressor Genes in Human Cancer

The analysis of the molecular mechanisms governing multistep carcinogenesis became experimentally approachable since the identification and characterization in tumor cells of altered or activated versions of cellular genes (oncogenes) that normally control cell growth and differentiation. The activating mutations confer new properties to the oncogene products and should therefore be considered as gain of function mutations. In addition, the oncogenes appear to act as dominant genetic traits since they act also in the presence of the homologous wild-type allele. However, the concept of a dominance of the transformed phenotype has been challenged by early experiments with somatic cell hybrids which showed that the fusion of normal and malignant cells may suppress the tumorigenic phenotype. The suppression or reversion of the malignant phenotype by the introduction of a normal chromosome into a tumor cell line has lent support to the idea that a family of cellular genes are coding for factors capable to interact with the cell-growth control machinery. These genes seem to reconstitute the normal control of cell growth even in the presence of an activated oncogene. In addition, a two-mutation model has been proposed to explain the epidemiological and clinical features of childhood cancers. According to the model, the development of these malignancies can be caused by the loss or inactivation of both alleles of cellular genes, as suggested by the somatic cell hybrid experiments where the function of the inactivated genes is restored by the contribution of those derived from the normal parental cells. This family of genes is designated as onco-suppressor genes since their product is necessary for the normal regulated cell growth and is lacking or inactivated in malignant cells. At gene level they should be considered as recessive genetic traits, since the tumor phenotype appears when both alleles of an oncosuppressor gene are inactivated. The mutations affecting their normal functions belong to the type « loss of function ». The molecular analysis of retinoblastoma has led to the cloning and sequencing of the related onco-suppressor gene (RB gene) whose product displays the features of a gene-regulatory protein. In addition, a binding between the RB product and various viral onco-proteins (E1A, large T, E7) has been demonstrated, thus suggesting a mechanism of RB inactivation by which some DNA viruses can transform the host cell. Finally, the increasing availability of DNA markers, defining restriction fragment length polymorphisms, has led to the mapping of the loci of inherited predisposition for familial cancer syndromes such as MEN-1, VHL and NF-2 and to the extension to common cancers of the allele losses analysis that can reveal onco-suppressor gene inactivation. This indirect approach has suggested the occurrence of different onco-suppressor genes for sporadic breast, colonic and lung cancers, bladder carcinoma, germinal tumors of the testis and malignant melanoma. In particular, colonic cancer provides a significant example of a possible multistep scenario for carcinogenesis in humans in which activated oncogenes (e.g. ras) and inactivated putative onco-suppressor genes (on chromosome 17 and 18) coexist in the same cell.

Inhibition of nuclear Wnt signalling: challenges of an elusive target for cancer therapy

The highly conserved Wnt signalling pathway plays an important role in embryonic development and disease pathogenesis, most notably cancer. The 'canonical' or β-catenin-dependent Wnt signal initiates at the cell plasma membrane with the binding of Wnt proteins to Frizzled:LRP5/LRP6 receptor complexes and is mediated by the translocation of the transcription co-activator protein, β-catenin, into the nucleus. β-Catenin then forms a complex with T-cell factor (TCF)/lymphoid enhancer binding factor (LEF) transcription factors to regulate multiple gene programmes. These programmes play roles in cell proliferation, migration, vasculogenesis, survival and metabolism. Mutations in Wnt signalling pathway components lead to constitutively active Wnt signalling that drives aberrant expression of these programmes and development of cancer. It has been a longstanding and challenging goal to develop therapies that can interfere with the TCF/LEF-β-catenin transcriptional complex. This review will focus on the (i) structural considerations for targeting the TCF/LEF-β-catenin and co-regulatory complexes in the nucleus, (ii) current molecules that directly target TCF/LEF-β-catenin activity and (iii) ideas for targeting newly discovered components of the TCF/LEF-β-catenin complex and/or downstream gene programmes regulated by these complexes.

LINKED ARTICLES

This article is part of a themed section on WNT Signalling: Mechanisms and Therapeutic Opportunities. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v174.24/issuetoc.

Integrating surgery and genetic testing for the modern surgeon

The field of cancer genetics is rapidly evolving and several genetic mutations have been identified in hereditary cancer syndromes. These mutations can be diagnosed via routine genetic testing allowing prompt intervention. This is especially true for certain variants of colorectal, breast, and thyroid cancers where genetic testing may guide surgical therapy. Ultimately, surgical intervention may drastically diminish disease manifestation or progression in individuals deemed as high-risk based on their genetic makeup. Understanding the concepts of gene-based testing and integrating into current surgical practice is crucial. This review addresses common genetic syndromes, tests, and interventions salient to the current surgeon.

Surveillance of Duodenal Polyposis in Familial Adenomatous Polyposis: Should the Spigelman Score Be Modified?

BACKGROUND

Duodenal polyposis is a manifestation of adenomatous polyposis that predisposes to duodenal or ampullary adenocarcinoma. Duodenal polyposis is monitored by upper GI endoscopies and may require iterative resections and prophylactic radical surgical treatment when malignancy is threatening.

OBJECTIVE

The purpose of this study was to evaluate severity scoring for surveillance and treatment in a large series of duodenal polyposis.

DESIGN

From 1982 to 2014, every patient surveyed by upper GI endoscopies for duodenal polyposis was included.

SETTINGS

The study was conducted at a single tertiary care center.

PATIENTS

We performed 1912 upper GI endoscopies in 437 patients (median = 3; interquartile range, 2-6 endoscopies).

MAIN OUTCOME MEASURES

Conservative treatment was performed in 103 patients (159 endoscopic and 17 surgical resections), whereas radical surgical treatment (Whipple procedure or duodenectomy) was required in 52 (median age, 47.5 y; range, 43.0-57.3 y) because of high-grade dysplasia or unresectable lesions.

RESULTS

Genes involved were APC (n = 274; 62.7%) and MUTYH (n = 21; 4.8%). First upper GI endoscopies (median age, 32 y; range, 21-44 y) revealed duodenal polyposis in 190 (43.5%). Rates of low-grade dysplasia, high-grade dysplasia, and duodenal or ampulary adenocarcinoma at 5 years were 65% (range, 61.7%-66.9%), 12.1% (range, 10.3%-13.9%), and 2.4% (range, 1.5%-3.3%), whereas 10-year rates were 75.8% (range, 73.1%-78.5%), 20.8% (range, 18.2%-23.4%), and 5.4% (range, 3.8%-7.0%). The rate of ampullary abnormalities rose during surveillance from 18.3% at the first upper GI endoscopies to 47.4% at the fourth. Predictive factors for high-grade dysplasia were age at first upper GI endoscopy, type and age of colorectal surgery, Spigelman score, presence of an ampullary abnormality, and number of endoscopic treatments. In multivariate analysis, only age at first upper GI endoscopy and presence of an ampullary abnormality were independent predictive factors. Histologic analysis after radical surgical treatment showed high-grade dysplasia in 30 patients and duodenal or ampulary adenocarcinoma in 11 (4 patients had lymph node involvement).

LIMITATIONS

The study was limited by its retrospective analysis of a prospective database.

CONCLUSIONS

More than 20% of patients developed high-grade dysplasia with duodenal polyposis after 10 years. Iterative endoscopic resections allowed extended control, but surgery remained necessary in 12% of the patients and happened too late in many cases; 20% of those operated had developed duodenal or ampulary adenocarcinoma, whereas 8% exhibited malignancy with lymph node involvement. The trigger for prophylactic surgery required a more accurate predictive score leading to closer endoscopic surveillance. Modifying the Spigelman score by accounting for ampullary abnormalities should be considered as a means to increase compliance with closer endoscopic follow-up in high-risk patients. See Video Abstract at http://links.lww.com/DCR/A430.

Postoperative outcome and quality of life after surgery for FAP-associated duodenal adenomatosis

INTRODUCTION

Prophylactic colon surgery has increased life expectancy of familial adenomatous polyposis patients. Extracolonic manifestations are life limiting, above all duodenal adenomas. Severe duodenal adenomatosis or cancer may necessitate pancreas-preserving total duodenectomy or partial pancreatico-duodenectomy, mostly after previous proctocolectomy and often after limited local resections of duodenal adenomas. Scarce information on long-term postoperative outcome and quality of life after surgery for duodenal adenomatosis is available. Aim of the present study was to analyze perioperative and long-term outcome after PD and PPTD for FAP-associated duodenal adenomatosis, including QoL and recurrence of adenomas in the neoduodenum after PPTD.

MATERIAL, METHODS AND PATIENTS

Thirty-eight patients, 27 after pancreas-preserving duodenectomy and 11 after partial pancreaticoduodenectomy, were included.

RESULTS

Pancreas-preserving total duodenectomy was associated with shorter operation time and less blood loss than partial pancreatico-duodenectomy. Clinically relevant pancreatic fistula occurred in 31.5%. In-hospital mortality was 5.3%. Long-term follow-up revealed recurrent pancreatitis after pancreas-preserving total duodenectomy in 22% of patients, two (7.4%) required re-operation. Recurrent adenomatosis was detected in 26% of patients. Quality of life was comparable to the German normal population after both surgical procedures. Patients with postoperative complications showed worse results than those without complications. Disease-specific 10-year survival rate with respect to duodenal adenomatosis was 100%.

CONCLUSION

Surgery for FAP-associated duodenal adenomatosis and cancer can be carried out with reasonable morbidity rates despite previous proctocolectomy. Long-term outcome, quality of life, and survival rates are favorable.

Different effection of p.1125Val>Ala and rs11954856 in APC on Wnt signaling pathway

Colorectal cancer (CRC) is among the most common and fatal forms of solid tumors worldwide and more than two thirds of CRC and adenomas patients have APC gene mutations. APC is a key regulator in the Wnt/β-catenin signaling pathway but its roles in CRC remains to be elucidated. In this study, we compared APC genes between CRC patients and controls to determine possible associations of nucleotide changes in the APC gene with the pathways involved in CRC pathogenesis. All participants received physical and enteroscopic examinations. The APC gene was sequenced for 300 Chinese Han CRC patients and 411 normal controls, and the expression levels of genes in the signaling pathway were analyzed using Western Blotting. Statistical analyses were conducted using SPSS (version 19.0) software. We found that rs11954856 in the APC gene was associated with colorectal cancer and could increase the expression levels of APC, β-catenin, TCF7L1, TCF7L2 and LEF1 genes in the pathway in the CRC patients, demonstrating the involvement of APC in the pathological processes leading to CRC.

Surgical considerations in FAP-related pouch surgery: Could we do better?

The ileoanal pouch has become the standard restorative procedure of choice for patients with the classical phenotype in FAP (familial adenomatous polyposis) and also for ulcerative colitis (UC). Whilst we tend to encounter descriptive analyses comparing functional outcome, fertility and quality of life (QOL) between series in literature, there may be an urgent need to discuss the subtle technical modifications that may be pivotal for improving long-term QOL in FAP patients. Our aim is to review the current literature and discuss the aspects of ileal pouch-anal anastomosis that may require specific reevaluation for FAP. Surgical strategies aimed at minimizing post-interventional desmoid growth is one of the most important aspects. For this study, the following topics of interest were selected: Timing of surgery, IRA or ileoanal pouch for classical FAP, laparoscopic or conventional surgery, TME or mesenteric dissection, preservation of the ileocolic vessels, handsewn or double-staple anastomosis, shape and size of pouch, protective ileostomy, Last and definitely not least: how to manage desmoid plaques or desmoids at the time of prophylactic surgery. For the depicted technicalities of the procedure, a review of recent literature was performed and evaluated. For the topics selected, only sparse reference in literature was identified that was focused on the specific condition situation of FAP. Almost all pouch literature focusses on the procedural aspects, and FAP patients are always a very minor number. Therefore it becomes obvious that the specific entity is not adequately taken into account. This is a serious bias for identification of important steps in the procedure that may be beneficial for patients with either of the diseases. The results of this study demonstrate that several technical differences for construction of ileoanal pouches in FAP patients deserve more attention and prospective evaluation-perhaps even randomized trials. The role, importance and potential benefit or deterioration of outcome in most of the discussed technicalities remains unclear to date. Significant differences between the underlying diseases (UC and FAP) have not been taken into consideration, such as specifically the management of precursor desmoid lesions at the time of prophylactic surgery as well as prevention of desmoid tumors. Several of the aspects discussed in this paper should be prospectively evaluated in larger and exclusive series of FAP patients.

Attenuated adenomatous polyposis of the large bowel: Present and future

Attenuated adenomatous polyposis (AAP) is a poorly understood syndrome, that can be defined as the presence of 10-99 synchronous adenomas in the large bowel, and it is considered a phenotypic variant of familial adenomatous polyposis (FAP). This definition has the advantage of simplicity, but it may include sporadic multiple adenomas of the large bowel at an extreme, or FAP cases on the other side. AAP shows a milder phenotype than FAP, with an older age of onset of adenomas and cancer, and less frequent extracolonic manifestations. AAP may be diagnosed as a single case in a family or, less frequently, it may be present in other family members, and it shows distinct pattern of inheritance. In less than 50% of cases, it may be caused by adenomatous polyposis coli (APC) or MUTYH mutations, referred to as APC-associated polyposis, inherited as an autosomal dominant trait, or MUTYH-associated polyposis, which shows an autosomal recessive mechanism of inheritance, respectively. Surveillance should rely on colonoscopy at regular intervals, with removal of adenomas and careful histological examination. When removal of polyps is not possible or advanced lesions are observed, the surgical approach is mandatory, being subtotal colectomy with ileo-rectal anastomosis the treatment of choice. Studies on this syndrome are lacking, and controversies are still present on many issues, thus, other clinical and genetic studies are requested.

Extracolonic cancer risk in Dutch patients with APC (adenomatous polyposis coli)-associated polyposis

BACKGROUND

Screening of patients with familial adenomatous polyposis (FAP) have led to a substantial reduction in mortality due to colorectal cancer (CRC). Recent guidelines suggest that surveillance of non-intestinal malignancies should also be considered in those patients. However, the value of these surveillance programmes is unknown. The aims of this study were (1) to assess the occurrence of extracolonic malignancies in a large series of adenomatous polyposis coli (APC) mutation carriers and (2) to evaluate the causes of death.

METHODS

All APC mutation carriers were selected from the Dutch polyposis registry. Data on causes of death were collected. Pathology reports were retrieved from the Dutch Pathology Registry.

RESULTS

A total of 85 extracolonic malignancies were diagnosed in 74 of 582 APC mutation carriers. Duodenal and skin cancers were the most prevalent cancers. Thyroid cancer was observed in only 1.5% of the cases. The main cause of death was cancer (59% of all deaths), with 42% due to CRC and 21% due to duodenal cancer. One patient died from thyroid cancer. The second and third most common causes of death were cardiovascular disease (13% of all deaths) and desmoid tumours (11% of all deaths), respectively.

CONCLUSION

Extending surveillance programmes to other cancers will not contribute significantly to the survival of patients with FAP.

Cellular context-dependent consequences of Apc mutations on gene regulation and cellular behavior

The spectrum of genetic mutations differs among cancers in different organs, implying a cellular context-dependent effect for genetic aberrations. However, the extent to which the cellular context affects the consequences of oncogenic mutations remains to be fully elucidated. We reprogrammed colon tumor cells in an Apc^Min/+ (adenomatous polyposis coli) mouse model, in which the loss of the Apc gene plays a critical role in tumor development and subsequently, established reprogrammed tumor cells (RTCs) that exhibit pluripotent stem cell (PSC)-like signatures of gene expression. We show that the majority of the genes in RTCs that were affected by Apc mutations did not overlap with the genes affected in the intestine. RTCs lacked pluripotency but exhibited an increased expression of Cdx2 and a differentiation propensity that was biased toward the trophectoderm cell lineage. Genetic rescue of the mutated Apc allele conferred pluripotency on RTCs and enabled their differentiation into various cell types in vivo. The redisruption of Apc in RTC-derived differentiated cells resulted in neoplastic growth that was exclusive to the intestine, but the majority of the intestinal lesions remained as pretumoral microadenomas. These results highlight the significant influence of cellular context on gene regulation, cellular plasticity, and cellular behavior in response to the loss of the Apc function. Our results also imply that the transition from microadenomas to macroscopic tumors is reprogrammable, which underscores the importance of epigenetic regulation on tumor promotion.

Evolution and heterogeneity of non-hereditary colorectal cancer revealed by single-cell exome sequencing

Recently single-cell whole-exome sequencing (scWES) has deeply expanded and sharpened our knowledge of cancer evolution and subclonality. Herein, with scWES and matched bulk whole-exome sequencing (bulk WES) on two colorectal cancer (CRC) patients with normal or adenomatous polyps, we found that both the adenoma and cancer were of monoclonal origin, and both shared partial mutations in the same signaling pathways, but each showed a specific spectrum of heterogeneous somatic mutations. In addition, the adenoma and cancer further developed intratumor heterogeneity with the accumulation of nonrandom somatic mutations specifically in GPCR, PI3K-Akt and FGFR signaling pathways. We identified novel driver mutations that developed during adenoma and cancer evolution, particularly in OR1B1 (GPCR signaling pathway) for adenoma evolution, and LAMA1 (PI3K-Akt signaling pathway) and ADCY3 (FGFR signaling pathway) for CRC evolution. In summary, we demonstrated that both colorectal adenoma and CRC are monoclonal in origin, and the CRCs further diversified into different subclones with heterogeneous mutation profiles accumulating in GPCR, PI3K-Akt and FGFR signaling pathways. ScWES provides evidence for the importance of mutations in certain pathways that would not be as apparent from bulk sequencing of tumors, and can potentially establish whether specific mutations are mutually exclusive or occur sequentially in the same subclone of cells.

Glucose-6-phosphate dehydrogenase deficiency and risk of colorectal cancer in Northern Sardinia: A retrospective observational study

Glucose-6-phosphate dehydrogenase (G6PD) deficiency has been associated with a lower cancer risk, possibly via a reduction of mutagenic oxygen-free radicals and by reducing nicotinamide-adeninedinucleotide-phosphate for replicating cells. In Sardinia, the enzyme defect is frequent as a consequence of selection by malaria in the past. This study investigated the relationship between G6PD deficiency and colorectal cancer (CRC).A retrospective case-control study of 3901 patients from Sardinia, who underwent a colonoscopy between 2006 and 2016, was performed. G6PD phenotype was assessed for each subject. The proportion of pre and malignant colorectal lesions was compared in cases (G6PD-deficient) and controls (G6PD-normal). Data concerning age, sex, family history of CRC, smoking habits, body height, and weight, and also associated diseases were collected.The CRC risk reduction was 43.2% among G6PD-deficient compared with G6PD-normal subjects (odds ratio 0.57, 95% confidence interval 0.37-0.87, P = 0.010). Age, sex, family history of CRC, and also comorbidities such as type 1 diabetes and ischemic heart disease, were significantly associated with CRC risk. The protective effect of G6PD deficiency remained significant after adjusting for all covariates by logistic regression analysis, and was consistently lower across all age groups.Glucose-6-phosphate dehydrogenase enzyme deficiency is associated with a reduced risk of CRC.

Association of APC I1307K and E1317Q polymorphisms with colorectal cancer among Egyptian subjects

Colorectal cancer is a multifactorial disease that involves both environmental and genetic factors. The gene encoding adenomatous polyposis coli (APC) has been reported to be associated with colorectal cancer (CRC) risk in several ethnic populations. The aim of this work is to assess the association of the APC I1307K and E1317Q polymorphisms with CRC risk among Egyptian subjects. This study included 120 unrelated CRC Egyptian patients who were compared to 100 healthy controls from the same locality. For all subjects, DNA was genotyped for APC I1307K and E1317Q polymorphisms using the PCR-ARMS technique. The frequency of APC I1307K carrier (TA+AA genotypes) was noted to be significantly higher among cases with CRC compared to controls (18.3 vs. 9.0 %, OR 2.58, 95 % CI 1.09-6.09, p = 0.03). Also the frequency of the APC I1307K A allele was significantly higher among cases compared to controls (10.4 vs. 4.5 %, OR 2.47; 95 % CI 1.12-5.42, p = 0.03). On the contrast, the frequencies of APC E1317Q GC genotype and C allele showed no significant difference among CRC patients compared to controls (3.3 vs. 2.0 %, OR 1.69; 95 % CI 0.30-9.42, p = 0.69 and 2.1 vs. 1.0 %, OR 2.11; 95 % CI 0.40-10.97, p = 0.46, respectively). Cases of the APC I1307K and E1317Q carriers (TA+AA and GC) showed no significant difference compared to those with I1307K and E1317Q non-carriers (TT and GG) regarding their clinical and laboratory markers. APC I1307K variant was associated with an increased risk of CRC among Egyptian subjects.

Familial Colorectal Cancer: Understanding the Alphabet Soup

While most colorectal cancers (CRCs) originate from nonhereditary spontaneous mutations, one-third of cases are familial or hereditary. Hereditary CRCs, which account for < 5% of all CRCs, have identifiable germline mutations and phenotypes, such as Lynch syndrome and familial adenomatous polyposis (FAP). Familial CRCs, which account for up to 30% of CRCs, have no identifiable germline mutation or specific pattern of inheritance, but higher-than-expected incidence within a family. Since the discovery that certain genotypes can lead to development of CRC, thousands of mutations have now been implicated in CRC. These new findings have enhanced our ability to identify at-risk patients, initiate better surveillance, and take preventative measures. Given the large number of genes now associated with hereditary and familial CRCs, clinicians should be familiar with the alphabet soup of genes to provide the highest quality of care for patients and families.

Clinicopathologic and Molecular Features of Colorectal Adenocarcinoma with Signet-Ring Cell Component

Background

We performed a retrospective study to assess the clinicopathological characters, molecular alterations and multigene mutation profiles in colorectal cancer patients with signet-ring cell component.

Methods

Between November 2008 and January 2015, 61 consecutive primary colorectal carcinomas with signet-ring cell component were available for pathological confirmation. RAS/BRAF status was performed by direct sequencing. 14 genes associated with hereditary cancer syndromes were analyzed by targeted gene sequencing.

Results

A slight male predominance was detected in these patients (59.0%). Colorectal carcinomas with signet-ring cell component were well distributed along the large intestine. A frequently higher TNM stage at the time of diagnosis was observed, compared with the conventional adenocarcinoma. Family history of malignant tumor was remarkable with 49.2% in 61 cases. The median OS time of stage IV patients in our study was 14 months. RAS mutations were detected in 22.2% (12/54) cases with KRAS mutations in 16.7% (9/54) cases and Nras mutations in 5.4%(3/54) cases. BRAF V600E mutation was detected in 3.7% (2/54) cases. As an exploration, we analyzed 14 genes by targeted gene sequencing. These genes were selected based on their biological role in association with hereditary cancer syndromes. 79.6% cases carried at least one pathogenic mutation. Finally, the patients were classified by the percentage of signet-ring cell. 39 (63.9%) cases were composed of ≥50% signet-ring cells; 22 (36.1%) cases were composed of <50% signet-ring cells. We compared clinical parameters, molecular and genetic alterations between the two groups and found no significant differences.

Conclusions

Colorectal adenocarcinoma with signet-ring cell component is characterized by advanced stage at diagnosis with remarkable family history of malignant tumor. It is likely a negative prognostic factor and tends to affect male patients with low rates of RAS /BRAF mutation. Colorectal patients with any component of signet-ring cells, regardless of the extent, shared similar clinicopathological characteristics, molecular alterations and genetic profiles.

Chemoprevention of hereditary colon cancers: time for new strategies

Colorectal cancer (CRC) is potentially preventable. Chemoprevention, a focus of research for the past three decades, aims to prevent or delay the onset of cancer through the regression or prevention of colonic adenomas. Ideal pharmacological agents for chemoprevention should be cheap and nontoxic. Although data indicate that aspirin can reduce the risk of CRC in the general population, the highest return from chemopreventive strategies would be expected in patients with the highest risk of developing the disease, particularly those with a defined hereditary predisposition. Despite compelling data showing that a large number of chemopreventive agents show promise in preclinical CRC models, clinical studies have yielded conflicting results. This Review provides a historical and methodological perspective of chemoprevention in familial adenomatous polyposis and Lynch syndrome, and summarizes the current status of CRC chemoprevention in humans. Our goal is to critically focus on important issues of trial design, with particular attention on the choice of appropriate trial end points, how such end points should be measured, and which patients are the ideal candidates to be included in a chemopreventive trial.

Can supplementation of phytoestrogens/insoluble fibers help the management of duodenal polyps in familial adenomatous polyposis?

Familial adenomatous polyposis (FAP) is an autosomal dominant inherited disorder, and prophylactic colectomy has been shown to decrease the incidence of colorectal cancer (CRC). Duodenal cancer and desmoids are now the leading causes of death in FAP. We evaluate whether 3 months of oral supplementation with a patented blend of phytoestrogens and indigestible insoluble fibers (ADI) help the management of FAP patients with ileal pouch-anal anastomosis (IPAA). In a prospective open label study, we enrolled 15 FAP patients with IPAA and duodenal polyps who underwent upper gastrointestinal endoscopy at baseline and after 3 months of treatment. The primary endpoint was the change in gene expression in polyp mucosa, whereas the secondary endpoint was the reduction in polyp number and size. After 3 months of ADI treatment, all patients showed a reduction in the number and size of duodenal polyps (P = 0.021). Analysis of the expression of CRC promoting/inhibiting genes in duodenal polyps biopsies demonstrated that different CRC-promoting genes (PCNA, MUC1 and COX-2) were significantly downregulated, whereas CRC-inhibiting genes (ER-β and MUC2) were significantly upregulated after ADI treatment. In conclusion, ADI proved to be safe and effective, and its long-term effects on FAP patients need further investigation. Judging from the results we observed on COX-2 and miR-101 expression, the short-term effects of ADI treatment could be comparable with those obtained using COX-2 inhibitors, with the advantage of being much more tolerable in chronic therapies and void of adverse events.

Genetic architecture of colorectal cancer

Colorectal cancer (CRC) is a complex disease that develops as a consequence of both genetic and environmental risk factors. A small proportion (3-5%) of cases arise from hereditary syndromes predisposing to early onset CRC as a result of mutations in over a dozen well defined genes. In contrast, CRC is predominantly a late onset 'sporadic' disease, developing in individuals with no obvious hereditary syndrome. In recent years, genome wide association studies have discovered that over 40 genetic regions are associated with weak effects on sporadic CRC, and it has been estimated that increasingly large genome wide scans will identify many additional novel genetic regions. Subsequent experimental validations have identified the causally related variant(s) in a limited number of these genetic regions. Further biological insight could be obtained through ethnically diverse study populations, larger genetic sequencing studies and development of higher throughput functional experiments. Along with inherited variation, integration of the tumour genome may shed light on the carcinogenic processes in CRC. In addition to summarising the genetic architecture of CRC, this review discusses genetic factors that modify environmental predictors of CRC, as well as examples of how genetic insight has improved clinical surveillance, prevention and treatment strategies. In summary, substantial progress has been made in uncovering the genetic architecture of CRC, and continued research efforts are expected to identify additional genetic risk factors that further our biological understanding of this disease. Subsequently these new insights will lead to improved treatment and prevention of colorectal cancer.

A Mathematician's Odyssey

In this overview of my research, I have aimed to give the background as to how I came to be involved in my various areas of interest, with an emphasis on the early phases of my career, which largely determined my future directions. I had the enormous good fortune to have worked under two of the most outstanding scientists of the twentieth century, R.A. Fisher and Joshua Lederberg. From mathematics and statistics, I went to population genetics and the early use of computers for modeling and simulation. Molecular biology took me into the laboratory and eventually to somatic cell genetics and human gene mapping. One chance encounter led me into the HLA field and another led me into research on cancer, especially colorectal cancer. On the way, I became a champion of the Human Genome Project and of the need for scientists to help promote the public understanding of science.

Absolute Proteome Analysis of Colorectal Mucosa, Adenoma, and Cancer Reveals Drastic Changes in Fatty Acid Metabolism and Plasma Membrane Transporters

Colorectal cancer is a leading cause of cancer-related death. It develops from normal enterocytes, through a benign adenoma stage, into the cancer and finally into the metastatic form. We previously compared the proteomes of normal colorectal enterocytes, cancer and nodal metastasis to a depth of 8100 proteins and found extensive quantitative remodeling between normal and cancer tissues but not cancer and metastasis (Wiśniewski et al. PMID 22968445). Here we utilize advances in the proteomic workflow to perform an in depth analysis of the normal tissue (N), the adenoma (A), and the cancer (C). Absolute proteomics of 10 000 proteins per patient from microdissected formalin-fixed and paraffin-embedded clinical material established a quantitative protein repository of the disease. Between N and A, 23% of all proteins changed significantly, 17.8% from A to C and 21.6% from N to C. Together with principal component analysis of the patient groups, this suggests that N, A, and C are equidistant but not on one developmental line. Our proteomics approach allowed us to assess changes in varied cell size, the composition of different subcellular components, and alterations in basic biological processes including the energy metabolism, plasma membrane transport, DNA replication, and transcription. This revealed several-fold higher concentrations of enzymes in fatty acid metabolism in C compared with N, and unexpectedly, the same held true of plasma membrane transporters.

Prophylactic surgery in familial adenomatous polyposis (FAP)--a single surgeon's short- and long-term experience with hand-assisted proctocolectomy and smaller J-pouches

PURPOSE

Prophylactic proctocolectomy with an ileoanal neo-reservoir is the established procedure in non-attenuated familial adenomatous polyposis (FAP). Traditionally, the ileal J-pouch is created by doubling 15 cm of the terminal ileum. Pouch inlet problems are not infrequently encountered in longer pouches. On this rationale, this series reports on the functional outcome and quality of life (QoL) following standardized construction of a shorter J-pouch with a limb of 8-9 cm length.

METHODS

All patients of a single-surgeon series with FAP who underwent hand-assisted laparoscopic proctocolectomy and small ileal pouch-anal anastomosis as the primary procedure between 10/2005 and 04/2010 and responded to the questionnaire were included and retrospectively analyzed.

RESULTS

A total of 46 patients (78 %) out of the consecutive series who underwent operation in this period were included in the study. After a mean follow-up of 38 months, 40/46 patients (87 %) did not report any incontinence and 3 patients (6.5 %) complained about occasional nocturnal incontinence (3 failed to answer this question). The mean stool frequency per 24 h was 6.25. No significant difference was encountered between the QoL outcome of our patients versus the German normative population. Comparable results were achieved in a study analyzing the long-term results in FAP patients with a 15-cm pouch.

CONCLUSIONS

Smaller, 8-9 cm J-pouches show excellent functional results both in short- and in long-term results. The hand-assisted procedure was safe and no conversions were required. QoL is equal to a normative population, as it is in a series of patients with larger J-pouches.

The prevalence of small intestinal polyps in patients with familial adenomatous polyposis: a prospective capsule endoscopy study

Familial adenomatous polyposis (FAP) is a genetic disorder in which multiple colorectal polyps and cancers develop. However, the prevalence of small intestinal tumors in patients with FAP remains unclear. We elucidated the prevalence of polyps in the small intestine and duodenum using capsule endoscopy (CE). Patients with FAP receiving a periodic screening colonoscopy at Kyoundo Hospital were encouraged to participate in the study. All study participants underwent esophagogastroduodenoscopy (EGD) within 2 weeks before CE. Outcome measurements were the prevalence of duodenal polyps (DP) and small intestinal polyp (SIP), detectability of the ampulla of Vater, and concordance of the duodenal findings between CE and EGD. Twenty-three patients (mean age, 47 years; 15 males) were enrolled in the study. CE showed DPs in 11 patients (52%) and SIPs in nine patients (43 %). The mean numbers of DPs and SIPs was 11.5 ± 6.2 and 11.9 ± 10.9, respectively. SIPs were more often detected in patients with DPs versus those without (62 vs. 13%, P = 0.07). The ampulla of Vater was observed by CE in four patients (21%). EGD showed DPs in 13 patients (62%). EGD missed DPs in two of 11 patients with DPs detected by CE. EGD found DPs in four of 10 patients without DPs using CE. The kappa index was 0.422. Patients with FAP have a high prevalence of polyps in the small intestine. Although the clinical significance of small intestinal polyps remains unclear, patients with FAP seem to be good candidates for CE.

Gardner's Syndrome revisited: a clinical case and overview of the literature

Gardner's syndrome (GS), a variant of familial adenomatous polyposis (FAP), remains a life-threatening condition of significant dental relevance. Clinicians can play an important role in the identification of this condition as the dental manifestations often precede the development of intestinal polyposis. This article describes a clinical case in which identification of the dental features of GS during routine orthodontic assessment resulted in the early diagnosis of this condition, which was previously unrecognised in a young female patient.

Endoscopy and EUS are key for effective surveillance and management of duodenal adenomas in familial adenomatous polyposis

BACKGROUND

Patients with familial adenomatous polyposis (FAP) are prone to developing duodenal adenoma and cancer. Optimal surveillance and management of these adenomas are not well established.

OBJECTIVE

We assessed the outcome of FAP patients undergoing intense multimodal surveillance and subsequent endoscopic resection of advanced lesions.

PATIENTS

Eighty consecutive FAP patients enrolled during 2001 to 2011 from the Familial Cancer Clinic of a tertiary hospital as part of routine surveillance.

DESIGN

Case series, prospective in years 2006 to 2011 and retrospective in years 2001 to 2006.

SETTING AND INTERVENTION

Patients were followed by annual forward-view and/or side-view upper endoscopy. A biopsy sample was obtained from visible lesions and normal papillae. Ampullary adenomas were further assessed by EUS to determine dimensions and resectability. Advanced adenomas (size ≥ 10 mm, villous type, high-grade dysplasia) underwent endoscopic ampullectomy or polypectomy and continued surveillance.

MAIN OUTCOME MEASUREMENTS

Detection of advanced adenomas by endoscopy and EUS, endoscopic maintenance of duodenum free of advanced adenoma and cancer.

RESULTS

Patients (38 men and 42 women, mean age 32.68 ± 13.60) were followed 7.2 years and underwent 5.36 diagnostic studies on average. Thirty-eight patients had ampullary adenomas. Advanced adenoma was diagnosed by endoscopy in 10 patients. Importantly, EUS upstaged 9 additional patients to advanced adenoma and downstaged 1, thus altering the treatment course in 36% of patients performing EUS. Endoscopic ampullectomy was performed in 15 patients. Adenoma recurred in 10. Five remained nonadvanced and 5 in advanced stages: 3 were successfully retreated endoscopically and 2 ultimately required surgery for residual adenoma. Advanced nonampullary adenomas were successfully resected endoscopically in 23 patients. No patient had duodenal cancer during the study period.

LIMITATIONS

Limited follow-up period, young age group, uncontrolled study.

CONCLUSIONS

In an intense surveillance program for FAP patients, both endoscopy and EUS were key in accurate selection of advanced adenomas for endoscopic resection. During a 10-year period, only 2 patients required elective surgery and no cancer was observed.

Colorectal neoplasia pathways: state of the art

Colorectal cancer (CRC) is a heterogeneous disease and each CRC possesses a unique molecular tumor profile. The main pathways of oncogenesis are the chromosomal instability, microsatellite instability and serrated neoplasia pathway. Sessile serrated adenomas/polyps (SSA/Ps) may be the precursor lesions of CRC arising via the serrated neoplasia pathway. This has led to a paradigm shift because all SSA/Ps should be detected and resected during colonoscopy. The ability to accurately detect and resect only those polyps with a malignant potential could result in safer and cost-effective practice. Optimization of the endoscopic classification systems is however needed to implement targeted prevention methods.

Giant mediastinal thymolipoma in a patient with Gardner's syndrome

Gardner's syndrome is a hereditary disorder inherited as an autosomal dominant with high penetrance and variable expression that is caused by a mutation of the adenomatous polyposis coli gene. It is characterized by gastrointestinal polyps associated with multiple osteomas, dental anomalies, and skin and soft tissue tumors. We present a case of 30-year-old female patient with Gardner's syndrome who presented with a giant mediastinal thymolipoma. The tumor was completely excised through a bilateral posterolateral thoracotomy. There was no recurrence after 20 months of follow-up. We therefore suggest that physicians who regularly treat patients with Gardner's syndrome carefully examine for thoracic manifestations.

Residual rectal mucosa after stapled vs. handsewn ileal J-pouch-anal anastomosis in patients with familial adenomatous polyposis coli (FAP)--a critical issue

INTRODUCTION

Restorative proctocolectomy has become the standard surgical procedure for familial adenomatous polyposis (FAP) patients. The use of stapler devices has initiated a controversial discussion concerning the ileal pouch-anal reconstruction. Some authors advocate a handsewn anastomosis after transanal mucosectomy. A double-stapled anastomosis leads to better functional results but seems to bear a higher risk of residual rectal mucosa with dysplasia and adenomas. The present study systematically analyses the rate of residual rectal mucosa after restorative proctocolectomy and handsewn vs. stapled anastomosis.

PATIENTS AND METHODS

One hundred FAP patients after restorative proctocolectomy undergoing regular follow-up at our outpatient clinic were included in the study. Proctoscopy with standardised biopsy sampling was performed.

RESULTS

Of the 100 patients, 50 had undergone a stapled and 50 a handsewn anastomosis. Median follow-up was 146.1 months (handsewn) vs. 44.8 months (stapled) (P < 0.0001). Eighty-seven patients received a proctoscopy with standardised biopsy sampling. Thirteen patients had been diagnosed with residual rectal mucosa before. Sixty-three patients (63 %) showed remaining rectal mucosa (42 (66.6 %) stapler, 21 (33.3 %) handsewn, P < 0.0001). Patients after stapled anastomosis had higher rates of circular rectal mucosa seams, while small mucosa islets predominated in the handsewn group. The rate of rectal adenomas was significantly higher in the stapler group (21 vs. 10, P = 0.02).

CONCLUSION

Rectal mucosa, especially wide mucosa seams, as well as rectal adenomas are found significantly more often after a stapled than after a handsewn anastomosis. As the follow-up interval in the stapler group was significantly shorter, the impact of these findings may still be underestimated.

The evolution of colorectal cancer genetics-Part 1: from discovery to practice

Colorectal cancer (CRC) is an increasing burden on our society. Identifying those who are at the greatest risk and improving triage for treatment will have the greatest impact on healthcare. CRC is a prime paradigm for cancer genetics: the majority of disease results from stages of progression lending itself to prevention by early detection of the pre-disease (neoplastic) state. Approximately 10% represent well defined hereditary cancer syndromes. Hereditary CRC has the added benefit that many are slow growing and family members are armed with the knowledge of potential risk of associated carcinomas and empowerment to reduce the disease burden. This knowledge provides the indication for early endoscopic and/or surgical intervention for prevention or treatment of an entire family cohort. The molecular basis of CRC allows enhanced characterization of carcinomas, leading to targeted therapies.

Targeting the Wnt pathway in human cancers: therapeutic targeting with a focus on OMP-54F28

The Wnt signaling pathways are a group of signal transduction pathways that play an important role in cell fate specification, cell proliferation and cell migration. Aberrant signaling in these pathways has been implicated in the development and progression of multiple cancers by allowing increased proliferation, angiogenesis, survival and metastasis. Activation of the Wnt pathway also contributes to the tumorigenicity of cancer stem cells (CSCs). Therefore, inhibiting this pathway has been a recent focus of cancer research with multiple targetable candidates in development. OMP-54F28 is a fusion protein that combines the cysteine-rich domain of frizzled family receptor 8 (Fzd8) with the immunoglobulin Fc domain that competes with the native Fzd8 receptor for its ligands and antagonizes Wnt signaling. Preclinical models with OMP-54F28 have shown reduced tumor growth and decreased CSC frequency as a single agent and in combination with other chemotherapeutic agents. Due to these findings, a phase 1a study is nearing completion with OMP-54F28 in advanced solid tumors and 3 phase 1b studies have been opened with OMP-54F28 in combination with standard-of-care chemotherapy backbones in ovarian, pancreatic and hepatocellular cancers. This article will review the Wnt signaling pathway, preclinical data on OMP-54F28 and other Wnt pathway inhibitors and ongoing clinical trials.

Architecture of inherited susceptibility to colorectal cancer: a voyage of discovery

This review looks back at five decades of research into genetic susceptibility to colorectal cancer (CRC) and the insights these studies have provided. Initial evidence of a genetic basis of CRC stems from epidemiological studies in the 1950s and is further provided by the existence of multiple dominant predisposition syndromes. Genetic linkage and positional cloning studies identified the first high-penetrance genes for CRC in the 1980s and 1990s. More recent genome-wide association studies have identified common low-penetrance susceptibility loci and provide support for a polygenic model of disease susceptibility. These observations suggest a high proportion of CRC may arise in a group of susceptible individuals as a consequence of the combined effects of common low-penetrance risk alleles and rare variants conferring moderate CRC risks. Despite these advances, however, currently identified loci explain only a small fraction of the estimated heritability to CRC. It is hoped that a new generation of sequencing projects will help explain this missing heritability.

Challenges of SNP genotyping and genetic variation: its future role in diagnosis and treatment of cancer

Thorough annotation of common germline genetic variation in the human genome has generated a foundation for the investigation of the contribution of genetics to the etiology and pathogenesis of cancer. For many malignancies, it has become increasingly apparent that numerous alleles, with small-to-moderate effects, additively contribute to cancer susceptibility. The most common genetic variant in the genome, the single nucleotide polymorphism, is of special interest for the study of susceptibility to and protection from cancer. Similarly, intense effort has focused on genetic variants that can predict either response or toxicity to therapeutic interventions. This review discusses the challenges and prospects of genetic association studies in cancer research. On the basis of recent changes in genomics and high-throughput genotyping platforms, future genetic findings of association studies could impact clinical care and public health screening.

CXCR2 inhibition enhances sulindac-mediated suppression of colon cancer development

Small chemical compound sulindac has been approved as a preventive approach against colon cancer for its effectiveness in treatment of precancerous adenoma. Due to its severe toxicities in the cardiovascular, gastrointestinal and renal systems, however, a combination of low-dose sulindac with other chemopreventive agents has been sought after as an alternative therapeutic strategy that could increase its effectiveness, while minimizing its adverse effects. To identify the promising alternative approach, we investigated the therapeutic potential of targeting the interleukin (IL)-8/CXCR2 pathway in colon cancer treatment using both loss-of-function (CXCR2 knockout) and gain-of-function (IL-8 overexpression) mouse models, as the IL-8/CXCR2 pathway has been shown to be activated in intestinal tumors of both human and experimental animals. We found that deletion of CXCR2 gene and ectopic expression of IL-8 suppresses and enhances, respectively, intestinal tumor development caused by a mutation in the APC gene. Moreover, a single copy deletion of CXCR2 gene resulted in abrogation of COX-2 and Gro-α upregulation in intestinal tumors caused by the APC mutation. Moreover, a single copy (heterozygote) deletion of CXCR2 gene was sufficient to synergize with a low-dose sulindac treatment in suppressing APCmin-induced intestinal polyposis. Together, our study provides a therapeutic justification of combined inhibition of CXCR2 and sulindac treatment in colon cancer prevention.

Toxicogenomics and cancer susceptibility: advances with next-generation sequencing

The aim of this review is to comprehensively summarize the recent achievements in the field of toxicogenomics and cancer research regarding genetic-environmental interactions in carcinogenesis and detection of genetic aberrations in cancer genomes by next-generation sequencing technology. Cancer is primarily a genetic disease in which genetic factors and environmental stimuli interact to cause genetic and epigenetic aberrations in human cells. Mutations in the germline act as either high-penetrance alleles that strongly increase the risk of cancer development, or as low-penetrance alleles that mildly change an individual's susceptibility to cancer. Somatic mutations, resulting from either DNA damage induced by exposure to environmental mutagens or from spontaneous errors in DNA replication or repair are involved in the development or progression of the cancer. Induced or spontaneous changes in the epigenome may also drive carcinogenesis. Advances in next-generation sequencing technology provide us opportunities to accurately, economically, and rapidly identify genetic variants, somatic mutations, gene expression profiles, and epigenetic alterations with single-base resolution. Whole genome sequencing, whole exome sequencing, and RNA sequencing of paired cancer and adjacent normal tissue present a comprehensive picture of the cancer genome. These new findings should benefit public health by providing insights in understanding cancer biology, and in improving cancer diagnosis and therapy.

The colon: from banal to brilliant

The colon serves as the habitat for trillions of microbes, which it must maintain, regulate, and sequester. This is managed by what is termed the mucosal barrier. The mucosal barrier separates the gut flora from the host tissues; regulates the absorption of water, electrolytes, minerals, and vitamins; and facilitates host-flora interactions. Colonic homeostasis depends on a complex interaction between the microflora and the mucosal epithelium, immune system, vasculature, stroma, and nervous system. Disruptions in the colonic microenvironment such as changes in microbial composition, epithelial cell function/proliferation/differentiation, mucus production/makeup, immune function, diet, motility, or blood flow may have substantial local and systemic consequences. Understanding the complex activities of the colon in health and disease is important in drug development, as xenobiotics can impact all segments of the colon. Direct and indirect effects of pharmaceuticals on intestinal function can produce adverse findings in laboratory animals and humans and can negatively impact drug development. This review will discuss normal colon homeostasis with examples, where applicable, of xenobiotics that disrupt normal function.

Linkage analysis in familial non-Lynch syndrome colorectal cancer families from Sweden

Family history is a major risk factor for colorectal cancer and many families segregate the disease as a seemingly monogenic trait. A minority of familial colorectal cancer could be explained by known monogenic genes and genetic loci. Familial polyposis and Lynch syndrome are two syndromes where the predisposing genes are known but numerous families have been tested without finding the predisposing gene. We performed a genome wide linkage analysis in 121 colorectal families with an increased risk of colorectal cancer. The families were ascertained from the department of clinical genetics at the Karolinska University Hospital in Stockholm, Sweden and were considered negative for Familial Polyposis and Lynch syndrome. In total 600 subjects were genotyped using single nucleotide polymorphism array chips. Parametric- and non-parametric linkage analyses were computed using MERLIN in all and subsets of families. No statistically significant result was seen, however, there were suggestive positive HLODs above two in parametric linkage analysis. This was observed in a recessive model for high-risk families, at locus 9q31.1 (HLOD=2.2, rs1338121) and for moderate-risk families, at locus Xp22.33 (LOD=2.2 and HLOD=2.5, rs2306737). Using families with early-onset, recessive analysis suggested one locus on 4p16.3 (LOD=2.2, rs920683) and one on 17p13.2 (LOD/HLOD=2.0, rs884250). No NPL score above two was seen for any of the families. Our linkage study provided additional support for the previously suggested region on chromosome 9 and suggested additional loci to be involved in colorectal cancer risk. Sequencing of genes in the regions will be done in future studies.

Primary intracranial ectopic craniopharyngioma in a patient with probable Gardner's syndrome

The authors describe a patient with an adamantinomatous craniopharyngioma (CPG) arising in the cerebellopontine angle (CPA), who also had probable Gardner's syndrome. This 31-year-old man presented with headache and dizziness. Brain CT and MRI showed a 5 × 4-cm lesion with multiple small calcifications in the left CPA. The patient underwent suboccipital craniotomy with tumor removal. Histopathological findings indicated an adamantinomatous CPG. This patient also showed characteristics of Gardner's syndrome. Although this syndrome is associated with intracranial neoplasms, it is unclear whether patients with both Gardner's syndrome and CPG are part of the heterogeneity of Gardner's syndrome.

Duodenal mucosal risk markers in patients with familial adenomatous polyposis: effects of celecoxib/ursodeoxycholic acid co-treatment and comparison with patient controls

Background

Familial adenomatous polyposis (FAP) is a disease characterized by the development of hundreds to thousands of adenomatous polyps in the colorectum early in life. Virtually all patients with FAP will develop colorectal cancer before the age of 40 to 50 years, unless prophylactic colectomy is performed, which significantly improves their prognosis. The mortality pattern has changed and duodenal cancer now is one of the main cancer-related causes of death in these patients. Practically all patients with FAP develop premalignant duodenal adenomas, which may develop to duodenal cancer in approximately 3-7% of patients. Duodenal cancer in patients with FAP has a poor prognosis. The clinical challenge is to identify patients at high-risk for duodenal carcinoma. Chemoprevention would be desirable to avoid duodenectomy. The main goal of this study is to identify risk markers in normal duodenal mucosa of patients with FAP, that could help identify patients at increased risk for malignant transformation.

Methods

Messenger RNA (mRNA) levels of glutathione S-transferase A1 (GSTA1), glutathione S-transferase P1 (GSTP1), KIAA1199, E-cadherin, peroxisome proliferative activated receptor δ (PPARδ), caspase-3, cyclin D1, β-catenin, and cyclooxygenase-2 (COX-2) were measured in duodenal mucosa, using the QuantiGene 2.0 Plex assay. Levels in normal appearing mucosa of patients with FAP (n = 37) were compared with levels in non-FAP patient controls (n = 16). In addition, levels before and after treatment with either celecoxib & ursodeoxycholic acid (UDCA, n = 14) or celecoxib & placebo (n = 13) were evaluated in patients with FAP.

Results

mRNA levels of glutathione S-transferase A1 (28.16% vs. 38.24%, p = 0.008) and caspase-3 (3.30% vs. 5.31%, p = 0.001) were significantly lower in patients with FAP vs. non-FAP patient controls, respectively. COX-2 mRNA levels in normal duodenal mucosa of patients with FAP were found to be unexpectedly low. None of the potential risk markers was influenced by celecoxib or celecoxib & UDCA.

Conclusions

Protection against toxins and carcinogens (GSTA1) and apoptosis (caspase-3) is low in patients with FAP, which could contribute to increased susceptibility for malignant transformation of duodenal mucosa.

Trial registration

http://ClinicalTrials.gov number NCT00808743