Multifocal neoplasia involving the colon and appendix in ulcerative colitis: pathological and molecular features

A randomized trial evaluating the utility of non-targeted biopsies for colorectal neoplasia detection in adults with inflammatory bowel disease: a pilot study protocol

BACKGROUND

Persons with inflammatory bowel diseases are at increased risk of developing colorectal cancer and require frequent colonoscopy surveillance. Guidelines recommend taking 30 to 40 non-targeted biopsies throughout the colorectum to detect "invisible" neoplasia in this setting, despite a lack of evidence supporting this practice. We sought to assess the utility of this practice through a randomized controlled trial. We first propose an internal pilot study to assess recruitment potential, protocol adherence and data capture to guide the full trial.

METHODS

We have designed a multi-centre, parallel-group, non-inferiority randomized controlled trial to test the utility of non-targeted biopsies as an adjunct to colonoscopy surveillance for neoplasia detection in persons with inflammatory bowel disease involving the colorectum in routine clinical practice. Participants are randomized 1:1, stratified by study site, to either standard of care high-definition white-light colonoscopy with 32 to 40 non-targeted biopsies of non-neoplastic-appearing mucosa along with a sampling of abnormal-appearing mucosa (control group) or modified colonoscopy with targeted sampling alone (intervention group). The primary outcome for the full trial will be the proportion of persons with ≥ 1 neoplastic focus detected during colonoscopy. For the pilot phase, we will assess the feasibility of recruiting a minimum of 15% of the estimated sample size within 1 year, under identical conditions as the full trial, while maintaining ≥ 90-95% rate of protocol adherence and data capture. These participants will contribute data to the full trial. The trial is being conducted at 12 centres across Canada, with a total sample size of 1952 persons.

DISCUSSIONS

The trial protocol has been approved by the ethics committees of all participating sites, and the pilot study has received funding through the Canadian Institutes of Health Research (PJT 159607). If feasibility metrics are met during the pilot phase, we will complete the full trial. The trial outcomes will contribute to update the practice guidelines in this area.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT04067778.

Appendiceal Mucinous Neoplasms and Inflammatory Bowel Disease: Systematic Review of the Literature

There is no clear evidence on the prevalence and clinical presentation of appendiceal mucinous neoplasm (AMN) among patients with inflammatory bowel disease (IBD), so a systematic review was performed to investigate the diagnosis, management and treatment of AMN in these patients. PubMed, Medline, Scopus and the Cochrane Library were searched for articles published up to September 2023. Twenty-three studies reporting data about 34 AMN patients were included. UC patients had a median age of 52 years and a median length of disease of 10 years; CD patients had a median age of 40.5 years and a median length of disease of 5 years. A pre-operative diagnosis was achieved in 44% of patients. Most patients were symptomatic (82.6%) and showed moderate-severe disease activity (61%). Surgical procedures were performed: laparoscopic appendectomy, ileocecal resection, right hemicolectomy and colectomy/proctocolectomy. Of the patients, 73.5% were diagnosed with low-grade mucinous neoplasm (LAMN) and nine with adenocarcinoma. Synchronous colorectal dysplasia/carcinoma was present in 23.5% of patients. IBD patients with long-standing disease should be routinely screened, not only for colorectal cancer but also for AMN, during gastro-enterologic follow-up. Laparoscopic appendectomy of unruptured LAMN as well as right hemicolectomy of non-metastatic adenocarcinoma are safe procedures in IBD patients.

Wound-healing plasticity enables clonal expansion of founder progenitor cells in colitis

Chronic colonic injury and inflammation pose high risks for field cancerization, wherein injury-associated mutations promote stem cell fitness and gradual clonal expansion. However, the long-term stability of some colitis-associated mutational fields could suggest alternate origins. Here, studies of acute murine colitis reveal a punctuated mechanism of massive, neutral clonal expansion during normal wound healing. Through three-dimensional (3D) imaging, quantitative fate mapping, and single-cell transcriptomics, we show that epithelial wound repair begins with the loss of structural constraints on regeneration, forming fused labyrinthine channels containing epithelial cells reprogrammed to a non-proliferative plastic state. A small but highly proliferative set of epithelial founder progenitor cells (FPCs) subsequently emerges and undergoes extensive cell division, enabling fluid-like lineage mixing and spreading across the colonic surface. Crypt budding restores the glandular organization, imprinting the pattern of clonal expansion. The emergence and functions of FPCs within a critical window of plasticity represent regenerative targets with implications for preneoplasia.

The 2023 Impact of Inflammatory Bowel Disease in Canada: Cancer and IBD

Cancer is a major cause of morbidity and mortality among people with inflammatory bowel disease (IBD). Intestinal cancers may arise as a complication of IBD itself, while extra-intestinal cancers may arise due to some of the immunosuppressive therapies used to treat IBD. Colorectal cancer (CRC) and small bowel cancer risks remain elevated among persons with IBD as compared to age-and sex-matched members of the general population, and the lifetime risk of these cancers is strongly correlated to cumulative intestinal inflammatory burden. However, the cumulative risk of cancer, even among those with IBD is still low. Some studies suggest that IBD-CRC incidence has declined over the years, possibly owing to improved treatment standards and improved detection and management of early neoplastic lesions. Across studies of extra-intestinal cancers, there are generally higher incidences of melanoma, hepatobiliary cancer, and lung cancer and no higher incidences of breast cancer or prostate cancer, with equivocal risk of cervical cancer, among persons with IBD. While the relative risks of some extra-intestinal cancers are increased with treatment, the absolute risks of these cancers remain low and the decision to forego treatment in light of these risks should be carefully weighed against the increased risks of intestinal cancers and other disease-related complications with undertreated inflammatory disease. Quality improvement efforts should focus on optimized surveillance of cancers for which surveillance strategies exist (colorectal cancer, hepatobiliary cancer, cervical cancers, and skin cancers) and the development of cost-effective surveillance strategies for less common cancers associated with IBD.

Colorectal Carcinoma, Cyclooxygenases, and COX Inhibitors

Colorectal carcinoma (CRC) is the most common of gastrointestinal cancers, the majority presenting with sporadic occurrence compared to the less frequently inherited syndromes. The increasing incidence, decreasing gender and age disparities, and the prevalent risk factors are concerning. The malignancy arising from benign precursor polyps transforms slowly over time. The adenoma variant polyps reported a marked upregulation of cyclooxygenases (COX), significantly COX-2 isoform, influenced by various determinants such as genetics, pathology, histology, and site of the carcinoma. These COX enzymes are responsible for prostaglandin synthesis and the consequent cascade of cell inflammation and proliferation. Therefore, COX inhibition by non-steroidal anti-inflammatory drugs (NSAIDs) targeted against both the isoforms COX-1 and COX-2 have been studied for decades in anticipation of preventing the occurrence of colorectal carcinoma in high-risk populations. This article has collated and highlighted the overexpression of COX enzymes by the adenomatous polyps and provides corroborating evidence from multiple studies in favor of COX inhibition by NSAIDs. Aspirin and Sulindac were two drugs to be initially proven to halt the progression and cause regression of the polyps. Celecoxib, a selective COX-2 inhibitor besides NSAIDs, was also used in experimental studies.

Pancolonic Dye Spray Chromoendoscopy to Detect and Resect Ill-Defined Neoplastic Lesions in Colonic Inflammatory Bowel Disease

Background

Pancolonic dye spray chromoendoscopy (DCE) is used as an adjunct to white light endoscopy (WLE) to enhance the detection and delineation of ill-defined neoplastic (dysplastic) lesions in persons with colonic inflammatory bowel diseases (cIBD). We evaluated the utility of DCE as follow-up to high-definition WLE (HD-WLE) to "unmask" and/or facilitate endoscopic resection of neoplastic lesions.

Methods

We retrospectively studied persons with cIBD who underwent DCE as follow-up to HD-WLE between 2013 and 2020. We describe neoplastic findings and management during HD-WLE and DCE exams and report outcomes from post-DCE surveillance exams.

Results

Twenty-four persons were studied (mean age 56.7 ± 13.8 years, 50.0% male, 70.8% ulcerative colitis, mean disease duration 18.0 ± 11.0 years). Overall, 32 visible neoplastic lesions were unmasked during DCE, of which 24 were endoscopically resected. DCE facilitated the diagnosis of two cancers. Among 17 persons referred for evaluation of "invisible" neoplasia (detected in non-targeted biopsies) during HD-WLE, DCE identified neoplastic lesions at the same site in eight persons and a different site in four persons. Among seven persons referred for ill-defined visible neoplasia, DCE facilitated complete endoscopic resection in four individuals, whereas two individuals required colectomy for a diagnosis of cancer. Among 19 individuals with post-DCE surveillance, five developed new visible neoplastic lesions, including one high-grade neoplasia which was completely resected.

Conclusions

In our cohort, DCE aided in unmasking invisible neoplasia and facilitated endoscopic resection of ill-defined neoplasia, suggesting that it is a useful surveillance tool in selected persons with cIBD. Large prospective studies are needed to validate these findings.

AGA Clinical Practice Update on Endoscopic Surveillance and Management of Colorectal Dysplasia in Inflammatory Bowel Diseases: Expert Review

Improvements in disease management, as well as endoscopic technology and quality, have dramatically changed the way in which we conceptualize and manage inflammatory bowel disease-related dysplasia over the past 20 years. Based on evolving literature, we propose a conceptual model and best practice advice statements for the prevention, detection, and management of colorectal dysplasia in people with inflammatory bowel disease. This expert review was commissioned and approved by the American Gastroenterological Association Institute Clinical Practice Updates Committee and the American Gastroenterological Association Governing Board to provide timely guidance on a topic of high clinical importance to the American Gastroenterological Association membership. It underwent internal peer review by the Clinical Practice Updates Committee and external peer review through standard procedures of Gastroenterology.

A rare cecal subepithelial tumor in a Crohn´s Disease patient

Appendiceal tumors comprise a variety of histologic types, including appendiceal mucinous neoplasms, which can be grouped as premalignant lesions, tumors of uncertain malignant potential, and malignant lesions. The appendiceal mucinous neoplasms are characterized by mucinous epithelial proliferation with extracellular mucin and pushing tumor margins, commonly an incidental finding during operative exploration. We report the case of a low-grade appendiceal mucinous neoplasm presenting as a subepithelial lesion in Crohn´s Disease patient. The diagnosis was not straightforward, and only surgical resection allowed an accurate diagnosis. Although Inflammatory Bowel Disease is a risk factor for the development of colorectal neoplasms, the absolute risk for appendiceal tumors is uncertain. The frequency of progression to malignancy remains to be determined.

Anti-inflammation of Erianin in dextran sulphate sodium-induced ulcerative colitis mice model via collaborative regulation of TLR4 and STAT3

Ulcerative colitis (UC) is a chronic, idiopathic and inflammatory disease of the rectal and colonic mucosa. Studies have shown that Toll-like receptors (TLR) 4 and Signal Transducer and Activator of Transcription 3 (STAT3)-mediated the decline in immune function and inflammatory infiltration are potential pathomechanism of UC occurrence and development. In this study, the anti-inflammation of Erianin, a natural bibenzyl compound with the antioxidant, antitumor, and anti-inflammatory activities, was investigated in a dextran sodium sulphate-induced UC mouse model. Three-week Erianin administration resulted in the increment on the body weight and colon length, and the reduction on the activity index score of UC mice. Liver, spleen, and renal organ indexes and pathological observations confirmed that Erianin was not cytotoxic and had an effect of improving immune organ function. The haematoxylin and eosin staining sections of colon tissue show Erianin's effect of reversing inflammation in the mucosal laye. Proteomic analysis and enzyme-linked immunosorbent assay indicated that Erianin regulated the levels of inflammatory and oxidative stress-related factors and immunochemokines in serum and colon tissues thereby reducing cell peroxidative damage and reducing immune inflammatory responses. Further data obtained by Western Blotting confirmed that Erianin's anti-UC activity was mediated by inhibiting the TLR4 and STAT3 signaling.

Appendiceal Adenocarcinoma Associated With Ulcerative Colitis

Ulcerative colitis (UC) is a known risk factor for colorectal cancer, but the association between UC and appendiceal adenocarcinoma remains rare. We present a 42-year-old patient with long-standing UC who presented with acute appendicitis shortly after a routine colonoscopy. Histopathological examination revealed moderately differentiated appendiceal adenocarcinoma. The recognition of appendiceal cancer as a complication of long-standing UC warrants increased clinical awareness.

Endoscopic Therapeutic Approach for Dysplasia in Inflammatory Bowel Disease

Long-standing intestinal inflammation in patients with inflammatory bowel disease (IBD) induces dysplastic change in the intestinal mucosa and increases the risk of subsequent colorectal cancer. The evolving endoscopic techniques and technologies, including dye spraying methods and high-definition images, have been replacing random biopsies and have been revealed as more practical and efficient for detection of dysplasia in IBD patients. In addition, they have potential usefulness in detailed characterization of lesions and in the assessment of endoscopic resectability. Most dysplastic lesions without an unclear margin, definite ulceration, non-lifting sign, and high index of malignant change with suspicion for lymph node or distant metastases can be removed endoscopically. However, endoscopic resection of dysplasia in chronic IBD patients is usually difficult because it is often complicated by submucosal fibrosis. In patients with dysplasias that demonstrate submucosa fibrosis or a large size (≥20 mm), endoscopic submucosal dissection (ESD) or ESD with snaring (simplified or hybrid ESD) is an alternative option and may avoid a colectomy. However, a standardized endoscopic therapeutic approach for dysplasia in IBD has not been established yet, and dedicated specialized endoscopists with interest in IBD are needed to fully investigate recent emerging techniques and technologies.

A giant mucinous cystadenocarcinoma of the appendix: a case report and review of the literature

BACKGROUND

Mucinous cystadenocarcinoma is the second most common etiology of appendiceal mucocele. We report a relatively rare case of a giant appendiceal mucocele caused by mucinous cystadenocarcinoma, which occupied the entire abdomen of an adult woman.

CASE PRESENTATION

A 63-year-old woman presented with a chief complaint of abdominal distention. Imaging studies showed a giant cystic mass occupying her entire abdomen. Laparotomy confirmed a giant appendiceal mucocele, and the patient underwent ileocecal resection. A mucinous deposit was not found in her abdominal cavity, and the ovaries were grossly normal bilaterally. The pathological diagnosis was mucinous adenocarcinoma with a low-grade mucinous neoplasm that invaded the subserosa. Regional lymph node metastasis was not found. She has had recurrence-free survival for 5 years.

CONCLUSIONS

The present case is the largest appendiceal cystadenocarcinoma ever reported. The optimal treatment of an appendiceal neoplasm requires further research based on consensus terminology of an appendiceal mucocele.

Identification of a common variant with potential pleiotropic effect on risk of inflammatory bowel disease and colorectal cancer

Although genome-wide association studies (GWAS) have separately identified many genetic susceptibility loci for ulcerative colitis (UC), Crohn's disease (CD) and colorectal cancer (CRC), there has been no large-scale examination for pleiotropy, or shared genetic susceptibility, for these conditions. We used logistic regression modeling to examine the associations of 181 UC and CD susceptibility variants previously identified by GWAS with risk of CRC using data from the Genetics and Epidemiology of Colorectal Cancer Consortium and the Colon Cancer Family Registry. We also examined associations of significant variants with clinical and molecular characteristics in a subset of the studies. Among 11794 CRC cases and 14190 controls, rs11676348, the susceptibility single nucleotide polymorphism (SNP) for UC, was significantly associated with reduced risk of CRC (P = 7E-05). The multivariate-adjusted odds ratio of CRC with each copy of the T allele was 0.93 (95% CI 0.89-0.96). The association of the SNP with risk of CRC differed according to mucinous histological features (P heterogeneity = 0.008). In addition, the (T) allele was associated with lower risk of tumors with Crohn's-like reaction but not tumors without such immune infiltrate (P heterogeneity = 0.02) and microsatellite instability-high (MSI-high) but not microsatellite stable or MSI-low tumors (P heterogeneity = 0.03). The minor allele (T) in SNP rs11676348, located downstream from CXCR2 that has been implicated in CRC progression, is associated with a lower risk of CRC, particularly tumors with a mucinous component, Crohn's-like reaction and MSI-high. Our findings offer the promise of risk stratification of inflammatory bowel disease patients for complications such as CRC.

High-level microsatellite instability in appendiceal carcinomas

High-level microsatellite instability (MSI-high) is found in approximately 15% of all colorectal adenocarcinomas (CRCs) and in at least 20% of right-sided cancers. It is most commonly due to somatic hypermethylation of the MLH1 gene promoter region, with familial cases (Lynch syndrome) representing only 2% to 3% of CRCs overall. In contrast to CRC, MSI-high in appendiceal adenocarcinomas is rare. Only 4 MSI-high appendiceal carcinomas and 1 MSI-high appendiceal serrated adenoma have been previously reported, and the prevalence of MSI in the appendix is unknown. We identified 108 appendiceal carcinomas from MD Anderson Cancer Center in which MSI status had been assessed by immunohistochemistry for the DNA mismatch-repair proteins MLH1, MSH2, MSH6, and PMS2 (n=83), polymerase chain reaction (n=7), or both (n=18). Three cases (2.8%) were MSI-high, and 1 was MSI-low. The 3 MSI-high cases included: (1) a poorly differentiated nonmucinous adenocarcinoma with loss of MLH1/PMS2 expression, lack of MLH1 promoter methylation, and lack of BRAF gene mutation, but no detected germline mutation in MLH1 from a 39-year-old man; (2) an undifferentiated carcinoma with loss of MSH2/MSH6, but no detected germline mutation in MSH2 or TACSTD1, from a 59-year-old woman; and (3) a moderately differentiated mucinous adenocarcinoma arising in a villous adenoma with loss of MSH2/MSH6 expression, in a 38-year-old man with a strong family history of CRC who declined germline testing. When the overall group of appendiceal carcinomas was classified according to histologic features and precursor lesions, the frequencies of MSI-high were: 3 of 108 (2.8%) invasive carcinomas, 3 of 96 (3.1%) invasive carcinomas that did not arise from a background of goblet cell carcinoid tumors, and 0 of 12 (0%) signet ring and mucinous carcinomas arising in goblet cell carcinoid tumors. These findings, in conjunction with the previously reported MSI-high appendiceal carcinomas, highlight the low prevalence of MSI in the appendix as compared with the right colon and suggest that MLH1 promoter methylation is not a mechanism for MSI in this location.

Synchronous colorectal neoplasms in ulcerative pancolitis of 6 years duration: pathological and molecular heterogeneity

Colorectal cancer (CRC) complicating ulcerative colitis (UC) accounts for about 1% of all cases of CRC. Such tumours develop from pre-existing foci of dysplasia in patients with extensive and long-standing UC. We report a case of UC-associated synchronous CRC and foci of high-grade dysplasia with an additional malignant focus in the appendix in a female patient after only 6 years of pancolitis who did not have other risk factors for the development of complications. The multiplicity and the timings of the early changes noted suggest that long-standing inflammation in UC randomly damages multiple genes in epithelial cells known to contribute to colorectal carcinogenesis. Current findings also support a molecular and pathological heterogeneity during multiclonal origin of synchronous tumours whereby differences occur at various sites that were absent during the initial stages of the disease.

Dysplastic lesions in inflammatory bowel disease: molecular pathogenesis to morphology

Context.-Inflammatory bowel disease (IBD) is a long-standing chronic active inflammatory process in the bowel with increased risk for the development of colorectal carcinoma. Several molecular events involved in chronic active inflammatory processes contribute to multistage progression of human cancer development, including reactive oxygen and nitrogen species, aberrant arachidonic acid metabolites and cytokines/growth factors, and immune dysfunction. These molecular events in IBD lead to genetic abnormality and promote aberrant cell proliferation, which further lead to epithelial changes encompassing a broad spectrum from inflammation-induced hyperplasia to dysplasia. Objective.-To review the (1) epidemiologic and molecular pathogenesis of the risk for colorectal cancer in IBD, (2) morphologic characterization, biomarker(s), and classification of dysplastic lesions, and (3) clinical management of dysplastic lesions arising in IBD. Data Sources.-The different IBD-related dysplastic lesions are illustrated by using morphology in conjunction with molecular pathways, and the "field cancerization" theory and its potential significance are discussed with a review of the literature. Conclusions.-Patients with IBD are at increased risk of developing colorectal cancer. The risk of developing carcinoma is related to the extent/duration/activity of the patient's disease. There is no consensus regarding the extent of carcinoma risk associated with IBD; however, all would agree that patients with IBD represent a group at significant risk for developing carcinoma and as such, warrant adequate surveillance and prevention. With better screening modalities and detection/characterization of dysplastic lesions, IBD-associated serrated lesions, and "field cancerization," we will improve our understanding of and approach to risk stratification.

Evolving endoscopic strategies for detection and treatment of neoplastic lesions in inflammatory bowel disease

The paradigm for neoplasia surveillance in IBD is rapidly evolving with advancements in endoscopic imaging technology. Modern technology has demonstrated a remarkably improved capacity to detect and characterize subtle neoplastic lesions. As such, practices of obtaining interval random biopsy specimens to identify “invisible”neoplasia and of recommending total proctocolectomy for treatment of early neoplastic lesions are gradually being phased out. Further research is required to confirm the safety and effectiveness of endoscopic resection of more advanced neoplastic lesions, including DALMs and lesions bearing HG-IEN. Moving forward, studies evaluating CRC risk profiles in IBD patients would be useful to develop rational and cost-effective individualized strategies for neoplasia surveillance and management. Overall, as we progress toward more sophisticated approaches to cancer prevention, the outlook for IBD patients grows ever better.

Inflammatory bowel disease and colon cancer

The inflammatory bowel diseases (IBD); Crohn's and Ulcerative colitis, result from an altered host response to intestinal flora. Recurrent inflammation with ulceration and tissue restitution confers an increased risk of cancer in both UC and Crohns, and genome wide searches have identified a number of disease susceptibility alleles. The carcinogenesis pathway in colitis-associated colorectal cancer (CACRC) is less clearly understood than it's sporadic counterpart. Clonal ordering experiments have indicated the order and timing of chromosomal instability and common genetic mutations. Epigenetic changes such as DNA methylation and histone modification are thought to play an increasingly important role in inflammation induced carcinogenesis. Clonal expansion of procarcinogenic mutations can lead to large fields of mutant tissue from which colitis associated cancers can arise (field cancerisation). Endoscopic screening is the mainstay of surveillance in high-risk patients although the development of appropriate, clinically applicable biomarkers remains a research priority. Despite the expanding field of biological therapy in inflammatory bowel disease the ASA compounds remain the best-studied and most efficacious chemopreventive agents. Colitis associated CRC appears to have a different aetiology, carcinogenesis pathway and clinical course to its sporadic counterpart. Further research including long-term follow up of patient cohorts taking biological therapies will improve the detection and treatment of these important, inflammation-induced malignancies.

Incidence of synchronous appendiceal neoplasm in patients with colorectal cancer and its clinical significance

BACKGROUND

The aims of this study were to evaluate the incidence of synchronous appendiceal neoplasm in patients with colorectal cancer, and to determine its clinical significance.

METHODS

Pathological reports and medical records were reviewed of patients with colorectal adenocarcinoma who underwent oncological resection of the tumor together with appendectomy at the Faculty of Medicine Siriraj Hospital, Mahidol University, Thailand between September 2000 and April 2008.

RESULTS

This study included 293 patients with an average age of 62 years (range 19-95) and 51 percent were male. Of the patients studied, 228 (78 percent) had right hemicolectomy, whereas the others (22 percent) had surgery for left-sided colon cancer or rectal cancer. One patient (0.3 percent) had epithelial appendiceal neoplasm (mucinous cystadenoma) and 3 patients (1.0 percent) had metastatic colorectal cancer in the mesoappendix. However, the presence of synchronous appendiceal tumors and/or metastasis did not alter postoperative management, as these patients had received adjuvant therapy and were scheduled for surveillance program because of nodal involvement.

CONCLUSION

The incidence of synchronous primary appendiceal neoplasm and secondary (metastatic) appendiceal neoplasm in colorectal cancer patients was 0.3 and 1.0 percent, respectively. However, these findings did not change the postoperative clinical management.

Appendiceal mucinous cystadenoma is a neoplastic complication of IBD: case-control study of primary appendiceal neoplasms

BACKGROUND

IBD is a risk factor for development of colorectal neoplasia. Although IBD frequently involves the appendix microscopically, it is uncertain whether it also predisposes to appendiceal neoplasia.

METHODS

We performed a retrospective case-control study of incidental appendiceal neoplasms in colectomy specimens of adults with and without IBD (cases and controls, respectively) based on surgical pathology records spanning 54 months. To minimize referral bias, patients were excluded if they had preoperative clinical evidence or a principal pathologic diagnosis of appendiceal disease. The pathologic diagnoses were confirmed retrospectively.

RESULTS

Eleven appendiceal cystadenomas and 6 appendiceal carcinoid tumors were identified among 705 IBD cases (377 ulcerative colitis, 317 Crohn's disease, 11 indeterminate colitis) and 498 non-IBD controls meeting our inclusion criteria. There was no significant difference in prevalence of cyst adenomas between the cases and controls (9/705 [1.3%] versus 2/498 [0.4%], respectively, OR 3.2 [95% CI 0.7-14.9]). However, cyst adenomas were 15-fold more prevalent among cases with synchronous colorectal neoplasia compared with controls (4/69 [5.8%] versus 2/498 [0.4%], OR 15.3 [95% CI 2.7-85]) and 8-fold higher compared with cases without synchronous neoplasia (4/69 [5.8%] versus 5/636 [0.8%], OR 7.8 [95% CI 2.0-29.6]). Appendiceal carcinoids were equally prevalent in cases and controls (4/705 [0.6%] versus 2/498 [0.4%], OR 1.4 [95% CI 0.3-7.8]), cases with synchronous neoplasia and controls (1/69 [1.4%] versus 2/498 [0.4%], OR 3.6 [95% CI 0.3-40.8]), and cases with and without synchronous colorectal neoplasia (1/69 [1.4%] versus 3/636 [0.5%], OR 3.1 [95% CI 0.3-30.2]).

CONCLUSIONS

IBD with synchronous colorectal dysplasia or cancer is a risk factor for development of appendiceal cystadenomas, implicating this tumor as a neoplastic complication of IBD. IBD does not predispose to the development of appendiceal carcinoids.

Clonality, founder mutations, and field cancerization in human ulcerative colitis-associated neoplasia

BACKGROUND & AIMS

The clonality of colitis-associated neoplasia has not been fully determined. One previous report showed polyclonal origins with subsequent monoclonal outgrowth. We aimed to assess the clonality and mutation burden of individual crypts in colitis-associated neoplasias to try to identify gatekeeping founder mutations, and explore the clonality of synchronous lesions to look for field effects.

METHODS

Individual crypts (range, 8-21 crypts) were microdissected from across 17 lesions from 10 patients. Individual crypt adenomatous polyposis coli (APC), p53, K-RAS, and 17p loss of heterozygosity mutation burden was established using polymerase chain reaction and sequencing analysis. Serial sections underwent immunostaining for p53, beta-catenin, and image cytometry to detect aneuploidy.

RESULTS

In most lesions an oncogenic mutation could be identified in all crypts across the lesion showing monoclonality. This founder mutation was a p53 lesion in the majority of neoplasms but 4 tumors had an initiating K-RAS mutation. Some nondysplastic crypts surrounding areas of dysplasia were found to contain clonal p53 mutations and in one case 3 clonal tumors arose from a patch of nondysplastic crypts containing a K-RAS mutation.

CONCLUSIONS

This study used mutation burden analysis of individual crypts across colitis-associated neoplasms to show lesion monoclonality. This study confirmed p53 mutation as initiating mutation in the majority of lesions, but also identified K-RAS activation as an alternative gatekeeping mutation. Local and segmental field cancerization was found by showing pro-oncogenic mutations in nondysplastic crypts surrounding neoplasms, although field changes are unlikely to involve the entire colon because widely separated tumors were genetically distinct.

Synchronous multifocal colorectal carcinoma in a patient with delayed diagnosis of ulcerative pancolitis

Patients with ulcerative colitis face an increased lifetime risk of developing colorectal cancer. Relatively often, the patients present with multiple synchronous or metachronous tumors. Here, we report a case of ulcerative colitis-associated synchronous multifocal colorectal carcinomas. A 36-year-old male presented with symptoms of persisting abdominal pain that had lasted for several months. Histology of the colonic biopsies showed active ulcerative pancolitis with extensive multifocal low- and high-grade dysplasia. Regardless of the diagnosis and medical advice, the patient initially refused therapy, and proctocolectomy was delayed for 12 months. In the resection specimen, four clinically unsuspected, partly mucinous adenocarcinomas accompanied by several foci of low- and high-grade dysplasia were found in the left colon and rectum. At the time of colectomy, advanced tumor stage was diagnosed and classified as pT3c(4) pN1(2/120) M0 V1 R0, UICC stage IIIB, G2. Furthermore, a mucinous cystadenoma was found in the appendix in the setting of ulcerative colitis. We discuss the neoplastic transformation, current surveillance guidelines, and the therapeutic management in ulcerative colitis.

[Clinico-pathological characteristics of colonic carcinoma in relation to localization and histologic type]

BACKGROUND/AIM

A significant increase in colonic carcinoma has been analyzed in numerous clinico-pathological studies and genetics models. The aim of this study was to determinate the differences in clinico-pathological parameters of colonic carcinoma regarding localization and histological type.

METHODS

The study enrolled 124 patients who had undergone surgery for colorectal carcinoma at the Clinic of Surgery in the town of Nis within 2005. Paraffin sections were stained with Hematoxilin-eosin (H&E), High iron diamine-Alcian blue (HID-AB) (pH-2.5) and Alcian blue-Preiodic arid Shiff (AB-PAS) (pH-2.5) methods. From pathological report we used data regarding: localization (right or left colon), histological type, histological grade, and parameters which determinate the tumor stage.

RESULTS

The total number of patients with right-sided colonic carcinoma was 40 (32.36%) and 84 (67.74%) with left-sided colonic carcinoma. Histopathologically, 96 (77.42%) adenocarcinomas and 28 (22.58%) mucinous adenocarcinomas were verified. There were no statistically significant differences between the right-sided and left-sided colonic carcinoma regarding sex, age, histological grade and tumor stage (p > 0.05). Mucinous adenocarcinomas was statistically significantly more frequent in right-sided colon (35.00%) than in left-sided colon (16.67%) (p < 0.05). There were no statistically significant differences between adenocarcinomas and mucinous adenocarcinomas regarding sex and disease stage. In younger patients the percentage of mucinous adenocarcinomas (28.57%) compared to non-mucinous ones (11.46%) was significantlly higher (p < 0.05) than in older patients. Mucinous adenocarcinomas had statistically significantly more frequently poor differentiation in comparision to adenocarcinomas (46.43% versus 9.37%, p < 0.001).

CONCLUSION

According to the presented results it can be concluded that the lower grade of differentiation of the colon adenocarcinoma and mucinous secretion are significantly often present in younger patients.

Genomic analysis of a case of multifocal adenocarcinoma in ulcerative colitis

Long-standing ulcerative colitis is associated with an elevated risk of developing colonic adenocarcinoma. A very limited group of patients present with multiple synchronous cancers. This could be due to either a multifocal presentation of the same neoplastic clone or different tumors arising in a large area of polyclonal dysplastic colonic mucosa ("field cancerization"). Here, we describe a patient with long-standing colitis and three different tumors in the rectosigmoid part of the large bowel. Clonal evaluation of the lesions was performed by array-based comparative genomic hybridization. These three neoplasms showed a comparable pattern of genomic alterations characterized by gains of chromosomes 12, 13, and 20. Noteworthy, dysplastic mucosa distal to the three cancers displayed a completely different pattern of genomic changes indicating that different cell lineages were present. In addition, all three carcinomas were microsatellite stable and revealed identical immunoprofiles for several cancer-associated genes. We conclude that these three multifocal tumors must have originated from the same preneoplastic lineage.

Immunohistochemical expressions of cytokeratins, mucin core proteins, p53, and neuroendocrine cell markers in epithelial neoplasm of appendix

Epithelial neoplasms of appendix are infrequent, and their pathological features are not fully characterized. We collected 33 cases of appendiceal tumors and examined immunohistochemically the expression of cytokeratins (CK, CK7, and CK20), mucin core protein (MUC1, MUC2, MUC5AC, and MUC6), E-cadherin, chromogranin A, and p53 protein. Gene analysis of TP53 was also conducted on exons 5 to 8. Clinically, mucinous tumors were predominant in females. Immunohistochemically, all the tumors expressed CK20, whereas CK7 was positive in one third of the cases. Similarly, MUC2 was expressed in all the tumors, whereas MUC1 and MUC5AC were detected in about a half of the cases. Although chromogranin A-positive cells are generally sparse in normal appendix, they were more common in mucinous tumors than in nonmucinous tumors. Contrary to the previous data reported (Mod Pathol 2002;15:599-605), mucinous carcinoma exhibited a higher frequency of p53-positive cells (mean 29%) compared with mucinous adenoma (2.8%) (P < .001), whereas nonmucinous tumors showed high levels of p53-positive cells to similar extent (51%-67%) in both adenoma and carcinoma. The high expression of p53 protein coincided with the presence of mutations in multiple sites of TP53 gene in mucinous tumors. This is the first report that characterized the immunophenotypic profile of appendiceal epithelial neoplasms with an emphasis of a higher frequency of p53 positivity in mucinous carcinoma cases compared with mucinous adenoma in the appendix.

15-hydroxy-eicosatetraenoic acid arrests growth of colorectal cancer cells via a peroxisome proliferator-activated receptor gamma-dependent pathway

Peroxisome proliferator-activated receptor gamma (PPARgamma) inhibits cell growth via promoting apoptosis. Human colorectal cancer tissues had abundant PPARgamma but the incidence of apoptosis was very low, suggesting a defect in the PPARgamma pathway. Here, we found that 15-hydroxy-eicosatetraenoic acid (15S-HETE), an endogenous ligand for PPARgamma, was significantly decreased in the serum of patients with colorectal cancer. Treatment of colon cancer cells with 15S-HETE inhibited cell proliferation and induced apoptosis, which was preceded by an increase in TGF-beta-inducible early gene (TIEG) and a decrease in Bcl-2. The action of 15S-HETE could be blocked when PPARgamma was suppressed. Overexpression of Bcl-2 prevented the apoptosis. The levels of TIEG and 15-lipoxygenase (15-LOX), the enzyme responsible for 15S-HETE production, was decreased in colorectal cancer. Therefore, colorectal cancer is associated with decreased 15S-HETE. Treatment of colon cancer cells with 15S-HETE inhibits cell proliferation and induces apoptosis in a PPARgamma-dependent pathway involving augmentation of TIEG and reduction of Bcl-2 expression.

Gross versus microscopic pancolitis and the occurrence of neoplasia in ulcerative colitis

OBJECTIVE

The gross extent of ulcerative colitis (UC) is a recognized risk factor for the development of colitis-related dysplasia and colorectal cancer (CRC). The risk of neoplasia associated with the microscopic extent of colitis is unknown. The aim of this study was to describe the gross and microscopic extent of colitis in patients with UC-related dysplasia/CRC.

METHODS

All patients who underwent colectomy at our institution between 1992-2001 with colitis-related dysplasia/CRC were identified. Histological sections from each colectomy specimen were reviewed for the microscopic extent of colitis and the location of all lesions with dysplasia/CRC.

RESULTS

Thirty-six patients with colitis-related dysplasia/CRC were identified of whom 30 had slides available for review. Gross pancolitis was identified in 19 patients, though microscopic pancolitis was evident in all 30 patients. Among the 11 patients with only distal gross colitis, 4/15 neoplastic lesions were proximal to the area of gross involvement.

CONCLUSIONS

UC-related neoplasia can occur in areas of the colon not grossly involved with colitis, though it did not occur in any patients without microscopic pancolitis. To devise rational cancer surveillance guidelines, further studies are needed to determine the risk of colitis-related neoplasia in patients with microscopic pancolitis but limited gross disease.

Microsatellite analysis of synchronous and metachronous tumors: a tool for double primary tumor and metastasis assessment

Despite well-established histopathological features and the development of immunostaining of human neoplasms, there are a number of cases in which surgical pathologists cannot assure the origin of synchronous and metachronous tumors. In many cases, the classification of these lesions as either two separate primary tumors or as a single primary tumor with a metastasis has significant implications with respect to patient prognosis and recommendations for therapy. To establish the origin of tumors, we assessed tumor cell clonality using PCR-based microsatellite analysis on microdissected archival tissues for loss of heterozygosity (LOH) and microsatellite instability (MSI) in a series of 19 paired synchronous and metachronous tumors from several organs. As a control group, 15 autopsy cases with an unequivocally recognizable primary tumor and associated metastases were also examined. Based on LOH and MSI findings, and using a panel of 4 to 12 (median 7) microsatellite markers, we were able to establish the clonal pattern of microsatellite changes in 17 out of 19 (89%) biopsy cases and thus determine if they were either double primary tumors (41%) or metastases (59%). Of interest, identical or similar pattern of microsatellite abnormalities were detected in 15 primary tumors and corresponding metastasis from autopsies. Our results indicate that microsatellite analysis for LOH and MSI, as an expression of clonality, provides a useful tool to distinguish double primary neoplasms and metastases in synchronous and metachronous tumors.

Pathogenesis of colorectal cancer

The development of colorectal cancer has been viewed as an ordered process in which three main phases can be identified: initiation, promotion and progression. There is definite proof that stable alterations of the structure or sequence of DNA (mutations) represent the initiating event; these are followed by an uncontrolled expansion of the neoplastic clones which characterizes tumoural growth. Several classes of genes have been identified foncogenes, tumour suppressor genes and "mutator" genes) the alterations of which are important in the initiation as well as in the promotion and progression of tumours. Colorectal cancer, therefore, results from a series of genetic changes which lead to the progressive and irreversible loss of normal control of cell growth and differentiation. Available evidence is consistent with the hypothesis that there are several molecular pathways underlying the passage from normal mucosa to colorectal carcinoma, thus explaining the existence of intestinal tumours with a different biological nature, which may represent specific targets for prevention and cure. Well-defined molecular pathways have been identified for: A) sporadic colorectal cancer ("Loss of heterozygosity pathway"); B) familial adenomatous polyposis and related polyposis syndromes; C) hereditary non-polyposis colorectal cancer ("mutator genes/microsatellite instability pathway"); D) cancer developing in inflammatory bowel diseases; E) familial colorectal cancer. Thus, there is consistent and considerable evidence suggesting the existence of several biological pathways leading to the same phenotypical expression (i.e., colorectal cancer), and it is likely that additional pathways will be clarified in the future. From a practical point of view, tumours with a diverse biology might offer different and more effective preventive and curative approaches.

Conversion of human colonic adenoma cells to adenocarcinoma cells through inflammation in nude mice

The roles of inflammation in the malignant progression of tumors during multistep carcinogenesis have been much discussed but remain to be elucidated. To determine the direct contribution of inflammation to colon carcinogenesis, we established a new model of progression of human colonic adenoma cells using a nude mouse; the progression is accelerated by coimplantation of a plastic plate. The FPCK-1-1 cell line, derived from a colonic polyp in a patient with familial adenomatous polyposis, is nontumorigenic when injected subcutaneously into nude mice in a cell suspension of up to 5 x 106 cells per mouse. However implantation of 1 x 10(5) FPCK-1-1 cells attached to a plastic plate induced first acute and then chronic inflammation, and formed progressively growing tumors that were histologically determined as moderately differentiated adenocarcinoma in 65% of mice. Moreover cell lines established from the growing tumors were found to be tumorigenic when injected into mice even without a plastic plate. The tumor arising from the adenoma cells implanted attached to a plastic plate was surrounded by highly proliferating fibrous stroma. This fibrous tissue was considered essential for malignant progression, rather than for attachment to the plastic plate substrate, because the tumors were formed after injection of FPCK-1-1 cells into the fibrous tissue from which the plastic plate had been removed before the cell injection. The conditioned medium (CM) obtained from the fibroblasts derived from a plastic plate-associated stromal tissue was found to contain factors that stimulated growth of FPCK-1-1 cells, but not of the derivative progressor cell lines. The factor was stable to heating and neuraminidase treatment, but labile to trypsin treatment. The main growth-potentiating activity was contained in the fraction larger than 100 kDa. In contrast, the activity to promote FPCK-1-1 cell growth was not present in the CM of subcutaneous fibroblasts from untreated nude mice or the fibroblast cell lines C3H10T 1/2 and NIH3T3. These results demonstrated that inflammation-associated stroma promoted the conversion of colonic adenoma cells to adenocarcinoma cells.

p27 expression in inflammatory bowel disease-associated neoplasia. Further evidence of a unique molecular pathogenesis

The cyclin-dependent kinase inhibitor p27 is a negative regulator of the transition from G1 to S phase of the cell cycle, protects against inflammatory injury and promotes epithelial differentiation. Because p27 protein has been shown to be abnormally expressed both in dysplasia associated with Barrett's esophagus and in sporadic colorectal adenomas, we used immunohistochemistry to evaluate p27 expression in inflammatory bowel disease (IBD)-associated dysplasia and carcinomas. Normal, inflamed, and transitional mucosa, sporadic adenomas, and sporadic colonic carcinomas were studied as controls. In normal colonic epithelium p27 expression was restricted to the superficial, terminally differentiated cells. In colitic and inflamed diverticular mucosa p27 was expressed in the base of the crypts in 86 and 70% of cases, respectively. Similarly, in transitional mucosa adjacent to sporadic carcinomas p27 was expressed in the base of the crypts in all cases. Strong p27 expression extended more frequently from the base of the crypts to superficial cells in IBD-associated dysplasia than in sporadic adenomas (P < 0.007). Twenty of 20 (100%) IBD-associated carcinomas showed low p27 expression (<50% nuclei positive) compared to 6 of 20 (30%) stage-matched sporadic colorectal carcinomas (P < 0.001). We conclude (i) aberrant p27 protein expression in inflamed and IBD-associated nondysplastic mucosa is indistinguishable from that found in transitional mucosa adjacent to sporadic carcinomas; (ii) p27 is overexpressed in dysplastic lesions, perhaps as an attempt to counterbalance proliferative stimuli; and (iii) IBD-associated colorectal carcinomas have significantly lower p27 expression, commonly associated with poor prognosis, than stage-matched sporadic colorectal carcinomas. These findings further substantiate the existence of divergent molecular pathogenetic pathways between these types of carcinomas and suggest an intrinsically more aggressive behavior of IBD-associated colon carcinomas compared to sporadic ones.