A comparison of multiple synchronous colorectal cancer in ulcerative colitis, familial polyposis coli, and de novo cancer

A Rare Presentation of Synchronous Colorectal Adenocarcinoma

Synchronous carcinoma is defined as multiple malignant lesions presented in a single patient at initial diagnosis. Synchronous colorectal adenocarcinoma is a rare entity that has been increasingly recognized, likely due to the significant improvement in imaging and diagnostic tools. Making the appropriate diagnosis of synchronous colorectal cancer has a major role in the management's determination and treatment plans. Herein, we are reporting a case of a 73-year-old gentleman who was diagnosed with synchronous colorectal adenocarcinoma with two masses in the left colon and was treated initially surgically followed by chemotherapy.

Management of Pouch Neoplasia

BACKGROUND

Pouch neoplasia occurs following ileal pouch-anal anastomosis, with or without mucosectomy in ulcerative colitis and familiar adenomatous polyposis.

OBJECTIVES

This study aimed to review available literature and make recommendations regarding pouch neoplasia.

DATA SOURCES

Data were collected from specialty hospitals, and a literature review was conducted due to the lack of published large-scale studies. Recommendations for treatment were made based on the literature review and expert opinions.

STUDY SELECTION

Large-scale studies of pouch neoplasia were selected.

INTERVENTION

The intervention was studies with details of pouch neoplasia.

MAIN OUTCOME MEASURES

We aimed to identify the management modalities for pouch neoplasia based on the type.

RESULTS

Pouch neoplasia can occur in each component of the pouch-afferent limb, pouch body, cuff, and anal transitional zone. In patients with ulcerative colitis, pouch neoplasia is treated because colitis-associated neoplasia comprises a multifocal lesion, which most commonly involves the cuff and anal transitional zone. Close surveillance or endoscopic complete resection is optimal for low-grade dysplasia. For adenocarcinoma, high-grade dysplasia, and low-grade dysplasia with difficult complete resection, pouch excision is recommended. In familiar adenomatous polyposis patients with adenomas of the afferent limb or pouch body, endoscopic resection is optimal. Endoscopic resection is feasible for discrete adenoma in the cuff and anal transitional zone, and surgical excision is optimal for laterally spreading, extensive, large, or flat adenoma. For adenocarcinomas involving any component, pouch excision is recommended.

LIMITATIONS

Published large-scale studies were lacking because of disease rarity.

CONCLUSION

Pouch neoplasia occurs in each pouch component. In patients with ulcerative colitis, pouch excision is recommended for adenocarcinomas and high-grade dysplasia, whereas endoscopic intervention may be preferable to low-grade dysplasia. In familiar adenomatous polyposis patients, pouch excision is necessary for adenocarcinoma, and endoscopic resection or excisional surgery is optimal for adenoma.

What Does Disease Progression Look Like in Ulcerative Colitis, and How Might It Be Prevented?

Ulcerative colitis (UC) has been characterized by inflammation limited to the mucosa. Although sustained and durable remission has been associated with mucosal healing, the recurrent phenomenon of persistent clinical disease activity despite mucosal healing has been observed in clinical practice and across pivotal trials. Over time, UC appears to confer an increased risk of progression, defined as changes of disease phenotype; adverse transmural effects on the bowel wall; increased risk of neoplasia development; worsening colorectal function; and increased risk of colectomy, hospitalizations, and other extraintestinal comorbidities. Although the treatment paradigm for Crohn's disease has shifted toward early aggressive intervention to prevent disease progression and irreversible bowel damage, such urgency in efforts to halt disease progression in UC have been largely overlooked. This review summarizes the multiple facets of UC contributing to a modified perception of the disease as a progressive one. We propose further study of the natural history and priorities for further treatment goals that include these considerations.

Risk of Colon Cancer and Recommended Surveillance Strategies in Patients with Ulcerative Colitis

Longstanding and extensive ulcerative colitis (UC) are associated with the subsequent development of colorectal cancer (CRC). This article summarizes key strategies for colonoscopic surveillance, the most widely used and evidence-based method of CRC prevention. As currently constituted and practiced, surveillance examinations every 1 to 3 years with lesion detection and removal using high-definition endoscopic systems with or without pancolonic spray-dye chromoendoscopy is the best method for mitigating the development of CRC morbidity and mortality. For patients with primary sclerosing cholangitis with UC, surveillance should begin at the time of diagnosis and colonoscopy should be performed annually.

Development of an MSI-positive colon tumor with aberrant DNA methylation in a PPAP patient

Polymerase proofreading-associated polyposis (PPAP) is a disease caused by germline variations in the POLE and POLD1 genes that encode catalytic subunits of DNA polymerases. Studies of cancer genomes have identified somatic mutations in these genes, suggesting the importance of polymerase proofreading of DNA replication in suppressing tumorigenesis. Here, we identified a germline frameshift variation in the POLE gene (c.4191_4192delCT, p.Tyr1398*) in a case with multiple adenomatous polyps and three synchronous colon cancers. Interestingly, one of the colon cancers showed microsatellite instability-high (MSI-H) and another microsatellite stable. Immunohistochemical staining revealed that the MSI-H tumor cells lost the expression of MLH1 protein. Whole genome sequencing of the MSI-H tumor did not find pathogenic somatic mutations in mismatch repair genes but found frameshift mutations in the TET genes that catalyze 5-methylcytosine hydroxylation. Bisulfite sequencing of the tumor corroborated an increase in the number of hypermethylated regions including the MLH1 promoter. These data indicate that PPAP patients might develop MSI-positive tumors through epigenetic silencing of MLH1. These findings will contribute to comprehensive understanding of the molecular basis of tumors that involve deficiency of proofreading activity of DNA polymerases.

Synchronous colorectal carcinoma: predisposing factors and characteristics

AIM

Whether some diseases are related to the occurrence of synchronous colorectal carcinoma (sCRC) is unknown. Investigating the risk factors and presentation of sCRC could aid in the treatment of patients with colorectal cancer (CRC). The prognosis of sCRC compared with that of solitary CRC remains unclear.

METHODS

A total of 17 093 CRC patients were recruited between 1st January 1995 and 31th December 2016. The risk factors of sCRC development were assessed using univariate and multivariate logistic regression. The effect of sCRC on survival was analysed using the multivariate Cox regression model.

RESULTS

The prevalence of sCRC was 5.6% in this study. The independent risk factors of sCRC development were advanced age (P < 0.001), male sex (P < 0.001), hereditary cancer (P < 0.001), hypertension (P < 0.001) and liver cirrhosis (P = 0.024). Compared with solitary CRC, a higher number of patients with sCRC presented with an abnormal carcinoembryonic antigen (CEA) level (P = 0.011), anaemia (P < 0.001) and hypoalbuminemia (P < 0.001). Multivariate analysis revealed that sCRC was a significant factor for poor survival in patients at TNM Stage I [hazard ratio (HR) = 1.86; P < 0.001], Stage II (HR = 1.65; P < 0.001) and Stage III (HR = 1.40; P < 0.001).

CONCLUSIONS

In addition to hypertension and liver cirrhosis, other risk factors for sCRC were identified in this study. The prognosis of patients with sCRC was significantly worse than that of those with solitary CRC through TNM Stages I to III. Anaemia, abnormal CEA and hypoalbuminemia were more commonly seen in patients with sCRC.

Exome and immune cell score analyses reveal great variation within synchronous primary colorectal cancers

Background

Approximately 4% of colorectal cancer (CRC) patients have at least two simultaneous cancers in the colon. Due to the shared environment, these synchronous CRCs (SCRCs) provide a unique setting to study colorectal carcinogenesis. Understanding whether these tumours are genetically similar or distinct is essential when designing therapeutic approaches.

Methods

We performed exome sequencing of 47 primary cancers and corresponding normal samples from 23 patients. Additionally, we carried out a comprehensive mutational signature analysis to assess whether tumours had undergone similar mutational processes and the first immune cell score analysis (IS) of SCRC to analyse the interplay between immune cell invasion and mutation profile in both lesions of an individual.

Results

The tumour pairs shared only few mutations, favouring different mutations in known CRC genes and signalling pathways and displayed variation in their signature content. Two tumour pairs had discordant mismatch repair statuses. In majority of the pairs, IS varied between primaries. Differences were not explained by any clinicopathological variable or mutation burden.

Conclusions

The study shows major diversity within SCRCs. Rather than rely on data from one tumour, our study highlights the need to evaluate both tumours of a synchronous pair for optimised targeted therapy.

The molecular landscape of synchronous colorectal cancer reveals genetic heterogeneity

Synchronous colorectal cancers (syCRCs), which present two or more lesions at diagnosis, are rare and pose a great challenge for clinical management. Although some predisposing factors associated with syCRCs have been studied with limited accession, the full repertoire of genomic events among the lesions within an individual and the causes of syCRCs remain unclear. We performed whole-exome sequencing of 40 surgical tumour samples of paired lesions from 20 patients to characterize the genetic alterations. Lesions from same patient showed distinct landscapes of somatic aberrations and shared few mutations, which suggests that they originate and develop independently, although they shared the similar genetic background. Canonical genes, such as APC, KRAS, TP53 and PIK3CA, were frequently mutated in the syCRCs, and most of them show different mutation profile compared with solitary colorectal cancer. We identified a recurrent somatic alteration (K15fs) in RPL22 in 25% of the syCRCs. Functional analysis indicated that mutated RPL22 may suppress cell apoptosis and promote the epithelial–mesenchymal transition (EMT). Potential drug targets were identified in several signalling pathways, and they present great discrepancy between lesions from the same patient. Our data show that the syCRCs within the same patient present great genetic heterogeneity, and they may be driven by distinct molecular events and develop independently. The discrepancy of potential drug targets and mutation burden in lesions from one patient provides valuable information in clinical management for patients with syCRCs.

Whole exome sequencing reveals intertumor heterogeneity and distinct genetic origins of sporadic synchronous colorectal cancer

Sporadic synchronous colorectal cancer (CRC) refers to more than one primary tumor detected in a single patient at the time of the first diagnosis without predisposition of cancer development. Given the same genetic and microenvironment they raise, sporadic synchronous CRC is a unique model to study CRC tumorigenesis. We performed whole exome sequencing in 32 fresh frozen tumor lesions from 15 patients with sporadic synchronous CRC to compare their genetic alterations. This approach identified ubiquitously mutated genes in the range from 0.34% to 4.22% and from 0.8% to 7.0% in non-hypermutated tumors and hypermutated tumors, respectively, in a single patient. We show that both ubiquitously mutated genes and candidate cancer genes from different tumors in the same patient mutated at different sites. Consistently, obvious differences in somatic copy number variations (SCNV) were found in most patients with non-hypermutated tumor lesions, which had ubiquitous copy number amplification rates ranging from 0% to 8.8% and ubiquitous copy number deletion rates ranging from 0% to 8.2%. Hypermutated lesions were nearly diploid with 0% to 18.8% common copy number aberrations. Accordingly, clonal structures, altered signaling pathways and druggable genes in a single patient with synchronous CRC varied significantly. Taken together, the disparate SCNVs and mutations in synchronous CRC supported the field effect theory of tumorigenesis. Moreover, the intertumor heterogeneity of synchronous CRCs implies that analysis of all tumor lesions from the same patient is necessary for appropriate clinical treatment decisions.

Treatment and Outcome of Synchronous Colorectal Carcinomas: A Nationwide Study

BACKGROUND

Synchronous colorectal carcinomas (CRC) occur in 1-8% of patients diagnosed with CRC. This study evaluated treatment patterns and patient outcomes in synchronous CRCs compared with solitary CRC patients.

METHODS

All patients diagnosed with primary CRC between 2008 and 2013, who underwent elective surgery, were selected from the Netherlands Cancer Registry. Using multivariable regressions, the effects of synchronous CRC were assessed for both short-term outcomes (prolonged postoperative hospital admission, anastomotic leakage, postoperative 30-day mortality, administration of neoadjuvant or adjuvant treatment), and 5-year relative survival (RS).

RESULTS

Of 41,060 CRC patients, 1969 patients (5%) had synchronous CRC. Patients with synchronous CRC were older (mean age 71 ± 10.6 vs. 69 ± 11.4 years), more often male (61 vs. 54%), and diagnosed with more advanced tumour stage (stage III-IV 54 vs. 49%) compared with solitary CRC (all p < 0.0001). In 50% of the synchronous CRCs, an extended surgery was conducted (n = 934). Synchronous CRCs with at least one stage II-III rectal tumour less likely received neoadjuvant (chemo)radiation [78 vs. 86%; adjusted OR 0.6 (0.48-0.84)], and synchronous CRCs with at least one stage III colon tumour less likely received adjuvant chemotherapy [49 vs. 63%; adjusted OR 0.7 (0.55-0.89)]. Synchronous CRCs were independently associated with decreased survival [RS 77 vs. 71%; adjusted RER 1.1 (1.01-1.23)].

CONCLUSIONS

The incidence of synchronous CRCs in the Dutch population is 5%. Synchronous CRCs were associated with decreased survival compared with solitary CRC. The results emphasize the importance of identifying synchronous tumours, preferably before surgery to provide optimal treatment.

A meta-analysis of the clinicopathological characteristics and survival outcomes of inflammatory bowel disease associated colorectal cancer

PURPOSE

The current study aims to use meta-analytical techniques to compare the clinicopathological characteristics and survival outcomes of inflammatory bowel disease (IBD) associated and sporadic colorectal carcinoma (CRC). Patients with IBD have an established increased risk of developing CRC. There is no consensus, however, on the clinicopathological characteristics and survival outcomes of IBD associated CRC when compared to sporadic CRC.

METHODS

A comprehensive search for published studies comparing IBD associated and sporadic CRC was performed. Random effect methods were used to combine data. This study adhered to the recommendations of the MOOSE guidelines.

RESULTS

Data were retrieved from 20 studies describing 571,278 patients. IBD associated CRC had an increased rate of synchronous tumors (OR 4.403, 95% CI 2.320-8.359; p < 0.001), poor differentiation (OR 1.875, 95% CI 1.425-2.466; p < 0.001), and a reduced rate of rectal cancer (OR 0.827, 95% CI 0.735-0.930; p = 0.002). IBD associated CRC however did not affect the frequency of T3/T4 tumors (OR 0.931, 95% CI 0.782-1.108; p = 0.421), lymph node positivity (OR 1.061, 95% CI 0.929-1.213; p = 0.381), metastasis at presentation (OR 0.970, 95% CI 0.776-1.211; p = 0.786), sex distribution (OR 0.978, 95% CI 0.890-1.074; p = 0.640), or 5-year overall survival (OR 1.105, 95% CI 0.414-2.949; p = 0.842).

CONCLUSIONS

In this large analysis of available data, IBD associated CRC was characterized by less rectal tumors and more synchronous and poorly differentiated tumors compared with sporadic cancers, but no discernable difference in sex distribution, stage at presentation, or survival could be identified.

Clinical characteristics of synchronous colorectal cancers in Japan

BACKGROUND

Incidence and clinical characteristics of synchronous colorectal cancer (sCRC) patients significantly vary among studies, likely due to differences in surveillance methodology. If remain undetected, sCRC can progress to more advanced stages seriously aggravating patient prognosis. We studied the incidence and clinicopathological characteristics of Japanese patients with sCRCs who underwent surgery for primary CRC and received exhaustive perioperative surveillance.

METHODS

We recruited 1005 patients with surgically resected CRCs between January 2007 and December 2011. The associations of clinical and pathological factors with sCRC development were assessed by univariate and multivariate logistic regression.

RESULTS

Eighty-four patients (8.4 %) developed sCRCs, 16 of them (19.0 %) harboring three or more cancers. Companion sCRCs were smaller and earlier stage than the index lesion (P < 0.0001). In multivariate analysis, advanced age (odds ratio (OR) 1.03 per year; P = 0.009) and left colon tumor location (OR 1.78; P = 0.013) are associated with higher risk of sCRCs, particularly in females. Overall survival did not differ between solitary CRC and sCRC (P = 0.62).

CONCLUSIONS

Our results highlight the importance of perioperative colonoscopy examination to ensure the absence of sCRCs that, being small and early staged, are more difficult to detect. The incidence of sCRC, and notably of triple or more sCRCs, was higher than previously recognized. Because they are also significantly higher than expected by merely stochastic accumulation of individual cancerous lesions, we suggest that the occurrence of many sCRC reflects a hitherto uncharacterized predisposition condition.

Patients with genetically heterogeneous synchronous colorectal cancer carry rare damaging germline mutations in immune-related genes

Synchronous colorectal cancers (syCRCs) are physically separated tumours that develop simultaneously. To understand how the genetic and environmental background influences the development of multiple tumours, here we conduct a comparative analysis of 20 syCRCs from 10 patients. We show that syCRCs have independent genetic origins, acquire dissimilar somatic alterations, and have different clone composition. This inter- and intratumour heterogeneity must be considered in the selection of therapy and in the monitoring of resistance. SyCRC patients show a higher occurrence of inherited damaging mutations in immune-related genes compared to patients with solitary colorectal cancer and to healthy individuals from the 1,000 Genomes Project. Moreover, they have a different composition of immune cell populations in tumour and normal mucosa, and transcriptional differences in immune-related biological processes. This suggests an environmental field effect that promotes multiple tumours likely in the background of inflammation.

Some individuals present with multiple synchronous colorectal tumours, but the genetic understanding of this is unclear. Here, the authors use a sequencing strategy to show that the synchronous tumours are genetically independent and the patients harbour rare germline damaging mutations in genes associated with the immune system.

Multiple primary colorectal cancer: Individual or familial predisposition?

Colorectal carcinoma (CRC) is one of the most frequent cancers. Along the surface of the large bowel, several foci of CRC may appear simultaneously or over the time. The development of at least two different tumours has been defined as multiple primary CRC (MPCRC): When more than one tumour is diagnosed at the same time, it is known as synchronous CRC (SCRC), while when a second neoplasm is diagnosed some time after the resection and/or diagnosis of the first lesion, it is called metachronous CRC (MCRC). Multiple issues can promote the development of MPCRC, ranging from different personal factors, such as environmental exposure, to familial predisposition due to hereditary factors. However, most studies do not distinguish this dichotomy. High- and low-pentrance genetic variants are involved in MPCRC. An increased risk for MPCRC has been described in Lynch syndrome, familial adenomatous polyposis, and serrated polyposis. Non-syndromic familial CRCs should also be considered as risk factors for MPCRC. Environmental factors can promote damage to colon mucosae that enable the concurrence of MPCRC. Epigenetics are thought to play a major role in the carcinogenesis of sporadic MPCRC. The methylation state of the DNA depends on multiple environmental factors (e.g., smoking and eating foods cooked at high temperatures), and this can contribute to increasing the MPCRC rate. Certain clinical features may also suggest individual predisposition for MPCRC. Different etiopathogenic factors are suspected to be involved in SCRC and MCRC, and different familial vs individual factors may be implicated. MCRC seems to follow a familial pattern, whereas individual factors are more important in SCRC. Further studies must be carried out to know the molecular basis of risks for MPCRC in order to modify, if necessary, its clinical management, especially from a preventive point of view.

Synchronous triple colorectal carcinoma: a case report and review of literature

Synchronous colorectal carcinoma defines as multiple malignant lesions presented in a single patient at initial diagnosis. We report a case of triple synchronous colorectal carcinoma without related familial history. Preoperative computed tomography (CT) scan and endoscopic examination suggested multiple malignant lesions occurred in separate segments of colon. Then we performed laparoscopic total colectomy and ileorectal anastomosis with a J-type pouch. Post operative pathological examination confirmed the malignant characteristics of the triple lesions. The mini review summarizes the clinicopathological and molecular features of synchronous colorectal carcinoma based on current literatures. It appears to probably have significant distinctions with solitary tumors in terms of pathological type, primary locations and microsatellite instability.

Forty-Year Analysis of Colonoscopic Surveillance Program for Neoplasia in Ulcerative Colitis: An Updated Overview

OBJECTIVES

This study provides an overview of the largest and longest-running colonoscopic surveillance program for colorectal cancer (CRC) in patients with long-standing ulcerative colitis (UC).

METHODS

Data were obtained from medical records, endoscopy, and histology reports. Primary end points were defined as death, colectomy, withdrawal from surveillance, or censor date (1 January 2013).

RESULTS

A total of 1,375 UC patients were followed up for 15,234 patient-years (median, 11 years per patient). CRC was detected in 72 patients (incidence rate (IR), 4.7 per 1,000 patient-years). Time-trend analysis revealed that although there was significant decrease in incidence of colectomy performed for dysplasia (linear regression, R=-0.43; P=0.007), IR of advanced CRC and interval CRC have steadily decreased over past four decades (Pearson's correlation, -0.99; P=0.01 for both trends). The IR of early CRC has increased 2.5-fold in the current decade compared with past decade (χ(2), P=0.045); however, its 10-year survival rate was high (79.6%). The IR of dysplasia has similarly increased (χ(2), P=0.01), potentially attributable to the recent use of chromoendoscopy that was twice more effective at detecting dysplasia compared with white-light endoscopy (χ(2), P<0.001). CRCs were frequently accompanied by synchronous CRC or spatially distinct dysplasia (37.5%). Finally, the risk of CRC was not significantly different between "indefinite" or low-grade dysplasia (log-rank, P=0.78).

CONCLUSIONS

Colonoscopic surveillance may have a significant role in reducing the risk of advanced and interval CRC while allowing more patients to retain their colon for longer. Given the ongoing risk of early CRC, patients with any grade of dysplasia who are managed endoscopically should be monitored closely with advanced techniques.

Quality bowel preparation for surveillance colonoscopy in patients with inflammatory bowel disease is a must

Colonoscopy is routinely performed in patients with inflammatory bowel disease (IBD) for surveillance of dysplasia. Thorough bowel preparation is necessary to facilitate lesion detection. Patients with IBD do not have poorer bowel preparation outcomes but may have decreased preparation tolerance affecting adherence to surveillance protocols. A low-fiber prepreparation diet may improve preparation tolerance without affecting preparation quality. The standard preparation regimen should consist of split-dose administration of a polyethylene glycol-based purgative. Low-volume, hyperosmolar purgatives may be considered in patients with previous preparation intolerance, heightened anxiety, stenotic disease, or dysmotility. Appropriate patient education is critical to enhance preparation quality.

Synchronous colorectal cancer: Clinical, pathological and molecular implications

Synchronous colorectal carcinoma refers to more than one primary colorectal carcinoma detected in a single patient at initial presentation. A literature review has shown that the prevalence of the disease is approximately 3.5% of all colorectal carcinomas. This disease has a male to female ratio of 1.8:1. The mean age at presentation of patients with synchronous colorectal cancer is in the early half of the seventh decade. Patients with inflammatory bowel diseases (ulcerative colitis and Crohn’s disease), hereditary non-polyposis colorectal cancer, familial adenomatous polyposis and serrated polyps/hyperplastic polyposis are known to have a higher risk of synchronous colorectal carcinoma. These predisposing factors account for slightly more than 10% of synchronous colorectal carcinomas. Synchronous colorectal carcinoma is more common in the right colon when compared to solitary colorectal cancer. On pathological examination, some synchronous colorectal carcinomas are mucinous adenocarcinomas. They are usually associated with adenomas and metachronous colorectal carcinomas. Most of the patients with synchronous colorectal cancer have two carcinomas but up to six have been reported in one patient. Patients with synchronous colorectal carcinoma have a higher proportion of microsatellite instability cancer than patients with a solitary colorectal carcinoma. Also, limited data have revealed that in many synchronous colorectal carcinomas, carcinomas in the same patient have different patterns of microsatellite instability status, p53 mutation and K-ras mutation. Overall, the prognosis of patients with synchronous colorectal carcinoma is not significantly different from that in patients with solitary colorectal carcinoma, although a marginally better prognosis has been reported in patients with synchronous colorectal carcinoma in some series. A different management approach and long-term clinical follow-up are recommended for some patients with synchronous colorectal cancer.

Microscopic features of colorectal neoplasia in inflammatory bowel diseases

The risk of developing dysplasia leading to colorectal cancer (CRC) is increased in both ulcerative colitis and Crohn’s disease. The prognosis of CRC may be poorer in patients with inflammatory bowel disease (IBD) than in those without IBD. Most CRCs, in general, develop from a dysplastic precursor lesion. The interpretation by the pathologist of the biopsy will guide decision making in clinical practice: colonoscopic surveillance or surgical management. This review summarizes features of dysplasia (or intraepithelial neoplasia) with macroscopic and microscopic characteristics. From an endoscopic (gross) point of view, dysplasia may be classified as flat or elevated (raised); from a histological point of view, dysplasia is separated into 3 distinct categories: negative for dysplasia, indefinite for dysplasia, and positive for dysplasia with low- or high-grade dysplasia. The morphologic criteria for dysplasia are based on a combination of cytologic (nuclear and cytoplasmic) and architectural aberrations of the crypt epithelium. Immunohistochemical and molecular markers for dysplasia are reviewed and may help with dysplasia diagnosis, although diagnosis is essentially based on morphological criteria. The clinical, epidemiologic, and pathologic characteristics of IBD-related cancers are, in many aspects, different from those that occur sporadically in the general population. Herein, we summarize macroscopic and microscopic features of IBD-related colorectal carcinoma.

FOXE1 and SYNE1 genes hypermethylation panel as promising biomarker in colitis-associated colorectal neoplasia

BACKGROUND

Colitis-associated colorectal cancer affects individuals with inflammatory bowel disease (IBD) more often and earlier than cancer in the general population. Colonoscopy provides the surveillance gold standard. Changes to the surveillance intervals depending on endoscopic activity have been made, given data demonstrating that this is an important predictor of future dysplasia or cancer, but adjuvant, noninvasive clinical tools are still warranted to improve surveillance outcomes and to assist in management and interpretation of dysplasia. Methylation markers may be able to do this.

METHODS

SYNE1, FOXE1, NDRG4, and PHACTR3 genes were screened using methylation-specific PCR that permit the methylation status of the genes to be determined directly on biopsies. Ninety-three patients with long-standing IBD undergoing a cancer surveillance program, and 30 healthy controls were studied. These included colorectal adenocarcinomas on a background of IBD of various stages (n = 25), IBD-associated dysplastic lesions (n = 29), adenomas arising on a background of ulcerative colitis (n = 8), samples from patients with no evidence of dysplasia or cancer but long-standing IBD (n = 31), and symptomatic patients found to have normal colonoscopy (controls) (n = 30).

RESULTS

Gene promotor hypermethylation of SYNE1 and FOXE1 genes varied significantly between the groups and was increasingly likely with increased disease severity. Neither occurred in controls, whereas promotor hypermethylation was detected in biopsies of 60% of patients with colitis-associated colorectal cancer for FOXE1 and 80% for SYNE1. Promotor hypermethylation of either gene was highly significantly different between the groups overall.

CONCLUSIONS

FOXE1 and SYNE1 hypermethylation markers demonstrated significantly increased expression in neoplastic tissue. Promoter methylation analysis of these genes might be a useful marker of neoplasia in long-standing IBD.

Methylated eyes absent 4 (EYA4) gene promotor in non-neoplastic mucosa of ulcerative colitis patients with colorectal cancer: evidence for a field effect

BACKGROUND

Aberrant methylation of the EYA4 gene (mEYA4) highly discriminates ulcerative colitis (UC) cases with colorectal neoplasia from UC controls in both tissue and stool. It is not known if mEYA4 is also present in nonadjacent non-neoplastic mucosa (NNM) of UC patients with colorectal neoplasia.

METHODS

Formalin-fixed tissues from 25 UC cases with colorectal cancer (CRC) and 25 UC controls with neither CRC nor dysplasia were matched on gender, age, disease duration, disease extent, and coexistence of primary sclerosing cholangitis. DNA was extracted from sections of CRC and NNM from cases and UC control mucosae. Bisulfite-treated DNA was amplified using real-time methylation-specific PCR. The Wilcoxon rank-sum test assessed differences in mEYA4 levels from CRC, NNM, and control samples. Logistic regression was used to estimate sensitivity and specificity.

RESULTS

Sufficient DNA was available for 20 cases and 20 controls. The median mEYA4 level (with interquartile range) was 2 (0-5.7) in control mucosae but 93 (38.5-306) in CRC (P < 0.0001) and 27.4 (3-140) in NNM (P = 0.0009). At 95% specificity, mEYA4 was present in 80% of CRC and 50% of NNM tissue samples. The odds ratio of mEYA4 in NNM as an indicator of synchronous CRC was 19 (95% confidence interval, 2-170).

CONCLUSIONS

The authors demonstrate significantly higher mEYA4 levels in NNM and synchronous CRC from UC cases than in colorectal mucosae of UC controls without neoplasia. The finding of this CRC-associated field change has important implications to the use of mEYA4 as a potential UC surveillance marker in tissue or stool.

The surgical treatment of inflammatory bowel disease-associated dysplasia

Surgical management of colonic dysplasia discovered in the inflammatory bowel disease patient is controversial. Total proctocolectomy (TPC) is the most definitive treatment for the eradication of undiagnosed synchronous dysplasias and/or carcinomas and the prevention of subsequent metachronous lesions in both Crohn's disease (CD) and ulcerative colitis (UC). However, TPC is not always an attractive option owing to patient comorbidities and patient preference. Historically, dysplasia has been most studied in patients with UC, where the option of reconstruction without a stoma makes TPC more acceptable. Due to a relative lack of research on CD-related dysplasia, surveillance and treatment of CD dysplasia has followed paradigms based on UC data. However, due to pathophysiological differences in CD versus UC, options for surgical management in CD may be more varied than simple TPC, particularly in the less healthy surgical candidate and those who refuse end ileostomy.

Synchronous triple carcinoma of the colon and rectum

Synchronous multiple colorectal cancers are defined as multiple malignant colorectal tumors that occur simultaneously. All tumors are distant from each other, and none are the result of metastasis from other tumors. Here, we present a case of a 79-year-old man who was admitted to our hospital because of a 3-month history of abdominal pain associated with anemia, loss of appetite, and body weight loss. The patient did not have a family history of cancer. Computed tomography revealed bowel wall thickness and mesentery inflammation at the hepatic flexure of the colon and cecum. Colonoscopy revealed a tumor located 10 cm from the anal verge. Colonoscopic examination of the large bowel was not possible because of bowel obstruction due to the rectal tumor. Synchronous triple adenocarcinoma of the colon and rectum was confirmed by pathologic examination. The tumor was surgically resected by two-segment resection of the colon, low anterior resection, and right hemicolectomy. We used intraoperative colonoscopy to confirm that there were no other lesions after the resection of the three tumors. To the best of our knowledge, this is the first case of synchronous triple carcinoma of the colon and rectum in Taiwan. We consider that comprehensive preoperative study, extensive intraoperative exploration, and radical resection can increase the survival rate of patients with synchronous multiple colorectal cancers.

Dysplasia in inflammatory bowel diseases

In both Crohn's disease and ulcerative colitis, the secondary prevention of colorectal cancer basically relies on the histological detection of dysplasia. In inflammatory bowel diseases, dysplasia identifies the subgroup of patients eligible for stricter surveillance (or prophylactic colectomy). In clinical practice, a number of issues may influence the benefits of clinico-pathological surveillance for inflammatory bowel disease patients with dysplasia, including: sampling errors, inconsistent biopsy assessments, patients' compliance with follow-up requirements, and how heath care is organized. Even in such a multifaceted context, it has been demonstrated that dysplasia surveillance is effective in reducing colorectal cancer-related mortality and morbidity. This paper focuses on current issues concerning the histological assessment of inflammatory bowel disease-associated dysplastic lesions.

Colorectal carcinoma in inflammatory bowel disease: a comparison between Crohn's and ulcerative colitis

AIM

The study assessed the clinicopathological features and survival rates of inflammatory bowel disease (IBD) patients with colorectal carcinoma (CRC), which accounts for ∼ 15% of all IBD associated death.

METHOD

The medical records of patients operated on for CRC in three institutions between 1992 and 2009 were reviewed, and those with Crohn's colitis (CC) and ulcerative colitis (UC) were identified. Data on age, gender, disease duration, colitis severity, surgical procedure, tumour stage and survival were retrieved.

RESULTS

Fifty-three patients (40 UC and 13 CC, 27 men, mean age at operation 54 years) were found. All parameters were comparable between the groups. Mean disease duration before CRC was 22.7 years for UC and 16.6 years for CC patients (P = 0.04). CRC was diagnosed preoperatively in 43 (81%) patients. Twenty-eight patients had colon cancer, 23 had rectal cancer and two patients had more than one cancer. All malignancies were located in segments with colitis. Over one-half were diagnosed at an advanced stage (36% stage III; 17% stage IV). At a mean follow up of 56 ± 65 months, 60% were alive (54% disease free) and 40% were dead from cancer-related causes. The 5-year survival rate was 61% for the UC and 37% for the CC patients (P = NS).

CONCLUSION

CRC in IBD patients is frequently diagnosed at an advanced stage, a factor that contributes to poor prognosis. The risk of CRC in CC patients is comparable to those with UC. Long-term surveillance is recommended for patients with long-standing CC and UC.

Clinicopathological significance of synchronous carcinoma in colorectal cancer

BACKGROUND

Synchronous colorectal carcinoma has seldom been studied in large series. The study was designed to examine the significance of colorectal synchronous carcinoma in a large cohort of patients.

METHODS

The clinicopathological features of 102 patients with synchronous colorectal carcinoma were compared with 1,793 patients with solitary colorectal carcinoma.

RESULTS

The prevalence of synchronous colorectal carcinoma was 3.6%. In these patients, 4% had FAP, 6% had hyperplastic polyposis, and 2% had ulcerative colitis. The index carcinoma was more likely to have higher histological grade and T stage than other carcinoma(s) in the same patient. When compared with solitary colorectal carcinoma, synchronous colorectal carcinoma was more often noted in males with coexisting FAP and in proximal location. The 5-year survival rate of patients with synchronous colorectal carcinoma was 53% and was similar to those with solitary colorectal carcinoma.

CONCLUSIONS

We examined the clinicopathological features of patients with synchronous colorectal carcinomas in a large cohort of patients. Attention to these features was important for better management of this group of cancer.

Inflammatory bowel disease-associated colorectal cancer: proctocolectomy and mucosectomy do not necessarily eliminate pouch-related cancer incidences

BACKGROUND

Colorectal cancer (CRC), the most lethal long-term complication of inflammatory bowel disease (IBD), is the culmination of a complex sequence of molecular and histologic derangements of the colon epithelium that are initiated and at least partially sustained by prolonged chronic inflammation. Dysplasia, the earliest histologic manifestation of this process, plays an important role in cancer prevention by providing the first clinical alert that this sequence is under way and by serving as an endpoint in colonoscopic surveillance of patients at high risk for CRC. Restorative proctocolectomy (RPC) is indicated for patients with IBD, specifically for ulcerative colitis that is refractory to medical treatment, emergency conditions, and/or in case of neoplastic transformation. Even after RPC with mucosectomy, pouch-related carcinomas have recently been reported with increasing frequency since the first report in 1984. We review IBD-associated CRC and pouch-related neoplasia prevalence, adverse events, risk factors, and surveillances.

METHODS

Literature of IBD-associated CRC patients and those undergoing RPC surgeries through 2010 were prospectively reviewed.

RESULTS

We found 12 studies from retrospective series and 15 case reports. To date, there are 43 reported cases of pouch-related cancers. Thirty-two patients had cancer in the anal transit zone (ATZ); of these, 28 patients had mucosectomy. Eleven patients had cancer found in the pouch body.

CONCLUSION

RPC with mucosectomy does not necessarily eliminate risks. There is little evidence to support routine surveillance of pouch mucosa and the ATZ except for patients associated with histological type C changes, sclerosing cholangitis, and unremitting pouchitis.

Colorectal dysplasia in chronic inflammatory bowel disease: pathology, clinical implications, and pathogenesis

CONTEXT

Colorectal cancer, the most lethal long-term complication of chronic inflammatory bowel disease (IBD), is the culmination of a complex sequence of molecular and histologic derangements of the intestinal epithelium that are initiated and at least partially sustained by chronic inflammation. Dysplasia, the earliest histologic manifestation of this process, plays an important role in cancer prevention by providing the first clinical alert that this sequence is underway and serving as an endpoint in colonoscopic surveillance of patients at high risk for colorectal cancer.

OBJECTIVE

To review the histology, nomenclature, clinical implications, and molecular pathogenesis of dysplasia in IBD.

DATA SOURCE

Literature review and illustrations from case material.

CONCLUSIONS

The diagnosis and grading of dysplasia in endoscopic surveillance biopsies play a decisive role in the management of patients with IBD. Although interpathologist variation, endoscopic sampling problems, and incomplete information regarding the natural history of dysplastic lesions are important limiting factors, indirect evidence that surveillance may be an effective means of reducing cancer-related mortality in the population with IBD has helped validate the histologic criteria, nomenclature, and clinical recommendations that are the basis of current practice among pathologists and clinicians. Emerging technologic advances in endoscopy may permit more effective surveillance, but ultimately the greatest promise for cancer prevention in IBD lies in expanding our thus far limited understanding of the molecular pathogenetic relationships between neoplasia and chronic inflammation.

Colorectal cancer surveillance in inflammatory bowel disease: The search continues

Patients with inflammatory bowel disease (IBD) are at increased risk for colorectal cancer (CRC). Risk factors for the development of CRC in the setting of IBD include disease duration, anatomic extent of disease, age at time of diagnosis, severity of inflammation, family history of colon cancer, and concomitant primary sclerosing cholangitis. The current surveillance strategy of surveillance colonoscopy with multiple random biopsies most likely reduces morbidity and mortality associated with IBD-related CRC. Unfortunately, surveillance colonoscopy also has severe limitations including high cost, sampling error at time of biopsy, and interobserver disagreement in histologically grading dysplasia. Furthermore, once dysplasia is detected there is disagreement about its management. Advances in endoscopic imaging techniques are already underway, and may potentially aid in dysplasia detection and improve overall surveillance outcomes. Management of dysplasia depends predominantly on the degree and focality of dysplasia, with the mainstay of management involving either proctocolectomy or continued colonoscopic surveillance. Lastly, continued research into additional chemopreventive agents may increase our arsenal in attempting to reduce the incidence of IBD-associated CRC.

Etiologic insights from surface adjustment of colorectal carcinoma incidences: an analysis of the U.S. SEER data 2000-2004

BACKGROUND AND AIMS

The subsite-specific comparison of the incidence of carcinoma within the colorectum is complicated because the mucosal surface, and therefore the amount of epithelial cells at risk, varies among the subsites. The aim of this study was to provide the subsite-specific estimates of the colon mucosal surface and the mucosal surface-adjusted carcinoma incidence estimates of colon subsites that allow a more valid comparison of the subsite-specific incidences.

METHODS

We extracted subsite-specific incidence rates of colorectal carcinoma from the Surveillance, Epidemiology, and End Results (SEER) Program of the years 2000-2004. The rates were age-standardized to the U.S. standard population in the year 2000. We estimated the mucosal surface of each segment of the colorectum and calculated the surface-adjusted incidence rates by dividing the observed age-standardized incidence rates by the estimated surface areas.

RESULTS

After adjustment for surface area, the incidence relations among the colorectal subsites changed. Within the colon, the surface-adjusted rates tend to be highest in the cecum, followed by the vermiform appendix, ascending colon, and sigmoid colon. The rates of the transverse and descending colon are considerably lower. The surfaced-adjusted incidence of rectal carcinoma is about 12- to 23-fold higher than the rate of carcinoma of the transverse colon.

CONCLUSIONS

The distribution of the incidence of carcinomas is markedly influenced by the adjustment of surface area of the colorectum. Similar surface-adjusted rates of the vermiform appendix and ascending colon may implicate that these subsites share a similar etiology. Considerable differences of the surface-adjusted rates of the sigmoid colon and rectum may indicate different etiologies of carcinomas of these subsites.

Epidemiology and management options for colorectal cancer in children

Colorectal carcinoma (CRC), although primarily a disease of adulthood, accounts for 2% of malignancies in adolescents and has been reported in children as young as 9 months of age. Our knowledge of CRC in pediatrics is based on a handful of case series and case reports. Apart from one small clinical trial, there has been a lack of prospective clinical studies in this age group. Based on these published reports, most CRC in children is sporadic, but it can also arise in the setting of predisposing conditions, such as gastrointestinal polyposis syndromes, nonpolyposis familial cancer syndromes, and inflammatory bowel disease. Despite some similarities to adult disease, CRC in childhood may be intrinsically different biologically, because it differs from adult-onset CRC in several respects. Childhood CRC tends to be diagnosed at an advanced stage, is largely of mucinous histology, and (probably because of these features) tends to have a poorer outcome. As a result of its rarity in children and the lack of prospective pediatric studies, recommendations for therapy are primarily extrapolated from adult clinical trials. A review of pediatric case series in the English literature emphasizes the prognostic significance of stage of disease, as well as extent of surgical resection. As in adults, early detection is critical in an effort to capture the disease at less advanced stages. Complete surgical resection with aggressive lymph node dissection is essential for cure, and neoadjuvant chemotherapy may be used in an effort to render unresectable lesions resectable. Active agents in adults with CRC include fluorouracil, folinic acid (leucovorin), oxaliplatin, and irinotecan. Furthermore, newer targeted therapeutic agents, such as bevacizumab and cetuximab, have added additional efficacy to the standard chemotherapy backbone. Collaborative multi-institutional pediatric clinical trials are needed to evaluate the prognosis, optimal treatment response, and the basic biology of childhood onset CRC.

Synchronous and metachronous adenocarcinomas of the large intestine

BACKGROUND AND AIM

The synchronous and consecutive (metachronous) development of two or more primary adenocarcinomas accounts for 3 to 5% of cases of colorectal cancer. Aim of this study is to review our experience in the management of patients with synchronous and metachronous lesions, and reach conclusions regarding their optimal diagnosis, treatment and follow-up.

PATIENTS AND METHODS

Between 1987 and 2004, 12 patients (seven men and five women, mean age 67.5 years, range 47-83 years) with synchronous (three patients) and metachronous (nine patients) lesions were treated, comprising 4.3% of all patients submitted to surgery for colorectal cancer. The diagnosis lag for metachronous lesions ranged from 1.5 to 14 years. All three patients with synchronous cancers had two lesions.

RESULTS

Staging colonoscopy and abdominal CT was conducted in 10 patients while the remaining two underwent only abdominal CT due to their critical condition at presentation. Surgery had curative intent in 10 patients and palliative in two. The mean postoperative hospital stay was 21 days (10-49 days). The postoperative mortality was zero. Patients survival after curative procedures was 80% for the first year, 60% for the third and 50% for the fifth year. After palliative surgery, survival was 50% for the first year, and zero for the third.

CONCLUSIONS

Patients with colorectal cancer must be followed up regularly after surgery. Follow up aims at early diagnosis and treatment of metachronous lesions that can appear many years after diagnosis of the primary lesion. Preoperative colonoscopy is an invaluable diagnostic (biopsy) and staging (exclusion of synchronous lesions, localization of the primary) modality, dictating the surgical approach. Additionally, it contributes to cancer prevention allowing the discovery and removal of small polyps before their transformation.

Role for epithelial dysregulation in early-onset colitis-associated colon cancer in Gi2-alpha-/- mice

BACKGROUND

Inflammatory bowel disease (IBD) is a risk factor for developing colorectal cancer but the mechanisms are poorly characterized. Mice lacking the G-protein alpha subunit Gi2-alpha spontaneously develop colitis and colon cancer with high penetrance. Compared to canonical Wnt/APC signaling-based animal models of colon cancer, the tumors in Gi2-alpha-/- mice more closely recapitulate the features of IBD-associated cancers seen in humans. They are predominantly right-sided, multifocal, mucinous, and arise from areas of flat dysplasia.

METHODS

In evaluating the potential contribution of epithelial Gi2-alpha signaling to this phenotype, we found that Gi2-alpha-/- colonic epithelium is hyperproliferative even before the onset of colitis, and resistant to the induction of apoptosis. We generated colon cancer cell lines overexpressing dominant-negative Gi2-alpha.

RESULTS

Like other cells lacking Gi2-alpha, these cells release less arachidonic acid, an important antiinflammatory and epithelial growth regulator. They are also hyperproliferative and resistant to camptothecin-induced apoptosis and caspase-3 activation.

CONCLUSIONS

The colitis-associated cancers in Gi2-alpha-/- mice appear very similar to those seen in human IBD patients, and Gi2-alpha is a direct negative regulator of colonic epithelial cell growth.

Surveillance of patients at increased risk of colon cancer: inflammatory bowel disease and other conditions

Colorectal cancer (CRC) is the second most common cause of cancer-related mortality in the United States. Colonoscopic screening with removal of adenomatous polyps in individuals at average risk is known to decrease the incidence and associated mortality from colon cancer. Certain conditions, notably inflammatory bowel disease involving the colon, a family history of polyps or cancer, a personal history of colon cancer or polyps, and other conditions such as acromegaly, ureterosigmoidostomy, and Streptococcus bovis bacteremia are associated with an increased risk of colonic neoplasia. This article reviews the CRC risks associated with these conditions and the currently recommended surveillance strategies.

Inflammatory bowel diseases in the elderly

Inflammatory bowel disease (IBD) in elderly individuals is associated with a unique set of challenges, some of which are related to age. This article examines the diagnosis and management of IBD in the context of recent advances in the understanding of its pathogenesis, and newer therapeutic modalities that have been possible from these advances.

Neoplastic precursor lesions related to the development of cancer in inflammatory bowel disease

Dysplasia is an intermediate stage in the progression from inflammation to cancer in patients with inflammatory bowel disease. Clinically, dysplasia is used to define appropriate endpoints for colectomy in high-risk patients undergoing endoscopic surveillance. Surveillance is currently the only credible alternative to prophylactic colectomy for high-risk patients. The success of surveillance can be maximized by adherence of gastroenterologists to recommended procedural guidelines, adherence of pathologists to standardized histological criteria and nomenclature, and a joint commitment to close clinical-pathological communication. Technical enhancements to conventional endoscopy hold promise of improved efficiency and accuracy. Molecular-based testing may have a future role for risk stratification and early detection of neoplasia in inflammatory bowel disease.

Colorectal cancer in a population with endemic Schistosoma mansoni: is this an at-risk population?

PURPOSE

Chronic infection with schistosomiasis has been clearly associated with the development of bladder cancer, and infestation is associated with a high incidence of colorectal cancer in endemic populations. Despite this association, the potential role of alterations in tumor suppressor genes colorectal cancers has never been evaluated in an endemically infected population. The aim of this paper was to compare histopathologic and genetic changes in schistosomal colitis-associated colorectal cancer (SCC) with colorectal cancer in a group of patients from the same population not affected by the disease (NDCC).

MATERIALS AND METHODS

Sixty patients were included in this study: SCC-40, NDCC-20. Data collected included age, sex, clinical presentation, presence of synchronous tumors, histopathology, and clinical stage. p53, DCC (deleted in colorectal cancer gene), and mismatch repair genes (MLH1 and MSH2) were studied using immunohistochemical staining.

RESULTS

Patients with SCC were significantly younger than the NDCC group (34.52+/-11.22 years vs 50.73+/-12.75 years, p=0.02). Mucinous adenocarcinoma occurred significantly more frequently in SCC (35 vs 10%, p=0.02). SCC tumors were more frequently stage III or IV, and significantly more synchronous tumors were present in the affected group (SCC-8/40 vs NDCC-1/20, p=0.05). p53 staining was far more frequent in SCC (SCC-32/40 vs NDCC-8/20, p=0.006). DCC expression was similar in two groups. There were only four cases, three in SCC and one in NDCC, that showed microsatellite instability.

CONCLUSION

The data suggest that schistosomal colitis is more commonly associated with earlier onset of multicentric colorectal cancer, high percentage of mucinous adenocarcinoma, and presents at an advanced stage. The identification of a higher incidence of altered p53 expression in the SCC group raises the possibility of an association between schistosomiasis and alterations in p53 activation as an inciting event in colorectal cancer development.

Pathology of dysplasia and cancer in inflammatory bowel disease

Morphologic identification of dysplasia in mucosal biopsies is the best and most reliable marker of an increased risk for malignancy in patients who have inflammatory bowel disease, and it forms the basis of the recommended endoscopic surveillance strategies that are in practice for patients who have this illness. In ulcerative colitis (UC) and Crohn's disease (CD), dysplasia is defined as unequivocal neoplastic epithelium that is confined to the basement membrane, without invasion into the lamina propria. Unfortunately, unlike in UC, only a few studies have evaluated the pathologic features and biologic characteristics of dysplasia and carcinoma in CD specifically. As a result, this article focuses mainly on the pathologic features, adjunctive diagnostic methods, and differential diagnosis of dysplasia in UC.

Ulcerative colitis practice guidelines in adults (update): American College of Gastroenterology, Practice Parameters Committee

Guidelines for clinical practice are intended to indicate preferred approaches to medical problems as established by scientifically valid research. Double-blind placebo-controlled studies are preferable, but compassionate use reports and expert review articles are utilized in a thorough review of the literature conducted through Medline with the National Library of Medicine. When only data that will not withstand objective scrutiny are available, a recommendation is identified as a consensus of experts. Guidelines are applicable to all physicians who address the subject without regard to the specialty training or interests and are intended to indicate the preferable but not necessarily the only acceptable approach to a specific problem. Guidelines are intended to be flexible and must be distinguished from standards of care, which are inflexible and rarely violated. Given the wide range of specifics in any health-care problem, the physician must always choose the course best suited to the individual patient and the variables in existence at the moment of decision. Guidelines are developed under the auspices of the American College of Gastroenterology and its Practice Parameters Committee and approved by the Board of Trustees. Each has been extensively reviewed and revised by the Committee, other experts in the field, physicians who will use them, and specialists in the science of decision of analysis. The recommendations of each guideline are therefore considered valid at the time of their production based on the data available. New developments in medical research and practice pertinent to each guideline will be reviewed at a time established and indicated at the publication in order to assure continued validity.

Development of colonic neoplasia in p53 deficient mice with experimental colitis induced by dextran sulphate sodium

BACKGROUND

Several animal models for human ulcerative colitis (UC) associated neoplasia have been reported. However, most neoplasias developed in these models have morphological and genetic characteristics different from UC associated neoplasia.

AIMS

To establish a new colitis associated neoplasia model in p53 deficient mice by treatment with dextran sulphate sodium (DSS).

METHODS

DSS colitis was induced in homozygous p53 deficient mice (p53(-/-)-DSS), heterozygous p53 deficient mice (p53(+/-)-DSS) and wild-type mice (p53+/+-DSS) by treatment with 4% DSS. Numbers of developed neoplasias were compared among the experimental groups, and macroscopic and microscopic features of the neoplasias were analysed. Furthermore, K-ras mutation and beta-catenin expression were assessed.

RESULTS

p53(-/-)-DSS mice showed 100% incidence of neoplasias whereas the incidences in p53(+/-)-DSS and p53+/+-DSS mice were 46.2% and 13.3%, respectively. No neoplasias were observed in the control groups. The mean numbers of total neoplasias per mouse were 5.0 (p53(-/-)-DSS), 0.62 (p53(+/-)-DSS), and 0.2 (p53+/+-DSS). The number of neoplasias per mouse in the p53(-/-)-DSS group was significantly higher than that in the other DSS groups. The incidences of superficial type neoplasias were 91.7% in p53(-/-)-DSS mice, 75.0% in p53(+/-)-DSS mice, and 33.3% in p53+/+-DSS mice. The K-ras mutation was not detected in any of the neoplasias tested. Translocation of beta-catenin from the cell membrane to the cytoplasm or nucleus was observed in 19 of 23 (82.6%) neoplasias.

CONCLUSIONS

The p53(-/-)-DSS mice is an excellent animal model of UC associated neoplasia because the morphological features and molecular genetics are similar to those of UC associated neoplasia. Therefore, this model will contribute to the analysis of tumorigenesis related to human UC associated neoplasia and the development of chemopreventive agents.

The role of hMLH1 methylation in the development of synchronous sporadic colorectal carcinomas

PURPOSE

AB. B. subset of sporadic colorectal carcinomas show microsatellite instability, usually as a result of biallelic hMLH1 gene promoter methylation. Synchronous tumors occur in up to 5 percent of patients with colorectal cancer, but their cause is poorly understood. We hypothesized that in the setting of sporadic microsatellite instability cancers, synchronicity may reflect a global predisposition of colorectal epithelium toward tumor development because of gene hypermethylation.

METHODS

We identified 14 individuals with 33 synchronous cancers from a series of 362 patients with 381 sporadic colorectal cancers. We then analyzed the synchronous lesions for microsatellite status, hMLH1 protein expression, and hMLH1 promoter methylation.

RESULTS

Seven of 33 synchronous tumors (21 percent) showed microsatellite instability, compared with 36 of 348 solitary tumors (10.3 percent, P = 0.06). The 14 patients with synchronous tumors were significantly older than those with solitary tumors (mean age 79.4 vs. 68.2 years, P = 0.01), and 5 of these patients had at least one microsatellite instability tumor. However, only one patient harbored synchronous tumors that were all of the microsatellite instability type. Methylation of the hMLH1 promoter was seen in 9 synchronous cancers from 27 assessable lesions in 7 patients and was associated with microsatellite instability (P = 0.01), right-sidedness (P = 0.01), and loss of expression of hMLH1 (P = 0.03). Only one case showed methylation in all synchronous tumors, whereas in five cases synchronous tumors showed different methylation status within the one individual.

CONCLUSION

Our data suggest that synchronous tumors arise as independent events and that the slightly greater frequency of synchronous tumors in individuals with microsatellite instability cancers is likely to be a chance event reflecting the older age of these individuals rather than arising from a predisposition toward cancer as a result of global hypermethylation of colorectal epithelium.

Synchronous and "early" metachronous colorectal adenocarcinoma: analysis of prognosis and current trends

PURPOSE

We evaluated the accuracy of preoperative diagnostic examinations and determined whether patients with synchronous colorectal cancers differ from patients with a single colorectal malignancy in clinicopathologic factors, the possibility of early metachronous colorectal cancer, and postoperative outcome.

METHODS

A retrospective evaluation of 1,780 patients with primary colorectal adenocarcinoma from 1987 to 1993 was performed. We divided patients into three groups: Group 1, single colorectal adenocarcinoma; Group 2, synchronous colorectal adenocarcinoma; and Group 3, early metachronous colorectal adenocarcinoma.

RESULTS

There were 52 cases (3 percent) in Group 2 and 13 cases (1 percent) in Group 3 (<3 years from the index colorectal cancer operation). Differences in age, gender, and cancer-free rate among the three groups did not reached statistical significance. Compared with cancers in Group 1, significantly more proximal tumor locations and early cancer stage were noted for the second and third cancers in Group 2. In Group 3 a significantly more proximal tumor site was noted for the index colorectal cancer but cancer stage showed no significant difference from cancers in Group 1. Better histologic type was also noted in the index and second cancers in Group 2 than in cancers in Group 1. There was a higher incidence of associated benign adenoma in Group 2 (35 vs. 15 percent in Group 1). The positivity rate of Group 2 was significantly higher by preoperative colonoscopy (71 percent) and incidental findings at surgery (58 percent) than barium enema examination (30 percent).

CONCLUSION

Preoperative barium enema examination was an unsatisfactory tool for detecting synchronous tumors. Preoperative colonoscopy demonstrated a higher positivity rate, but it still failed to detect nearly 30 percent of cases with synchronous tumors. Intraoperative palpation of the whole colorectum could detect nearly 60 percent of unexpected synchronous tumors. We believe both colonoscopy and intraoperative palpation of the whole colorectum are crucial to the early detection of synchronous colorectal cancer.

Discordance of p53 mutations of synchronous colorectal carcinomas

It is unclear whether synchronous multiple tumors arise from multicentric or monoclonal origins. To verify the multicentric origin of synchronous colorectal carcinomas at a genetic level, immunohistochemical and molecular techniques were used to determine the p53 alterations in individual lesions of synchronous colorectal carcinomas. This study was based on a total of 32 colorectal tumors from 16 patients. Twenty-one of the 32 (66%) advanced tumors examined had positive staining for p53. Single-strand conformation polymorphism and polymerase chain reaction direct sequencing were carried out for exons 5 to 8 of p53. All cases had p53 mutations in one or more tumors of synchronous lesions. In nine patients in this series, individual lesions were found to carry a different mutated codon of the p53 gene. In the other seven patients, a p53 mutation was found in one tumor but not in another. These results indicate discordance of the mutation pattern of p53 in individual lesions of multiple colorectal carcinomas and support the idea that most synchronous colorectal carcinomas are genetically distinguishable and are multicentric in origin. We also confirmed the high frequency of p53 mutations in left-sided (71%) and rectal (91%) carcinomas, rather than right-sided (43%; P = .04) carcinomas, suggesting that the molecular mechanism of synchronous colorectal carcinomas might differ between right- and left-sided tumors in the same patient.

Colorectal adenocarcinoma in Crohn's disease

OBJECTIVE

The authors' aim was to review the clinical features and estimate the long-term survival of patients with colorectal carcinoma complicating Crohn's disease.

SUMMARY BACKGROUND DATA

Recent studies have demonstrated a significantly increased risk of colorectal carcinoma in patients with Crohns disease.

METHODS

The authors reviewed retrospectively the medical records of 30 patients with Crohn's disease admitted to The Mount Sinai Hospital between 1960 and 1989 in whom colorectal adenocarcinoma developed. All patients were operated on and follow-up was complete for all patients to 10 years after operation, to the time of death, or to the closing date of the study in December 1989.

RESULTS

The 30 patients in the series had 33 colorectal adenocarcinomas; three patients (10%) presented with two synchronous cancers. The patients were relatively young (mean age, 53 years) and had long-standing Crohn's disease (duration >20 years in 87%). The 5-year actuarial survival was 44% for the overall series: 100% for stage A, 86% for stage B, 60% for stage C. All five patients with excluded bowel tumor died of large bowel cancer within 2.4 years; by contrast, the actuarial 5-year survival for patients with in-continuity tumors was 56%.

CONCLUSIONS

The incidence, characteristics, and prognosis of colorectal carcinoma complicating Crohn's disease are similar to the features of cancer in ulcerative colitis, including young age, multiple neoplasms, long duration of disease, and greater than a 50% 5-year survival rate (without excluded loops). These observations suggest the advisability of surveillance programs for Crohn's disease of the colon similar to those for ulcerative colitis of comparable duration and extent.

Premalignant changes in ulcerative colitis

Colitis-associated carcinoma is often associated with, or preceded by, noninvasive epithelial neoplastic changes termed dysplasia. Surveillance colonoscopy with biopsies looking for dysplasia is now standard practice in the management of the cancer problem in ulcerative colitis. However, this practice continues to have a number of limitations and problems that need to be understood by surgeons who may be referring such patients. A number of recent reports indicate that colitis associated carcinoma is predominantly left-sided and incorporation of this distribution in the surveillance methods merits consideration. The molecular and genetic abnormalities involved in the pathogenesis of colitis associated neoplasia are being actively investigated and may yield supplementary methods to better define individual patient risk.