Colitis-associated Carcinoma Research Articles

Ulcerative colitis-associated colorectal carcinoma. DNA ploidy as indicator of impending malignant transformation?

The onset of a malignant transformation in long-standing ulcerative colitis is difficult to predict. The value of the clinical and histomorphological parameters in current use is limited. It was thus aim of the present study to investigate the value of DNA-ploidy for the early detection of a malignant transformation in long-standing ulcerative colitis. This retrospective study comprised 20 patients with long-standing ulcerative colitis. The average observation time was 7.3 years (range: four to twelve years). All patients took part in a surveillance program and had between four and seven colonoscopies within a minimum period of time of five years. At these instances mucosal biopsies were taken in a standardized manner at eight different locations throughout the colon. These paraffin-embedded specimens (n = 542) were analyzed histomorphologically and DNA-cytometrically. During the observation time five patients developed an ulcerative colitis-associated colorectal carcinoma (UCA). In these patients epithelial dysplasias were not more common than in the remaining 15 cases. The vast majority of the specimen of the patients with UCA showed distinct DNA-cytometrical alterations, i.e. they were aneuploid. Such aneuploid mucosal cell populations were distributed over the whole colon, irrespectively of the later site of the carcinoma. These aneuploid lesions were found in one case eleven years, in an average seven years prior to the final diagnosis of a UCA. In contrast, the colon epithelium of the patients without UCA showed only proliferative-diploid DNA-distribution patterns during the observation time. In summary, affected patients had multiple highly aneuploid lesions of the colon mucosa at an average of seven years prior to the final diagnosis of UCA. These lesions came from macroscopically chronic inflamed tissue, and where histomorphologically without signs of dysplastic transformation. DNA-cytometrical investigations could thus be of additional predictive value for the individual risk assessment as regards an impending malignant transformation.

Decreased expression of CD44, alpha-catenin, and deleted colon carcinoma and altered expression of beta-catenin in ulcerative colitis-associated dysplasia and carcinoma, as compared with sporadic colon neoplasms

To clarify the cell adhesion status in ulcerative colitis (UC)-associated colon neoplasm, expression of cell adhesion molecules were investigated and compared with that of sporadic colon neoplasm.A total of 14 low grade dysplasias, 16 high grade dysplasias, and 8 adenocarcinomas associated with UC and 17 sporadic adenomas with mild to moderate dysplasia, 22 adenomas with severe dysplasia, and 15 invasive adenocarcinomas were immunohistochemically examined using monoclonal antibodies against CD44, E-cadherin, alpha- and beta-catenin, and deleted colon carcinoma (DCC).CD44, especially its standard form, and DCC expression was stronger in the sporadic colon neoplasms than in the UC-associated lesions. Although E-cadherin did not show significant differences between the two cases, alpha-catenin was more expressed in sporadic colon adenomas with severe dysplasia and carcinomas than in their UC-associated counterparts. Membranous beta-catenin staining was stronger in UC-associated neoplasms, whereas sporadic lesions had greater cytoplasmic and nuclear expression.The differences in cell adhesion molecule expression suggests that UC-associated and sporadic colon neoplasms arise from different pathways of tumorigenesis.

Decreased expression of CD44, alpha-catenin, and deleted colon carcinoma and altered expression of beta-catenin in ulcerative colitis-associated dysplasia and carcinoma, as compared with sporadic colon neoplasms.

To clarify the cell adhesion status in ulcerative colitis (UC)-associated colon neoplasm, expression of cell adhesion molecules were investigated and compared with that of sporadic colon neoplasm. A total of 14 low grade dysplasias, 16 high grade dysplasias, and 8 adenocarcinomas associated with UC and 17 sporadic adenomas with mild to moderate dysplasia, 22 adenomas with severe dysplasia, and 15 invasive adenocarcinomas were immunohistochemically examined using monoclonal antibodies against CD44, E-cadherin, alpha- and beta-catenin, and deleted colon carcinoma (DCC). CD44, especially its standard form, and DCC expression was stronger in the sporadic colon neoplasms than in the UC-associated lesions. Although E-cadherin did not show significant differences between the two cases, alpha-catenin was more expressed in sporadic colon adenomas with severe dysplasia and carcinomas than in their UC-associated counterparts. Membranous beta-catenin staining was stronger in UC-associated neoplasms, whereas sporadic lesions had greater cytoplasmic and nuclear expression. The differences in cell adhesion molecule expression suggests that UC-associated and sporadic colon neoplasms arise from different pathways of tumorigenesis.

Is dysplasie surveillance effective in the prevention of ulcerative colitis-associated colorectal carcinoma?

Is dysplasie surveillance effective in the prevention of ulcerative colitis-associated colorectal carcinoma?

Metallothionein—An early marker in the carcinogenesis of ulcerative colitis-associated colorectal carcinoma

A variety of imaging modalities have been developed to determine the characteristics of tumors in the colon. Endoscopic ultrasonography has been applied clinically to stage the depth of invasion of colon cancers and more recently, optical coherence tomography has been developed in the laboratory to increase imaging of the mucosal surface. We have initiated the first application of ultrasound modulated laser tomography to colonic tumors. This technique has the advantage of combining ultrasound and light to characterize tissue. Methods: The principle behind this technique is to use ultrasound waves to modulate laser light passing through a tissue. The modulated laser light can then be detected and amplified to generate a signal that is characteristic of that tissue. The system we used consists of a helium-neon laser to generate a 632-nm beam, which is focused on the tissue. A function generator is used to create a sinusoidal wave at I MHz, which is amplified to drive an ultrasound transducer placed perpendicular to the tissue. The signal is detected by a photodiode, which converts the modulated light to a current, which can be filtered using the current from the function generator. The time domain signal can then be processed and displayed. Results: The following graphs display the signal taken from 8 resected normal colon tissue and colon cancers. The X-axis represent wavelength while the Y-axis represents absorption in AU. The graph on the right represents colon cancer while the graph on the left represents the modulated signal from normal colon. The most prominant difference was noted between two samples at wave length of 350 nm. Conclusions: The signal received from ultrasound modulated optical tomography appears to differentiate between colonic cancer and normal tissue. This tool may be 6283

P53 immunohistochemistry of ulcerative colitis-associated with dysplasia and carcinoma.

In order to evaluate the usefulness of p53 immunohistochemistry (IHC) in the diagnosis of ulcerative colitis-associated colorectal carcinoma (UCACRC), ordinary paraffin sections were examined in 61 cases with ulcerative colitis (UC) and 29 control cases without UC. Among the 61 cases with UC, 11 were complicated by carcinoma coexisting with dysplasia, three with dysplasia, and two cases with adenoma. There were a total of 38 dysplasias, including 33 low grade dysplasias (LGD) and five mixed low and high grade dysplasias (LGD + HGD). The results of p53 IHC were divided into diffuse, nested, scattered and sporadic patterns for 29 control cases. Diffuse and nested patterns were presumed to reflect mutant forms of p53 protein and were defined as overexpression of p53 protein. In non-neoplastic mucosa of UC, the frequency of p53 positive tubules was significantly higher in active phase (13.5-17.9%) than in resolving phase (3.9-6.5%) and in remission (0.7-2.4%), regardless of association with neoplasia. Eight of the 37 lesions of dysplasia (21. 6%) showed p53 overexpression: 12.5% in LGD and 80.0% in LGD + HGD. The rate of p53 overexpression was significantly higher in UCACRC (90.9%) than in non-neoplastic mucosa of UC (0%), LGD and sporadic colorectal carcinoma (54.5%), but it did not differ between UCACRC and LGD + HGD. Interestingly, the mucosa without dysplasia showed p53 overexpression in one case of UCACRC. The biopsy specimen taken 4 years before the diagnosis of carcinoma revealed p53 overexpression in another case with UCACRC. These results suggest that p53 abnormalities play an important role in UC-associated tumorigenesis in its relatively early phase. For the diagnosis of dysplasia and carcinoma in UC, p53 IHC seems to be useful.

Comparison of genetic alterations in colonic adenoma and ulcerative colitis-associated dysplasia and carcinoma

Carcinoma is an important complication of ulcerative colitis (UC) and develops from dysplastic precursor lesions. Genetic changes involved in the malignant transformation have not been fully characterized. We studied 19 cases of UC with high-grade dysplasia (HGD) and eight samples of associated carcinoma (CA). Microdissection of normal epithelium, epithelium at the site of chronic inflammation, HGD, and CA was performed. Polymerase chain reaction (PCR) amplification for loss of heterozygosity (LOH) of the following polymorphic microsatellites of putative tumor suppressor gene loci was done: APC (5q), DCC (l8q), p16 (9p), p53 (17p), and 8p12. To compare genetic alterations, 22 typical adenomas of the colon were studied with the markers for APC and p16 gene loci. p ]The results indicated that LOH of p16 and p53 were present in nondysplastic epithelium, HGD, and CA. However, the LOH in nondysplastic epithelium was detected in some associated HGD, but not all. Whereas LOH of p16 was present in 7 of 14 cases of HGD (50%), it was noted in only 1 of 22 adenomas (5.0%). LOH in the APC and DCC gene loci in UC was noted in HGD with associated CA, but LOH of APC was not present either in cases of nondysplastic epithelium or in HGD alone. Conversely, LOH in APC was present in 4 of 19 colonic adenomas. We conclude that LOH of p53 and p16 in nondysplastic epithelium may be associated with chronic reparative processes. These changes may lead to susceptibility to further genetic damage involving the APC and DCC gene loci in the development of dysplasia and progression of CA in UC. The low frequency of LOH in the p16 gene (9p) in adenomas compared with dysplasia in UC combined with infrequent LOH in APC gene loci in cases of pure dysplasia in UC may support this combination of markers as a clinical test for the differentiation of polypoid dysplasia from adenomas in UC.

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.

P53 protein expression in ulcerative colitis-associated colorectal dysplasia and carcinoma

The frequency and timing of p53 inactivation in ulcerative colitis (UC)-associated tumorigenesis were investigated using immunohistochemistry (IHC) to detect p53 protein overexpression in 56 carcinomas and 40 dysplastic epithelia derived from 58 patients with UC undergoing colectomy for neoplasia. p53 DNA in 25 of the carcinomas also was evaluated by single-strand conformation polymorphism analysis (SSCP) to detect point mutations in exons 5–8 and by loss of heterozygosity analysis to detect allelic deletions. Point mutations were detected in 20 of the 25 carcinomas (80.0%) undergoing both IHC and DNA analysis. One carcinoma contained an allelic deletion but no mutations of the corresponding allele within the region tested. p53 overexpression occurred in 16 (76.2%) of the 21 carcinomas with point mutations and/or allelic deletions but not in any of those with wild type DNA. Of the 56 carcinomas evaluated by IHC, p53 overexpression occurred in 34 carcinomas (60.7%). The proportion of positive tumors was independent of stage, anatomic location, differentiation, and histological subtype. Overexpression was observed in nine of 20 dysplastic masses devoid of and situated remote from carcinoma (45.0%) and correlated positively with increasing grade of dysplasia ( P < .025). In contrast, overexpression occurred in 16 of 20 dysplastic epithelia situated adjacent to carcinoma (80.0%) and correlated with overexpression by the corresponding carcinomas but not with the grade of dysplasia present ( P = .013). It is concluded that p53 overexpression can be detected by IHC in most, although not all, UC-associated carcinomas with p53 mutations and/or allelic deletions. Based on this method, p53 overexpression occurs frequently in UC-associated carcinomas regardless of stage and pathological characteristics, in noncancerous dysplastic masses with high grade dysplasia, and in dysplasias of all grades situated adjacent to carcinomas. These findings implicate p53 inactivation in the progression from dysplasia to carcinoma in UC and suggest that its occurrence in dysplastic epithelium may be an independent marker of malignant potential.

P53 Point mutations in dysplastic and cancerous ulcerative colitis lesions

Background: The molecular basis of colorectal dysplasia and carcinoma arising in ulcerative colitis is poorly understood. Loss of heterozygosity involving the tumor suppressor gene p53 occurs frequently in neoplastic ulcerative colitis lesions. Point mutation affecting p53 is associated with loss of heterozygosity in other cancers. Therefore, it was determined whether p53 point mutation occurs in ulcerative colitis-associated neoplasia. Methods: Single-strand conformation polymorphism analysis, DNA sequencing, and loss of heterozygosity studies were performed on 45 patients with ulcerative colitis-associated dysplasia and carcinoma. Results: Point mutations were detected in 26 lesions from 20 patients, including 18 carcinomas, 6 dysplasia-associated masses, 1 flat dysplasia, and 1 lymph node metastasis. In two cases, identical p53 mutations were observed in both carcinoma and adjacent dysplasia. Missense mutations causing amino acid substitutions as well as nonsense mutations resulting in premature stop codons were seen. Tandem mutations, in which more than 1 sequence alteration occurred on the same allele of p53, were also detected. Point mutation was accompanied by loss of the other p53 allele in 8 of 10 patients informative for both loss of heterozygosity and mutation assays. Conclusions: These findings suggest that inactivation of p53 by mutation and loss of heterozygosity is a common mechanism of malignant transformation in ulcerative colitis. They also imply that in contrast to sporadic colorectal carcinoma, ulcerative colitis-associated neoplastic progression may involve p53 inactivation at relatively earlynoninvasive stages.

Lymphoma in inflammatory bowel disease

Nine patients with lymphoma occurring in association with inflammatory bowel disease were admitted to The Mount Sinai Hospital between 1960 and 1983. Five (two men and three women) occurred among 1156 patients (0.43%) with ulcerative colitis (UC) and four (men), among 1480 patients (0.27%) with Crohn's disease (CD), a strong male preponderance in the latter group. In all four of the patients with CD and in four of the five patients with UC, the lymphomas were extraintestinal. The mean age of onset of UC in these patients was late (46 years, 19 years older than in our overall series), with lymphomas occurring a mean of only 12 years later. By contrast, patients with CD had bowel disease much younger (mean age, 26 years), and their lymphomas appeared after a longer disease duration (mean, 24 years). The risk factors for the one patient with colonic lymphoma were similar to those with colitis-associated colorectal carcinoma: extensive and long-standing colitis and relatively young age when malignant disease developed. Four of the patients with lymphoma had associated colonic carcinoma; in three of them, the carcinoma appeared within the first decade of colitis, an unusual occurrence. A second malignant lesion also occurred in three patients with UC.