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Rubio CA, Slezak P. The unique pathology of nonpolypoid colorectal neoplasia in IBD. Gastrointest Endosc Clin N Am 2014; 24:455-68. [PMID: 24975536 DOI: 10.1016/j.giec.2014.03.009] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Patients with inflammatory bowel disease may develop dysplasia in the cryptal epithelium, polypoid neoplasias, and nonpolypoid (flat) adenomas, lesions at risk to proceed to colorectal carcinoma. The onset of invasion in nonpolypoid adenomas may occur without changes in the shape or the size of the lesion. In experimental animals, some colonotropic carcinogens induce polypoid and nonpolypoid neoplasias and others induce polypoid neoplasias exclusively. Some of the biologic attributes of nonpolypoid adenomas in humans can be demonstrated in laboratory animals.
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Affiliation(s)
- Carlos A Rubio
- Gastrointestinal and Liver Pathology Research Laboratory, Department of Pathology, Karolinska Institute and University Hospital, Stockholm 17176, Sweden.
| | - Premysl Slezak
- Department of Gastrointestinal Endoscopy, Karolinska University Hospital, Stockholm 17176, Sweden
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Abstract
Colorectal cancer is a heterogeneous disease arising through multiple possible pathways. Elucidating the genetic factors controlling molecular phenotype, morphology, histology, and prognosis of different tumor types continues to be a challenge. Non-polypoid colorectal neoplasms provide opportunities for ongoing study of their underlying genetic abnormalities and molecular phenotypes. The varied data from different groups, however, highlight the need for further studies in different populations.
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Kudo SE, Lambert R, Allen JI, Fujii H, Fujii T, Kashida H, Matsuda T, Mori M, Saito H, Shimoda T, Tanaka S, Watanabe H, Sung JJ, Feld AD, Inadomi JM, O'Brien MJ, Lieberman DA, Ransohoff DF, Soetikno RM, Triadafilopoulos G, Zauber A, Teixeira CR, Rey JF, Jaramillo E, Rubio CA, Van Gossum A, Jung M, Vieth M, Jass JR, Hurlstone PD. Nonpolypoid neoplastic lesions of the colorectal mucosa. Gastrointest Endosc 2008; 68:S3-47. [PMID: 18805238 DOI: 10.1016/j.gie.2008.07.052] [Citation(s) in RCA: 338] [Impact Index Per Article: 21.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/30/2008] [Accepted: 07/30/2008] [Indexed: 02/08/2023]
Affiliation(s)
- Shin ei Kudo
- Digestive Disease Center, Northern Yokohama Hospital, Showa University, Yokohama, Japan
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Orita H, Sakamoto N, Ajioka Y, Terai T, Hino O, Sato N, Shimoda T, Kamano T, Tsurumaru M, Fujii H. Allelic loss analysis of early-stage flat-type colorectal tumors. Ann Oncol 2006; 17:43-9. [PMID: 16249214 DOI: 10.1093/annonc/mdj017] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
BACKGROUND Flat-type colorectal tumors are rare, but are known for their unusual flat morphology and aggressive clinical behavior despite their small size. To identify distinct genetic alterations, loss of heterozygosity (LOH) analysis was performed on microdissected tissues. MATERIALS AND METHODS DNA was extracted from multiple microdissected foci in 43 cases of early-stage flat-type colorectal tumors and LOH analysis was performed on 2q, 4q, 5q, 12q, 14q, 15q, 17p, 18q, 18p and 22q. RESULTS LOH patterns were detected in one of two forms: (i) homogeneous LOH throughout the microdissected foci, which indicated the early acquisition of LOH; and (ii) heterogeneous LOH, which were detected in a part of analyzed foci. Homogeneous and heterogeneous LOH were most frequently detected on 17p (92%) followed by 18q (81%), 18p (81%), 5q (61%), 22q (51%), 14q (44%), 15q (41%), 2q (39%), 12q (36%) and 4q (32%). Homogeneous LOH was detected most frequently on 17p (68%) followed by 18p (53%), 18q (53%), 22q (34%) and 12q (27%). The average fractional allelic loss (FAL) for heterogeneous and homogeneous LOH was 0.57 and the average FAL for homogeneous LOH was 0.37. CONCLUSIONS Early flat-type colorectal tumors frequently shows the early occurrence of multiple LOH including 17p, 18p, 18q and 22q, which is coupled with additional LOH of other loci either simultaneously or in the early clonal progression phase. The extent and sequences of LOH may be the mechanisms responsible for the aggressive clinical behaviors of these tumors.
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Affiliation(s)
- H Orita
- Department of Surgery, Juntendo University, Tokyo, Japan
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Kinney TP, Merel N, Hart J, Joseph L, Waxman I. Microsatellite analysis of sporadic flat and depressed lesions of the colon. Dig Dis Sci 2005; 50:327-30. [PMID: 15745095 DOI: 10.1007/s10620-005-1605-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/09/2022]
Abstract
Prior studies of molecular and genetic derangements in flat and depressed lesions of the colon have revealed lower frequencies in a number of markers commonly present in exophytic lesions. These and other differences suggest that flat lesions are driven by alternative pathways. We reviewed a database of patients who had undergone endoscopic mucosal resection (EMR) for flat and depressed lesions at the University of Chicago from January 2001 to April 2003. Formalin-fixed and paraffin-embedded colonic samples were retrieved from the tissue bank, and five standardized mononucleotide and dinucleotide microsatellite regions were analyzed for instability (MSI) using fluorescently labeled forward primers in nonmultiplex reactions. Sixteen patients were identified with flat or depressed lesions who had adequate tissue specimens available for MSI analysis. Of these specimens, eight were tubular adenomas, three were tubulovillous adenomas, and five were carcinomas in situ. Four of the lesions were microsatellite unstable, each at a single locus, and one lesion showed probable instability at a second locus. Eleven lesions were microsatellite stable. Aberrations in DNA repair mechanisms do not appear to significantly contribute to the molecular derangements underlying sporadic flat or depressed colonic lesions. The molecular bases that underlie the aggressive behavior of sporadic flat and depressed lesions remain to be determined, and further investigation is warranted.
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Affiliation(s)
- Timothy P Kinney
- Department of Medicine, Section of Endoscopy and Therapeutics, University of Chicago, Chicago, Illinois 60637-1463, USA
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Sakamoto N, Terai T, Ajioka Y, Abe S, Kobayasi O, Hirai S, Hino O, Watanabe H, Sato N, Shimoda T, Fujii H. Frequent hypermethylation of RASSF1A in early flat-type colorectal tumors. Oncogene 2004; 23:8900-7. [PMID: 15480433 DOI: 10.1038/sj.onc.1207993] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Flat colorectal tumors, characterized by high-grade dysplasia from early small flat mucosal lesions, exhibit a relatively aggressive clinical behavior and are known for their infrequent K-ras mutations. In this study, we investigated the methylation status of the RASSF1A promoter in association with 3p LOH and K-ras mutations in 48 flat colorectal tumors (39 early carcinomas and nine intramucosal high-grade dysplasias). RASSF1A hypermethylation was detected in 39 of 48 (81.3%) tumors and RASSF1A methylation was also detected in 19 of 39 (49%) normal colonic mucosal tissues. 3p21.3 LOH was detected in 20 of 42 (47.6%) cases, but RASSF1 methylation was detected in cases with LOH (14 cases) and retention of 3p21.3 (20 cases). K-ras mutations were detected in seven of 48 (14.6%) tumors and the concordant occurrence of K-ras mutation and RASSF1A methylation was detected in three of 48 cases (6.3%). Overall, there was a statistically significant mutually exclusive relationship between K-ras mutations and RASSF1A methylation. In conclusion, promoter hypermethylation of RASSF1A is a frequent event and may start early in the background normal mucosa in this tumor type. An alternative cascade of abnormalities in RAS transduction pathways may be responsible for the flat morphology and aggressive nature of flat colorectal neoplasms.
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Affiliation(s)
- Naoto Sakamoto
- Department of Pathology(II), Juntendo University, Juntendo University School of Medicine, 2-1-1 Hongo, Tokyo 113-8421, Japan
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Abstract
OBJECTIVE Small, flat colorectal cancers have been widely reported in the Japanese literature but are thought to occur rarely outside Japan. The aim of this retrospective cohort study was to clarify the prevalence of flat colorectal cancer in a Western population. METHODS One thousand and twenty-six consecutive colonoscopies performed by a single experienced endoscopist were retrospectively analysed over a two-year period. The morphology, site and histological appearance of all documented colorectal cancers (CRC) were recorded. RESULTS Forty-seven cases of CRC were detected, five of which (10%) demonstrated flat configuration. Flat cancers varied between 8 and 15 mm in diameter (mean 11 mm). Histologically, all flat lesions were moderately differentiated Dukes A adenocarcinomas. Two of these cancers contained no adenomatous component. CONCLUSION This study confirms that small, flat colorectal cancers are not an uncommon finding at colonoscopy in Western patients. Compared to polypoid neoplastic lesions, flat cancers appear to undergo malignant change at a smaller size.
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Affiliation(s)
- N Suzuki
- Wolfson Unit for Endoscopy Academic Department of Histopathology, St Mark's Hospital, Harrow, UK
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Terry MB, Neugut AI, Mansukhani M, Waye J, Harpaz N, Hibshoosh H. Tobacco, alcohol, and p53 overexpression in early colorectal neoplasia. BMC Cancer 2003; 3:29. [PMID: 14604438 PMCID: PMC280655 DOI: 10.1186/1471-2407-3-29] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2003] [Accepted: 11/06/2003] [Indexed: 01/06/2023] Open
Abstract
Background The p53 tumor suppressor gene is commonly mutated in colorectal cancer. While the effect of p53 mutations on colorectal cancer prognosis has been heavily studied, less is known about how epidemiologic risk factors relate to p53 status, particularly in early colorectal neoplasia prior to clinically invasive colorectal cancer (including adenomas, carcinoma in situ (CIS), and intramucosal carcinoma). Methods We examined p53 status, as measured by protein overexpression, in 157 cases with early colorectal neoplasia selected from three New York City colonoscopy clinics. After collecting paraffin-embedded tissue blocks, immunohistochemistry was performed using an anti-p53 monoclonal mouse IgG2a [BP53-12-1] antibody. We analyzed whether p53 status was different for risk factors for colorectal neoplasia relative to a polyp-free control group (n = 508). Results p53 overexpression was found in 10.3%, 21.7%, and 34.9%, of adenomatous polyps, CIS, and intramucosal cases, respectively. Over 90% of the tumors with p53 overexpression were located in the distal colon and rectum. Heavy cigarette smoking (30+ years) was associated with cases not overexpressing p53 (OR = 1.8, 95% CI = 1.1–2.9) but not with those cases overexpressing p53 (OR = 1.0, 95% CI = 0.4–2.6). Heavy beer consumption (8+ bottles per week) was associated with cases overexpressing p53 (OR = 4.0, 95% CI = 1.3–12.0) but not with cases without p53 overexpression (OR = 1.6, 95% CI = 0.7–3.7). Conclusion Our findings that p53 overexpression in early colorectal neoplasia may be positively associated with alcohol intake and inversely associated with cigarette smoking are consistent with those of several studies of p53 expression and invasive cancer, and suggest that there may be relationships of smoking and alcohol with p53 early in the adenoma to carcinoma sequence.
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Affiliation(s)
- Mary Beth Terry
- Department of Epidemiology, Columbia University Mailman School of Public Health, New York, New York, 10032 U.S.A
- Herbert Irving Comprehensive Cancer Center, College of Physicians and Surgeons, Columbia University, New York, NY 10032 U.S.A
| | - Alfred I Neugut
- Department of Epidemiology, Columbia University Mailman School of Public Health, New York, New York, 10032 U.S.A
- Herbert Irving Comprehensive Cancer Center, College of Physicians and Surgeons, Columbia University, New York, NY 10032 U.S.A
- Department of Medicine, College of Physicians and Surgeons, Columbia University, New York, NY 10032, U.S.A
| | - Mahesh Mansukhani
- Department of Pathology, College of Physicians and Surgeons, Columbia University, New York, New York, 10032 U.S.A
| | - Jerome Waye
- Department of Medicine, Mt. Sinai School of Medicine, New York, New York, 10029 U.S.A
| | - Noam Harpaz
- Department of Pathology, Mt. Sinai School of Medicine, New York, New York, 10029 U.S.A
| | - Hanina Hibshoosh
- Department of Pathology, College of Physicians and Surgeons, Columbia University, New York, New York, 10032 U.S.A
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Fujii H, Ajioka Y, Kazami S, Takagaki T, Gong Zhu X, Hirose S, Watanabe H, Shirai T. Loss of heterozygosity in the clonal evolution of flat colorectal neoplasms. J Pathol 2002; 197:298-306. [PMID: 12115875 DOI: 10.1002/path.1122] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
In contrast to invasive colorectal carcinomas that develop in typical exophytic adenoma-carcinoma sequences, some invasive cancers may evolve from flat mucosal dysplastic lesions. Despite their relatively small size, these flat colorectal lesions are often associated with high-grade dysplasia and may show an aggressive clinical course. To delineate the genetic pathways in the clonal evolution of these tumors, multiple foci were microdissected from 13 cases and the allelic deletions of 15 chromosomal arms were analysed. Loss of heterozygosity (LOH) was detected most frequently on 17p (77%), followed by 18q (69%), and 5q (54%). In five cases with concomitant low-grade adenomas, only one case showed LOH in low-grade adenoma foci. In high-grade dysplasia with/without submucosal invasion, early and homogeneous LOH of one to several chromosomal arms was detected. Overall, homogeneous and thus early LOH were most frequently detected on 17p (seven of 10 cases with 17p LOH), followed by 3p (two of three cases with 3p LOH), and 5q (four of seven cases with 5q LOH). In addition to homogeneous LOH, the LOH patterns observed in different portions of dysplasias and invasive cancers in individual cases identified several different genetic patterns of tumour progression, either with linear or branching (divergent) trees. Positive immunostaining for p53 was detected in 10 of the 13 cases; of these, five cases were concomitant with 17p LOH in all of the microdissected foci, four cases were concomitant with 17p LOH in a majority of foci and, one case showed retention of 17p. Except for the flat configuration and early 17p LOH, genetic heterogeneity in the flat high-grade dysplastic foci was found to be similar to genetic chaos in the late dysplastic and preinvasive stages of exophytic adenoma. These findings suggest a potentially aggressive course for these neoplasms.
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Affiliation(s)
- Hiroaki Fujii
- Department of Pathology (II), Juntendo University School of Medicine, Tokyo, Japan.
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Topping DL, Clifton PM. Short-chain fatty acids and human colonic function: roles of resistant starch and nonstarch polysaccharides. Physiol Rev 2001; 81:1031-64. [PMID: 11427691 DOI: 10.1152/physrev.2001.81.3.1031] [Citation(s) in RCA: 1934] [Impact Index Per Article: 84.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Resistant starch (RS) is starch and products of its small intestinal digestion that enter the large bowel. It occurs for various reasons including chemical structure, cooking of food, chemical modification, and food mastication. Human colonic bacteria ferment RS and nonstarch polysaccharides (NSP; major components of dietary fiber) to short-chain fatty acids (SCFA), mainly acetate, propionate, and butyrate. SCFA stimulate colonic blood flow and fluid and electrolyte uptake. Butyrate is a preferred substrate for colonocytes and appears to promote a normal phenotype in these cells. Fermentation of some RS types favors butyrate production. Measurement of colonic fermentation in humans is difficult, and indirect measures (e.g., fecal samples) or animal models have been used. Of the latter, rodents appear to be of limited value, and pigs or dogs are preferable. RS is less effective than NSP in stool bulking, but epidemiological data suggest that it is more protective against colorectal cancer, possibly via butyrate. RS is a prebiotic, but knowledge of its other interactions with the microflora is limited. The contribution of RS to fermentation and colonic physiology seems to be greater than that of NSP. However, the lack of a generally accepted analytical procedure that accommodates the major influences on RS means this is yet to be established.
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Affiliation(s)
- D L Topping
- Commonwealth Scientific and Industrial Research Organization, Health Sciences and Nutrition, Adelaide, Australia.
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Saitoh Y, Waxman I, West AB, Popnikolov NK, Gatalica Z, Watari J, Obara T, Kohgo Y, Pasricha PJ. Prevalence and distinctive biologic features of flat colorectal adenomas in a North American population. Gastroenterology 2001; 120:1657-65. [PMID: 11375947 DOI: 10.1053/gast.2001.24886] [Citation(s) in RCA: 278] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
BACKGROUND & AIMS To assess the prevalence of flat and depressed (F&D) colorectal adenomas in the United States, we performed a prospective study of 211 American patients. METHODS Dye-assisted colonoscopy was performed in the presence of both an American and a Japanese investigator. RESULTS F&D lesions were found in 22.7% of patients, and these were more likely to be adenomatous than polypoid lesions (82% vs. 67%; P = 0.03) and contained more invasive cancer (4.5% vs. 0%; P = 0.04), which also appeared to be at a disproportionately advanced stage. The average size of all F&D advanced lesions (high-grade dysplasia and cancer) was significantly smaller than comparable polypoid lesions (10.75 +/- 2.7 mm vs. 20 +/- 2.9 mm; P < 0.05). F&D adenomas showed significantly stronger fragile histidine triad (FHIT) expression and lower p53 reactivity than similarly sized polypoid adenomas, whereas proliferative and apoptotic indices were similar in both groups. CONCLUSIONS We conclude that there is a significant prevalence of colonic F&D colorectal adenomas in this country and that these lesions have significantly different biologic features than polypoid lesions. The clinical and epidemiologic implications of these findings for American patients need to be addressed in further studies.
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Affiliation(s)
- Y Saitoh
- Third Department of Internal Medicine, Asahikawa Medical College, Asahikawa, Japan
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Ozawa A, Konishi F, Fukayama M, Kanazawa K. Apoptosis and its regulation in flat-type early colorectal carcinoma: comparison with that in polypoid-type early colorectal carcinoma. Dis Colon Rectum 2000; 43:S23-8. [PMID: 11052474 DOI: 10.1007/bf02237222] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
PURPOSE The aim of this study was to investigate the relationship among apoptotic cell death, proliferative activity, and the expression of apoptosis-regulating proteins (p53, p21 (WAF1/CIP1), and bax) in flat-type early colorectal carcinoma and to compare these factors with those in polypoid-type early colorectal carcinoma. METHODS Formalin-fixed, paraffin-embedded tissues of 11 flat-type early colorectal carcinomas and 17 polypoid-type early carcinomas were studied. The histologic diagnosis was either well-differentiated adenocarcinoma or carcinoma in adenoma, and the depth of invasion was limited to mucosa or submucosa. Apoptotic cells were detected by terminal deoxynucleotide transferase-mediated deoxyuridine triphosphate-biotin nick end-labeling method, and proliferative activity was determined by Ki-67 immunohistochemistry using monoclonal antibody MIB-1. Apoptosis-regulating proteins were determined by immunohistochemistry using antibody DO-7 (p53), Cip1 (p21 (WAF1/CIP1)), and Bax (bax). RESULTS There was no significant difference in terminal deoxynucleotide transferase-mediated deoxy-uridine triphosphate-biotin nick end-labeling index between flat-type early colorectal carcinoma and polypoid-type early carcinoma, at 1.9 vs. 1.1, respectively. In flat-type carcinoma terminal deoxynucleotide transferase-mediated deoxyuridine triphosphate-biotin nick end-labeling index in the p53 protein overexpression group was significantly smaller than that in the p53 protein-negative group (P < 0.05). The Ki-67 labeling index/terminal deoxynucleotide transferase-mediated deoxyuridine triphosphate-biotin nick end-labeling index ratio in the p53 protein overexpression group was significantly higher than that in the p53 protein-negative group (P < 0.05). In polypoid-type carcinoma, the terminal deoxynucleotide transferase-mediated deoxyuridine triphosphate-biotin nick end-labeling index and Ki67/terminal deoxynucleotide transferase-mediated deoxyuridine triphosphate-biotin nick end-labeling index ratio showed no significant difference between the p53 protein overexpression group and p53 protein-negative group. CONCLUSION p53-dependent apoptosis may contribute to the development of flat-type early colorectal carcinoma. Apoptosis and its regulation in flat-type early colorectal carcinoma may differ from those in polypoid-type carcinoma.
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Affiliation(s)
- A Ozawa
- Department of Surgery, Jichi Medical School, Tochigi, Japan
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Rubio CA, Rodensjö M. p53 overexpression in flat serrated adenomas and flat tubular adenomas of the colorectal mucosa. J Cancer Res Clin Oncol 1995; 121:571-6. [PMID: 7559739 DOI: 10.1007/bf01197772] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
The expression of the p53 protein was investigated in flat serrated neoplasias as well as in other histological phenotypes of flat or exophytic hyperplasias or neoplasias of the colorectal mucosa. A total of 104 such lesions were analyzed: 24 were flat serrated neoplasias (22 flat serrated adenomas and 2 flat serrated adenocarcinomas), 26 flat tubular adenomas, 17 flat hyperplastic polyps, 29 exophytic tubular and/or villous neoplasias (23 adenomas and 6 exophytic adenocarcinomas) and the remaining 8, exophytic hyperplastic polyps. Deparaffinized, rehydrated sections were treated immunohistochemically to detect those overexpressing the p53 protein. Lesions having slight (+), moderate (++) or intense ( ) staining were considered immunoreactive. The results showed that 50% of the flat serrated adenomas with low-grade dysplasia (LGD) and 66.7% of those with high-grade dysplasia (HGD) had p53 immunoreactivity. None of the flat tubular or of the exophytic adenomas with LGD expressed p53, but immunoreactivity was present in 61.5% of the flat tubular adenomas with HGD and in 52.3% of the exophytic adenomas with HGD. All adenocarcinomas had an intense p53 reaction. Weak p53 expression was demonstrated by 11.7% of the flat hyperplastic polyps but none of the exophytic polyps reacted. The occurrence of p53 expression in flat serrated adenomas with LGD suggested that, despite its low histological profile, one-half of those lesions could be biologically already committed to independent growth. The occurrence of p53 expression in nearly 12% of the flat hyperplastic polyps was totally unexpected and deserves further investigation. Flat serrated adenoma emerges as a novel, independent histological entity among the various phenotypes of flat neoplasias of the colorectal mucosa.
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Affiliation(s)
- C A Rubio
- Department of Pathology, Karolinska Institute, Stockholm, Sweden
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