Flat adenoma-carcinoma sequence with high-malignancy potential as demonstrated by CD10 and beta-catenin expression: a different pathway from the polypoid adenoma-carcinoma sequence

Two histologic compartments in nonpolypoid conventional colon adenomas

Two intertwined compartments coexisting in nonpolypoid conventional (i.e. tubular or villous) adenomas are highlighted in this review: one built of dysplastic tissue on top and the other portraying crypts with irregular, corrupted shapes, albeit lined with normal epithelium, below. The latter compartment has remained unattended in the literature. Recently, however, the histologic characteristics of the nondysplastic compartment in nonpolypoid conventional adenomas were closely examined, and some of its biological attributes were unveiled. Studies with the proliferation marker ki67 showed that the crypts with irregular, corrupted shapes in the nondysplastic compartment displayed haphazardly distributed proliferating cell-domains. Given that the proliferating cells are generated by stem cells, the relocation of proliferating cell-domains in those crypts seems to be the result of a reorganization of the stem cells within the crypts. The abnormal distribution of proliferating cells, the finding of p53-upregulated cells, and of crypts in asymmetric fission suggest that the crypts in that compartment are histo-biologically altered, probably somatically mutated. This new information might contribute to unravel the riddle of crypto-histogenesis of nonpolypoid conventional adenomas of the colon. More research along these lines is necessary, before the biology of the crypts in the nondysplastic compartment can be fully translated into molecular terms.

Histological Classification and Immunohistochemical Study of Feline Colorectal Epithelial Tumors

Among 113 feline gastrointestinal epithelial tumors diagnosed between 2006 and 2019, 78 (69%) were detected in the colorectum. Fifty colorectal tumors were selected for further pathological evaluations, of which 9 (18%) were histopathologically diagnosed as adenomas and 41 (82%) as carcinoma. The carcinomas included 33 tubular adenocarcinomas (TAC), 5 tubulovillous adenocarcinomas (TVAC), 2 mucinous adenocarcinomas, and 1 undifferentiated carcinoma. Histopathologically, TAC frequently showed vascular invasion (17/33 cases, 52%). In TAC cases, serosal infiltration (13/15 cases, 87%) and lymph node metastasis (8/9 cases, 89%) were common in bowel resection and lymphadenectomy samples, respectively. Immunohistochemically, the tumor cells of most cases were positive for cytokeratin (CK) 20 (50/50 cases, 100%) and CDX2 (48/50 cases, 96%). Focal immunopositivity for CD10 (11/50 cases, 22%) and CK7 (15/50 cases, 30%) was observed irrespective of the histological subtype. Only a few cases showed diffuse nuclear accumulation of β-catenin (2/50 cases, 4%) and p53 (5/50 cases, 10%). A lack of tubule formation, female sex, and low CDX2 labeling were statistically associated with carcinoma compared to adenoma (ρ = 0.615, P < .001; ρ = 0.279, P = .050; and ρ = -0.265, P = .063, respectively). Other features, including mucin profiles, Ki67 labeling index, and accumulation of β-catenin and p53, were not associated with malignancy. A sequence analysis revealed KRAS mutations in 3/7 TAC cases. These results suggest that KRAS mutations-rather than excessive Wnt/β-catenin signaling and the inactivation of TP53-contribute to the tumorigenesis of feline colorectal carcinoma.

Clinicopathological features and phenotypic classification of de novo-type colorectal carcinomas differ from those of colorectal carcinomas derived from flat adenomas

Since adenoma components disappear with tumor progression, it is not known whether colorectal carcinomas (CRCs) are derived from an adenoma-carcinoma sequence or are de novo. We compared 38 cases of ≤10-mm flat CRCs without an adenoma component (de novo type) with 39 cases of ≤10-mm flat CRCs with an adenoma component (carcinoma in adenoma (CIA) type). Compared to the CIA type, the de novo-type CRCs were more frequently located in the proximal colon; more frequently invaded submucosa, and more frequently had venous permeation. Regarding the phenotypic classification based on the immunohistochemical expressions of CD10, MUC2 and MUC5AC, the incidence of unclassified type (CD10-, MUC2- and MUC5AC-) was significantly more frequent in the de novo (32%) than CIA (5%) type. In one de novo-type case, mismatch repair (MMR) protein loss was judged, because MLH1 and PMS2 protein expressions were immunohistochemically negative. BRAF mutation (V600E) was seen in one de novo-type case and two CIA-type cases, but none of these cases had MMR protein loss. In conclusion, small-intestinal type (CD10+ and MUC5AC-) is the most common in flat CRC and unclassified type is mainly characteristic of de novo type. In this study, small flat CRCs with BRAF mutation do not have MMR protein loss.

High expression of CD10 in anaplastic thyroid carcinomas

AIMS

CD10 is an endopeptidase that degrades various bioactive peptides in the extracellular matrix. In addition to enzymatic degradation, it affects multiple intracellular signal transduction pathways. CD10 expression has been extensively studied in human epithelial cancers of numerous organs and sites. However, its presence in thyroid carcinomas, especially in anaplastic thyroid carcinoma (ATC), has not been fully determined. An actual CD10 expression in thyroid lesions including a large series of ATC was evaluated.

METHODS AND RESULTS

We examined CD10 by immunohistochemistry (IHC) in 152 thyroid lesions: nine adenomatous goitres (AGs) and 143 tumours, including 47 anaplastic carcinomas. IHC showed diffuse and strong positivity for CD10 in the epithelial components of almost all ATCs. However, epithelia with squamous metaplasia and oncocytic change from AGs, follicular adenomas and differentiated carcinomas had focal CD10 reactivity. Some papillary thyroid carcinomas (PTCs), along with the PTC components of some ATCs, showed CD10 positivity in fibroblast-like stromal cells and fibrous material.

CONCLUSION

Our results imply that the CD10 expression pattern depended on the histotypes of thyroid lesions. When possible metastatic tumours and non-epithelial tumours are excluded, high CD10 expression may be useful in determining whether a primary thyroid carcinoma includes an anaplastic component.

A point mutation in the extracellular domain of L1 blocks its capacity to confer metastasis in colon cancer cells via CD10

The neural L1 transmembrane cell adhesion receptor of the immunoglobulin-like family is a target gene of Wnt-β-catenin signaling in human colorectal cancer (CRC) cells and is expressed at the invasive edge of the tumor tissue. L1 overexpression in cultured CRC cells confers enhanced proliferation, motility and liver metastasis. We have analyzed the mechanisms of L1-mediated signaling in CRC cells by using various point mutations in the L1 ectodomain that are known to cause severe genetically inherited mental retardation disorders in patients. We found that all such L1 ectodomain mutations abolish the ability of L1 to confer metastatic properties in CRC cells. Using gene array analysis, we identified L1-mutation-specific gene expression signatures for the L1/H210Q and L1/D598N mutations. We identified CD10, a metalloprotease (neprilysin, neutral endopeptidase) and a gene that is specifically induced in CRC cells by L1 in an L1/H210Q mutation-specific manner. CD10 expression was required for the L1-mediated induction of cell proliferation, motility and metastasis, as suppression of CD10 levels in L1-expressing CRC cells abolished the L1 effects on CRC progression. The signaling from L1 to CD10 was mediated through the L1-ezrin-NF-κB pathway. In human CRC tissue L1 and CD10 were localized in partially overlapping regions in the more invasive areas of the tumor tissue. The results suggest that CD10 is a necessary component conferring the L1 effects in CRC cells. The identification of gene expression patterns of L1-domain-specific point mutations may provide novel markers and targets for interfering with L1-mediated CRC progression.

Tumoral Versus Flat Intraepithelial Neoplasia of Pancreatobiliary Tract, Gallbladder, and Ampulla of Vater

Context.—The identification of a precursor lesion is important to understanding the histopathologic and genetic alterations in carcinogenesis. There are a plethora of terminologies that describe precursor lesions of the pancreatobiliary tract, ampulla of Vater, and gallbladder. The current terminologies for precursor lesions may make it difficult to understand the tumor biology. Here, we propose the concept of tumoral and flat intraepithelial neoplasia to improve our understanding of precursor lesions of many epithelial organs, including the pancreatobiliary tract, ampulla of Vater, and gallbladder.

Objective.—To understand the dichotomous pattern of tumoral and flat intraepithelial neoplasia in carcinogenesis of pancreatobiliary tract, ampulla of Vater, and gallbladder.

Data Sources.—Review of relevant literatures indexed in PubMed.

Conclusions.—Tumoral intraepithelial neoplasia presents as an intraluminal or intraductal, mass-forming, polypoid lesion or a macroscopic, visible, cystic lesion without intracystic papillae. Microscopically, tumoral intraepithelial neoplasia shows various proportions of papillary and tubular architecture, often with a mixed pattern, such as papillary, tubular, and papillary-tubular. The malignant potential depends on the degree of dysplasia and the cell phenotype of the epithelium. Flat intraepithelial neoplasia presents as a flat or superficial, spreading, mucosal lesion that is frequently accompanied by an invasive carcinoma. Tumoral and flat intraepithelial neoplasias are not homogeneous entities and may exhibit histopathologic spectrum changes and different genetic profiles. Although intraepithelial neoplasia showed a dichotomous pattern in the tumoral versus flat types, they can coexist. Tumoral and flat intraepithelial neoplasia can be interpreted as part of a spectrum of changes in the carcinogenesis pathway of each organ.

Expression Profiling of Proliferation and Apoptotic Markers along the Adenoma-Carcinoma Sequence in Familial Adenomatous Polyposis Patients

Introduction. Familial adenomatous polyposis (FAP) patients have a germline mutation in the adenomatous polyposis coli (APC) gene. The APC protein interacts with beta-catenin, resulting in the activation of the Wnt signalling pathway. This results in alterations in cell proliferation and apoptosis. We investigated the expression of beta-catenin and related proliferation and apoptotic factors in FAP patients, exploring the expression along the adenoma-carcinoma sequence. Methods. The expression of beta-catenin, p53, bcl-2, cyclin-D1, caspase-3, CD10, and Ki-67 proteins was studied by immunohistochemistry in samples of colonic nonneoplastic mucosa (n = 71), adenomas (n = 152), and adenocarcinomas (n = 19) from each of the16 FAP patients. Results. The expression of beta-catenin, caspase-3, cyclin-D1, and Ki-67 was increased in both adenomas and carcinomas in FAP patients, compared with normal mucosa. p53 and CD10 expression was only slightly increased in adenomas, but more frequently expressed in carcinomas. Bcl-2 expression was increased in adenomas, but decreased in carcinomas. Conclusion. This is the first study investigating collectively the expression of these molecules together in nonneoplastic mucosa, adenomas, and carcinomas from FAP patients. We find that beta-catenin and related proliferative and apoptotic factors (cyclin-D1, bcl-2, caspase-3, and Ki-67) are expressed early in the sequence, in adenomas. However, p53 and CD10 are often expressed later in the sequence, in carcinomas.

Early colorectal carcinomas: CD10 expression, mucin phenotype and submucosal invasion

We analyzed 170 tumors (polypoid, 98; non-polypoid, 72) of early colorectal carcinoma with or without submucosal invasions (Tis and T1 of TNM classification) from 161 patients to evaluate correlations between clinicopathological factors and immunohistochemical expressions of CD10, MUC2, and MUC5AC. The coexistence of adenomatous components was significantly less common in non-polypoid carcinomas (4.2%) than in polypoid carcinomas (66.3%) (P < 0.0001). Non-polypoid carcinomas were smaller in size and tended to infiltrate into the submucosa with higher incidence of lymphatic and venous permeations. CD10 was more frequently expressed in non-polypoid carcinomas (70.8%) than in polypoid carcinomas (51.0%) (P= 0.01). Total carcinomas with high grade atypia showed higher incidence of CD10 expression (60.6%) than those with low grade atypia (28.9%) (P < 0.0001). Carcinomas with low grade atypia exhibited a higher incidence of MUC2 and MUC5AC expression (91.1% and 57.8%, respectively), when compared with carcinomas with high grade atypia (41.6% and 20.0%, respectively) (both, P < 0.0001). In submucosal invasive carcinomas with residual intramucosal carcinoma component (IMCC), CD10 expression in IMCC and submucosal invasive carcinoma component (SMCC) simultaneously exhibited identical positive or negative results, regardless of the polypoid or non-polypoid growth pattern. The CD10 expression may occur in the early stage of carcinogenesis within the mucosa, and these neoplasms may retain CD10 in SMCC, possibly resulting in more advanced stages of stromal invasion and distant metastases. In conclusion, our data suggest that the CD10 expression and mucin phenotypes may be potentially useful markers for estimating biological properties of early colorectal carcinomas.

MUC5AC/β-catenin expression and KRAS gene alteration in laterally spreading colorectal tumors

AIM: To clarify differences in mucin phenotype, proliferative activity and oncogenetic alteration among subtypes of colorectal laterally spreading tumor (LST).

METHODS: LSTs, defined as superficial elevated lesions greater than 10 mm in diameter with a low vertical axis, were macroscopically classified into two subtypes: (1) a granular type (Gr-LST) composed of superficially spreading aggregates of nodules forming a flat-based lesion with a granulonodular and uneven surface; and (2) a non-granular type (NGr-LST) with a flat smooth surface and an absence of granulonodular formation. A total of 69 LSTs, comprising 36 Gr-LSTs and 33 NGr-LSTs, were immunohistochemically stained with MUC2, MUC5AC, MUC6, CD10 (markers of gastrointestinal cell lineage), p53, β-catenin and Ki-67 antibodies, and examined for alteration in exon 1 of v-Ki-ras2 Kirsten rat sarcoma viral oncogene homolog (KRAS) and exon 15 of v-raf murine sarcoma viral oncogene homologue B1 (BRAF) by polymerase chain reaction followed by direct sequencing.

RESULTS: Histologically, 15 Gr-LST samples were adenomas with low-grade dysplasia (LGD), 12 were high-grade dysplasia (HGD) and 9 were adenocarcinomas invading the submucosa (INV), while 12 NGr-LSTs demonstrated LGD, 14 HGD and 7 INV. In the proximal colon, MUC5AC expression was significantly higher in the Gr-type than the NGr-type. MUC6 was expressed only in NGr-LST. MUC2 or CD10 did not differ. P53 expression demonstrated a significant stepwise increment in progression through LGD-HGD-INV with both types of LST. Nuclear β-catenin expression was significantly higher in the NGr-type. Ki-67 expression was significantly higher in the Gr-type in the lower one third zone of the tumor. In proximal, but not distal colon tumors, the incidence of KRAS provided mutation was significantly higher in the Gr-type harboring a specific mutational pattern (G12V). BRAF mutations (V600E) were detected only in two Gr-LSTs.

CONCLUSION: The two subtypes of LST, especially in the proximal colon, have differing phenotypes of gastrointestinal cell lineage, proliferation and activation of Wnt/β-catenin or RAS/RAF/extracellular signal-regulated kinase signaling.

Genetic aspects of non-polypoid colorectal neoplasms

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.

[Clinical and histopathological results after the neo-adjuvant treatment of advanced rectal tumors]

The role of the surgical intervention is decisive in treating colorectal tumors. The neo-adjuvant radio-chemotherapy has improved the efficacy of the treatment of advanced rectum tumors. In order to decrease the size and stage of advanced rectal carcinoma and to increase the rate of resecability, we introduced neoadjuvant radio-chemotherapy. We carried out neo-adjuvant and surgical treatment in case of 67 patients with rectal adenocarcinoma (T 2-4 N 1-2 M 0 ) between June 1, 2005 and July 31, 2008. The average age of the patients was 61.2 years, the division according to sex was 44 males/23 females. Regarding the local stage of the rectal process or the proximity to the sphincter, we applied radio-chemotherapy (radiotherapy 25 times altogether 45 Gy and on the first and last week for 5-5 days they received 350 mg/m 2 /day 5-FU and 20 mg/m 2 /day leucovorin chemotherapy, recently complemented with 3 x 1.8 Gy advanced boost radiation aiming at the macroscopic tumor site with security zone). Patients underwent surgery 8 weeks on average after restaging examinations. Thirty-eight patients underwent anterior rectal resection with double stapler procedure; there were 18 abdominoperineal rectal extirpations, 7 Hartmann operations and 4 per annum excisions. Compared to the preoperative staging, the histological evaluation of the resected specimens showed total remission (pT 0 N 0 ) in 11% and partial remission in 43%. The morbidity necessitating reoperation was 5.9%, without mortality and suture insufficiency. The long-term neo-adjuvant oncological treatment led to down-staging of rectal tumors in most cases and increased the resecability and rate of resection operations.

Incorporating frailty in a multi-state model: application to disease natural history modelling of adenoma-carcinoma in the large bowel

Homogeneous multi-state models of disease progression have been widely used for designing and evaluating cancer screening programs. However, in screening for premalignant conditions of the cervix or large bowel, it is unlikely that all premalignant lesions have the same underlying propensity for progression. Incorporating frailty into multi-state models raises practical difficulties as it precludes the derivation of finite transition probabilities by matrix solution of the Kolmogorov equations. We address this problem by formulating a heterogeneous process as a series of homogeneous processes linked by transitions which are subject to heterogeneity (frailty). Continuous frailty and discrete mover—stayer models were developed. We applied these to the example of progression of adenoma to colorectal cancer in a three-state model and to a five-state model including consideration of adenoma size. Results were compared with those of purely homogeneous models in a previous study in terms of cumulative risk of malignant transformation from adenoma to invasive colorectal cancer.

Endoscopic mucosal resection for treatment of colorectal polyps occurring in the senium and presenium: a report of 561 cases

AIM: To investigate the efficacy of endoscopic mucosal resection (EMR) for colorectal polyps occurring in the senium and presenium, and analyze the clinical and pathological features of resected lesions as well as the indications for and the complications of EMR.

METHODS: A total of 513 patients with 766 lesions were included in this study. The "inject and cut]EMR technique was used. The resected lesions were observed pathohistologically. The patients were followed up for a period of 1 to 60 months to evaluate the efficacy of EMR. Intraoperative and postoperative complications and treatments were recorded.

RESULTS: A cure rate of 96.3% was achieved by EMR. Twenty-one patients (2.7%) were referred for surgery because of invasive cancer revealed by pathological examination after EMR. Bleeding occurred in 23 patients (4.2%) during EMR procedures, all of which underwent successful endoscopic hemostasis. Delayed bleeding occurred in ten patients (1.8%), of which seven underwent successful endoscopic hemostasis, and three received blood transfusion and conservative medical management. No perforation, infection and other complications occurred. The incidences of inflammatory polyps, hyperplastic polyps, adenomatous polyps and cancerous adenoma were 29.0%, 21.1%, 45.7% and 4.2%, respectively. The incidence of adenomatous polyps increased gradually with age. No recurrence was found during the follow-up period.

CONCLUSION: EMR is safe, minimally invasive, and more effective than traditional endoscopic approach in the treatment of colorectal polyps.

Increased expression of beta-catenin, phosphorylated glycogen synthase kinase 3beta, cyclin D1, and c-myc in laterally spreading colorectal tumors

Laterally spreading tumors (LSTs) are considered a special subtype of superficial colorectal tumor. This study was performed to characterize the clinicopathological features and examine activation of the Wnt/beta-catenin pathway in LSTs and protruded-type colorectal adenomas (PAs). Fifty LSTs and 54 PAs were collected, and their clinicopathological characteristics were compared. The expression of E-cadherin, beta-catenin, glycogen synthase kinase-3beta (GSK-3beta), phosphorylated GSK-3beta, (phospho-GSK-3beta), cyclin D1, and c-myc was investigated by immunohistochemical staining on serial sections. Patients with LSTs were significantly older than those bearing PAs (63.4 vs 47.4 years old; p<0.001). The mean size of LSTs was significantly larger than that of PAs (27.0 mm vs 14.6 mm; p<0.01). Forty-eight percent of LSTs were located in the proximal colon, which was significantly higher than that of PAs (18.5%; p<0.05). Expression of beta-catenin, phospho-GSK-3beta, cyclin D1, and c-myc was significantly increased in LSTs compared with PAs (p<0.05). However, E-cadherin and total GSK-3beta expression was not significantly different between the two groups. The level of beta-catenin expression correlated strongly with phospho-GSK-3beta, cyclin D1, and c-myc expression in LSTs but not in PAs. Our findings suggest that activation of the Wnt/beta-catenin pathway is more prevalent in LSTs than in PAs, suggesting that phosphorylation-dependent inactivation of GSK-3beta may be involved in LST carcinogenesis.