Xiangshan Fan

Expression of Lgr5 in human colorectal carcinogenesis and its potential correlation with β-catenin

Backgrounds and aimsLgr5 is a member of the G protein receptor super-family and was shown recently to be a stem cell marker for cells with intestinal differentiation. Its over-expression has been demonstrated in hepatocellular, basal cell carcinoma, and ovarian cancers but the underlying mechanisms are poorly understood. The aim of this study was to investigate if Lgr5 over-expression was correlated with human colorectal carcinogenesis and its potential correlation with β-catenin.MethodsThe study was carried out on a tissue microarray that consisted of 102 colorectal carcinomas (CRC; M:F = 55:47), 18 colon adenoma, and 12 colon normal mucosa cases. Immunostains were performed with the standard EnVision method with primary antibodies against Lgr5, β-catenin, and p53 antigens. Immunoreactivity of neoplastic cells to each antibody was double-blindly semi-quantified by two pathologists and the data were analyzed with the Chi-square and Spearman rank correlation tests. Subsequently, expression of Lgr5 in tissue sections of tumor centre and invasive margins of 21 cases of CRC certified to be immunoreactive of Lgr5 in TMA were evaluated and possible differences of Lgr5 expression between them were analyzed.ResultsLgr5 immunoreactivity was observed only in single cells in the base of normal colon mucosal crypts but high in 28% (five out of 18) adenomas, and significantly higher in 54% (55/102, p = 0.016) CRC cases. In normal mucosa, adenoma, and CRC, β-catenin expression was seen in 25% (three out of 12), 27% (five out of 18), and 81% (83/102) cases, respectively, in contrast to 0, 0, and 40% (41/102) for p53 expression, respectively. In CRC, Lgr5 expression was more intense in women than men (p < 0.0001), and positively correlated with β-catenin expression (p < 0.001), but not with patients’ ages, tumor sizes, nodal status, TNM stages, and p53 expression. Different expression of Lgr5 between tumor centre and invasive margins was not found (p > 0.05).ConclusionsThe results suggest that up-regulation of Lgr5 expression, especially in female patients, may play an important role in colorectal carcinogenesis, probably through the WNT/β-catenin pathway, but not involve the progression of the CRC.

Gastric cardiac carcinomas involving the esophagus are more adequately staged as gastric cancers by the 7th edition of the American Joint Commission on Cancer Staging System

The aim of this study was to compare the 7th with the 6th edition of the American Joint Commission on Cancer Staging System for prognostic stratification of gastric cardiac carcinomas involving the esophagus. We retrospectively compared differences in pathological stages with patient survival between the 7th and the 6th staging systems in 142 consecutive resection cases of this cancer. Patient median age was 65 years. The male–female ratio was 3.3. The epicenter of all tumors was within 5 cm below the gastroesophageal junction. The median tumor size was 5.0 cm. Most tumors (79%) were typical adenocarcinomas and the rest showed uncommon histology types. Using the guidelines for gastric cancer, this group of cancer was better stratified by the 7th than the 6th edition of the staging system, especially for pathological nodal (pN) and overall stage pIIIC. Patients with celiac axis nodal disease had the 5-year survival rate worse than those staged at pN3A and pIIIA. Patients staged at pT3 and pN3B had the 5-year survival rate worse than those at pM1 and pIV. We showed that the overall stage of gastric cardiac carcinomas was better stratified by gastric than by esophageal cancer grouping. We conclude that these tumors are better stratified with the 7th than the 6th edition of the gastric staging system, especially for pIII cancers, and better staged by the new gastric than esophageal cancer staging system. We propose that the staging of these tumors be reverted to gastric grouping and combine pT3 and pN3B into the overall stage pIV.

Comparison of gastro-oesophageal junction carcinomas in Chinese versus American patients.

Huang Q, Fan X, Agoston A T, Feng A, Yu H, Lauwers G, Zhang L & Odze R D 
(2011) Histopathology59, 188–197

Immunostaining with EGFR mutation–specific antibodies: a reliable screening method for lung adenocarcinomas harboring EGFR mutation in biopsy and resection samples

Mutation analysis of epidermal growth factor receptor (EGFR) is essential in determining the therapeutic strategy for lung adenocarcinoma. Immunohistochemical (IHC) staining with EGFR mutation-specific antibodies of del E746-A750 in exon 19 and L858R in exon 21 has been evaluated in resection specimens in a few studies but rarely in biopsy samples. A total of 169 cases (78 biopsies and 91 resected specimens) of lung adenocarcinoma with EGFR mutation status predefined by direct DNA sequencing were histologically examined, and IHC was performed using EGFR mutation-specific antibodies of del E746-A750 and L858R. The cases with positive results by IHC but negative results by direct DNA sequencing were examined by amplified refractory mutation system. Our results showed that the frequency of EGFR mutations for both E746-A750 deletion and L858R mutation was 38.5% (65/169) by DNA sequencing or amplified refractory mutation system and 34.3% (58/169) by IHC in lung adenocarcinomas. Based on molecular test results, the overall sensitivity, specificity, positive predictive value, and negative predictive value of IHC using these 2 antibodies in all (biopsy/resection) cases were 87.7% (80%/94.3%), 99.0% (97.9%/100%), 98.3% (96%/100%), and 92.8% (88.7%/96.6%), respectively. Lung adenocarcinomas with a predominant acinar, papillary, lepidic, or solid growth pattern more often harbor EGFR mutation of del E746-A750 or L858R. In conclusion, the immunostaining with EGFR del E746-A750 and L858R mutation antibodies is a reliable screening method with high specificity and sensitivity for identifying the EGFR mutation in both resected and biopsied lung adenocarcinomas.

Distal esophageal carcinomas in Chinese patients vary widely in histopathology, but adenocarcinomas remain rare.

In Western countries, distal esophageal adenocarcinoma has outnumbered squamous cell carcinoma because of a dramatic increase in the prevalence of columnar-lined esophagus. Because the relative prevalence of these diseases remains unknown in China, we investigated the histopathology of distal esophageal neoplasm in resection specimens from a high-volume medical center in China. A computerized search of esophageal cancer was conducted in the pathology database between 2004 and 2010. Cancers with epicenter located within 5 cm above the gastroesophageal junction were retained for analysis. Pathology reports were reviewed along with medical, radiologic, and endoscopic records. All histology slides of selected cases were reevaluated (median, 13 per case). Conventional and basaloid squamous cell, adenosquamous, mucoepidermoid, and neuroendocrine carcinomas and esophageal adenocarcinoma were categorized according to the World Health Organization classification of esophageal cancers. The presence of columnar-lined esophagus and other pathologic changes were assessed in cases with residual esophageal mucosa. Among 1101 resections, 204 (19%) qualified for the study. Conventional and basaloid squamous cell, adenosquamous, mucoepidermoid, and neuroendocrine carcinomas and esophageal adenocarcinoma represented 76%, 11%, 3%, 2%, 6%, and 1% of the cases, respectively. Synchronous carcinomas were found in 12% and consisted of primarily squamous cell carcinoma (50%) and proximal gastric adenocarcinoma (38%). Columnar-lined esophagus was detected in 18% of the cases, among which intestinal metaplasia was present in 30% and low-grade dysplasia in 7%. In conclusion, distal esophageal carcinomas in Chinese patients showed a wide histopathologic spectrum with predominant squamous cell carcinoma and rare esophageal adenocarcinoma. Although common, columnar-lined esophagus appears pathogenetically insignificant for most distal esophageal carcinomas.

Concurrent loss of INI1, PBRM1, and BRM expression in epithelioid sarcoma: implications for the cocontributions of multiple SWI/SNF complex members to pathogenesis.

The loss of INI1 (SMARCB1) expression, caused by SMARCB1 (INI1, SNF5L4, BAF47) inactivation, frequently occurs in epithelioid sarcoma (ES) and could aid in confirming the diagnosis. Except for INI1, the expression of switch in mating type/sucrose nonfermentation complex members in ES has never been examined. In this study, the expression of key subunits of this complex-INI1, BRG1 (SMARCA4), BRM (SNF2L2, SMARCA2), PBRM1 (hPB1, BAF180), and BAF155 (SMARCC1)-was analyzed in 23 ES cases: 15 conventional and 8 proximal type. All of the cases were reviewed and reclassified by hematoxylin-eosin staining and immunostaining for cytokeratin AE1/3, epithelial membrane antigen, CD34, vimentin, and INI1 expression. Of the 23 ES cases, 19 (82.6%) showed a loss of PBRM1, and 18 (78.3%), a loss of INI1. In most cases (17, 73.9%), loss of INI1 and PBRM1 expression was observed. The pattern of PBRM1 expression was similar to that of INI1, that is, not correlated with changes in cellular morphology. The concurrent loss of BRM, PBRM1, and INI1expression was detected in 2 cases with pure rhabdoid tumor features. The frequent observation of concurrent loss of INI1 and PBRM1 suggests that certain switch in mating type/sucrose nonfermentation complex components might act synergistically in the pathogenesis of ES by unknown mechanisms and that these components could provide new targets for therapy. The usefulness of PBRM1 as a biomarker of ES and its mechanism in ES require further investigation. Loss of BRM in ES with pure rhabdoid features suggests that BRM might be involved in the underlying mechanisms of this type of ES.

Pancreatic acinar-like adenocarcinoma of the proximal stomach invading the esophagus

The aim of this study was to systematically investigate clinicopathologic features of the recently described pancreatic acinar-like adenocarcinoma of the proximal stomach invading the esophagus (n = 43). Patient median age was 66 years (range, 51-90 years). The male-to-female ratio was 7.6. Grossly, pancreatic acinar-like adenocarcinoma tumors were nonencapsulated with the median size of 5.5 cm (range, 2-10.5). Bormanns types 1 to 4 tumors were in 7%, 9%, 67%, and 16% cases, respectively. Frank necrosis, hemorrhage, and cysts were rare or absent. Lymphovascular (81%), perineural (74%), and lymph node (81%) invasions were more common in the pancreatic acinar-like adenocarcinoma than in the non-pancreatic acinar-like adenocarcinoma (n = 94) groups. Microscopically, pancreatic acinar-like adenocarcinoma tumors showed acinar (78%), micropapillary (12%), microcystic, solid, trabecular, and mixed neuroendocrine or signet ring (33%) patterns of growth. No adenosquamous differentiation was noted in the pancreatic acinar-like adenocarcinoma group. Nuclei were round to oval with thickened nuclear membrane, stippled chromatin, and single prominent nucleoli. Mitotic figures were variable. The cytoplasm was moderate, eosinophilic, finely granular, and diffusely immunoreactive to the α1-chymotrypsin antibody in all cases to various degrees. Tumor stroma was nondesmoplastic, delicate, and fibrovascular. Pancreatic acinar-like adenocarcinoma tumors staged pI, pII, pIII, and pIV were in 2%, 21%, 70%, and 7% of cases, respectively. The median number of follow-up months after surgery was 29. The 2-year survival rate was 67%, lower than that (73%) in the non-pancreatic acinar-like adenocarcinoma group. A worse overall survival trend was found for patients in the pancreatic acinar-like adenocarcinoma than in non-pancreatic acinar-like adenocarcinoma groups, but the difference was not statistically significant. Age older than 75 years and overall pathology stage were independent risk factors.

Thyroid carcinoma showing thymus-like elements: a clinicopathologic, immunohistochemical, ultrastructural, and molecular analysis.

OBJECTIVES To investigate the clinicopathologic, immunophenotypic, ultrastructural, and molecular features of thyroid carcinoma showing thymus-like elements (CASTLE). METHODS We retrospectively analyzed the clinicopathologic data of 10 patients with CASTLE and described the immunophenotypic and ultrastructural features of these tumors. The expression of Epstein-Barr virus-encoded RNA and the gene status of EGFR, C-KIT, and HER-2 were also assessed by molecular techniques. RESULTS The tumor cells were positive for CD5, CD117, p63, HMWK, EGFR, GLUT-1, Pax8, E-cadherin, bcl-2, and p53 in all cases and for CA-IX, CEA, p16, HER-2, and neuroendocrine markers in some cases. Ultrastructural examination indicated that the tumor cells contained large quantities of tonofilament with abundant intercellular desmosomes, including intracytoplasmic neuroendocrine granules in one case. EGFR gene amplification in two patients and polyploidy of chromosome 7 in one patient were identified by fluorescence in situ hybridization. Sequencing analysis revealed that a synonymous mutation, Q787Q 2363 (G→A), occurred on exon 20 of the EGFR gene in three patients. CONCLUSIONS GLUT-1 can be used as a novel biomarker for CASTLE, and combined detection of GLUT-1 with CD5 and CD117 aids in the diagnosis of this tumor. Aberrant expression of Bcl-2, p53, p16, E-cadherin, EGFR, C-KIT, and HER-2 may play important roles in the development of CASTLE.

Clinicopathological significance of SIRT1 and p300/CBP expression in gastroesophageal junction (GEJ) cancer and the correlation with E-cadherin and MLH1.

SIRT1 and p300/CBP, which are considered to be essential histone deacetylases and acetyltransferases, are also considered to be relative to tumorigenesis because they modulate the expression of several tumor suppressor genes. Therefore, this study investigated the expression of SIRT1 and p300/CBP in gastroesophageal junction (GEJ) cancer and their correlation with E-cadherin and MLH1 in order to explore the clinicopathological significance of SIRT1 and p300/CBP expression and their possible effects involving E-cadherin and MLH1 expression. Tissue microarray technique and immunohistochemical stains were applied to evaluate the SIRT1, p300/CBP, E-cadherin, and MLH1 expression in 176 GEJ cancer tissues and 32 normal GEJ region tissues. The results showed that the over-expression of SIRT1 was associated with a higher number of metastasis lymph nodes, more advanced staging, and shorter mean survival time. SIRT1 and p300/CBP were negatively and positively correlated with the expression of E-cadherin and MLH1, respectively, in the cancer cases. These results indicated a possible effect of SIRT1 and p300/CBP involved in regulating the expression of E-cadherin and MLH1, thus participating in the tumor progression of GEJ cancer.

Gastric mixed adenoneuroendocrine carcinoma: correlation of histologic characteristics with prognosis ☆

Gastric mixed adenoneuroendocrine carcinomas (MANECs) are rare, with both the exocrine and neuroendocrine components exceeding 30% volume. Several classifications for MANECs have been proposed, yet they have not been clinically evaluated. The aim of this study was to evaluate the correlation between tumor grade, histologic characteristics, and prognosis of gastric MANECs. We collected eligible 14 cases in our series and 31 cases in the literature and compared the prognostic difference among gastric MANECs with different histologic characteristics. Gastric MANECs could be divided into subgroups according to tumor grade of the neuroendocrine component and adenocarcinoma types. The high grade and large proportion of neuroendocrine component correlated with aggressive behavior and a tendency of poor clinical outcome. Gastric MANECs with a poorly differentiated adenocarcinoma showed a significant lower survival rate than did MANECs with a differentiated adenocarcinoma or mucin-producing carcinoma (P = .0008). Gastric MANECs were a heterogeneous group with different tumor grades, histologic subtypes, combination patterns, and patient outcomes. Previous classifications were evaluated. This study proves that histologic characteristics correlate with clinical outcomes. Our findings are complements to the latest prognostic classification.