Proto-oncogene Pokemon in thyroid cancer: a potential promoter of tumorigenesis in papillary thyroid carcinoma

Background@#Pokemon is an oncogenic transcription regulator that plays a critical role in cellular differentiation. Although it has been found to be overexpressed in several types of cancer involving different organs, its role in thyroid gland has yet to be reported. The objective of this study was to evaluate the expression of Pokemon in papillary thyroid carcinoma (PTC) based on clinicopathological parameters. @*Methods@#Tissue microarray samples derived from patients with PTC or benign thyroid disease were used to evaluate Pokemon expression based on immunohistochemical analysis. Correlations of its expression with various clinicopathological parameters were then analyzed. @*Results@#Pokemon expression was observed in 22.0% of thyroid follicular cells from the normal group, 44.0% from the group with benign thyroid diseases, and 92.1% from the group with PTC (p < .001). The intensity of Pokemon expression was markedly higher in the PTC group. Pokemon expression level and PTC tumor size showed an inverse correlation. T1a tumors showed strong expression levels of Pokemon. However, larger tumors showed weak expression (p = .006). @*Conclusions@#Pokemon expression is associated with tumorigenesis of PTC, with expression showing an inverse correlation with PTC tumor size. This might be related to the negative regulation of aerobic glycolysis by Pokemon.

Standardization of the pathologic diagnosis of appendiceal mucinous neoplasms

Although the understanding of appendiceal mucinous neoplasms (AMNs) and their relationship with disseminated peritoneal mucinous disease have advanced, the diagnosis, classification, and treatment of AMNs are still confusing for pathologists and clinicians. The Gastrointestinal Pathology Study Group of the Korean Society of Pathologists (GPSG-KSP) proposed a multicenter study and held a workshop for the “Standardization of the Pathologic Diagnosis of the Appendiceal Mucinous Neoplasm” to overcome the controversy and potential conflicts. The present article is focused on the diagnostic criteria, terminologies, tumor grading, pathologic staging, biologic behavior, treatment, and prognosis of AMNs and disseminated peritoneal mucinous disease. In addition, GPSG-KSP proposes a checklist of standard data elements of appendiceal epithelial neoplasms to standardize pathologic diagnosis. We hope the present article will provide pathologists with updated knowledge on how to handle and diagnose AMNs and disseminated peritoneal mucinous disease.

Proto-oncogene Pokemon in thyroid cancer: a potential promoter of tumorigenesis in papillary thyroid carcinoma

Background@#Pokemon is an oncogenic transcription regulator that plays a critical role in cellular differentiation. Although it has been found to be overexpressed in several types of cancer involving different organs, its role in thyroid gland has yet to be reported. The objective of this study was to evaluate the expression of Pokemon in papillary thyroid carcinoma (PTC) based on clinicopathological parameters. @*Methods@#Tissue microarray samples derived from patients with PTC or benign thyroid disease were used to evaluate Pokemon expression based on immunohistochemical analysis. Correlations of its expression with various clinicopathological parameters were then analyzed. @*Results@#Pokemon expression was observed in 22.0% of thyroid follicular cells from the normal group, 44.0% from the group with benign thyroid diseases, and 92.1% from the group with PTC (p < .001). The intensity of Pokemon expression was markedly higher in the PTC group. Pokemon expression level and PTC tumor size showed an inverse correlation. T1a tumors showed strong expression levels of Pokemon. However, larger tumors showed weak expression (p = .006). @*Conclusions@#Pokemon expression is associated with tumorigenesis of PTC, with expression showing an inverse correlation with PTC tumor size. This might be related to the negative regulation of aerobic glycolysis by Pokemon.

Standardization of the pathologic diagnosis of appendiceal mucinous neoplasms

Although the understanding of appendiceal mucinous neoplasms (AMNs) and their relationship with disseminated peritoneal mucinous disease have advanced, the diagnosis, classification, and treatment of AMNs are still confusing for pathologists and clinicians. The Gastrointestinal Pathology Study Group of the Korean Society of Pathologists (GPSG-KSP) proposed a multicenter study and held a workshop for the “Standardization of the Pathologic Diagnosis of the Appendiceal Mucinous Neoplasm” to overcome the controversy and potential conflicts. The present article is focused on the diagnostic criteria, terminologies, tumor grading, pathologic staging, biologic behavior, treatment, and prognosis of AMNs and disseminated peritoneal mucinous disease. In addition, GPSG-KSP proposes a checklist of standard data elements of appendiceal epithelial neoplasms to standardize pathologic diagnosis. We hope the present article will provide pathologists with updated knowledge on how to handle and diagnose AMNs and disseminated peritoneal mucinous disease.

A scoring system for the diagnosis of non-alcoholic steatohepatitis from liver biopsy

Background@#Liver biopsy is the essential method to diagnose non-alcoholic steatohepatitis (NASH), but histological features of NASH are too subjective to achieve reproducible diagnoses in early stages of disease. We aimed to identify the key histological features of NASH and devise a scoring model for diagnosis. @*Methods@#Thirteen pathologists blindly assessed 12 histological factors and final histological diagnoses (‘not-NASH,’ ‘borderline,’ and ‘NASH’) of 31 liver biopsies that were diagnosed as non-alcoholic fatty liver disease (NAFLD) or NASH before and after consensus. The main histological parameters to diagnose NASH were selected based on histological diagnoses and the diagnostic accuracy and agreement of 12 scoring models were compared for final diagnosis and the NAFLD Activity Score (NAS) system. @*Results@#Inter-observer agreement of final diagnosis was fair (κ = 0.25) before consensus and slightly improved after consensus (κ = 0.33). Steatosis at more than 5% was the essential parameter for diagnosis. Major diagnostic factors for diagnosis were fibrosis except 1C grade and presence of ballooned cells. Minor diagnostic factors were lobular inflammation ( ≥ 2 foci/ × 200 field), microgranuloma, and glycogenated nuclei. All 12 models showed higher inter-observer agreement rates than NAS and post-consensus diagnosis (κ = 0.52–0.69 vs. 0.33). Considering the reproducibility of factors and practicability of the model, summation of the scores of major (× 2) and minor factors may be used for the practical diagnosis of NASH. @*Conclusions@#A scoring system for the diagnosis of NAFLD would be helpful as guidelines for pathologists and clinicians by improving the reproducibility of histological diagnosis of NAFLD.

Standardized Pathology Report for Colorectal Cancer, 2nd Edition

The first edition of the ‘Standardized Pathology Report for Colorectal Cancer,’ which was developed by the Gastrointestinal Pathology Study Group (GIP) of the Korean Society of Pathologists, was published 13 years ago. Meanwhile, there have been many changes in the pathologic diagnosis of colorectal cancer (CRC), pathologic findings included in the pathology report, and immunohistochemical and molecular pathology required for the diagnosis and treatment of colorectal cancer. In order to reflect these changes, we (GIP) decided to make the second edition of the report. The purpose of this standardized pathology report is to provide a practical protocol for Korean pathologists, which could help diagnose and treat CRC patients. This report consists of “standard data elements” and “conditional data elements.” Basic pathologic findings and parts necessary for prognostication of CRC patients are classified as “standard data elements,” while other prognostic factors and factors related to adjuvant therapy are classified as “conditional data elements” so that each institution could select the contents according to the characteristics of the institution. The Korean version is also provided separately so that Korean pathologists can easily understand and use this report. We hope that this report will be helpful in the daily practice of CRC diagnosis.

Inter-observer Reproducibility in the Pathologic Diagnosis of Gastric Intraepithelial Neoplasia and Early Carcinoma in Endoscopic Submucosal Dissection Specimens: A Multi-center Study / Journal of the Korean Cancer Association, 대한암학회지

PURPOSE: The diagnostic criteria of gastric intraepithelial neoplasia (IEN) are controversial across the world. We investigated how many discrepancies occur in the pathologic diagnosis of IEN and early gastric carcinoma in endoscopic submucosal dissection (ESD) specimens, and evaluated the reasons of the discordance. MATERIALS AND METHODS: We retrospectively reviewed 1,202 ESD specimens that were originally diagnosed as gastric IEN and early carcinoma at 12 institutions. RESULTS: The final consensus diagnosis of carcinoma were 756 cases, which were originally 692 carcinomas (91.5%), 43 high-grade dysplasias (5.7%), 20 low-grade dysplasias (2.6%), and 1 others (0.1%), respectively. High- and low-grade dysplasia were finally made in 63 and 342 cases, respectively. The diagnostic concordance with the consensus diagnosis was the highest for carcinoma (91.5%), followed by low-grade dysplasia (86.3%), others (63.4%) and high-grade dysplasia (50.8%). The general kappa value was 0.83, indicating excellent concordance. The kappa values of individual institutions ranged from 0.74 to 1 and correlated with the proportion of carcinoma cases. The cases revised to a final diagnosis of carcinoma exhibited both architectural abnormalities and cytologic atypia. The main differential points between low- and high-grade dysplasias were the glandular distribution and glandular shape. Additional features such as the glandular axis, surface maturation, nuclear stratification and nuclear polarity were also important. CONCLUSION: The overall concordance of the diagnosis of gastric IEN and early carcinoma in ESD specimens was excellent. It correlated with the proportion of carcinoma cases, demonstrating that the diagnostic criteria for carcinoma are more reproducible than those for dysplasia.

Coexistence of metastatic thyroid cancer and tuberculosis in a single neck lymph node: a rare association

No abstract available.

Prognostic Role of Metastatic Lymph Node Ratio in Papillary Thyroid Carcinoma

BACKGROUND: The aim of this study is to elucidate the clinicopathological significances, including the prognostic role, of metastatic lymph node ratio (mLNR) and tumor deposit diameter in papillary thyroid carcinoma (PTC) through a retrospective review and meta-analysis. METHODS: We categorized the cases into high (≥ 0.44) and low mLNR (< 0.44) and investigated the correlations with clinicopathological parameters in 64 PTCs with neck level VI lymph node (LN) metastasis. In addition, meta-analysis of seven eligible studies was used to investigate the correlation between mLNR and survival. RESULTS: Among 64 PTCs with neck level VI LN metastasis, high mLNR was found in 34 PTCs (53.1%). High mLNR was significantly correlated with macrometastasis (tumor deposit diameter ≥ 0.2 cm), extracapsular spread, and number of metastatic LNs. Based on linear regression test, mLNR was significantly increased by the largest LN size but not the largest metastatic LN (mLN) size. High mLNR was not correlated with nuclear factor κB or cyclin D1 immunohistochemical expression, Ki-67 labeling index, or other pathological parameters of primary tumor. Based on meta-analysis, high mLNR significantly correlated with worse disease-free survival at the 5-year and 10-year follow-up (hazard ratio [HR], 4.866; 95% confidence interval [CI], 3.527 to 6.714 and HR, 5.769; 95% CI, 2.951 to 11.275, respectively). CONCLUSIONS: Our data showed that high mLNR significantly correlated with worse survival, macrometastasis, and extracapsular spread of mLNs. Further cumulative studies for more detailed criteria of mLNR are needed before application in daily practice.

External Validation of the Endoscopic Features of Sessile Serrated Adenomas in Expert and Trainee Colonoscopists

BACKGROUND/AIMS: It is unclear whether the endoscopic features of sessile serrated adenomas (SSAs) would be useful to trainee colonoscopists to predict SSA. Therefore, the present study aimed to identify features that expert and trainee colonoscopists can use to independently and reliably predict SSA by using high-resolution white-light endoscopy. METHODS: Endoscopic images of 81 polyps (39 SSAs, 22 hyperplastic polyps, and 20 tubular adenomas) from 43 patients were retrospectively evaluated by 10 colonoscopists (four experts and six trainees). Eight endoscopic features of SSAs were assessed for each polyp. RESULTS: According to multivariable analysis, a mucous cap (odds ratio [OR], 10.44; 95% confidence interval [CI], 5.72 to 19.07), indistinctive borders (OR, 4.21; 95% CI, 2.74 to 7.16), dark spots (OR, 3.64; 95% CI, 1.89 to 7.00), and cloud-like surface (OR, 2.43; 95% CI, 1.27 to 4.668) were independent predictors of SSAs. Among these, a mucous cap, indistinctive borders, and cloud-like surface showed moderate interobserver agreement (mean κ>0.40) among experts and trainees. When ≥1 of the three predictors was observed, the sensitivity and specificity for diagnosing SSAs were 79.0% and 81.4%, respectively. CONCLUSIONS: Colonoscopy trainees and experts can use several specific endoscopic features to independently and reliably predict SSAs.

Detection of Tumor Multifocality Is Important for Prediction of Tumor Recurrence in Papillary Thyroid Microcarcinoma: A Retrospective Study and Meta-Analysis

BACKGROUND: The clinicopathological characteristics and conclusive treatment modality for multifocal papillary thyroid microcarcinoma (mPTMC) have not been fully established. METHODS: A retrospective study, systematic review, and meta-analysis were conducted to elucidate the clinicopathological significance of mPTMC. We investigated the multiplicity of 383 classical papillary thyroid microcarcinomas (PTMCs) and the clinicopathological significance of incidental mPTMCs. Correlation between tumor recurrence and multifocality in PTMCs was evaluated through a systematic review and meta-analysis. RESULTS: Tumor multifocality was identified in 103 of 383 PTMCs (26.9%). On linear regression analysis, primary tumor diameter was significantly correlated with tumor number (R2=0.014, p=.021) and supplemental tumor diameter (R2=0.117, p=.023). Of 103 mPTMCs, 61 (59.2%) were non-incidental, with tumor detected on preoperative ultrasonography, and 42 (40.8%) were diagnosed (incidental mPTMCs) on pathological examination. Lymph node metastasis and higher tumor stage were significantly correlated with tumor multifocality. However, there was no difference in nodal metastasis or tumor stage between incidental and non-incidental mPTMCs. On meta-analysis, tumor multifocality was significantly correlated with tumor recurrence in PTMCs (odds ratio, 2.002; 95% confidence interval, 1.475 to 2.719, p<.001). CONCLUSIONS: Our results show that tumor multifocality in PTMC, regardless of manner of detection, is significantly correlated with aggressive tumor behavior.

Interobserver Agreement on Pathologic Features of Liver Biopsy Tissue in Patients with Nonalcoholic Fatty Liver Disease

BACKGROUND: The histomorphologic criteria for the pathological features of liver tissue from patients with non-alcoholic fatty liver disease (NAFLD) remain subjective, causing confusion among pathologists and clinicians. In this report, we studied interobserver agreement of NAFLD pathologic features and analyzed causes of disagreement. METHODS: Thirty-one cases of clinicopathologically diagnosed NAFLD from 10 hospitals were selected. One hematoxylin and eosin and one Masson's trichrome-stained virtual slide from each case were blindly reviewed with regard to 12 histological parameters by 13 pathologists in a gastrointestinal study group of the Korean Society of Pathologists. After the first review, we analyzed the causes of disagreement and defined detailed morphological criteria. The glass slides from each case were reviewed a second time after a consensus meeting. The degree of interobserver agreement was determined by multi-rater kappa statistics. RESULTS: Kappa values of the first review ranged from 0.0091-0.7618. Acidophilic bodies (k = 0.7618) and portal inflammation (k = 0.5914) showed high levels of agreement, whereas microgranuloma (k = 0.0984) and microvesicular fatty change (k = 0.0091) showed low levels of agreement. After the second review, the kappa values of the four major pathological features increased from 0.3830 to 0.5638 for steatosis grade, from 0.1398 to 0.2815 for lobular inflammation, from 0.1923 to 0.3362 for ballooning degeneration, and from 0.3303 to 0.4664 for fibrosis. CONCLUSIONS: More detailed histomorphological criteria must be defined for correct diagnosis and high interobserver agreement of NAFLD.

Core Needle Biopsy Is a More Conclusive Follow-up Method Than Repeat Fine Needle Aspiration for Thyroid Nodules with Initially Inconclusive Results: A Systematic Review and Meta-Analysis

BACKGROUND: This study investigated the appropriate management of thyroid nodules with prior non-diagnostic or atypia of undetermined significance/follicular lesion of undetermined significance (AUS/FLUS) through a systematic review and meta-analysis. METHODS: This study included 4,235 thyroid nodules from 26 eligible studies. We investigated the conclusive rate of follow-up core needle biopsy (CNB) or repeat fine needle aspiration (rFNA) after initial fine needle aspiration (FNA) with non-diagnostic or AUS/FLUS results. A diagnostic test accuracy (DTA) review was performed to determine the diagnostic role of the follow-up CNB and to calculate the area under the curve (AUC) on the summary receiver operating characteristic (SROC) curve. RESULTS: The conclusive rates of follow-up CNB and rFNA after initial FNA were 0.879 (95% confidence interval [CI], 0.801 to 0.929) and 0.684 (95% CI, 0.627 to 0.736), respectively. In comparison of the odds ratios of CNB and rFNA, CNB had more frequent conclusive results than rFNA (odds ratio, 5.707; 95% CI, 2.530 to 12.875). Upon subgroup analysis, follow-up CNB showed a higher conclusive rate than rFNA in both initial non-diagnostic and AUS/FLUS subgroups. In DTA review of followup CNB, the pooled sensitivity and specificity were 0.94 (95% CI, 0.88 to 0.97) and 0.88 (95% CI, 0.84 to 0.91), respectively. The AUC for the SROC curve was 0.981, nearing 1. CONCLUSIONS: Our results show that CNB has a higher conclusive rate than rFNA when the initial FNA produced inconclusive results. Further prospective studies with more detailed criteria are necessary before follow-up CNB can be applied in daily practice.

Using Forceps Biopsy after Small Submucosal Dissection in the Diagnosis of Gastric Subepithelial Tumors

The current tissue sampling techniques for subepithelial tumors (SETs) of the gastrointestinal (GI) tract have limited diagnostic efficacy. We evaluated the diagnostic yield and safety of forceps biopsies after small endoscopic submucosal dissection (SESD biopsies) in the diagnosis of gastric SETs. A total of 42 patients with gastric SETs > 10 mm were prospectively enrolled between May 2013 and October 2014. A dual knife was used to incise the mucosa and submucosa and forceps biopsies were then introduced deep into the lesion. To compare SESD biopsies with EUS-FNA, we used the retrospective data of 30 EUS-FNA cases. The diagnostic yield of SESD biopsies was comparable to that of EUS-FNA (35/42, 83.3% vs. 24/30, 80.0%, P = 0.717). The mean procedure time of SESD biopsies was shorter than that of EUS-FNA (10 vs. 37 minutes, P < 0.001). There were no procedure-related adverse events in the both group. The pathological diagnoses in SESD biopsies group included 15 leiomyomas, 7 GISTs, 10 heterotopic pancreases, 2 lipomas, and one other lesion. SESD biopsies are an easy, effective and safe technique for the diagnosis of gastric SETs and its diagnostic yield is comparable to that of EUS-FNA. This technique may be a reliable alternative to conventional EUS-FNA (Clinical trial registration No. KCT0000730).

High Expression of Urokinase-Type Plasminogen Activator Is Associated with Lymph Node Metastasis of Invasive Ductal Carcinoma of the Breast / 한국유방암학회지

PURPOSE: In the present study, we evaluated the levels of urokinase-type plasminogen activator (uPA) and plasminogen activator inhibitor 1 (PAI-1) by performing immunohistochemical staining to determine whether they were reliable prognostic markers in patients with breast cancer. METHODS: Demographic and clinicopathological parameters of 214 patients with invasive ductal carcinoma (IDC) and 80 patients with ductal carcinoma in situ (DCIS) who were diagnosed and treated from 2006 to 2010 were analyzed. Tissue microarray was constructed and immunohistochemical staining was performed for each specimen. RESULTS: Univariate analyses showed that age at diagnosis, history of hormone replacement therapy, radiation therapy, skin and chest wall invasion, Paget disease, lymphovascular invasion, estrogen receptor positivity, and triple-negative subtype were significantly associated with patient prognosis (p<0.005). Patients with DCIS showed higher PAI-1 expression than patients with IDC (82.5% and 36.2%, respectively; p=0.012). Lymph node metastasis was more frequent in patients with high uPA levels than in patients with low uPA levels (p=0.001). CONCLUSION: Our results suggested that PAI-1 was involved in tumor progression in the early stages of breast cancer, such as DCIS. In addition, our results suggested that high uPA levels were associated with the lymph node metastasis of IDC.

Total Surface Area Is Useful for Differentiating between Aggressive and Favorable Multifocal Papillary Thyroid Carcinomas

PURPOSE: The purpose of the present study was to identify more useful parameters for predicting behaviors of multifocal papillary thyroid carcinoma (PTC). MATERIALS AND METHODS: We investigated dominant tumor diameter (TD), total tumor diameter (TTD), and total surface area (TSA) in tumors from 588 patients and evaluated their usefulness as parameters for assessment of tumor behaviors in multifocal PTCs. RESULTS: In 588 PTCs, tumor multifocality was found in 179 PTCs (30.4%). Multifocal tumors were significantly associated with extrathyroidal extension, lymph node metastasis, and higher tumor stage grouping (p3.14 cm2 had higher rates of nodal metastasis than mPMCs with TSA 1.0 cm and with TTD 3.14 cm2 than in unifocal papillary thyroid microcarcinomas (uPMCs) (TD 1.0 cm) (p=0.244). CONCLUSION: Our results suggest that mPMCs with TSA >3.14 cm2 show more aggressive behavior than uPMCs and mPMCs with TSA < or =3.14 cm2. TSA could be useful in distinguishing aggressive mPMCs from favorable cases.

Prognostic Significance of Defining L-Cell Type on the Biologic Behavior of Rectal Neuroendocrine Tumors in Relation with Pathological Parameters / Journal of the Korean Cancer Association, 대한암학회지

PURPOSE: In 2010, the World Health Organization categorized L-cell type neuroendocrine tumors (NETs) as tumors of uncertain malignancy, while all others were classified as malignant. However, the diagnostic necessity of L-cell immunophenotyping is unclear, as are tumor stage and grade that may guide diagnosis and management. To clarify the predictive markers of rectal neuroendocrine neoplasms (NENs), 5- and 10-year overall survival (OS) was analyzed by pathological parameters including L-cell phenotype. MATERIALS AND METHODS: A total of 2,385 rectal NENs were analyzed from our previous multicenter study and a subset of 170 rectal NENs was immunophenotyped. RESULTS: In univariate survival analysis, tumor grade (p 10, is useful in defining L-Cell type. In this study, an L-cell immunophenotype was found in 83.5% of all rectal NENs and most, but not all L-cell type tumors were NET G1, small (< 10 mm) and confined to the mucosa/submucosa. CONCLUSION: From these results, the biological behavior of rectal NENs does not appear to be determined by L-cell type alone but instead by a combination of pathological parameters.

Diagnostic Coding for Intramucosal Carcinoma and Neuroendocrine Tumor in the Colorectum: Proposal for Avoiding Confusing Coding in Korea

Applying proper coding is important for doctors practicing gastroenterology. The coding systems established by various organizations define tumors differently. As a result of changing concepts of tumor classification, there are coding and reimbursement issues following the confirmation of malignant lesions by nationwide cancer screening in patients with intramucosal carcinoma and neuroendocrine tumors of the colorectum. In addition, there have been discrepancies between the views of endoscopists and pathologists regarding tumor coding. The Korean Society of Gastrointestinal Endoscopy held an expert meeting and established a consensus for the coding of intramucosal carcinoma and neuroendocrine tumor of the colorectum.

Diagnostic Coding for Intramucosal Carcinoma and Neuroendocrine Tumor in the Colorectum: Proposal for Avoiding Confusing Coding in Korea

Applying proper coding is important for doctors practicing gastroenterology. The coding systems established by various organizations define tumors differently. As a result of changing concepts of tumor classification, there are coding and reimbursement issues following the confirmation of malignant lesions by nationwide cancer screening in patients with intramucosal carcinoma and neuroendocrine tumors of the colorectum. In addition, there have been discrepancies between the views of endoscopists and pathologists regarding tumor coding. The Korean Society of Gastrointestinal Endoscopy held an expert meeting and established a consensus for the coding of intramucosal carcinoma and neuroendocrine tumor of the colorectum.

MUC2 Expression Is Correlated with Tumor Differentiation and Inhibits Tumor Invasion in Gastric Carcinomas: A Systematic Review and Meta-analysis

BACKGROUND: While MUC2 is expressed in intestinal metaplasia and malignant lesions, the clinicopathological significance of MUC2 expression is not fully elucidated in gastric carcinoma (GC). METHODS: The present study investigated the correlation between MUC2 expression and clinicopathological parameters in 167 human GCs. In addition, to confirm the clinicopathological significance of MUC2 expression, we performed a systematic review and meta-analysis in 1,832 GCs. RESULTS: MUC2 expression was found in 58 of 167 GCs (34.7%). MUC2-expressing GC showed lower primary tumor (T), regional lymph node (N), and tumor node metastasis (TNM) stages compared with GCs without MUC2 expression (p=.001, p=.001, and p=.011, respectively). However, MUC2 expression was not correlated with Lauren's classification and tumor differentiation. In meta-analysis, MUC2 expression was significantly correlated with differentiation and lower tumor stage (odds ratio [OR], 1.303; 95% confidence interval [CI], 1.020 to 1.664; p = .034 and OR, 1.352; 95% CI, 1.055 to 1.734; p = .017, respectively) but not with Lauren's classification, pN stage, or pTNM stage. CONCLUSIONS: MUC2 expression was correlated with a lower tumor depth and lower lymph node metastasis in our study; the meta-analysis showed a correlation of MUC2 expression with tumor differentiation and lower tumor depth.