Mucinous gastric carcinomas: clinicopathologic and molecular analyses

Comparison of Clinicopathological Features and Prognosis of Mucinous Gastric Carcinoma and other Gastric Cancers: A Retrospective Study of 4,417 Patients

BACKGROUND

Mucinous gastric carcinoma (MGC) is a distinct histologic subtype of gastric cancer (GC) that is often diagnosed at an advanced stage. The clinicopathological characteristics and prognosis of MGC, when compared to adenocarcinoma and signet-ring cell carcinoma (SRCC), are currently subjects of debate and require further investigation.

METHODS

In this study, we conducted an investigation on 4,417 patients who were hospitalized with GC at Zhejiang Cancer Hospital between April 2008 and December 2019. The objective was to compare the prognosis and clinicopathological characteristics of MGC with other types of GC.

RESULTS

In comparison to adenocarcinoma, MGC patients exhibited more advanced tumor infiltration (p < 0.001), lower tumor differentiation (p < 0.001), and higher rates of preoperative tumor marker positivity (except for AFP and CA125) (all p < 0.05). However, after propensity score matching (PSM) to eliminate confounding factors, MGC patients surprisingly exhibited a better prognosis than adenocarcinoma patients (p = 0.008), and the results in multifactorial COX regression were similar (HR = 0.792, 95% CI 0.629-0.997, p = 0.047). Among patients with MGC, age, pN stage, as well as preoperative levels of CA125 and CA724 (all p < 0.05), emerged as independent prognostic markers. While overall survival did not significantly differ between MGC and SRCC (p = 0.196), significant survival disparities emerged in advanced-stage patients (p = 0.009), with MGC showing better survival rates. Furthermore, a nomogram was developed to predict 1-, 3-, and 5-year survival in gastric cancer patients based on various factors, achieving a C-index of 0.772 (95% CI: 0.745-0.799).

CONCLUSIONS

While the poorer prognosis associated with MGC may be linked to its advanced stage and lower degree of differentiation, its biological behavior could contribute to improved survival.

The Role of Mucin Expression in the Diagnosis of Oesophago-Gastric Cancer: A Systematic Literature Review

Survival in oesophago-gastric cancer (OGC) is poor due to early diagnostic challenges. Non-invasive risk stratification may identify susceptible patients with pre-malignant or benign disease. Following diagnostic confirmation with endoscopic biopsy, early OGC may be treated sooner. Mucins are transmembrane glycoproteins implicated in OGC with potential use as biomarkers of malignant transformation. This systematic review defines the role of mucins in OGC diagnosis. A literature search of MEDLINE, Web of Science, Embase and Cochrane databases was performed following PRISMA protocols for studies published January 1960-December 2022. Demographic data and data on mucin sampling and analysis methods were extracted. The review included 124 studies (n = 11,386 patients). Gastric adenocarcinoma (GAc) was the commonest OG malignancy (n = 101) followed by oesophageal adenocarcinoma (OAc, n = 24) and squamous cell carcinoma (OSqCc, n = 10). Mucins MUC1, MUC2, MUC5AC and MUC6 were the most frequently implicated. High MUC1 expression correlated with poorer prognosis and metastases in OSqCc. MUC2 expression decreases during progression from healthy mucosa to OAc, causing reduced protection from gastric acid. MUC5AC was upregulated, and MUC6 downregulated in GAc. Mucin expression varies in OGC; changes may be epigenetic or mutational. Profiling upper GI mucin expression in OGC, with pre-malignant, benign and healthy controls may identify potential early diagnostic biomarkers.

Cd44v6 acts as a directional responding factor in the process of transcoelomic metastasis from gastric carcinoma to Krukenberg tumor

INTRODUCTION

Due to the limited number of studies focusing on the optimal treatment of multiple Krukenberg tumor (KT)-gastric carcinoma (KT - GC), it is necessary to conduct large-scale studies to confirm the definite role of serum tumor markers in the diagnosis and prognosis of KT. Moreover, the clinical significance of variant 6 of CD44 (CD44v6) in transcoelomic metastasis should be considered.

AREAS COVERED

This review covers molecular pre-cancer diagnosis, gastric carcinoma metastasis, and anti-cancer treatments. Additionally, gastrointestinal cancer metastasis is a key area for improvement.

EXPERT OPINION

The detection of CD44v6 differs in the World Health Organization Classification of Gastric Adenocarcinoma, the Lauren Classification of Gastric Adenocarcinoma, and the anatomic location of gastric adenocarcinoma. The results were compared among the three groups. The mechanism of gastric adenocarcinoma metastasis still requires further elucidation. CD44v6 molecular detection helps clarify the pre-cancer diagnosis of KT before seeding. If subsequent studies confirm its role as a signaling molecule, it could pave the way for new research directions in clinical practice; however, additional academic confirmation is necessary.

Primary renal mucinous adenocarcinoma masquerading as a giant renal cyst: a case report

Mucinous adenocarcinoma of the kidney is rarely reported in the literature. We present a previously unreported mucinous adenocarcinoma arising from the renal parenchyma. A 55-year-old male patient with no complaints showed a large cystic hypodense lesion in the upper left kidney on contrast-enhanced computed tomography (CT) scan. A left renal cyst was initially considered, and a partial nephrectomy (PN) was performed. During the operation, a large amount of jelly-like mucus and bean-curd-like necrotic tissue was found in the focus. The pathological diagnosis was mucinous adenocarcinoma, and further systemic examination revealed no clinical evidence of primary disease elsewhere. Then the patient underwent left radical nephrectomy (RN), and the cystic lesion was found in the renal parenchyma, while neither the collecting system nor the ureters were involved. Postoperative sequential chemotherapy and radiotherapy were administered, and no signs of disease recurrence were observed over 30 months of follow-up. Based on a literature review, we summarize the lesion with rarity and the associated dilemma in preoperative diagnosis and treatment. Given the high degree of malignancy, a careful history analysis accompanied by dynamic observation of imaging and tumor markers is recommended for the diagnosis of the disease. Comprehensive treatment based on surgery may improve its clinical outcomes.

Relationship between the deep features of the full-scan pathological map of mucinous gastric carcinoma and related genes based on deep learning

Background

Long-term differential expression of disease-associated genes is a crucial driver of pathological changes in mucinous gastric carcinoma. Therefore, there should be a correlation between depth features extracted from pathology-based full-scan images using deep learning and disease-associated gene expression. This study tried to provides preliminary evidence that long-term differentially expressed (disease-associated) genes lead to subtle changes in disease pathology by exploring their correlation, and offer a new ideas for precise analysis of pathomics and combined analysis of pathomics and genomics.

Methods

Full pathological scans, gene sequencing data, and clinical data of patients with mucinous gastric carcinoma were downloaded from TCGA data. The VGG-16 network architecture was used to construct a binary classification model to explore the potential of VGG-16 applications and extract the deep features of the pathology-based full-scan map. Differential gene expression analysis was performed and a protein-protein interaction network was constructed to screen disease-related core genes. Differential, Lasso regression, and extensive correlation analyses were used to screen for valuable deep features. Finally, a correlation analysis was used to determine whether there was a correlation between valuable deep features and disease-related core genes.

Result

The accuracy of the binary classification model was 0.775 ± 0.129. A total of 24 disease-related core genes were screened, including ASPM, AURKA, AURKB, BUB1, BUB1B, CCNA2, CCNB1, CCNB2, CDCA8, CDK1, CENPF, DLGAP5, KIF11, KIF20A, KIF2C, KIF4A, MELK, PBK, RRM2, TOP2A, TPX2, TTK, UBE2C, and ZWINT. In addition, differential, Lasso regression, and extensive correlation analyses were used to screen eight valuable deep features, including features 51, 106, 109, 118, 257, 282, 326, and 487. Finally, the results of the correlation analysis suggested that valuable deep features were either positively or negatively correlated with core gene expression.

Conclusion

The preliminary results of this study support our hypotheses. Deep learning may be an important bridge for the joint analysis of pathomics and genomics and provides preliminary evidence for long-term abnormal expression of genes leading to subtle changes in pathology.

Korean Practice Guidelines for Gastric Cancer 2022: An Evidence-based, Multidisciplinary Approach

Gastric cancer is one of the most common cancers in Korea and the world. Since 2004, this is the 4th gastric cancer guideline published in Korea which is the revised version of previous evidence-based approach in 2018. Current guideline is a collaborative work of the interdisciplinary working group including experts in the field of gastric surgery, gastroenterology, endoscopy, medical oncology, abdominal radiology, pathology, nuclear medicine, radiation oncology and guideline development methodology. Total of 33 key questions were updated or proposed after a collaborative review by the working group and 40 statements were developed according to the systematic review using the MEDLINE, Embase, Cochrane Library and KoreaMed database. The level of evidence and the grading of recommendations were categorized according to the Grading of Recommendations, Assessment, Development and Evaluation proposition. Evidence level, benefit, harm, and clinical applicability was considered as the significant factors for recommendation. The working group reviewed recommendations and discussed for consensus. In the earlier part, general consideration discusses screening, diagnosis and staging of endoscopy, pathology, radiology, and nuclear medicine. Flowchart is depicted with statements which is supported by meta-analysis and references. Since clinical trial and systematic review was not suitable for postoperative oncologic and nutritional follow-up, working group agreed to conduct a nationwide survey investigating the clinical practice of all tertiary or general hospitals in Korea. The purpose of this survey was to provide baseline information on follow up. Herein we present a multidisciplinary-evidence based gastric cancer guideline.

Clinicopathologic and genomic characteristics of mucinous gastric adenocarcinoma

BACKGROUND

Mucinous gastric adenocarcinoma (MGC) is a rare but distinctive histologic subtype of gastric cancer (GC). The clinico-pathologic and genomic characteristics of MGC have not been well evaluated.

METHODS

We collected individual data from five cohorts targeting the microsatellite instability (MSI) of GC (n = 5089) to evaluate the clinico-pathologic characteristics of MGC. In addition, public genomic databases were used for genomic analysis. The characteristics of MGC were compared with those of non-mucinous GC (NMGC).

RESULTS

MGC (n = 158, 3.1%) showed distinctive characteristics in terms of age, sex, and TNM stage compared to NMGC (n = 4931). MGC was frequently associated with MSI-high (OR: 2.24, 95% confidence interval [CI] 1.44-3.40, p < 0.001), while mutually exclusive to the Epstein-Barr virus type. The prognosis of MGC was better than that of NMGC (adj.HR: 0.731, 95% CI 0.556-0.962, p = 0.025). There was no clear benefit from postoperative chemotherapy in MGC. TP53 was the main driver mutation in the MGC without recurrent variants. MGC was related to high expression of GPR120 and B3GNT6 and moderate regulation of epithelial-mesenchymal transition (EMT)-up signature with a high EMT-down signature, and those characteristics was related to favorable prognosis of GC (log-rank p = 0.044, p < 0.001, p < 0.001, respectively). MSI-H of MGC was associated with low cancer-associate fibroblasts but high CD274 (PD-L1) expression compared to microsatellite stable MGC, suggesting that immune checkpoint inhibitors may be useful for the MSI-H of MGC.

CONCLUSION

MGC could be a surrogate for performing MSI but not the EBV test in GC. Further, its genetic characteristics lead to a favorable prognosis for MGC.

Gastric cancer with calcifications: A case report

BACKGROUND

Mucinous gastric carcinoma (MGC) is a rare histological type of gastric carcinoma. Calcifications, seen on imaging and histopathological preparations, and which are infrequent in other types of gastric carcinoma, are characteristic of MGC. We present a patient with MGC with calcifications of the gastric wall and describe the computerized tomography (CT) features of the lesion and changes in the calcifications before and after chemotherapy.

CASE SUMMARY

A 61-year-old man was admitted to our hospital in May 2020 because of a large, tender abdominal mass. Abdominal CT showed diffuse, irregular thickening of the gastric walls, with miliary and punctate calcifications. There were metastases to the perigastric and retroperitoneal lymph nodes and also peritoneal seeding. Histological examination of a specimen obtained by endoscopic biopsy showed poorly differentiated calcified signet-ring cell gastric cancer. The patient was clinically staged with T4N+M1 disease. He was treated with docetaxel, cisplatin, and fluorouracil as first-line therapy, irinotecan combined with S-1 as second-line chemotherapy, and programmed cell death protein 1 as third-line therapy. The patient underwent a total of nine cycles of chemotherapy. Follow-up CT scans every 3 mo showed continually increasing calcifications. As of this writing, the patient has survived almost 1 year.

CONCLUSION

In this case report, we describe the histopathological and imaging characteristics of a patient with gastric cancer receiving chemotherapy. Multiple punctate calcifications were seen, which gradually increased during chemotherapy. Several possible mechanisms for the calcifications are described, but further research is needed. Future findings may lead to new approaches for the evaluation and treatment of such tumors.

Histological differentiation impacts the tumor immune microenvironment in gastric carcinoma: Relation to the immune cycle

BACKGROUND

Various histological types of gastric carcinomas (GCs) differ in terms of their pathogenesis and their preexisting background, both of which could impact the tumor immune microenvironment (TIME). However, the current understanding of the immune contexture of GC is far from complete.

AIM

To clarify the tumor-host immune interplay through histopathological features and the tumor immune cycle concept.

METHODS

In total, 50 GC cases were examined (15 cases of diffuse GC, 31 patients with intestinal-type GC and 4 cases of mucinous GC). The immunophenotype of GC was assessed and classified as immune desert (ID), immune excluded (IE) or inflamed (Inf) according to CD8+ cell count and spatial pattern. In addition, CD68+ and CD163+ macrophages and programmed death-ligand 1 (PD-L1) expression were estimated.

RESULTS

We found that GCs with different histological differentiation demonstrated distinct immune contexture. Most intestinal-type GCs had inflamed TIMEs rich in both CD8+ cells and macrophages. In contrast, more aggressive diffuse-type GC more often possessed ID characteristics with few CD8+ lymphocytes but abundant CD68+ macrophages, while mucinous GC had an IE-TIME with a prevalence of CD68+ macrophages and CD8+ lymphocytes in the peritumor stroma. PD-L1 expression prevailed mostly in intestinal-type Inf-GC, with numerous CD163+ cells observed. Therefore, GCs of different histological patterns have specific mechanisms of immune escape. While intestinal-type GC was more often related to PD-L1 expression, diffuse and mucinous GCs possessing more aggressive behavior demonstrated low immunogenicity and a lack of tumor antigen recognition or immune cell recruitment into the tumor clusters.

CONCLUSION

These data help to clarify the links between tumor histogenesis and immunogenicity for a better understanding of GC biology and more tailored patient management.

Clinical Outcomes of Mucinous Gastric Carcinomas Compared with Non-mucinous and Signet Ring Cell Carcinomas

Background/Aims

This study examined the clinical features and prognosis of patients with mucinous gastric carcinoma (MGC), non-mucinous gastric carcinoma (NMGC), and signet ring cell gastric carcinoma (SRC).

Methods

A retrospective cohort study was performed, enrolling 65 patients with MGC from January 2007 to December 2016. During the same period, 1,814 patients with histologically proven gastric cancers underwent curative or palliative operations. One hundred and ninety-five NMGC patients were selected as the 1:3 age- and sex-matched control groups. In addition, 200 SRC patients were identified. This study evaluated the demographic features of the patients, pathologic features of the tumor, and the predictive factors, such as the recurrence-free survival and overall survival.

Results

The recurrence rates were significantly high in MGC than in NMGC or SRC (both p<0.01). The proportion of early gastric cancer was lower in the MGC group than in the other groups (p<0.01). In addition, metastatic lymph nodes were found more frequently in the MGC group (p<0.01), and the proportion of initial pT4, M1 stage, was highest in the MGC group. The recurrence-free survival and overall survival in the MGC group were significantly lower than those in the NMGC or SRC. Subgroup analysis showed that patients with the same American Joint Committee on Cancer (AJCC) stage of each cancer group showed a similar prognosis.

Conclusions

MGC frequently presents an advanced stage with an unfavorable prognosis compared to NMGC or SRC. On the other hand, MGC of the same AJCC stage had a similar prognosis to NMGC and SRC.

Musashi1 expression is negatively correlated with numb expression in brain metastases

The expression of tumor stem cell markers musashi1 (msi1) and numb in brain metastases were detected to explore their roles in the development of brain metastases.A total of 51 cases of brain metastasis, 29 cases of primary tumor and 15 cases of normal brain tissue were selected. Immunohistochemistry and reverse transcription polymerase chain reaction (RT-PCR) were used to detect msi1 and numb expression at the protein and mRNA levels. Correlation between msi1 and numb in brain metastases were evaluated.Immunohistochemistry and RT-PCR showed that no significant difference in the expression of msi1 and numb between brain metastases and primary tumors was observed (P > .05); the expression of msi1 and numb in brain metastases was significantly higher than that in normal brain tissues (P < .05); and the expression of msi1 and numb in primary tumors was significantly higher than that in normal brain tissues (P < .05). In general, the expression of msi1 gene was negatively correlated with the expression of numb at mRNA level by Pearson correlation analysis (r = -0.345, P < .05). Additionally, the expression of msi1 and numb in brain metastases was not related to gender, age, and tissue origin (P > .05).Msi1 is highly expressed in brain metastases and primary tumors, while numb is lowly expressed in brain metastases and primary tumors; msi1 and numb are negatively correlated in brain metastases, suggesting that msi1 and numb may have regulatory mechanisms in the development of brain metastases.

Relationship between neuropilin-1 expression and prognosis, according to gastric cancer histology

Neuropilin-1 (NRP-1) is known to be related to various types of cancer and is considered a novel tumor marker or therapeutic target. The aim of this study was to identify the clinical implications of NRP-1 expression in terms of prognosis in patients with gastric cancer. A total of 265 patients who underwent radical gastrectomy for the treatment of gastric cancer from 2008 to 2011 were included in this retrospective study. NRP-1 expression of tumors was determined by immunohistochemistry. The patients' clinicopathological characteristics, operative details, and long-term outcomes were retrospectively analyzed. A total of 181 (68.3%) patients demonstrated expression of NRP-1. No survival difference was observed according to NRP-1 expression in any patient. The patients were divided into the gland formation (GF) and the no gland formation (nGF) types, according to histology. NRP-1 expression rates were 65.6% (84/128) and 70.8% (97/137), respectively. NRP-1 expression was not an independent prognostic factor in the GF group, although patients who expressed NRP-1 had better survival outcomes. In contrast, patients who expressed NRP-1 in the nGF group had worse 5-year survival rates (p = 0.027), and NRP-1 was an independent prognostic factor in a multivariate analysis (hazard ratio, 1.923; 95% confidence interval, 1.041-3.551). NRP-1 expression in patients with nGF type gastric cancer is predictive of a poor prognosis.

The clinicopathological characteristics and genetic alterations of mucinous carcinoma of the stomach

BACKGROUND

Mucinous gastric carcinoma (MGC) is rare and often associated with an advanced stage. The clinicopathological features and prognosis of MGC and non-MGC (NMGC) are controversial.

METHODS

In total, 2637 gastric cancer (GC) patients receiving curative surgery were enrolled. The clinicopathological features and genetic alterations were compared between patients with MGC and NMGC.

RESULTS

Among the 2637 GC patients, 92 (3.5%) had MGC. After propensity score matching, compared to patients with NMGC, patients with MGC had more poorly differentiated tumors, medullary stromal reaction-type tumors, tumors with infiltrating Ming's classification, diffuse-type tumors, more abnormal preoperative serum carbohydrate antigen 19-9 levels, and more advanced T categories. After propensity score matching, there were no significant differences between MGC and NMGC regarding the initial recurrence patterns, 5-year overall survival (OS), and disease-free survival (DFS) rates. Multivariate analysis demonstrated that the MGC cell type is not an independent prognostic factor of OS and DFS. No significant differences in microsatellite instability status, Epstein-Barr virus infection, Helicobacter pylori infection, or genetic mutations were observed between MGC and NMGC. The expression of programmed death-ligand 1 (PD-L1) was significantly higher in MGC than that in NMGC. MGC was diagnosed at a more advanced stage compared with NMGC.

CONCLUSION

MGC itself was not an independent prognostic factor of worse survival. MGC was correlated with higher PD-L1 expression than NMGC, which may have a clinical impact on the treatment of MGC in the future.

Ramifications of secreted mucin MUC5AC in malignant journey: a holistic view

Heavily glycosylated secreted mucin MUC5AC, by the virtue of its cysteine-rich repeats, can form inter- and intramolecular disulfide linkages resulting in complex polymers, which in turn craft the framework of the polymeric mucus gel on epithelial cell surfaces. MUC5AC is a molecule with versatile functional implications including barrier functions to epithelial cells, host-pathogen interaction, immune cell attraction to sites of premalignant or malignant lesions and tumor progression in a context-dependent manner. Differential expression, glycosylation and localization of MUC5AC have been associated with a plethora of benign and malignant pathologies. In this era of robust technologies, overexpression strategies and genetically engineered mouse models, MUC5AC is emerging as a potential diagnostic, prognostic and therapeutic target for various malignancies. Considering the clinical relevance of MUC5AC, this review holistically encompasses its genomic organization, domain structure, glycosylation patterns, regulation, functional and molecular connotation from benign to malignant pathologies. Furthermore, we have here explored the incipient and significant experimental tools that are being developed to study this structurally complex and evolutionary conserved gel-forming mucin.

Mucinous adenocarcinoma and non-mucinous adenocarcinoma: differing clinicopathological characteristics and computed tomography features in gastric cancer

Mucinous gastric carcinoma (MGC) is a rare histological subtype of gastric cancer. The clinicopathological characteristics and CT features of MGC remain controversial. This study aimed to determine the clinicopathological characteristics and CT features of MGC. We reviewed 62 patients with MGC and 104 patients with non-mucinous gastric carcinoma (NMGC), pathologically confirmed between 2003 and 2015. There are significant differences in some clinicopathological characteristics and CT features between MGC and NMGC. NMGC occurs preferentially in males and more frequently in the lower third of the stomach. Patients with MGC were characterized by larger tumor size, more advanced tumor stages (II and III) and fewer lymphatic invasions. Layered enhancement (83.3%) was the main pattern of MGC, while the most common pattern in NMGC was homogeneous enhancement (52.6%), followed by heterogonous enhancement (34.6%). The degree of enhancement of the inner layer in MGC was significantly higher than in NMGC (ΔCT of portal venous phase: 54.57 Hu vs. 47.19 Hu, P = 0.034), while the middle or outer layer in MGC was significantly less enhanced (ΔCT of portal venous phase: 19.07 Hu vs. 33.09 Hu, P <0.001). Calcifications were more common in MGC (P <0.001). ROC curves revealed that the most effective variables in distinguishing MGC and NMGC were ΔCT of the middle or outer layer in the arterial phase (AUC=0.774) and portal venous phase (AUC=0.774), followed by the attenuation value of the middle or outer layer in the unenhanced phase (AUC=0.763). Calcifications had a high specificity (98.7%) in the diagnosis of MGC. The accuracy (86.1%), sensitivity (83.3%) and specificity (87.2%) of layered enhancement in diagnosing MGC were all high. Therefore, MGC was more likely to have larger tumor size and more advanced tumor stage (II and III) than NMGC. The thicker gastric wall, layered enhancement pattern and calcification were highly suggestive CT features for differentiating MGC from NMGC.

Metastatic spread in patients with gastric cancer

Background

The epidemiology of metastatic gastric cancer is unexplored because cancer registries seldom cover metastatic involvement apart from “present or not”. We used a novel approach by utilizing Swedish registers to assess metastatic spread in gastric cancer. To our knowledge, this is the first nationwide description of metastases in gastric cancer.

Results

The most common sites of metastasis were liver (in 48% of metastatic cancer patients), peritoneum (32%), lung (15%), and bone (12%). Metastases to the lung, nervous system, and bone were more frequent in cardia cancer and men, whereas non-cardia cancer more frequently metastasized within the peritoneum. Signet ring adenocarcinomas more frequently metastasized within the peritoneum, bone and ovaries, and less frequently to the lungs and liver compared with generic adenocarcinoma. The liver and the peritoneum were commonly single metastases while lung metastases occurred frequently together with liver metastases. The median survival in metastatic gastric cancer was 3 months, worst among those with bone and liver metastases (2 months).

Methods

A total of 7,559 patients with gastric cancer were identified. Metastatic patterns and survival depending on sex, age, stage, anatomical location (cardia and non-cardia), and histological type were assessed.

Conclusions

The patterns of metastasis differ notably depending on histological type. Cardia cancer exhibits a completely different metastatic behavior than non-cardia cancer. Awareness of the differing patterns may guide in tailored diagnosis of metastases. Survivors from cardia cancer would benefit from increased surveillance of extraperitoneal metastases. Bone metastases should be considered in patients with signet ring adenocarcinoma if symptoms emerge.

The role of mucin-educated platelet activation in tumor invasiveness: An unfolding concern in the realm of cancer biology

Metastasis is a complex and well-coordinated phenotypic transformation of cancer cells governed by aberrant genetic and molecular pathways. It has been approved as the most consistent cause of cancer death. With emerging insight into the genomics, transcriptomics and proteomics, progress has been made and reasonably large number of molecular pathways of metastasis has been forwarded, but our understanding of precise underlying molecular mechanisms remains largely scarce. It has been well-known for around a decade and more that platelets are intriguingly contributing to the cancer metastasis. However, it is only recently that cancer cells can activate platelets have started to become apparent. Surprisingly, platelets in response to cancer cell activation, supported by research observations, allow cancer cells to escape immune removal, prolong survival in vascular compartment, increased cellular adhesion and develop new cellular niches which eventually help to favor cancer metastasis. Although a widely acknowledged plausible explanation that cancer cells activate platelets to facilitate in their distant spread, the description of this remains to be confirmed. In recent years, mucins, heavily glycosylated peptide structure, have been introduced to be released by several types of cancer cells. They account for poor prognosis in wide array of malignancies, because of their significant ability to induce metastatic process. The mechanism responsible for their increased metastatic propensity remains uncharacterized, but recent work suggested the role of cancer expressed mucins in initiating platelet thrombus. The association of cancer yield mucins, platelets and metastasis therefore suggests a pressing need to explore novel molecular mechanisms and therapeutic targets thereafter.

Gastric cancer: texture analysis from multidetector computed tomography as a potential preoperative prognostic biomarker

OBJECTIVES

To investigate the association between preoperative texture analysis from multidetector computed tomography (MDCT) and overall survival in patients with gastric cancer.

METHODS

Institutional review board approval and informed consent were obtained. Fifty-six patients with biopsy-proved gastric cancer were examined by MDCT and treated with surgery. Image features from texture analysis were quantified, with and without filters for fine to coarse textures. The association with survival time was assessed using Kaplan-Meier and Cox analysis.

RESULTS

The following parameters were significantly associated with a negative prognosis, according to different thresholds: energy [no filter] - Logarithm of relative risk (Log RR): 3.25; p = 0.046; entropy [no filter] (Log RR: 5.96; p = 0.002); entropy [filter 1.5] (Log RR: 3.54; p = 0.027); maximum Hounsfield unit value [filter 1.5] (Log RR: 3.44; p = 0.027); skewness [filter 2] (Log RR: 5.83; p = 0.004); root mean square [filter 1] (Log RR: - 2.66; p = 0.024) and mean absolute deviation [filter 2] (Log RR: - 4.22; p = 0.007).

CONCLUSIONS

Texture analysis could increase the performance of a multivariate prognostic model for risk stratification in gastric cancer. Further evaluations are warranted to clarify the clinical role of texture analysis from MDCT.

KEY POINTS

• Textural analysis from computed tomography can be applied in gastric cancer. • Preoperative non-invasive texture features are related to prognosis in gastric cancer. • Texture analysis could help to evaluate the aggressiveness of this tumour.

Expression of Mismatch Repair Proteins in Early and Advanced Gastric Cancer in Poland

BACKGROUND Mutations in DNA of mismatch repair (MMR) genes result in failure to repair errors that occur during DNA replication in microsatellites, resulting in accumulation of frameshift mutations in these genes and leading to DNA mismatch replication errors and microsatellite instability. Gastric cancers (GCs) with high MSI (MSI-H) are a well-defined subset of carcinomas showing distinctive clinicopathological features. In this study we investigated the rate of MSI and the correlation between MSI status and clinicopathological features of GC. MATERIAL AND METHODS The study included 107 patients with GCs: 61 with advanced gastric cancers (AGC) and 46 with early gastric cancer (EGC). MSI deficiency in GCs was assessed by the immunohistochemical analysis of expression of MMR proteins - MLH1, MSH2, MSH6, and PMS2 - using formalin-fixed and paraffin-embedded tissue. RESULTS A total of 6 (5.6%) MSI-H were observed. The loss of MMR proteins expression was associated with the intestinal type of GC in Lauren classification, and tubular and papillary architecture in WHO classification. There was no statistically significant association between negative MMR expression and other selected clinical parameters: age, sex, tumor location, depth of invasion (EGC and AGC), lymph nodes status, presence of the ulceration, and lymphocytic infiltrate. CONCLUSIONS In the present era of personalized medicine, the histological type of GC and MMR proteins status in cancer cells are very important for the proper surveillance of patients with familial GC and sporadic GCs, as well as for selecting the proper follow-up and treatment. Larger collaborative studies are needed to verify the features of MSI-H GCs in Poland.

Clinicopathological characteristics and outcomes in stage I-III mucinous gastric adenocarcinoma: a retrospective study at a single medical center

Background

The clinicopathological characteristics and outcomes of mucinous gastric adenocarcinoma (GC) remain unclear. We report the clinicopathological features and prognosis of patients with mucinous histology who underwent radical-intent gastrectomy.

Methods

We reviewed the medical records of 1470 patients with pathologically proven undifferentiated GC undergoing radical-intent gastrectomy between 1995 and 2007. The patients were stratified into three groups according to their histological type: mucinous carcinoma (MC), signet ring cell carcinoma (SRCC), and poorly differentiated carcinoma (PDC). Clinicopathological factors affecting prognosis were collected prospectively and analyzed.

Results

In stage III MC, the age and size were significantly greater and larger than in SRCC and PDC; a lower proportion of perineural invasion was identified in MC, and female predominance was noted in SRCC in comparison with MC and PDC. The cumulative overall survival rates of stage I–III GC patients with MC were significantly superior compared to those with PDC, but not SRCC. Stage III GC patients with MC had a better prognosis than those with SRCC or PDC; the difference in survival was not evident in stages I or II.

Conclusions

Thus, MC presents with different clinicopathological features and prognosis from SRCC and PDC. The patients with stage III gastric MC had favorable outcomes.

The Clinicopathological Features and Long-Term Survival Outcomes of Mucinous Gastric Carcinoma: a Consecutive Series of 244 Cases from a Single Institute

BACKGROUND AND OBJECTIVES

Mucinous gastric carcinoma (MGC) is a rare kind of malignancy with unclear prognosis. This study aims to assess the clinicopathological features and prognosis of MGC.

METHODS

We retrospectively analyzed a consecutive series of 244 MGC patients who underwent radical gastrectomy with D2 lymphadenectomy, and compared the data with 260 gastric signet ring cell carcinoma (SRC) patients.

RESULTS

The univariate survival analysis showed that the surgical types, diameter of the primary tumor, the Borrmann type, pathological depth of tumor invasion (pT), pathological number of metastatic lymph node (pN), pathological tumor lymph metastasis (pTNM), and vascular invasion were all significant predictors of survival (all P < 0.05). The multivariate survival analysis revealed that the diameter of the tumor, the Borrmann type, pT, pTNM stage, and vascular invasion as an independent predictive factor of survival (all P < 0.05). Compared with the SRC group, the MGC group had more male patients, more elder patients, larger tumor diameter, more T3 and T4 invasion to the gastric wall, more patients with metastatic lymph nodes, more pTNM stage III, and less Borrmann type 1. The overall survival rate of patients with MGC was significantly lower than that of patients with SRC (P < 0.001).

CONCLUSIONS

MGC was an aggressive malignancy which had unique clinicopathological features.

Mucinous ovarian cancer: A therapeutic review

Mucinous ovarian cancer represents approximately 3% of epithelial ovarian cancers (EOC). Despite this seemingly low prevalence, it remains a diagnostic and therapeutic conundrum that has resulted in numerous attempts to adopt novel strategies in managing this disease. Anecdotally, there has been a prevailing notion that established gold standard systemic regimens should be substituted for those utilised in cancers such as gastrointestinal (GI) malignancies; tumours that share more biological similarities than other EOC subtypes. This review summarises the plethora of small studies which have adopted this philosophy and influenced the design of the multinational GOG142 study, which was ultimately terminated due to poor accrual. To date, there is a paucity of evidence to support delivering 'GI style' chemotherapy for mucinous ovarian cancer over and above carboplatin-paclitaxel doublet therapy. Hence there is an urge to develop studies focused on targeted therapeutic agents driven by refined mutational analysis and conducted within the context of harmonised international collaborations.

Exploring the role and diversity of mucins in health and disease with special insight into non-communicable diseases

Mucins are major glycoprotein components of the mucus that coats the surfaces of cells lining the respiratory, digestive, gastrointestinal and urogenital tracts. They function to protect epithelial cells from infection, dehydration and physical or chemical injury, as well as to aid the passage of materials through a tract i.e., lubrication. They are also implicated in the pathogenesis of benign and malignant diseases of secretory epithelial cells. In Human there are two types of mucins, membrane-bound and secreted that are originated from mucous producing goblet cells localized in the epithelial cell layer or in mucous producing glands and encoded by MUC gene. Mucins belong to a heterogeneous family of high molecular weight proteins composed of a long peptidic chain with a large number of tandem repeats that form the so-called mucin domain. The molecular weight is generally high, ranging between 0.2 and 10 million Dalton and all mucins contain one or more domains which are highly glycosylated. The size and number of repeats vary between mucins and the genetic polymorphism represents number of repeats (VNTR polymorphisms), which means the size of individual mucins can differ substantially between individuals which can be used as markers. In human it is only MUC1 and MUC7 that have mucin domains with less than 40% serine and threonine which in turn could reduce number of PTS domains. Mucins can be considered as powerful two-edged sword, as its normal function protects from unwanted substances and organisms at an arm's length while, malfunction of mucus may be an important factor in human diseases. In this review we have unearthed the current status of different mucin proteins in understanding its role and function in various non-communicable diseases in human with special reference to its organ specific locations. The findings described in this review may be of direct relevance to the major research area in biomedicine with reference to mucin and mucin associated diseases.

Clinicopathologic and molecular features associated with patient age in gastric cancer

AIM: To compare characteristics and prognosis of gastric cancer based on age.

METHODS: A retrospective study was conducted on clinical and molecular data from patients (n = 1658) with confirmed cases of gastric cancer in Seoul National University Bundang Hospital (Seoul, South Korea) from 2003 to 2010 after exclusion of patients diagnosed with lymphoma, gastrointestinal stromal tumor, and metastatic cancer in the stomach. DNA was isolated from tumor and adjacent normal tissue, and a set of five markers was amplified by polymerase chain reaction to assess microsatellite instability (MSI). MSI was categorized as high, low, or stable if ≥ 2, 1, or 0 markers, respectively, had changed. Immunohistochemistry was performed on tissue sections to detect levels of expression of p53, human epidermal growth factor receptor (HER)-2, and epidermal growth factor receptor. Statistical analysis of clinical and molecular data was performed to assess prognosis based on the stratification of patients by age (≤ 45 and > 45 years).

RESULTS: Among the 1658 gastric cancer patients, the number of patients with an age ≤ 45 years was 202 (12.2%; 38.9 ± 0.4 years) and the number of patients > 45 years was 1456 (87.8%; 64.1 ± 0.3 years). Analyses revealed that females were predominant in the younger group (P < 0.001). Gastric cancers in the younger patients exhibited more aggressive features and were at a more advanced stage than those in older patients. Precancerous lesions, such as atrophic gastritis and intestinal metaplasia, were observed less frequently in the older than in the younger group (P < 0.001). Molecular characteristics, including overexpression of p53 (P < 0.001), overexpression of HER-2 (P = 0.006), and MSI (P = 0.006), were less frequent in gastric cancer of younger patients. Cancer related mortality was higher in younger patients (P = 0.048), but this difference was not significant after adjusting for the stage of cancer.

CONCLUSION: Gastric cancer is distinguishable between younger and older patients based on both clinicopathologic and molecular features, but stage is the most important predictor of prognosis.

Clinicopathologic factors and molecular markers related to lymph node metastasis in early gastric cancer

AIM: To analyze predictive factors for lymph node metastasis in early gastric cancer.

METHODS: We analyzed 1104 patients with early gastric cancer (EGC) who underwent a gastrectomy with lymph-node dissection from May 2003 through July 2011. The clinicopathologic factors and molecular markers were assessed as predictors for lymph node metastasis. Molecular markers such as microsatellite instability, human mutL homolog 1, p53, epidermal growth factor receptor (EGFR) and human epidermal growth factor receptor 2 (HER2) were included. The χ² test and logistic regression analysis were used to determine clinicopathologic parameters.

RESULTS: Lymph node metastasis was observed in 104 (9.4%) of 1104 patients. Among 104 cases of lymph node positive patients, 24 patients (3.8%) were mucosal cancers and 80 patients (16.7%) were submucosal. According to histologic evaluation, the number of lymph node metastasis found was 4 (1.7%) for well differentiated tubular adenocarcinoma, 45 (11.3%) for moderately differentiated tubular adenocarcinoma, 36 (14.8%) for poorly differentiated tubular adenocarcinoma, and 19 (8.4%) for signet ring cell carcinoma. Of 690 EGC cases, 77 cases (11.2%) showed EGFR overexpression. HER2 overexpression was present in 110 cases (27.1%) of 406 EGC patients. With multivariate analysis, female gender (OR = 2.281, P = 0.009), presence of lymphovascular invasion (OR = 10.950, P < 0.0001), diameter (≥ 20 mm, OR = 3.173, P = 0.01), and EGFR overexpression (OR = 2.185, P = 0.044) were independent risk factors for lymph node involvement.

CONCLUSION: Female gender, tumor size, lymphovascular invasion and EGFR overexpression were predictive risk factors for lymph node metastasis in EGC.

The molecular background of mucinous carcinoma beyond MUC2

The increasing interest of the oncology community in tumour classification and prediction of outcome to targeted therapies has put emphasis on an improved identification of tumour types. Colorectal mucinous adenocarcinoma (MC) is a subtype that is characterized by the presence of abundant extracellular mucin that comprises at least 50% of the tumour volume and is found in 10–15% of colorectal cancer patients. MC development is poorly understood, however, the distinct clinical and pathological presentation of MC suggests a deviant development and molecular background. In this review we identify common molecular and genetic alterations in colorectal MC. MC is characterized by a high rate of MUC2 expression. Mutation rates in the therapeutically important RAS/RAF/MAPK and PI3K/AKT pathways are significantly higher in MC compared with non‐mucinous adenocarcinoma. Furthermore, mucinous adenocarcinoma shows higher rates of microsatellite instability and is more frequently of the CpG island methylator phenotype. Although the majority of MCs arise from the large intestine, this subtype also develops in other organs, such as the stomach, pancreas, biliary tract, ovary, breast and lung. We compared findings from colorectal MC with tumour characteristics of MCs from other organs. In these organs, MCs show different mutation rates in the RAS/RAF/MAPK and PI3K/AKT pathways as well, but a common mucinous pathway cannot be identified. Identification of conditions and molecular aberrations that are associated with MC generates insight into the aetiology of this subtype and improves understanding of resistance to therapies.

Tropomyosin-related receptor kinase B at the invasive front and tumour cell dedifferentiation in gastric cancer

Background:

Tropomyosin-related receptor kinase B (TrkB) promotes proliferation and invasion, relating to poor prognosis of various malignancies. We examined the role of TrkB at the invasive front of gastric cancer (GC) and its association with tumour cell dedifferentiation and tumour budding.

Methods:

Immunoreactive TrkB was evaluated at the tumour centre and margin using whole-tissue sections of 320 GC patients. Tumour cell dedifferentiation was defined as higher histologic grade at the tumour margin than the surface or tumour centre. Tumour budding was also scored on cytokeratin-stained sections.

Results:

Sixty-five patients (20%) showed higher TrkB expression at the invasive front (TrkB expression was higher at the tumour margin than tumour centre). It was significantly associated with several aggressive phenotypes in the full cohort (n=320). It showed a prognostic significance in test subgroup (n=98) and was identified as an independent prognostic factor (HR=2.09; 95% CI: 1.26–3.53) by multivariate analysis in validation subgroup (n=222). Twenty-one patients showed tumour cell dedifferentiation. In predominantly differentiated tumour, higher TrkB at the invasive front was significantly associated with tumour budding rather than tumour cell dedifferentiation.

Conclusions:

Assessment of immunoreactive TrkB at the invasive front by whole-tissue sections provides prognostic information for GC patients.

The co-expression of functional gastric proteins in dynamic gastric diseases and its clinical significance

Background

Pepsinogen C (PGC) and mucin1 (MUC1) are important physiologically functional gastric proteins; Mucin2 (MUC2) is an “ectopic” functional protein in intestinal metaplasia of gastric mucosa. We analyzed the co-expression of the above-mentioned three proteins in dynamic gastric diseases {superficial gastritis (SG)-atrophic gastritis (AG)--gastric cancer (GC)} as well as different histological types of gastric cancer in order to find molecular phenotypes of gastric cancer and precancerous disease and further explore the potential co-function of PGC, MUC1 and MUC2 in the occurrence and development of gastric cancer.

Methods

The SG-AG-GC sequence was 57-57-70 cases in this case–control study, respectively. Different histological types of GC were 28 cases of highly and moderately differentiated aden ocarcinoma (HMDA)、30 of poorly differentiated adenocarcinoma (PDA) and 12 of mucinous adenocarcinoma (MA) or signet ring cell carcinoma (SRCC). PGC, MUC1 and MUC2 expression in situ were detected in all 184 cases using immunohistochemistry.

Results

Both PGC and MUC1 had a significantly decreased expression in GC than in SG and AG (P < 0.0001 and P < 0.01, respectively); While MUC2 had a significant increased expression in AG than in SG and GC (P < 0.0001). Seven phenotypes of PGC, MUC1 and MUC2 co-expression were found in which PGC+/MUC1+/MUC2- phenotype took 94.7%(54/57) in SG group; PGC+/MUC1+/MUC2+ and PGC-/MUC1+/MUC2+ phenotype took 43.9% (25/57) and 52.6% (30/57) in AG; the phenotypes in GC group appeared variable; extraordinarily, PGC-/MUC1-/MUC2+ phenotype took 100% (6/6) in MA or SRCC group and had a statistical significance compared with others (P < 0.05).

Conclusions

Phenotypes of PGC, MUC1 and MUC2 co-expression in dynamic gastric diseases are variable. In SG group it always showed PGC+/MUC1+/MUC2- phenotype and AG group showed two phenotypes (PGC+/MUC1+/MUC2+ and PGC-/MUC1+/MUC2+); the phenotypes in GC group appeared variable but the phenotype of PGC-/MUC1-/MUC2+ may be a predictive biomarker for diagnosing MA or SRCC, or distinguishing histological MA or SRCC from tubular adenocarcinoma accompanied by mucinous secretion or signet ring cell scattered distribution.

Undifferentiated-type gastric adenocarcinoma: prognostic impact of three histological types

BACKGROUND

The prognostic value of the three constituents of undifferentiated-type gastric adenocarcinoma remains unclear. The present study assessed the clinicopathological characteristics and prognosis of undifferentiated-type mucinous adenocarcinoma (uMAC) and signet ring cell carcinoma (SRC) compared with those of poorly differentiated adenocarcinoma (PDAC).

METHODS

In total, 1,376 patients with undifferentiated-type gastric adenocarcinoma were included, consisting of 1,002 patients diagnosed with PDAC, 54 with uMAC and 320 with SRC. Clinicopathological factors and survival rates were compared among the three histological types.

RESULTS

Significant differences in the distribution of pathological stages were observed among the groups. Patients with SRC had a significantly better survival rate than those with PDAC or uMAC, in both the all patients including non-curative resected patients and curative-resected groups. In addition, there was significant difference in survival between the PDAC and uMAC groups. Multivariate analysis suggested that age, gender, tumor depth, lymph node metastasis and curability significantly affected survival. Histological type was not an independent prognostic factor. There was no significant difference in the pattern of recurrence among the three groups.

CONCLUSIONS

The uMAC and SRC had worse and favorable prognosis compared with PDCA, respectively. However, there were no differences in survival by pathological stage, thus histological type was not an independent predictor of prognosis.

Markers for screening lynch syndrome are reliable and useful for identifying the specimen mislabeling

Background

During specimen processing in surgical pathology laboratories, specimen-related adverse events (SRAEs), such as mislabeling and specimen mixed-up might occur. In these situations, molecular techniques using short tandem repeat (STR) loci are required to identify the personal identity. Microsatellite instability (MSI) test is widely used for screening the hereditary non-polyposis colon cancer (Lynch syndrome) in surgical pathologies using polymorphic STR markers. We tried to evaluate the applicability of the MSI test for SRAEs.

Methods

We obtained 253 MSI test results to analyze the allele frequencies. After calibrating the estimated nucleotide lengths, we calculated the allele frequencies, a random match probability, and a likelihood ratio (LR) of three dinucleotide STR markers (D5S349, D17S250, and D2S123).

Results

The distribution of LR was 136.38 to 5,606,213.10. There was no case of LR<100. In addition, there were 153 cases (60.5%) of LR ranging from 100 to 10,000 and 100 cases (39.5%) of LR>10,000. Furthermore, the combined probability of identity was 9.23×10^-4 and the combined power of exclusion was 0.99908.

Conclusions

Using the three STR markers that are recommended for MSI test, all the cases were positively identified in 1% range and about one-third cases showed high LR (>10,000). These results showed that MSI tests are useful to screen the personal identity in case of SRAE in pathology laboratories.

Tumor size predicts survival in mucinous gastric carcinoma

BACKGROUND

Mucinous gastric carcinoma (MGC) is a distinct histologic subtype of gastric cancer. However, the prognostic significances of the current TNM staging system and histology in MGC have not been studied.

METHODS

206 patients who underwent R0 resection for MGC were classified by tumor size (<3 cm as T1; ≥ 3-5 cm as T2; ≥ 5-9 cm as T3; and ≥ 9 cm as T4). Immunohistochemistry for EGFR and HER2 was also performed.

RESULTS

Tumor sizes ranged from 1.2 to 21.0 cm (median 6.2 cm). Large tumor size (≥ 5 cm) was significantly associated with older patient age, deeper invasion depth, and more frequent lymph node metastasis (P < 0.05). Tumor size was a significant prognostic factor in both univariate (P < 0.001) and multivariate (P < 0.04) analyses. However, depth of invasion was not significant in multivariate analyses. A modified staging system based on tumor size predicted survival more accurately than did the conventional TNM staging system. We verified our results in an independent validation cohort of 123 MGC patients. Overexpression of either EGFR or HER2 was rare.

CONCLUSIONS

In MGCs, tumor size is an independent prognostic factor and a modified TNM system based on tumor size predicted survival accurately.

Histotype-based prognostic classification of gastric cancer

AIM: To test the efficiency of a recently proposed histotype-based grading system in a consecutive series of gastric cancers.

METHODS: Two hundred advanced gastric cancers operated upon in 1980-1987 and followed for a median 159 mo were investigated on hematoxylin-eosin-stained sections to identify low-grade [muconodular, well differentiated tubular, diffuse desmoplastic and high lymphoid response (HLR)], high-grade (anaplastic and mucinous invasive) and intermediate-grade (ordinary cohesive, diffuse and mucinous) cancers, in parallel with a previously investigated series of 292 cases. In addition, immunohistochemical analyses for CD8, CD11 and HLA-DR antigens, pancytokeratin and podoplanin, as well as immunohistochemical and molecular tests for microsatellite DNA instability and in situ hybridization for the Epstein-Barr virus (EBV) EBER1 gene were performed. Patient survival was assessed with death rates per 100 person-years and with Kaplan-Meier or Cox model estimates.

RESULTS: Collectively, the four low-grade histotypes accounted for 22% and the two high-grade histotypes for 7% of the consecutive cancers investigated, while the remaining 71% of cases were intermediate-grade cancers, with highly significant, stage-independent, survival differences among the three tumor grades (P = 0.004 for grade 1 vs 2 and P = 0.0019 for grade 2 vs grade 3), thus confirming the results in the original series. A combined analysis of 492 cases showed an improved prognostic value of histotype-based grading compared with the Lauren classification. In addition, it allowed better characterization of rare histotypes, particularly the three subsets of prognostically different mucinous neoplasms, of which 10 ordinary mucinous cancers showed stage-inclusive survival worse than that of 20 muconodular (P = 0.037) and better than that of 21 high-grade (P < 0.001) cases. Tumors with high-level microsatellite DNA instability (MSI-H) or EBV infection, together with a third subset negative for both conditions, formed the T8 cell-rich HLR group, the largest group among low-grade histotypes. Coexisting HLR proved to be a factor in improved prognosis in tumors with microsatellite instability (P = 0.0015 vs HLR-/MSI-H tumors) or DR type human leukocyte antigen expression (P = 0.033 vs HLR^-/HLA-DR⁺ tumors).

CONCLUSION: Identification of low- and high-grade histotypes can improve the prognostic assessment of a substantial proportion of gastric cancers in routine diagnostic practice.

Clinicopathologic factors associated with HER2-positive gastric cancer and its impact on survival outcomes--a systematic review

With the availability of a therapeutic target and an effective agent in trastuzumab, a systematic examination of the literature to investigate the role of human epidermal growth factor 2 (HER2) as a prognostic factor for survival and its association with clinicopathologic markers may improve treatment. An electronic search of the MEDLINE and PubMed databases (January 1990 to January 2011) was undertaken to identify translational studies that correlated HER2 with clinicopathologic markers and/or survival outcome. This review included 49 studies totaling 11,337 patients. Forty-four percent of patients had Stage I/II, and 56% had Stage III/IV disease. Immunohistochemistry was most commonly used to assess HER2 expression, identifying a median rate of 18% (range, 4-53%) of gastric cancer demonstrating HER2 overexpression. In patients with and without HER2 overexpression, the median 3-year disease-free survival rate was 58% (range, 50-88%) and 86% (range, 62-97%), respectively. Of the 35 studies reporting the impact of HER2 overexpression on survival, 20 studies (57%) reported no difference in overall survival, two studies (6%) reported significantly longer overall survival in patients with HER2 overexpression and 13 studies (37%) reported significantly poorer overall survival in patients with HER2 overexpression. The median overall survival and 5-year survival rate was 21 (range, 10-57) months and 42%, and 33 (range, 13-80) months and 52% in patients with and without HER2 overexpression, respectively. HER2 overexpression appears to be associated with poorer survival and with intestinal-type gastric cancer in this group of patients for whom majority undergone curative gastrectomy.

Clinicopathological characteristics and computed tomography features of mucinous gastric carcinoma

This study investigated the clinicopathological characteristics of mucinous gastric carcinoma (MGC) and assessed whether multidetector-row computed tomography (MDCT) could differentiate MGC from non-mucinous gastric carcinoma (NGC). Clinicopathological data from 542 patients with gastric carcinoma (23 MGC, 519 NGC), who underwent pre-operative MDCT examination and curative or palliative gastrectomy, were analysed. Only seven of the 23 patients with MGC were correctly diagnosed pre-operatively by endoscopic biopsy. The MGC patients had larger tumours, a higher frequency of lymph node metastases, were more likely to have tumours of tumour, node, metastasis stages III and IV, and were less likely to have a curative resection than NGC patients. In addition, five MGC patients had calcifications in the thickened gastric wall. In conclusion, MGC is rare and is detected mostly at an advanced stage. The diagnostic sensitivity of MGC by endoscopic biopsy was relatively low, whereas MDCT was helpful in distinguishing MGC from NGC.

Clinicopathologic features and prognosis analysis of mucinous gastric carcinoma

Mucious gastric carcinoma (MGC) is a subtype of gastric carcinoma and its clinicopathologic features and prognosis still remain unclear. To investigate the clinical significance and surgical outcomes of mucinous gastric carcinoma, 2,769 patients with gastric carcinoma were analyzed in a case control study. We reviewed the records of 196 patients with mucinous gastric carcinoma and 2,573 with nonmucinous gastric carcinoma (NGC). Clinicopathologic features and survival rate of patients were analyzed. In all registered patients, patients with MGC had a larger size, more T3 and T4 invasion to the gastric wall, more positive lymph node metastasis, more III and IV stage and more positive peritoneal dissemination, but less curative gastrectomy. In curative gastrectomy patients, MGC had larger size, deeper invasion to gastric wall, more positive lymph node metastasis and more advanced TNM stage. The overall survival rate in curative gastrectomy patients with MGC was significantly lower than that for patients with NGC (P < 0.021). Age (P = 0.001), location of tumor (P < 0.001), Borrmann type (P = 0.037), depth of invasion (P < 0.001), lymph node metastasis (P < 0.001) and lymphovascular invasion (P = 0.001) were independent prognostic factors of gastric carcinoma, but MGC itself was not. The prognosis of MGC did not have significant difference compared with NGC. Frequently, MGC was of advanced stage at the time of diagnosis. Age, location of tumor, Borrmann type, depth of invasion, lymph node metastasis and lymphovascular invasion are independent prognostic factors of gastric carcinoma, but mucinous histological type itself is not. Further study on the origin and progression of MGC is needed in future.

Current status of mucins in the diagnosis and therapy of cancer

Mucins are the most abundant high molecular weight glycoproteins in mucus. Their nature and glycosylation content dictates the biochemical and biophysical properties of viscoelastic secretions, pointing out an important role in diverse biological functions, such as differentiation, cell adhesions, immune responses, and cell signaling. Mucins are expressed in tubular organs by specialized epithelial cells in the body. Their aberrant expression is well documented in a variety of inflammatory or malignant diseases. From a prognosis point of view, their expression and alterations in glycosylation are associated with the development and progression of malignant diseases. Therefore, mucins can be used as valuable markers to distinguish between normal and disease conditions. Indeed, this alteration in glycosylation patterns generates several epitopes in the oligosaccharide side chains that can be used as diagnostic and/or prognostic markers. Furthermore, these characteristic tumor-associated epitopes are extensively used as appropriate immunotargets of malignant epithelial cells. Therefore, in an effort to detect and treat cancer at the earliest stage possible, mucins are analyzed as potential markers of disease for diagnosis, progression, and for therapeutic purposes. In this review, we focused on the current status of the distribution of mucins in normal and pathologic conditions and their clinical use both in cancer diagnosis and therapeutics treatments.