Serum 25-hydroxyvitamin D level and the risk of mild cognitive impairment and dementia: the Korean Longitudinal Study on Health and Aging (KLoSHA)

OBJECTIVE

The association of low vitamin D status with mild cognitive impairment (MCI), a preclinical condition that can lead to dementia, has not yet been fully explored. Our aim was to investigate the association between vitamin D status and the future risk of MCI and dementia in older adults.

DESIGN, SETTING AND PARTICIPANTS

We conducted a population-based prospective study as a part of the Korean Longitudinal Study on Health and Aging. Four hundred and twelve elderly participants who completed evaluations of cognitive function and metabolic parameters in 2005-2006 and 2010-2011 were analysed.

MAJOR OUTCOME MEASURE

The rate of development of MCI or dementia during the study period was compared according to baseline vitamin D status. Binary logistic regression analysis was performed to investigate any independent association between vitamin D status and the risks of MCI or dementia.

RESULTS

Among 405 subjects that remained after excluding seven demented subjects at baseline, 338 subjects remained unchanged or improved in their diagnosis for cognitive function during the study period, whereas 67 subjects showed progression to MCI or dementia. When analyzing 236 subjects whose baseline mini-mental state examination (MMSE) scores were <27, severe vitamin D deficiency at baseline, defined as <25 nmol/l, was independently associated with the progression of cognitive impairment. Among 297 subjects who were normal at baseline, 50 acquired MCI and 247 remained normal. Severe vitamin D deficiency was also independently associated with the development of MCI when analyzing 145 subjects whose baseline MMSE scores were <27.

CONCLUSION

Severe vitamin D deficiency was independently associated with the future risk of MCI as well as dementia, especially in older adults whose baseline MMSE scores had decreased only modestly.

Negative Biopsy after Referral for Biopsy-Proven Gastric Cancer

Background/Aims

Repeat endoscopy with biopsy is often performed in patients with previously diagnosed gastric cancer to determine further treatment plans. However, biopsy results may differ from the original pathologic report. We reviewed patients who had a negative biopsy after referral for gastric cancer.

Methods

A total of 116 patients with negative biopsy results after referral for biopsy-proven gastric cancer were enrolled. Outside pathology slides were reviewed. Images of the first and second endoscopic examinations were reviewed. We reviewed the clinical history from referral to the final treatment.

Results

Eighty-eight patients (76%) arrived with information about the lesion from the referring physician. Among 96 patients with available outside slides, the rate of interobserver variation was 24%. Endoscopy was repeated at our institution; 85 patients (73%) were found to have definite lesions, whereas 31 patients (27%) had indeterminate lesions. In the group with definite lesions, 71% of the lesions were depressed in shape. The most common cause of a negative biopsy was mistargeting. In the group with indeterminate lesions, 94% had insufficient information. All patients with adequate follow-up were successfully treated based on the findings in the follow-up endoscopy.

Conclusions

A negative biopsy after referral for biopsy-proven gastric cancer is mainly caused by mistargeting and insufficient information during the referral.

Exuberant squamous metaplasia of the gastric mucosa in a patient with gastric adenocarcinoma

Background

The presence of squamous epithelium in the stomach is only occasionally encountered and is associated with prolonged mucosal injury. Squamous metaplasia in patients with cancer is relatively rare and only four cases have been reported in the stomach, all of which have been associated with squamous cell carcinomas. We present the first case of exuberant squamous metaplasia in a patient with gastric adenocarcinoma of the cardia.

Case presentation

A 56-year-old woman presented with epigastric pain and weight loss. Endoscopy showed an irregular depressed hyperemic lesion covered with a whitish plaque on the cardia. A total gastrectomy was performed and the tumor in the subcardia was found to extend up to the proximal stomach with diffuse squamous metaplasia in the surface of the tumor and proximal gastric mucosa in contiguity with the esophageal squamous epithelium. It is believed that the squamous extension from the esophagus to the proximal stomach and the gastric adenocarcinoma occurred at the same time.

Conclusions

Synchronous squamous metaplasia and underlying adenocarcinoma in the stomach is extremely rare. Recognition of this entity would be beneficial for clinicians to avoid unnecessary treatment.

Virtual Slides

The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/1035146445160150.

Molecular analysis of gastric cancer identifies subtypes associated with distinct clinical outcomes

Gastric cancer, a leading cause of cancer-related deaths, is a heterogeneous disease. We aim to establish clinically relevant molecular subtypes that would encompass this heterogeneity and provide useful clinical information. We use gene expression data to describe four molecular subtypes linked to distinct patterns of molecular alterations, disease progression and prognosis. The mesenchymal-like type includes diffuse-subtype tumors with the worst prognosis, the tendency to occur at an earlier age and the highest recurrence frequency (63%) of the four subtypes. Microsatellite-unstable tumors are hyper-mutated intestinal-subtype tumors occurring in the antrum; these have the best overall prognosis and the lowest frequency of recurrence (22%) of the four subtypes. The tumor protein 53 (TP53)-active and TP53-inactive types include patients with intermediate prognosis and recurrence rates (with respect to the other two subtypes), with the TP53-active group showing better prognosis. We describe key molecular alterations in each of the four subtypes using targeted sequencing and genome-wide copy number microarrays. We validate these subtypes in independent cohorts in order to provide a consistent and unified framework for further clinical and preclinical translational research.

Preoperative predictive factors for gastrointestinal stromal tumors: analysis of 375 surgically resected gastric subepithelial tumors

BACKGROUND

Gastrointestinal stromal tumors (GISTs) and non-GIST subepithelial tumors (SETs) account for about 75 and 25% of gastric hypoechoic SETs ≥2 cm, respectively. Therefore, identifying preoperative predictive factors for GISTs are required to refine surgical indications.

METHODS

We performed a retrospective review of 375 surgically resected gastric hypoechoic SETs ≥2 cm. Demographic data and tumor characteristics based on upper endoscopy and CT findings were compared between GIST and non-GIST SETs originating from muscularis propria layer (leiomyomas, Schwannomas, glomus tumors, and ectopic pancreas).

RESULTS

In cardia, leiomyomas were found twice more frequently than GISTs (63.6 versus 31.8%). Perilesional lymph node enlargement (PLNE) was found only in patients with GIST or Schwannomas. Patients with GIST showed a significantly lower rate of PLNE than those with Schwannomas (3.5 versus 29.0%). In multivariate analysis, tumor site outside cardia (odds ratio, 9.157), absence of PLNE (odds ratio, 11.519), old age, large tumor size, exophytic growth pattern, and ulceration or dimpling were identified as independent preoperative predictive factors for GISTs versus non-GIST SETs.

CONCLUSIONS

The effort for preoperative pathologic diagnosis such as endosonography-guided tissue sampling might be positively considered for SETs at cardia and SETs with PLNE where the possibility of GIST is low.

The impact of concomitant genomic alterations on treatment outcome for trastuzumab therapy in HER2-positive gastric cancer

Clinical benefit from trastuzumab and other anti-human epidermal growth factor receptor-2 (HER2) therapies in patients with HER2-positive gastric cancer (GC) remains limited by primary or acquired resistance. We aimed to investigate the impact of concomitant molecular alterations to HER2 amplification on the clinical outcome of trastuzumab-treated patients. Using immunohistochemistry (IHC), copy number variations (CNVs), and Ion Ampliseq Cancer Panel, we analyzed the status of concomitant alterations in 50 HER2-positive advanced GC patients treated with trastuzumab in combination with other chemotherapeutic agents. The percentage of tumor samples with at least one concomitant alteration was 40% as assessed by IHC, 16% by CNVs, and 64% by Ampliseq sequencing. Median progression-free survival (PFS) was 8.0 months (95% confidence interval, 4.8-11.3). Patients were divided into two subgroups according to PFS values with a cutoff point of 8 months; results show that concomitant genomic alterations do not correlate with trastuzumab response. However, CNVs of CCNE1 significantly correlated (p < 0.05) with a shorter survival time. Our findings indicate that additional alterations implemented for prediction of clinical benefit from HER2-targeting agents in GC remained unclear. Further studies will be needed to elucidate the role of each specific biomarker and to optimize therapeutic approaches.

Prognostic Significance of Defining L-Cell Type on the Biologic Behavior of Rectal Neuroendocrine Tumors in Relation with Pathological Parameters

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 < 0.0001), extent (p < 0.0001), size (p < 0.0001), lymph node metastasis (p=0.0063), and L-cell phenotype (p < 0.0001) showed significant correlation with the prognosis of rectal NENs; however, none of these markers achieved independent significance in multivariate analysis. The 10-year OS of tumors of NET grade 1, < 10 mm, the mucosa/submucosa was 97.58%, 99.47%, and 99.03%, respectively. L-Cell marker, glucagon II (GLP-1&2), with a cut off score of > 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.

Factors associated with consciousness recovery time after liver transplantation in recipients with hepatic encephalopathy

BACKGROUND

Hepatic encephalopathy (HE) occurs as a result of liver failure and is often considered to be a clinical indication for liver transplantation (LT). An assessment of post-transplantation consciousness level in recipients with HE is crucial, because recovery of consciousness implies reestablishment of transplant liver function and lack of perioperative brain damage. The purpose of this study is to evaluate factors associated with consciousness recovery time after LT in recipients with HE.

METHODS

Out of 633 adult recipients who underwent LT, recipients who exhibited HE at the time of LT were analyzed retrospectively. The time between graft reperfusion and postoperative consciousness recovery was determined, and recipients were divided into 2 groups: group E with recovery of consciousness early (≤48 hours), and group L with recovery of consciousness late (>48 hours). Analyzed variables included recipient sex, age, graft type, Model for End-Stage Liver Disease score, HE history/duration/type/grade, and preoperative laboratory values, including blood ammonia concentration.

RESULTS

HE was present at the time of LT in 69 (10.9%) of 633 recipients. Among the 69 recipients, 11 recipients who died or underwent reoperation before consciousness recovery were excluded, and 58 recipients (group E: n = 32; group L: n = 26) were enrolled into analysis. Multivariate analysis showed that HE duration >5 days (odds ratio [OR], 15.58; 95% confidence interval [CI], 1.35-179.56; P = .028) and HE type C (OR, 30.90; 95% CI, 1.67-573.48; P = .021) were the independent factors associated with late recovery from HE after LT.

CONCLUSIONS

We suggest that recipients with long-duration or type C HE should be carefully managed during the post-transplantation period to prevent deterioration of HE.

Gastroenteropancreatic Neuroendocrine Tumors with Liver Metastases in Korea: A Clinicopathological Analysis of 72 Cases in a Single Institute

Purpose

Management of gastroenteropancreatic (GEP) neuroendocrine tumors with liver metastases (NETLM) presents many clinical challenges. Assessment of the extent of disease and primary tumor site is crucial for management. In this study, we investigated the primary tumor sites and prognostic factors in GEP NETLM among Korean patients.

Materials and Methods

We reviewed the medical records of 72 Korean patients diagnosed with GEP NETLM between January 1999 and May 2013, focusing on their clinical and pathologic characteristics.

Results

The most frequently encountered primary tumor sites were the pancreas (n=25, 35%), stomach (n=8, 11%), gall bladder (n=4, 6%) and rectum (n=3, 4%). Twenty-five patients (35%) had occult primary tumor. Twelve patients (17%) had histological grade G1 tumors, 30 patients (42%) had G2 tumors, and 30 patients (42%) had G3 tumors. The mean follow-up period after histological confirmation of hepatic metastases was 11.30±2.44 months for G3 tumors, 19.67±4.09 months for G2 tumors, and 30.67±6.51 months for G1 tumors. Multivariate analyses revealed that an unknown primary tumor site (p=0.001) and higher histological grade (p < 0.001) were independent prognostic indicators for shorter overall survival (OS). Most long-term survivors (OS > 24 months) had received antitumor treatment.

Conclusion

The primary tumor site most frequently associated with GEP NETLM was the pancreas. Unknown primary tumor and higher histological grade were independent prognostic indicators for shorter OS. Patients identified as being at a risk of shorter OS should be followed up closely.

PHH3 as an Ancillary Mitotic Marker in Gastrointestinal Stromal Tumors

Background:

Counting mitoses is subjective and time-consuming. The adjunctive diagnostic utility of a recently reported mitotic marker, phosphohistone H3 (PHH3), was investigated in gastrointestinal stromal tumors (GISTs).

Methods:

We reviewed 77 GISTs for several proliferative indices. These included the mitotic count per 50 high power fields (HPFs), the immunohistochemical Ki- 67 labeling index and the immunohistochemical PHH3 mitotic index (MI). For comparison, Spearman’s rank correlation and interclass correlation coefficient were used.

Results:

Mitotic counts ranged from 0–138 (mean, 7.57±2.34) and the PHH3 MI ranged from 0–126 per 50 HPFs (mean, 9.61±2.27). We found a positive correlation between mitotic counts and PHH3 MI (r=0.810, p<.001). The inter-observer correlation coefficient for three participants was 0.975 for mitotic counts and 0.940 for the PHH3 MI. When using the PHH3 MI instead of mitotic counts in the Armed Forces Institute of Pathology (AFIP) stratification criteria, 10 cases were reclassified. In one patient with a mitotic count of 2 and a PHH3 MI of 6 per 50 HPFs, distant metastasis occurred.

Conclusions:

In GISTs, the PHH3 MI correlated adequately with mitotic counts and can be used as a useful adjunctive to count mitotic figures efficiently.

Deregulation of immune response genes in patients with Epstein-Barr virus-associated gastric cancer and outcomes

BACKGROUND & AIMS

Patients with Epstein-Barr virus-associated gastric carcinoma (EBVaGC) have a better prognosis than those with gastric cancer not associated with EBV infection (EBVnGC). This is partly because EBV infection recruits lymphocytes, which infiltrate the tumor. A high degree of tumor heterogeneity is likely to be associated with poor response. We investigated differences in gene expression patterns between EBVaGC and EBVnGC.

METHODS

We used gene expression profile analysis to compare tumor and nontumor gastric tissues from 12 patients with EBVaGC and 14 patients with EBVnGC. Findings were validated by whole transcriptome RNAseq and real-time quantitative polymerase chain reaction analyses. CD3(+) primary T cells were isolated from human blood samples; migration of these cells and of Jurkat cells were measured in culture with EBV-infected and uninfected gastric cancer cells.

RESULTS

Based on Pearson correlation matrix analysis, EBVaGCs had a higher degree of homogeneity than EBVnGCs. Although 4550 genes were differentially expressed between tumor and nontumor gastric tissues of patients with EBVnGC, only 186 genes were differentially expressed between tumor and nontumor gastric tissues of patients with EBVaGC (P < .001). This finding supports the concept that EBVaGCs have fewer genetic and epigenetic alterations than EBVnGCs. Expression of major histocompatibility complex class II genes and genes that regulate chemokine activity were more often deregulated in EBVaGCs compared with nontumor tissues. In culture, more T cells migrated to EBV-infected gastric cancer cells than to uninfected cells; migration was blocked with a neutralizing antibody against CXCR3 (a receptor for many chemokines).

CONCLUSIONS

Fewer genes are deregulated in EBVaGC than in EBVnGC. Most changes in EBVaGCs occur in immune response genes. These changes might allow EBVaGC to recruit reactive immune cells; this might contribute to the better outcomes of these patients compared with those with EBVnGC.

Associations between serum 25-hydroxyvitamin D and bone mineral density and proximal femur geometry in Koreans: the Korean National Health and Nutrition Examination Survey (KNHANES) 2008-2009

The association between 25-hydroxyvitamin D (25(OH)D) levels and bone mineral density (BMD) and proximal femur bone geometry was examined in the Korean population. A positive relationship between skeletal health and 25(OH)D levels was observed. However, there were no significant differences in skeletal health between the groups with 25(OH)D level of 50-75 nmol/L and greater than 75 nmol/L.

INTRODUCTION

Vitamin D plays an important role in calcium and phosphate homeostasis and normal mineralization of bone. However, the optimal level of vitamin D for skeletal health has not been clearly established. We analyzed the associations between serum 25(OH)D and BMD and proximal femur bone geometry and determined the optimal 25(OH)D level.

METHODS

This was a cross-sectional study of 10,062 participants (20-95 years, 4,455 men, 5,607 women) in the Fourth Korea National Health and Nutrition Examination Surveys (KNHANES IV) conducted from 2008 to 2009. Participants were divided into groups according to 25(OH)D level (<25, 25-50, 50-75, and ≥75 nmol/L). BMD and proximal femur geometric indices were measured.

RESULTS

The group with 25(OH)D levels of 50-75 nmol/L had greater bone density values, with the exception of the lumbar spine, and also had greater femur neck cortical thickness, cross-sectional area, and cross-sectional moment of inertia, as well as a lesser buckling ratio than the groups with 25(OH)D level of 25-50 nmol/L and less than 25 nmol/L. However, there were no significant differences in BMD and proximal femur geometry properties between the groups with 50-75 nmol/L and greater than 75 nmol/L of 25(OH)D.

CONCLUSION

The skeletal outcomes, including BMD and proximal femur geometric indices observed in this study, suggest that serum 25(OH)D levels of 50 to <75 nmol/L are optimal for skeletal health.

Lymphoepithelioma-like carcinoma: a distinct type of gastric cancer

BACKGROUND

Lymphoepithelioma-like carcinoma (LELC) is a rare type of gastric carcinoma and has histologic features of intense lymphocytic infiltration. In this study, we attempted to analyze the clinicopathologic characteristics and survival outcome of patients with LELC compared with those with non-lymphoepithelioma-like carcinoma (NLELC).

METHODS

We studied 4282 patients who underwent gastrectomies to treat gastric cancer at the Department of Surgery of the Samsung Medical Center in Seoul, between January 2008 and December 2010. The clinicopathologic features and clinical outcomes of patients with LELC (n = 46) were compared with those with NLELC (n = 4236). In situ hybridization for Epstein-Barr virus (EBV) positivity was performed on the tissue of patients with LELC (n = 46) and NLELC (n = 1247).

RESULTS

The patients with LELC are male predominant and had more upper locations, more indeterminate Lauren classifications, lower T stages, less lymphatic invasion, and more positive EBV in situ hybridization compared with those of the NLELC group (80.4% versus 6.5%). Age, histologic type, Lauren type, the location of the tumor, the depth of the invasion, lymph node metastasis, and venous invasion were independent prognostic factors; however, the LELC type itself was not predictive of outcome. The 5-y survival rate of the LELC group (97.7%) was better than that of the NLELC group (89.4%); however, this difference was not statistically significant (P = 0.127).

CONCLUSIONS

The results of our study suggest that LELC is a less advanced disease than NLELC in terms of depth of invasion and lymphatic invasion at diagnosis. However, our study does not examine LELC as an independent prognostic factor of gastric cancer. Further studies are needed to explore its associations with EBV and a distinct pathway of carcinogenesis from NLELC.

Clinical presentation and risk factors for cytomegalovirus colitis in immunocompetent adult patients

BACKGROUND

Cytomegalovirus (CMV) colitis is a common manifestation of CMV end-organ disease, which has typically been described in immunocompromised hosts. Recently, it has been noted that this also occurs in immunocompetent patients. To gather relevant data about clinical presentation, prognosis, and risk factors for development of CMV colitis in immunocompetent hosts, we analyzed all cases that occurred during a 19-year period at our institution.

METHODS

A case-control study was performed to identify risk factors for CMV colitis in immunocompetent hosts. Electronic medical records of individuals who were admitted and diagnosed with CMV colitis between January 1995 and February 2014 at a tertiary care university hospital were reviewed. Two non-CMV colitis patients who were age- and sex-matched were selected as controls for each case.

RESULTS

A total of 51 patients with CMV colitis were included in this study along with 102 control patients. Certain conditions including renal disease on hemodialysis, neurologic disease, rheumatologic disease, intensive care unit admission, and exposure to antibiotics, antacids, steroids, or red blood cell (RBC) transfusions within 1 month of diagnosis of colitis were associated with CMV colitis on univariate analysis. Among these, steroid use and RBC transfusion within 1 month were identified as independent risk factors for developing CMV colitis on multivariate analysis. The 30-day mortality rate was 7.8% without any attributable mortality.

CONCLUSIONS

Steroid use and RBC transfusion within 1 month of the diagnosis of colitis were independent risk factors for development of CMV colitis in immunocompetent hosts.

CD133-positive tumor cell content is a predictor of early recurrence in colorectal cancer

BACKGROUND

The aims of this study were to demonstrate the tumorigenicity of CD133+ colon cancer cells in vitro, analyze the correlations between spheroid formation and clinicopathologic variables, and screen for overexpressed genes in CD133+ colon cancer stem cells. Moreover, the aim of this study was to establish a living tumor tissue bank using surgically resected specimens.

METHODS

Using LoVo cell line, we isolated CD133+ cells and performed clonogenic assay and animal experiment to test tumorigenicity of CD133+ cells. Twenty-nine surgical samples were freshly collected from 27 patients who received curative or palliative surgery, and the samples were mechanically and enzymatically dissociated into single cells.

RESULTS

We confirmed the enhanced tumorigenicity of CD133+ cells isolated from LoVo cell line both in vitro and in vivo. Of these 29 samples, 8 (28%) contained >3% CD133+ cells. Sphere formation was significantly higher in samples from patients with lymphatic invasion than in those without lymphatic invasion [54.5% (6/11) vs. 12.5% (2/16); P=0.033] and in samples containing >3% of CD133+ cells than in those containing ≤3% of CD133+ cells [36.4% (4/11) vs. 0% (0/16); P=0.019].

CONCLUSIONS

These findings indicate that CD133 is a valid marker for identifying cancer stem cells from fresh surgically resected colorectal cancer tissues. Furthermore, we successfully established a living tumor tissue bank using surgically resected colorectal tissues with a viability of >70%.

Genomic landscape and genetic heterogeneity in gastric adenocarcinoma revealed by whole-genome sequencing

Gastric cancer (GC) is the second most common cause of cancer-related deaths. It is known to be a heterogeneous disease with several molecular and histological subtypes. Here we perform whole-genome sequencing of 49 GCs with diffuse (N=31) and intestinal (N=18) histological subtypes and identify three mutational signatures, impacting TpT, CpG and TpCp[A/T] nucleotides. The diffuse-type GCs show significantly lower clonality and smaller numbers of somatic and structural variants compared with intestinal subtype. We further divide the diffuse subtype into one with infrequent genetic changes/low clonality and another with relatively higher clonality and mutations impacting TpT dinucleotide. Notably, we discover frequent and exclusive mutations in Ephrins and SLIT/ROBO signalling pathway genes. Overall, this study delivers new insights into the mutational heterogeneity underlying distinct histologic subtypes of GC that could have important implications for future research in the diagnosis and treatment of GC.

Preexisting oncogenic events impact trastuzumab sensitivity in ERBB2-amplified gastroesophageal adenocarcinoma

Patients with gastric and esophageal (GE) adenocarcinoma tumors in which the oncogene ERBB2 has been amplified are routinely treated with a combination of cytotoxic chemotherapy and the ERBB2-directed antibody trastuzumab; however, the addition of trastuzumab, even when tested in a selected biomarker-positive patient population, provides only modest survival gains. To investigate the potential reasons for the modest impact of ERBB2-directed therapies, we explored the hypothesis that secondary molecular features of ERBB2-amplified GE adenocarcinomas attenuate the impact of ERBB2 blockade. We analyzed genomic profiles of ERBB2-amplified GE adenocarcinomas and determined that the majority of ERBB2-amplified tumors harbor secondary oncogenic alterations that have the potential to be therapeutically targeted. These secondary events spanned genes involved in cell-cycle regulation as well as phosphatidylinositol-3 kinase and receptor tyrosine kinase signaling. Using ERBB2-amplified cell lines, we demonstrated that secondary oncogenic events could confer resistance to ERBB2-directed therapies. Moreover, this resistance could be overcome by targeting the secondary oncogene in conjunction with ERBB2-directed therapy. EGFR is commonly coamplified with ERBB2, and in the setting of ERBB2 amplification, higher EGFR expression appears to mark tumors with greater sensitivity to dual EGFR/ERBB2 kinase inhibitors. These data suggest that combination inhibitor strategies, guided by secondary events in ERBB2-amplified GE adenocarcinomas, should be evaluated in clinical trials.

Gastrointestinal stromal tumours: correlation of modified NIH risk stratification with diffusion-weighted MR imaging as an imaging biomarker

PURPOSE

To evaluate the correlation of risk grade of gastrointestinal stromal tumours (GISTs) based on modified National Institutes of Health (NIH) criteria with conventional magnetic resonance (MR) imaging and diffusion-weighted (DW) imaging.

METHODS

We included 22 patients with histopathologically proven GISTs in the stomach or small bowel who underwent pre-operative gadoxetic acid-enhanced MR imaging and DW imaging. We retrospectively assessed correlations between morphologic findings, qualitative (signal intensity, consensus from two observers) and quantitative (degree of dynamic enhancement using signal intensity of tumour/muscle ratio and apparent diffusion coefficient [ADC]) values, and the modified NIH criteria for risk stratification. Spearman partial correlation analysis was used to control for tumour size as a confounding factor. The optimal cut-off level of ADC values for intermediate or high risk GISTs was analyzed using a receiver operating characteristic analysis.

RESULTS

Except tumour size and necrosis, conventional MR imaging findings, including the degree of dynamic enhancement, were not significantly different according to the modified NIH criteria (p>0.05). Tumour ADC values were negatively correlated with the modified NIH criteria, before and after adjustment of tumour size (ρ=-0.754; p<0.001 and ρ=-0.513; p=0.017, respectively). The optimal cut-off value for the determination of intermediate or high-risk GISTs was 1.279 × 10(-3)mm(2)/s (100% sensitivity, 69.2% specificity, 81.8% accuracy).

CONCLUSION

Except tumour size and necrosis, conventional MR imaging findings did not correlate with the risk grade. However, the ADC value can be used as an imaging biomarker to assess the risk grade of GISTs, regardless of tumour size.

GAGE12 mediates human gastric carcinoma growth and metastasis

The spontaneous metastasis from human gastric carcinoma (GC) remains poorly reproduced in animal models. Here, we established an experimental mouse model in which GC progressively developed in the orthotopic stomach wall and metastasized to multiple organs; the tumors colonized in the ovary exhibited typical characteristics of Krukenberg tumor. The expression of mesenchymal markers was low in primary tumors and high in those in intravasating and extravasating veins. However, the expression of epithelial markers did not differ, indicating that the acquisition of mesenchymal markers without a concordant loss of typical epithelial markers was associated with metastasis. We identified 35 differentially expressed genes (DEGs) in GC cells metastasized to ovary, among which overexpression of GAGE12 family genes, the top-ranked DEGs, were validated. In addition, knockdown of the GAGE12 gene family affected transcription of many of the aforementioned 35 DEGs and inhibited trans-well migration, tumor sphere formation in vitro and tumor growth in vivo. In accordance, GAGE12 overexpression augmented migration, tumor sphere formation and sustained in vivo tumor growth. Taken together, the GAGE12 gene family promotes GC growth and metastasis by modulating the expression of GC metastasis-related genes.

High-throughput sequencing and copy number variation detection using formalin fixed embedded tissue in metastatic gastric cancer

In the era of targeted therapy, mutation profiling of cancer is a crucial aspect of making therapeutic decisions. To characterize cancer at a molecular level, the use of formalin-fixed paraffin-embedded tissue is important. We tested the Ion AmpliSeq Cancer Hotspot Panel v2 and nCounter Copy Number Variation Assay in 89 formalin-fixed paraffin-embedded gastric cancer samples to determine whether they are applicable in archival clinical samples for personalized targeted therapies. We validated the results with Sanger sequencing, real-time quantitative PCR, fluorescence in situ hybridization and immunohistochemistry. Frequently detected somatic mutations included TP53 (28.17%), APC (10.1%), PIK3CA (5.6%), KRAS (4.5%), SMO (3.4%), STK11 (3.4%), CDKN2A (3.4%) and SMAD4 (3.4%). Amplifications of HER2, CCNE1, MYC, KRAS and EGFR genes were observed in 8 (8.9%), 4 (4.5%), 2 (2.2%), 1 (1.1%) and 1 (1.1%) cases, respectively. In the cases with amplification, fluorescence in situ hybridization for HER2 verified gene amplification and immunohistochemistry for HER2, EGFR and CCNE1 verified the overexpression of proteins in tumor cells. In conclusion, we successfully performed semiconductor-based sequencing and nCounter copy number variation analyses in formalin-fixed paraffin-embedded gastric cancer samples. High-throughput screening in archival clinical samples enables faster, more accurate and cost-effective detection of hotspot mutations or amplification in genes.

Endoscopic resection for undifferentiated early gastric cancer: focusing on histologic discrepancies between forceps biopsy-based and endoscopic resection specimen-based diagnosis

BACKGROUND

Before endoscopic resection (ER), a considerable number of undifferentiated early gastric cancer (UD-EGC) cases were initially diagnosed as atypical glands, dysplasia, or differentiated EGC (D-EGC) based on forceps biopsy specimens. As UD-EGC carries a high risk of resection margin involvement, identifying the predictive factors for UD-EGC cases with histologic discrepancy (HD) is of clinical importance.

AIMS

To investigate the outcomes of ER for UD-EGC and to identify the predictive factors for UD-EGC with HD.

METHODS

Among 2,194 EGC lesions treated by ER, 59 lesions were finally diagnosed as UD-EGC and 50 UD-EGC cases showed HD. The demographic and endoscopic characteristics were compared between D-EGC and UD-EGC with HD, and the predictive factors for the latter were investigated among cases of forceps biopsy-based diagnosis of atypical glands, dysplasia, or D-EGC.

RESULTS

UD-EGC showed significantly higher rate of lateral margin involvement compared to D-EGC (18.6 vs. 3.4%). Among the UD-EGC cases meeting the expanded criteria and not involving additional surgery, no local or extragastric tumor recurrence was observed during the median follow-up of 27.5 months. Multivariate analysis demonstrated that age (≤60 years), female gender, gastric body, flat or depressed type, and tumor size (>2 cm) were independent predictive factors for UD-EGC with HD among cases of forceps biopsy-based diagnosis of atypical glands, dysplasia, or D-EGC.

CONCLUSIONS

For lesions with predictive factors for UD-EGC with HD, a circumferential mapping biopsy before ER or wide marking during ER could be considered to avoid the potential risk of incomplete resection.

Pazopanib, a novel multitargeted kinase inhibitor, shows potent in vitro antitumor activity in gastric cancer cell lines with FGFR2 amplification

Pazopanib is an orally bioavailable, ATP-competitive, multitargeted tyrosine kinase inhibitor mainly targeting VEGFR2 and PDGFR tyrosine kinases, but the biologic sequences of pazopanib activities beyond antiangiogenesis are poorly defined. We used a panel of 38 gastric cancer cell lines to test the efficacy of pazopanib. In a growth inhibition assay, genomic changes indicated that pazopanib had differential effects on cell growth. Treatment of the KATO-III, OCUM-2M, SNU-16, and HSC-39 gastric cancer cell lines harboring FGFR2 amplification with pazopanib resulted in marked decreases of cell survival with IC50 in ranges of 0.1 to 2.0 μmol/L, whereas the same treatment of those cell lines without FGFR2 amplification had no growth-inhibitory effects. In the ectopic FGFR2-expressing model, treatment with the indicated concentrations of pazopanib significantly inhibited cell growth and colony formation by FGFR2-expressing NIH 3T3 cells with wild-type (WT) FGFR2 and mutant FGFR2 (S252W). Pazopanib also selectively suppressed constitutive FGFR2 signaling and phosphorylation of downstream effectors. In cell-cycle analysis, FGFR2-amplified cells underwent cell-cycle arrest at the G1-S phase after pazopanib treatment, whereas there were no significant effects on cell-cycle progression in cells without FGFR2 amplification treated with pazopanib. In addition, pazopanib increased a substantial fraction of sub-G1 only in FGFR2-amplified cells. These findings show that the activation of FGFR2 signaling by amplification may be a critical mediator of cell proliferation in a small subset of gastric cancer patients and that pazopanib may provide genotype-correlated clinical benefits beyond the setting of highly vascular tumors.