Tumor growth patterns and biological characteristics of early gastric carcinoma

A radiomics nomogram based on contrast-enhanced CT for preoperative prediction of Lymphovascular invasion in esophageal squamous cell carcinoma

Background and purpose

To develop a radiomics nomogram based on contrast-enhanced computed tomography (CECT) for preoperative prediction of lymphovascular invasion (LVI) status of esophageal squamous cell carcinoma (ESCC).

Materials and methods

The clinical and imaging data of 258 patients with ESCC who underwent surgical resection and were confirmed by pathology from June 2017 to December 2021 were retrospectively analyzed.The clinical imaging features and radiomic features were extracted from arterial-phase CECT. The least absolute shrinkage and selection operator (LASSO) regression model was used for radiomics feature selection and signature construction. Multivariate logistic regression analysis was used to develop a radiomics nomogram prediction model. The receiver operating characteristic (ROC) curve and decision curve analysis (DCA) were used to evaluate the performance and clinical effectiveness of the model in preoperative prediction of LVI status.

Results

We constructed a radiomics signature based on eight radiomics features after dimensionality reduction. In the training cohort, the area under the curve (AUC) of radiomics signature was 0.805 (95% CI: 0.740-0.860), and in the validation cohort it was 0.836 (95% CI: 0.735-0.911). There were four predictive factors that made up the individualized nomogram prediction model: radiomic signatures, TNRs, tumor lengths, and tumor thicknesses.The accuracy of the nomogram for LVI prediction in the training and validation cohorts was 0.790 and 0.768, respectively, the specificity was 0.800 and 0.618, and the sensitivity was 0.786 and 0.917, respectively. The Delong test results showed that the AUC value of the nomogram model was significantly higher than that of the clinical model and radiomics model in the training and validation cohort(P<0.05). DCA results showed that the radiomics nomogram model had higher overall benefits than the clinical model and the radiomics model.

Conclusions

This study proposes a radiomics nomogram based on CECT radiomics signature and clinical image features, which is helpful for preoperative individualized prediction of LVI status in ESCC.

Prognostic analysis of 2-5 cm diameter gastric stromal tumors with exogenous or endogenous growth

BACKGROUND

There has been limited research on the prognosis differences in patients with gastric stromal tumor invasion of the plasma membrane surface. This study intended to investigate whether there is a difference in prognosis in patients with endogenous or exogenous 2-5 cm diameter GISTs.

METHODS

We retrospectively analyzed the clinicopathological and follow-up data of gastric stromal tumor patients, all of whom underwent surgical resection for primary GIST at Nanjing Drum Tower Hospital from December 2010 to February 2022. We classified patients based on tumor growth patterns and then investigated the association between tumor growth patterns and clinical outcomes. Progression-free survival (PFS) and overall survival (OS) were calculated by the Kaplan‒Meier method.

RESULTS

A total of 496 gastric stromal tumor patients were enrolled in this study, among which 276 patients had tumors of 2-5 cm in diameter. Of these 276 patients, 193 had exogenous tumors, and 83 had endogenous tumors. Tumor growth patterns were significantly related to age, rupture status, resection style, tumor site, tumor size, and intraoperative bleeding. According to Kaplan‒Meier curve analysis, the tumor growth pattern among patients with 2-5 cm diameter tumors was significantly correlated with worse progression-free survival (PFS). Ultimately, multivariate analyses identified the Ki-67 index (P = 0.008), surgical history (P = 0.031), and resection style (P = 0.045) as independent prognostic markers for PFS.

CONCLUSIONS

Although gastric stromal tumors with a diameter of 2-5 cm are classified as low risk, the prognosis is lower for exogenous tumors than for endogenous tumors, and exogenous gastric stromal tumors have a risk of recurrence. Consequently, clinicians should be vigilant regarding the prognosis of patients with this type of tumor.

Can Lymphovascular Invasion be Predicted by Preoperative Contrast-Enhanced CT in Esophageal Squamous Cell Carcinoma?

Objective: To explore whether preoperative contrast-enhanced computed tomogrpahy (CT) can predict lymphovascular invasion (LVI) in esophageal squamous cell carcinoma (ESCC), and provide a reliable reference for the formulation of clinical individualized treatment plans. Methods: This retrospective study enrolled 228 patients with surgically resected and pathologically confirmed ESCC, including 36 patients with LVI and 192 patients without LVI. All patients underwent contrast-enhanced CT (CECT) scan within 2 weeks before the operation. Tumor size (including tumor length and maximum tumor thickness), tumor-to-normal wall enhancement ratio (TNR), and gross tumor volume (GTV) were obtained. All clinical features and CECT-derived parameters associated with LVI were analyzed by univariate and multivariate analysis. The independent predictors for LVI were identified, and their combination was built by multivariate logistic regression analysis, using the significant variables from the univariate analysis as inputs. Results: Univariate analysis of clinical features and CECT-derived parameters revealed that age, TNR, and clinical N stage (cN stage) were significantly associated with LVI. The multivariable analysis results demonstrated that age (odds ratio [OR]: 5.32, 95% confidence interval [CI]: 2.224-12.743, P<.001), TNR (OR: 5.399, 95% CI: 1.609-18.110, P  =  .006), and cN stage (cN1: OR: 2.874, 95% CI: 1.182-6.989, P  =  .02; cN2: OR: 6.876, 95% CI: 2.222-21.227) were identified to be independent predictors for LVI. The combination of age, TNR, and cN stage achieved a relatively higher area under the curve (AUC) (0.798), accuracy (ACC) (65.4%), sensitivity (SEN) (69.4%), specificity (SPE) (79.7%), positive predictive value (PPV) (77.4%), and negative predictive value (NPV) (71.6%). Conclusions: The combination of clinical features and CECT-derived parameters may be effective in predicting LVI status preoperatively in ESCC.

Predictive risk factors associated with synchronous multiple early gastric cancer

The aim of this study was to elucidate the predictive risk factors of synchronous multiple early gastric cancer regardless of the treatment modality.Patients who underwent early gastric cancer treatment between July 2005 and June 2015 were retrospectively reviewed. In total, 1529 patients who were treated for early gastric cancer were included. We analyzed the patient's data to find predictive factors of synchronous multiple early gastric cancer compared to solitary early gastric cancer. Further analysis was performed to verify the difference between endoscopic and surgical treatment groups.Among the 1529 patients, synchronous multiple early gastric cancer was diagnosed in 68 (4.4%) patients. Significant differences in sex (P = .004), gross appearance (P = .038), depth of invasion (P = .007), and lymphovascular invasion (P = .039) were found between patients with solitary early gastric cancer and synchronous multiple early gastric cancer by univariate analysis. In multivariate analysis, male sex (odds ratio, 2.475; P = .011) and submucosal invasion (odds ratio, 1.850; P = .033) were independent predictive risk factors of synchronous multiple early gastric cancer. In addition, in multivariate analysis, significant differences in age, tumor size, longitudinal location, depth of invasion, and histology were found between patients groups depending on the mode of treatment.Male sex and submucosal invasion were predictive risk factors of synchronous multiple early gastric cancer. Patients with these factors should undergo more meticulous endoscopic surveillance.

Can lymphovascular invasion be predicted by preoperative multiphasic dynamic CT in patients with advanced gastric cancer?

OBJECTIVES

To determine whether multiphasic dynamic CT can preoperatively predict lymphovascular invasion (LVI) in advanced gastric cancer (AGC).

METHODS

278 patients with AGC who underwent preoperative multiphasic dynamic CT were retrospectively recruited. Tumour CT attenuation difference between non-contrast and arterial (Δ_AP), portal (Δ_PP) and delayed phase (Δ_DP), tumour-spleen attenuation difference in the portal phase (Δ_T-S), tumour contrast enhancement ratios (CERs), tumour-to-spleen ratio (TSR) and tumour volumes were obtained. All CT-derived parameters and clinicopathological variables associated with LVI were analysed by univariate analysis, followed by multivariate and receiver operator characteristics (ROC) analysis. Associations between CT predictors for LVI and histopathological characteristics were evaluated by the chi-square test.

RESULTS

Δ_PP (OR, 1.056; 95% CI: 1.032-1.080) and Δ_T-S (OR, 1.043; 95% CI: 1.020-1.066) are independent predictors for LVI in AGC. Δ_PP, Δ_T-S and their combination correctly predicted LVI in 74.8% (AUC, 0.775; sensitivity, 88.6%; specificity, 54.1%), 68.7% (AUC, 0.747; sensitivity, 68.3%; specificity, 69.4%) and 71.7% (AUC, 0.800; sensitivity, 67.6%; specificity, 77.8%), respectively. There were significant associations between CT predictors for LVI with tumour histological differentiation and Lauren classification.

CONCLUSION

Multiphasic dynamic CT provides a non-invasive method to predict LVI in AGC through quantitative enhancement measurement.

KEY POINTS

• Lymphovascular invasion rarely can be evaluated preoperatively in advanced gastric cancer (AGC). • Δ _PP and Δ _T-S were independent predictors for LVI in patients with AGC. • Δ _PP and Δ _T-S showed acceptable predictive performance for LVI. • Combination of Δ _PP and Δ _T-S improved predictive performance for LVI. • Multiphasic dynamic CT may be a useful adjunct for detecting LVI preoperatively.

Clinicopathologic Similarities of the Main and Minor Lesions of Synchronous Multiple Early Gastric Cancer

The detection rate of early gastric cancer (EGC) is increasing due to improvements in diagnostic methods, but synchronous multiple EGC (SMEGC) remains a major problem. Therefore, we investigated the characteristics of and the correlation between the main and minor lesions of SMEGC. We retrospectively reviewed the medical records of patients with EGC between April 2008 and May 2013. The main lesion was defined as the one with the greatest invasion depth. If lesions had the same invasion depth, the tumor diameter was used to define the main lesion. Of 963 patients who had treatment for EGC, 37 patients with SMEGC were analyzed. The main and minor lesions showed a significant positive correlation of size (r = 0.533, P = 0.001). The main and minor lesions of SMEGC showed the same vertical and horizontal locations at 70.3% and 64.9%, respectively (P = 0.002 and P = 0.002). Macroscopic types were identical in 67.6% (P < 0.001), and 32.4% had identical macroscopic type and location. The main and minor lesions had identical characteristics of invasion depth, presence of lymphovascular invasion (LVI), and differentiation in 78.4%, 83.8%, and 83.8%, respectively. Differentiation, LVI, and invasion depth (microscopic characteristics) were simultaneously the same in 62.2%. The location, macroscopic type, and 3 microscopic characteristics were matched in 27%. The main and minor lesions of SMEGC have similar clinicopathologic characteristics. Therefore, the possibility of SMEGC should not be neglected in cases of EGC, considering an understanding of the characteristics and association of lesions.

Loss of gastric gland mucin-specific O-glycan is associated with progression of differentiated-type adenocarcinoma of the stomach

Gastric gland mucin secreted from the lower portion of the gastric mucosa contains unique O-linked oligosaccharides having terminal α1,4-linked N-acetylglucosamine (αGlcNAc) residues largely attached to a MUC6 scaffold. Previously, we generated A4gnt-deficient mice, which totally lack αGlcNAc, and showed that αGlcNAc functions as a tumor suppressor for gastric cancer. Here, to determine the clinicopathological significance of αGlcNAc in gastric carcinomas, we examined immunohistochemical expression of αGlcNAc and mucin phenotypic markers including MUC5AC, MUC6, MUC2, and CD10 in 214 gastric adenocarcinomas and compared those expression patterns with clinicopathological parameters and cancer-specific survival. The αGlcNAc loss was evaluated in MUC6-positive gastric carcinoma. Thirty-three (61.1%) of 54 differentiated-type gastric adenocarcinomas exhibiting MUC6 in cancer cells lacked αGlcNAc expression. Loss of αGlcNAc was significantly correlated with depth of invasion, stage, and venous invasion by differentiated-type adenocarcinoma. Loss of αGlcNAc was also significantly associated with poorer patient prognosis in MUC6-positive differentiated-type adenocarcinoma. By contrast, no significant correlation between αGlcNAc loss and any clinicopathologic variable was observed in undifferentiated-type adenocarcinoma. Expression of MUC6 was also significantly correlated with several clinicopathological variables in differentiated-type adenocarcinoma. However, unlike the case with αGlcNAc, its expression showed no correlation with cancer-specific survival in patients. In undifferentiated-type adenocarcinoma, we observed no significant correlation between mucin phenotypic marker expression, including MUC6, and any clinicopathologic variable. These results together indicate that loss of αGlcNAc in MUC6-positive cancer cells is associated with progression and poor prognosis in differentiated, but not undifferentiated, types of gastric adenocarcinoma.

Extent of arterial tumor enhancement measured with preoperative MDCT gastrography is a prognostic factor in advanced gastric cancer after curative resection

OBJECTIVE

The objective of this study was to investigate the correlation between pathologic findings and arterial tumor enhancement at MDCT gastrography of patients with a prognosis of advanced gastric cancer after curative resection.

MATERIALS AND METHODS

The cases of 41 patients with advanced gastric cancer (23 men, 18 women; age range, 35-92 years; median, 60 years) who underwent MDCT gastrography and optical endoscopy before surgery were retrospectively evaluated. Two radiologists reviewed virtual endoscopic and multiplanar reconstruction images to measure arterial phase CT values of the inner tumor margin and healthy gastric wall. They used consensus regions of interest on a cross-sectional image of the largest tumor diameter and then calculated tumor-to-normal wall enhancement ratio (TNR). Advanced gastric cancers were divided into high- and low-TNR groups with mean TNR as the cutoff. The correlations between groups and pathologic factors, patient survival, and mode of recurrence were studied.

RESULTS

Multivariate logistic regression analysis showed that the arterial tumor enhancement ratio correlated with both microvessel density and lymphatic vessel invasion. The survival rate after curative resection was worse for the high-TNR group than for the low-TNR group. The rate of lymphatic and hematogenous recurrences was also higher in the high-TNR group. Multivariate survival analysis revealed that TNR was an independent prognostic factor.

CONCLUSION

The extent of arterial tumor enhancement correlated with tumor angiogenesis and lymphatic vessel invasion and was a useful prognostic indicator after curative resection in patients with advanced gastric cancer.

Inhibitory effects of eupatilin on tumor invasion of human gastric cancer MKN-1 cells

Extracts of the whole herb of Artemisia asiatica Nakai (Asteraceae) are used in traditional oriental medicine to treat inflammation. Eupatilin (5,7-dihydroxy-3',4',6-trimethoxyflavone) is one of the pharmacologically active components found in A. asiatica, and has been shown to possess anti-tumoral effects in some malignancies, including gastric cancer. However, its anti-metastatic effect in gastric cancer is hardly known. In this study, anti-metastatic effect of eupatilin was investigated in the human gastric cancer cell line, MKN-1. Eupatilin inhibited MKN-1 growth in a dose- and a time-dependent manner, and induced apoptosis with a concomitant increase of caspase-3 activity. ELISA demonstrated that release of pro-inflammatory cytokines (IL-1β, TNF-α, IL-6, and IL-8) was significantly reduced by eupatilin. And p-AKT and p-ERK (p44/42) was reduced. Expression level of β-catenin and integrin was reduced and p-GSKβ was increased. In transcription reporter system, the activity of the transcriptional factor, NF-κB, was reduced by eupatilin and the expression of p65 was down-regulated when MKN-1 cells were treated with eupatilin. Moreover, a zymography study revealed that this reduction in invasive potential resulted from a reduction in type IV collagenolytic (gelatinolytic) activity. The expressions of metalloproteinases (MMP-2 and MMP-9) were also reduced in MKN-1 cells treated with eupatilin. In vitro invasion assay, eupatilin inhibited MKN-1 penetrating reconstituted basement membrane barriers. These results suggest that eupatilin inhibits the MKN-1 gastric cancer cell proliferation via activation of caspase-3 and the metastatic potential of gastric cancer cells via down-regulation of NF-κB activity followed by reduction of pro-inflammatory cytokine-mediated MMPs expressions.

Metachronous liver metastasis from early gastric cancer

INTRODUCTION

Early gastric cancer (EGC) has an excellent prognosis, but tumors recur in some patients even after apparently successful treatment. Among recurrent sites, the liver is one of the most common. In this study, we investigated clinicopathological features and factors predicting the development of liver metastasis from EGC.

PATIENTS AND METHODS

We examined the medical records of 2,707 consecutive patients who underwent open gastrectomy for EGC (pT1; m, sm) between 1991 and 2005. We assessed clinicopathological features and predictive factors for EGC metastasis in the liver.

RESULTS

Fifteen (0.6%) of the 2,707 patients developed liver metastasis. All primary gastric tumors of patients with liver recurrence demonstrated invasion to the submucosal layer. Macroscopically, nine patients had elevated-type and six depressed-type. Nodal metastasis was documented in seven patients (47%). Lymphatic and vascular involvements were seen in 11 (73%) and 7 (47%) patients, respectively. Multivariate analysis of patients with submucosal invasion revealed macroscopic elevated type and vascular involvement to be independent risk factors for liver metastasis.

CONCLUSIONS

With submucosal cancer, the macroscopic elevated type and vascular involvement are significant predictive factors for EGC recurrence in the liver.

Prognostic significance of p53 protein expression in early gastric cancer

Mutations of the p53 tumor suppressor gene have been associated with abnormalities in cell cycle regulation, DNA repair and synthesis, apoptosis, and it has been implicated in the prognosis of advanced gastric cancer. The aim of this study was to evaluate the occurrence of p53 gene mutation and its possible prognostic implications in early gastric cancer. In a retrospective study, we studied 80 patients with early gastric cancer treated surgically between 1982 and 2001. Mutation of p53 gene was investigated in surgical gastric specimens by immunohistochemistry, and results were analyzed in relation to gender, age, macroscopic appearance, size and location of tumor, presence of lymph nodes, Lauren's histological type, degree of differentiation, and the 5-year survival. The expression of p53 was more frequent among the intestinal type (p = 0.003), the differentiated (p = 0.007), and the macroscopically elevated tumors (p = 0.038). Nevertheless, the isolated expression of p53 was not associated with the 5-year survival, or with the frequency of lymph node involvement. The degree of differentiation was detected as an independent factor related to the outcome of patients (0.044). Significantly shorter survival time was found in p53-negative compared with p53-positive patients, when considering the degree of differentiation of tumors, as assessed by Cox regression analysis (0.049). The association of p53 with the intestinal type, the degree of differentiation and morphological characteristics, may reflect the involvement of chronic inflammatory process underlying early gastric cancer. In this population sample, the expression of p53 alone has no prognostic value for early gastric cancer. However, the significant difference in p53 expression between subgroups of degree of differentiation of tumors can influence post-operative outcome of patients and may be related to possible distinct etiopathogenic subtypes.

Checkpoint with forkhead-associated and ring finger promoter hypermethylation correlates with microsatellite instability in gastric cancer

AIM: To examine the methylation status of the promoter region of the checkpoint with forkhead-associated and ring finger (CHFR) and microsatellite mutator status in 59 primary gastric cancers.

METHODS: We investigated the promoter methylation of CHFR in 59 cases of gastric cancer using methylation-specific PCR. Five microsatellite loci were analyzed using high-intensity microsatellite analysis reported previously, and p53 gene mutations were investigated by direct sequencing.

RESULTS: Twenty cases (33.9%) showed promoter methylation and no relation was observed with the clinicopathological factors. We found that the promoter methylation of CHFR was frequently accompanied with microsatellite instability (MIN). Seven of 20 (35.0%) cases showed MIN in hypermethylation of the CHFR tumor, while three of 39 (7.7%) cases showed MIN in the non-methylated CHFR tumor (P < 0.01). However, we failed to find any relationship between CHFR methylation and p53 mutation status.

CONCLUSION: The coordinated loss of both the mitotic check point function and mismatch repair system suggests the potential to overcome the cell cycle check point, which may lead to an accumulation of mutations. However, the p53 mutation was not related to hypermethylation of the CHFR promoter and MIN, which indicates that an abnormality in p53 occurs as an independent process from the mismatch repair deficiency in carcinogenesis.

Does neoadjuvant treatment for gastric cancer patients with positive peritoneal cytology at staging laparoscopy improve survival?

BACKGROUND

The purpose of this study was to identify clinicopathologic factors associated with positive peritoneal cytology (PPC) in patients with gastric cancer and to compare the overall survival (OS) of patients with PPC treated with and without neoadjuvant therapy.

METHODS

The medical records of 3,747 patients with gastric or gastroesophageal adenocarcinoma presenting to our institution (January 1995 to December 2005) were reviewed to identify those patients who underwent diagnostic laparoscopy as a staging procedure prior to consideration for neoadjuvant therapy. Associations between various clinicopathologic factors and OS were examined with Cox proportional hazards models. Kaplan-Meier curves were created to compare OS between groups.

RESULTS

Of 381 patients who underwent diagnostic laparoscopy for staging, 39 were found to have PPC without gross metastatic disease. Linitis plastica and tumors located at the gastroesophageal junction were identified as predictors of PPC (P < 0.01). Median follow-up for living patients was 51 months. Median OS for patients with PPC and no gross metastatic disease at laparoscopy (13 months) was no different from that for patients with gross metastatic disease at laparoscopy (10 months, P = 0.06). For the 39 patients with PPC and no gross metastatic disease, use of neoadjuvant therapy resulted in a 3-year OS rate of 12% versus 0% for patients who did not receive neoadjuvant therapy.

CONCLUSION

Outcomes for patients with PPC without gross metastatic disease are not significantly different from those patients with gross metastatic disease at laparoscopy. However, some patients can achieve long-term survival and should be considered for neoadjuvant treatment prior to attempts at surgical resection.

The postoperative recurrence and the occurrence of second primary carcinomas in patients with early gastric carcinoma

OBJECTIVE

Early gastric cancers have recently become more prevalent, and therefore, characterization of the features of patients who develop recurrence and second cancers is necessary for the development of effective postoperative follow-up strategies.

METHODS

We evaluated the clinicopathological features and the timing of the development of both recurrence and second primary cancer after surgery for early gastric cancer in 671 patients.

RESULTS

The incidence rate of recurrent early gastric cancer was 2.1%, and the incidence rate of second primary cancer was 4.8%, with an associated death rate of 3.3%. Most multiple primary cancers cases involved the colorectum and the lung. A multivariate analysis of overall survival identified multiple primary cancers, age, and sex as prognostic factors for early gastric cancer. The average interval from surgery to diagnosis of recurrence was identified as 3.4 +/- 2.1 years. The average interval for peritoneal recurrence was shorter than that for hematogenous recurrence (P < 0.05). The average interval from diagnosis of early gastric cancer to diagnosis of the second primary cancer was 7.1 +/- 4.6 years.

CONCLUSION

Patients with early gastric cancer, particularly patients who are males, elderly and have lymphatic involvement, tend to have a greater risk of developing a second primary cancer and recurrence, respectively.

Relationship between VEGF and p53 expression and tumor cell proliferation in human gastrointestinal carcinomas

PURPOSE

The vascular endothelial growth factor (VEGF) and p53 play important roles in the growth of tumor. However, the relationship between the expression of VEGF and p53 and tumor cell proliferation in human gastrointestinal cancer remains unknown. In the present study, therefore, we have examined the relationship between VEGF and p53 expression and tumor cell proliferation in gastrointestinal carcinoma (GITC), as well as the association between these biomarkers and clinicopathological factors.

METHODS

Surgical specimens from 30 patients with GITC were examined for VEGF, p53, and proliferating cell nuclear antigen (PCNA) expression by immunohistochemical staining.

RESULTS

We found a predominant VEGF expression of moderate intensity in 16(54.84%) of 30 GITC cases, while p53 expression was mainly high in 13(45.16%) of 30 GITC cases. PCNA expression was high in 20(64.52%) of 30 GITC cases. Tumor size, infiltration, vascular invasion, and gastritis were significantly correlated with VEGF, p53, and PCNA expression. There was a significant correlation between VEGF and p53 expression (P = 0.0001), VEGF and PCNA expression (P = 0.00004), and between p53 expression and PCNA expression (P = 0.0016). When the VEGF and p53 expression, and PCNA expression were considered together, both VEGF and p53 expression were not significantly associated with PCNA. A significant correlation between the PCNA expression and the mitotic index (P = 0.0016) was also found.

CONCLUSION

These results demonstrate that VEGF and p53 expression are significantly correlated as independent prognostic factors with tumor cell proliferation, and might be associated with relevant events involved in gastrointestinal tumor biology.

VEGF-C and VEGF-A synergistically enhance lymph node metastasis of gastric cancer

PURPOSE

Vascular endothelial growth factor C (VEGF-C) is the most important molecule in lymphangiogenesis and its relationship with lymph node metastasis has attracted considerable interest. We investigated the relationship of VEGF-C or VEGF-A with clinicopathological factors in gastric cancer patients.

METHODS

Eighty gastric cancer patients who underwent gastric resection were analyzed immunohistochemically for expression of VEGF-C and VEGF-A protein.

RESULTS

Positive immunoreactivity of VEGF-C and VEGF-A was observed in 75 (93.8%) and 41 (51.3%) patients, respectively. VEGF-A expression was significantly correlated with tumor differentiation (p=0.0017) and vascular invasion (p=0.0004). And positive relationship of VEGF-C expression was only demonstrated with tumor differentiation (p=0.0168). Interestingly, however, the frequency of lymph node metastasis was significantly higher in the patients with expression of both VEGF-C and VEGF-A (strong positive expression, p=0.036). Furthermore, the expression of both was also significantly correlated with depth of tumor invasion, tumor differentiation, lymphatic invasion, and vascular invasion.

CONCLUSION

The present results suggest that strong expression of VEGF-A in addition to VEGF-C expression is essential in lymph node metastasis, presumably because enhanced metastatic potential including lymphangiogenesis induced by both VEGF-A and VEGF-C is vital in lymph node metastasis of gastric cancer.

Peritoneal dissemination of early gastric cancer: report of a case

Recurrence of early gastric cancer is rare, with an incidence of less than 10% in Japan. Using peritoneal lavage cytological examination, we detected tumor cells in the peritoneal cavity of a 73-year-old man undergoing surgery for early gastric cancer. Peritoneal dissemination of early gastric cancer is rare. Thus, we summarized the clinicopathological findings of the total 15 cases of peritoneal dissemination of early gastric cancer documented in the English medical literature, including this case. All of the patients had a tumor size >2 cm, submucosal invasion, differentiated adenocarcinoma, lymph node metastasis, and a shorter disease-free interval (average 33.1 months) than patients with other types of recurrent early gastric cancer, and the involvement of both recurrent lymph nodes and peritoneal dissemination. Based on this analysis, we conclude that patients with early gastric cancer, especially if the tumor is >2 cm with submucosal invasion, should be examined carefully for any form of recurrence.

Identification of protein expression signatures associated with Helicobacter pylori infection and gastric adenocarcinoma using recombinant antibody microarrays

Antibody microarray based technology is a powerful emerging tool in proteomics, target discovery, and differential analysis. Here, we report the first study where recombinant antibody fragments have been used to construct large scale antibody microarrays, composed of 127 different antibodies against mostly immunoregulatory antigens. The arrays were based on single framework recombinant antibody fragments (SinFabs) designed for high on-chip stability and functionality and were used for the analysis of malignant and normal stomach tissue samples from Helicobacter pylori-positive and -negative patients. Our results demonstrate that distinct tumor- as well as infection-associated protein expression signatures could be identified from these complex tissue proteomes, as well as biomarkers such as IL-9, IL-11, and MCP-4, previously not found in these diseases. In a longer perspective, this study may improve the understanding of H. pylori-induced stomach cancer and lead to development of improved diagnostics.

Impact of loss of heterozygosity of encoding phosphate and tensin homolog on the prognosis of gastric cancer

BACKGROUND AND AIM

Encoding phosphate and tensin homolog (PTEN) is a cancer suppressor gene and it has been assumed that gene mutation and loss of heterozygosity (LOH) occurs frequently in various types of carcinoma. However, the role of LOH of PTEN and its outcome variables in gastric cancer have not been well established. In the present study, we investigated the roles of PTEN, LOH and their outcomes.

METHODS

Fresh frozen tumor samples from 119 gastric cancer patients with a primary diagnosis of gastric carcinoma were evaluated for LOH of PTEN using an automated sequencer. Results were compared with pathological parameters. The median follow-up period was 559 days.

RESULTS

Loss of heterozygosity of PTEN was observed in 17.1% of patients (13/76) diagnosed with gastric cancer. No particular relationship was found with any clinicopathological factor. However, the prognosis of patients with LOH of PTEN was significantly poor. Multivariate analyses revealed that vascular invasion, invasion depth, LOH of PTEN, histology and lymph node metastasis were correlated with survival of the patient.

CONCLUSIONS

Even though mutation of PTEN in gastric cancer has rarely been reported, according to our findings, LOH of PTEN frequently occurs in gastric cancers and is correlated with disease-related deaths. The LOH of PTEN is an independent prognostic factor and PTEN is a candidate as a haploinsufficient tumor suppressor in gastric cancers.

Effective follow-up for recurrence or a second primary cancer in patients with early gastric cancer

BACKGROUND

Patients with early gastric cancer have an excellent prognosis with low rates of recurrence, but may have an increased risk of developing a second primary cancer. Because the number of early gastric cancers has increased, clarification of both recurrences and second primary cancers is important for the development of effective postoperative follow-up programmes.

METHODS

Data on 1070 patients with early gastric cancer were analysed retrospectively with respect to the clinicopathological features of both recurrence and second primary cancers after surgical treatment.

RESULTS

Multivariate analysis showed that lymph node metastasis and older age were independent risk factors for recurrence of early gastric cancer. The incidence of second primary cancers was 5.0 per cent; lung and colorectal cancers were detected most frequently, followed by cancers in the oesophagus, breast and remnant stomach.

CONCLUSION

Clinicopathological features of patients with early gastric cancer can be used to identify those most at risk of developing either recurrence or a second primary cancer.

Genetic mutual relationship between PTEN and p53 in gastric cancer

Both PTEN (encoding phosphate and tensin homologue) and p53 are known as cancer suppressor genes, and they are assumed that their gene mutations and loss of heterozygosity (LOH) occur frequently in various types of carcinoma. In the present study, we investigated both the p53 mutation and LOH of PTEN in 113 gastric cancer patients. We observed the LOH of PTEN in 11.1% of the patients with normal p53s and 46.2% of the patients with p53 gene mutations. The result that LOH of PTEN was frequently observed in the cases with p53 gene mutations and other data in this study suggested that both PTEN and p53 have complimentary roles in gastric carcinoma development.

Survival after surgical treatment of early gastric cancer, surgical techniques, and long-term survival

Early gastric cancer (EGC) is well accepted as having a favorable prognosis after surgical treatment. Difference in treatment strategies for EGC between Japan and western countries indicates a need for current information to be evaluated with regard to long-term survival rates of EGC patients throughout the world. To analyze survival rates and recurrence after resection of EGC, we investigated 51 reports in English that each included more than 50 cases of EGC treated by gastrectomy and had been published during the past 12 years (1992-2003). Prevalence of EGC among all gastric cancers was 45%-51% in Japan, but only 7%-28% in western countries. Mean age at diagnosis was less than 60 years in Japan and Korea, but was more than 60 in most of the Western countries. Actuarial and disease-specific 5-year survival rates for EGC were 72%-95.8% and 88%-98.3%, respectively. Those for EGC that were invading the submucosal layer were 71.6%-94.1% and 82%-96.6%, respectively. Those for EGC with lymph node metastasis were 57%-89.1% and 72%-93.5%, respectively. Prevalence of recurrence ranged from 1.0% to 13.8%. Larger clinical series with more EGC cases showed a lower prevalence of recurrence (P=0.531, P=0.0026). Liver and blood-borne distant metastasis represented the predominant pattern of relapse, accounting for over half (54%). Local recurrence and peritoneal dissemination represented 20% and 18% of all recurrences, respectively. Clinicopathological studies have shown lymph node metastasis to be closely related to depth of invasion, size of lesion, histological type, presence of ulcer or ulcer scar, and vessel involvement. Information on these factors is the key to successful treatment of EGC. When sufficient information has been assessed preoperatively, surgeons can select patients for whom less-invasive surgery should not increase the risk of recurrence.

Effect of Chinese medicine Weikangning on expression of VEGF and its receptors Flt and KDR in gastric carcinoma cells

AIM: To study effect of traditional Chinese medicine Weikangning (WKN) on the expression of VEGF and its receptors Flt and KDR in gastric carcinoma cells.

METHODS: We used different dosage of WKN on rats to prepare serum containing WKN.The gastric carcinoma cells were cultured in the RPMI1640 media with serum containing WKN for 48 h. The expression of VEGF, Flt-1 and KDR was determined by reverse transcription-polymerase chain reaction (RT-PCR) and immunohistochemistry in gastric cancer cell lines respectively.

RESULTS: All gastric cancer cell lines analyzed expressed VEGF Flt-1 and KDR. But the expression of fVEGF (186.82±0.22, 195.35±0.45, 172.62±0.52), Flt-1 (198.44±0.44, 188.66±0.46, 197.01±0.91) in cells cultured in serum containing WKN decreased in a dose-dependent manner as compared with control (VEGF162. 78±0.58, Flt: 172.65±0.65)(P < 0.05).

CONCLUSION: VEGF and its receptors KDR and Flt-1 are expressed widely in gastric carcinoma cells and WKN can inhibit their expression.

Bystander cell killing spreading from endothelial to tumor cells in a three-dimensional multicellular nodule model after Escherichia coli nitroreductase gene delivery

Tumor cells are elusive targets for standard anticancer chemotherapy due to their heterogeneity and genetic instability. On the other hand, proliferating host endothelial cells (ECs) are genetically stable and have a low mutational rate. Thus, antiangiogenic therapy directed against tumor's ECs should, in principle, improve the efficacy of antitumor therapy by inducing little or no drug resistance. Here we present a gene-directed enzyme prodrug therapy (GDEPT) strategy for targeting the tumor vasculature, using the Escherichia coli nitroreductase (ntr) gene delivery associated with the treatment with the prodrug CB1954. In a first time we demonstrated the ability of the ntr/CB1954 system to induce an apoptotic-mediated cell death on monolayer cultures of human umbilical vein ECs (HUV-EC-C). Then, when ntr-transfected HUV-EC-C cells (HUV-EC-C/ntr(+)) were associated in a three-dimensional (3-D) multicellular nodule model with untransfected B16-F10 murine melanoma cell line, we observed a CB1954-mediated bystander cell killing effect from endothelial to neighboring melanoma cells. To our knowledge, this is the first report indicating that GDEPT-based antiangiogenic targeting may be an effective approach for cancer treatment relied on the spreading of the bystander effect from endothelial to tumor cells.