p53 overexpression and proliferative activity do not correlate with lymph node metastasis in early gastric cancer

Establishment of a nomogram for predicting lymph node metastasis in patients with early gastric cancer after endoscopic submucosal dissection

Background

Endoscopic submucosal dissection (ESD) has been accepted as the standard treatment for the appropriate indication of early gastric cancer (EGC). Determining the risk of lymph node metastasis (LNM) is critical for the following treatment selection after ESD. This study aimed to develop a predictive model to quantify the probability of LNM in EGC to help minimize the invasive procedures.

Methods

A total of 952 patients with EGC who underwent radical gastrectomy were retrospectively reviewed. LASSO regression was used to help screen the potential risk factors. Multivariate logistic regression was used to establish a predictive nomogram, which was subjected to discrimination and calibration evaluation, bootstrapping internal validation, and decision curve analysis.

Results

Results of multivariate analyses revealed that gender, fecal occult blood test, CEA, CA19-9, histologic differentiation grade, lymphovascular invasion, depth of infiltration, and Ki67 labeling index were independent prognostic factors for LNM. The nomogram had good discriminatory performance, with a concordance index of 0.816 (95% CI 0.781–0.853). The validation dataset yielded a corrected concordance index of 0.805 (95% CI 0.770–0.842). High agreements between ideal curves and calibration curves were observed.

Conclusions

The nomogram is clinically useful for predicting LNM after ESD in EGC, which is beneficial to identifying patients who are at low risk for LNM and would benefit from avoiding an unnecessary gastrectomy.

A Comparison by Meta-Analysis of Papillary Early Gastric Carcinoma to Its Tubular Counterpart for the Risk of Lymph Node Metastasis and Submucosal Invasion

BACKGROUND AND AIM

At present, the decision to perform endoscopic resection for treating either papillary early gastric cancer (EGC) or tubular EGC is made according to identical criteria. However, there is controversy in the literature whether the risk of lymph node metastasis (LNM) and submucosal invasion for both disease modalities is equal, and this prompts investigation to clarify this issue.

METHODS

The PubMed and Web of Science databases were searched for relevant studies published up to January 2017. Data were extracted, and the pooled odds ratios (ORs) and 95% confidence intervals (95% CIs) were calculated using a random-effects or a fixed-effects model, according to heterogeneity.

RESULTS

A total of 13 studies were included in this analysis. Papillary EGC had a significantly higher LNM risk (OR, 1.97; 95% CI, 1.38-2.82) and submucosal invasion risk (OR, 1.44; 95% CI, 1.08-1.93), compared with tubular EGC. Stratified by geographic location, a significantly increased risk of LNM (OR, 2.28; 95% CI, 1.57-3.30) and submucosal invasion (OR, 1.52; 95% CI, 1.13-2.04) associated with papillary EGC was found in Asian studies. In addition, papillary EGC exhibited significantly more frequent elevated/flat growth patterns (OR, 7.54, 95% CI, 4.76-11.96).

CONCLUSIONS

Our study identifies an increased risk for submucosal invasion and LNM in papillary EGC compared with tubular EGC, indicating that papillary EGC requires more careful clinical management compared with tubular EGC.

Predictable factors for lymph node metastasis in early gastric cancer analysis of clinicopathologic factors and biological markers

Predicting lymph node metastasis (LNM) accurately is very important to decide treatment strategies preoperatively. The aim of this study was to explore risk factors that predict the presence of LNM in early gastric cancer (EGC). A total of 230 patients with EGC who underwent curative gastrectomy with lymph adenectomy at Xinhua Hospital from January 2006 to July 2014 were retrospectively reviewed. We studied the relationship between clinicopathological factors, biological markers (p53, ki67, nm23, vascular endothelial growth factor (VEGF), epidermal growth factor receptor (EGFR), E-cadherin (E-cad), beta-catenin (b-catenin), glutathione S-transferase (GST), and topoisomerase II (Topo II)), and LNM of EGC patients by chi-square test and logistic regression analysis. Meta-analyses were further conducted to review the effects of the proteins (P53, ki67, E-cad, and b-catenin) on LNM in ECG patients. LNM was detected in 42 (18.3 %) of 230 patients. Incidences of LNM was distinct in different tumor size (p = 0.044), depth of submucosal invasion (p < 0.0001), and P53 overexpression (p = 0.004). Multivariate analysis further indentified that large tumor size (≥20 mm, odds ratio (OR) = 2.168, p = 0.041), submucosa (OR = 4.000, p = 0.0005), and P53 overexpression (OR = 3.010, p = 0.022) were independent risk factors of LNM in EGC patients. The meta-analysis revealed a significantly statistical association of P53, ki67, and b-catenin with an increased risk of LNM in EGC patients (P53, OR = 1.81, p = 0.017; ki67, OR = 2.53, p = 0.0003; b-catenin, OR = 0.53, p = 0.01). Tumor size (≥20 mm), the depth of invasion (submucosa), and P53 overexpression may be helpful predictors of LNM in EGC patients. Furthermore, the results of meta-analysis revealed that P53, ki67 overexpression, and abnormal expression of b-catenin may be associated with LNM in EGC. The results need further validation in single large studies.

Expression of stromal cell-derived factor-1α is an independent risk factor for lymph node metastasis in early gastric cancer

Lymph node metastasis is considered to be a significant prognostic factor for early gastric cancer (EGC). However, no real consensus exists on which patient and/or tumor characteristics are associated with lymph node metastasis. We investigated whether stromal cell-derived factor (SDF)-1α expression correlates with lymph node metastasis in patients with EGC by immunohistochemically examining the expression of SDF-1α in 138 archival tissue specimens of EGC. Of these specimens, 59 (42.8%) and 79 (57.2%) were grouped into SDF-1α-positive and SDF-1α-negative groups, respectively. No significant differences existed with respect to age, gender, tumor location, proportion of tumors >20 mm in size, macroscopic type, depth of invasion or histology between the SDF-1α-positive and -negative groups. However, the SDF-1α-positive group was significantly correlated with lymphovascular invasion and lymph node metastasis. Results of the univariate analyses indicated that lymphovascular invasion, undifferentiated histology and SDF-1α positivity were statistically significant risk factors affecting lymph node metastasis in patients with EGC. Multivariate analyses showed that lymphovascular invasion [hazard ratio (HR), 8.595; 95% confidence interval (CI), 1.694-43.595; P=0.009], undifferentiated histology (HR, 2.965; 95% CI, 1.037-8.471; P=0.043) and SDF-1α positivity (HR, 2.108; 95% CI, 1.316-10.135; P=0.013) were independent risk factors predicting lymph node metastasis in EGC. In conclusion, these results suggest that SDF-1α expression in tumor cells is a predictive marker of lymph node metastasis in EGC.

Molecular analysis of gastric differentiated-type intramucosal and submucosal cancers

Identification of the molecular characteristics of intramucosal (IMCs) and submucosal cancers (SMCs) is essential to our understanding of early gastric carcinogenesis. However, little is known regarding the differences between the 2 lesions. One hundred and forty-eight patients with primary early gastric cancer [IMC, 106; SMC, 42] were characterized for expression of cell cycle-related proteins and loss of heterozygosity (LOH). We also examined microsatellite instability (MSI) and methylation status. For LOH and methylation studies, we used a panel of 17 microsatellite markers (3p, 4p, 5q, 9p. 13q, 17p, 18q and 22q) and promoter regions of 9 genes (MLH-1, RUNX3, p16, HPP1, RASSF2A, SFRP1, DKK-1, ZFP64 and SALL4) that are frequently altered or methylated in gastric cancers. Overexpression of p53 and cyclin D1 was observed in SMC. In addition, low expression of p27 was more frequent in SMC than in IMC. Frequencies of 4p, 9p, 13q and 22q were significantly higher in SMC than in IMC. The SALL4 gene was frequently methylated in SMC compared with IMC. However, other gene methylations were common in both IMC and SMC. The frequency of LOH-high status/methylation-low status was significantly higher in SMC than in IMC. However, LOH-low status/methylation-high status in SMC was more frequently found in IMC. Our data confirm that methylation of cancer-related genes plays a major role in the development of IMCs. Importantly, the results also show that gastric submucosal progression is characterized by the accumulation of specific genetic alterations. In addition, changes of cell cycle-related proteins are associated with cancer progression.

Low Ki-67 proliferation index is an indicator of poor prognosis in gastric cancer

BACKGROUND AND OBJECTIVES

We designed this study to assess the biologic significance of Ki-67 proliferation index (PI) in gastric cancer.

METHODS

Gastric cancer tissue from 245 patients were immunostained for Ki-67. Ki-67 PI was defined as the percentage of tumor cells positive for Ki-67. In addition, we have previously evaluated the expressions of nine epithelial mesenchymal transition (EMT)-related proteins. The relationship between Ki-67 PI and clinicopathologic parameters, patient survival, and EMT data were sought.

RESULTS

Low Ki-67 PI was correlated with poorly differentiated histology (P = 0.034), an advanced T stage (P < 0.001), and lymph node metastasis (P = 0.011). Also, the low PI group was found to have a significantly worse prognosis than the high PI group (P = 0.003, log-rank test). Multivariate analysis revealed that Ki-67 PI remained as an independent prognostic factor (hazard ratio (95% CI) = 0.670 (0.450-0.999)). Furthermore, greater expressional changes of EMT-related proteins were found to be significantly associated with low Ki-67 PI (P = 0.025).

CONCLUSIONS

These findings suggest that Ki-67 PI is an effective tool for predicting survival in gastric cancer. In addition, we found that an invasive property presented as EMT-related protein expressional changes was inversely correlated with a proliferative activity in gastric cancer.

Predicting lymph node status in early gastric cancer

Accurate prediction of lymph node (LN) status is of crucial importance for appropriate treatment planning in patients with early gastric cancer (EGC). However, there is no definitive consensus yet on which patient and/or tumor characteristics are associated with LN metastasis. A systematic search for studies investigating the relationship between patient and/or tumor characteristics and LN metastasis in EGC was performed in PubMed/MEDLINE. Patient and/or tumor characteristics associated with LN metastasis were identified by meta-analyzing results of individual studies. Forty-five studies were included. Variables significantly associated with LN metastasis in gastric cancer limited to the mucosa were: age younger than 57 years, tumor location in the middle part of the stomach, larger tumor size, macroscopically depressed tumor type, tumor ulcerations, undifferentiated tumors, diffuse tumor type according to the Lauren classification, lymphatic tumor invasion, tumors with a proliferating cell nuclear antigen (PCNA) labeling index of more than 25%, and matrix metalloproteinase-9-positive tumors. Variables significantly associated with LN metastasis in gastric cancer limited to the submucosa were: female sex, tumor location in the lower part of the stomach, larger tumor size, undifferentiated tumors, increasing depth of submucosal invasion, lymphatic tumor invasion, vascular tumor invasion, increased submucosal vascularity, tumors with a PCNA labeling index of more than 25%, tumors with a gastric mucin phenotype, and vascular endothelial growth factor-C-positive tumors. We identified several variables associated with LN metastasis in EGC. These variables should be included in future research, in order to assess which of these variables remain as significant predictors of LN metastasis.

Lymphatic and/or blood vessel invasion in gastric cancer: relationship with clinicopathological parameters, biological factors and prognostic significance

BACKGROUND

Lymphatic and/or blood vessel tumoral invasion (LBVI) is a common histopathologic finding of gastric carcinomas, which could make it an additional cost efficient marker and help in the detection of patients at risk for recurrence.

MATERIALS AND METHODS

The subjects of this study were 144 patients with primary gastric adenocarcinoma, who consecutively underwent surgery. LBVI was evaluated by H&E staining and complementary with immunohistochemical staining with anti-CD34. Intratumoral levels of EGFR were analyzed with a radioligand technique, whereas c-erbB-2 and tPA were determined by ELISA methods; pS2, cathepsin D and hyaluronic acid by immunoradiometric assays; and VEGFR-1 and -2 by immunohistochemical assays. The mean follow-up period for these patients was 33.1 months.

RESULTS

LBVI was present in 46 patients (31.9%). The presence of LBVI correlated significantly with tumor stage, lymph node involvement, surgical resectability, histological type and histological grade, being present in a higher percentage among II-IV tumor stage (P = 0.0001), poorly differentiated (P = 0.01), diffuse type (P = 0.009), R1-R2 (P = 0.002) and lymph node-positive (P = 0.005) tumors. In addition, statistical analysis demonstrated that LBVI was significantly associated with a poorer overall patients' survival in the univariate analysis (P = 0.0001) as well as in the multivariate analysis (P = 0.009). However, our results failed to show any significant relationship between LBVI and any of the intratumoral biological parameters studied.

CONCLUSION

LBVI provides additional useful information that could be applied to identify gastric cancer patients at risk for recurrence, who might be candidates for further adjuvant therapies.

Outcome of distal gastric cancer with pyloric stenosis after curative resection

AIMS

Pyloric stenosis usually presents with symptoms, and this may lead patients to consult their physician. We evaluate whether distal gastric cancer patients with pyloric stenosis had a better outcome than those without.

METHODS

A total of 551 distal gastric cancer patients who received curative subtotal gastrectomy between January 1988 and December 2003 at Taipei Veterans General Hospital were analyzed. Among them, 174 patients were sorted into the pyloric stenosis group according to obstructive symptoms. Their clinicopathological features, survival and prognostic factors were evaluated.

RESULTS

The 5-year overall and disease-free survival rate of distal third gastric adenocarcinoma for the pyloric stenosis group was significantly lower than those without pyloric stenosis. Multivariate analysis revealed the pyloric stenosis group had deeper cancer invasion (relative to pT1, RR of pT2 3.1, p=0.009; pT3 6.1, p<0.001; pT4 16.5, p<0.001), and more lymph node metastasis (RR 3.6; p=0.001). The pyloric stenosis group had a tendency to lymph node metastasis toward the hepatoduodenal ligament, but this did not reach statistical difference. However, the pyloric stenosis group had significantly higher lymph node metastasis in the retropancreatic region (5.17% vs. 0.53%; p=0.001).

CONCLUSIONS

Distal gastric cancers with pyloric stenosis have worse biological behavior than those without, and consequently have a poor outcome.

Expression of cyclooxygenase-2, p53 and Ki-67 in gastric cancer

It has been reported that p53 mutation may contribute to upregulate cyclooxygenase (COX)-2 expression that is observed in malignant tissues. These molecules are involved in carcinogenesis by affecting tumor cell proliferation. The aim of this study was to examine the relationship between COX-2 or p53 expression and clinico-pathological characteristics including tumor cell proliferation in gastric cancer. COX-2 and p53 expressions were investigated with immunostaining, in tissue specimens obtained from 119 patients who underwent surgery for gastric cancer. The Ki-67 labeling index (LI) was counted by Ki-67 immunostaining. COX-2 and p53 expressions correlated significantly with depth of tumor invasion. However, there was no association between COX-2 or p53 expression and survival. p53 expression did not correlate with COX-2 expression. There was no significant difference in various clinicopathological variables between Ki-67 LI subgroups. The mean Ki-67 LI value of COX-2 positive tumors was significantly higher than that of negative tumors. The mean Ki-67 LI value of p53 positive tumors was not significantly higher than that of negative tumors. The mean Ki-67 LI value of both COX-2 and p53 positive tumors was significantly higher than that of both negative tumors. These results imply that COX-2 expression is associated with tumor cell proliferation of gastric cancer.

Prognostic use of growth characteristics of early gastric cancer and expression patterns of apoptotic, cell proliferation, and cell adhesion proteins

BACKGROUND AND OBJECTIVES

Selection of suitable treatment for early gastric cancers, such as endoscopic mucosal resection or the major surgical option of resection of the cancer together with a radical lymph node dissection, may be assisted by comparing the growth characteristics of the cancer with selected molecular characteristics. The results could be used to predict those cases that have a higher risk of developing secondary metastases.

METHODS

A total of 1,196 Japanese patients with early gastric cancers (648 mucosal cancers and 548 submucosal) were included in the selection of two groups: a metastatic group made up 57 cancers with lymph node metastasis (9 mucosal, 48 submucosal), and a nonmetastatic group of 61 cases (6 mucosal, 55 submucosal) without lymph node metastasis. Growth characteristics of the cancers (superficially spreading, penetrating or invasive, lymph node metastasis) were compared with immunohistochemical expression of single-stranded DNA (ssDNA) protein (apoptosis indicator), bcl-2 and p53 (apoptosis-associated), Ki-67 (cell proliferation), and E-cadherin (cell adhesion) proteins.

RESULTS

The lesions in the nonmetastatic group had higher levels of apoptosis and lower expression of bcl-2 than in the metastatic group, indicating an inhibitory role for apoptosis in malignant progression. Apoptosis was also higher in the superficial compared with the invasive lesions of both groups. The lesions in the metastatic group had higher p53 expression than that of the nonmetastatic group, whereas apoptosis in the metastatic group was lower than in the nonmetastatic group. An unproved explanation for this finding may be that, although increased, p53 was mutated and ineffective in promoting apoptotic control of metastatic progression. E-cadherin was decreased in the invasive lesions of both groups, indicating a greater ability of these cells to lose adhesion, to invade the submucosa, and to metastasize. Cell proliferation was highest in the superficial lesions of both metastatic and nonmetastatic groups.

CONCLUSIONS

Early gastric cancers with low levels of apoptosis, increased bcl-2, and high levels of p53 expression are more likely to invade and metastasize.

Carcinomatous lymphatic invasion in early gastric cancer invading into the submucosa

BACKGROUND

Lymphatic invasion is a risk factor for lymph node metastases in patients with gastric cancer. No studies have been reported, however, on the correlation between lymphatic invasion and lymph node metastasis in early gastric cancer invading into the submucosa.

METHODS

We performed a retrospective analysis of lymphatic invasion in 170 patients with early gastric cancer invading into the submucosa.

RESULTS

Lymphatic invasion was found in 76 patients. Lymphatic invasion correlated significantly with the presence of lymph node metastasis and vascular invasion (P < .05) and with the degree of cancerous submucosal involvement (P < .05). The presence of lymph node metastasis also correlated with the grade of submucosal invasion and lymphatic invasion. The 5-year survival of patients with lymphatic invasion was poorer than that of patients without lymphatic invasion (P < .05). Node-negative patients had similar survival, regardless of the presence of lymphatic invasion. All patients with severe lymphatic invasion had sm3 invasion and lymph node metastases.

CONCLUSION

Although lymphatic invasion is the first stage of lymph node metastasis, lymphatic invasion in itself does not have clinical importance except for severe invasion in early gastric cancer. It is possible to predict lymph node metastases from the combined evaluation of degree of lymphatic invasion and submucosal involvement of the tumor in patients with early gastric cancer invading into the submucosa.