Risk factors of survival and surgical treatment for advanced gastric cancer with large tumor size

Development and validation of a nomogram to predict cancer-specific survival of elderly patients with unresected gastric cancer who received chemotherapy

This investigation aimed to explore the prognostic factors in elderly patients with unresected gastric cancer (GC) who have received chemotherapy and to develop a nomogram for predicting their cancer-specific survival (CSS). Elderly gastric cancer patients who have received chemotherapy but no surgery in the Surveillance, Epidemiology, and End Results Database between 2004 and 2015 were included in this study. Cox analyses were conducted to identify prognostic factors, leading to the formulation of a nomogram. The nomogram was validated using receiver operating characteristic (ROC) and calibration curves. The findings elucidated six prognostic factors encompassing grade, histology, M stage, radiotherapy, tumor size, and T stage, culminating in the development of a nomogram. The ROC curve indicated that the area under curve of the nomogram used to predict CSS for 3, 4, and 5 years in the training queue as 0.689, 0.708, and 0.731, and in the validation queue, as 0.666, 0.693, and 0.708. The calibration curve indicated a high degree of consistency between actual and predicted CSS for 3, 4, and 5 years. This nomogram created to predict the CSS of elderly patients with unresected GC who have received chemotherapy could significantly enhance treatment accuracy.

Tumor size impact on TNM staging which define post-operative complications in rectal cancer

The purpose of this study was to see how accurate tumor size was at predicting T and N stages in rectal malignancies. Tumor sizes of 40 mm and greater than 40 mm were used to assess post-operative challenges in related to T1-T2 and T3-T4 stages, as well as between node N0 and node N1 and N2 patients. A total of 131 patients were treated for colorectal cancer, with 54 patients < 40 mm and 77 patients > 40 mm receiving Da Vinci colorectal surgery. Conferring to the Clavien-Dindo classification grade III, there's an increase in the percentage of tumors > 40 mm, which also impacts the percentage of intestinal obstruction, anastomotic leakage, GERD, and sepsis with a P < 0.05. A tumor size of more than 40 mm is strongly associated with advanced pT stages. Tumor size may serve in addition to clinical staging and improve the management of rectal cancer.

Nomogram for predicting overall survival after curative gastrectomy using inflammatory, nutritional and pathological factors

PURPOSE

To establish a nomogram for predicting the overall survival (OS) in patients with gastric cancer (GC) based on inflammatory, nutritional and pathological factors.

METHODS

GC patients underwent curative gastrectomy from January 2012 to June 2017 in our hospital were included, and were classified into training set and validation set with a ratio of 7:3. Then variables associated with OS were analyzed using univariate and multivariate Cox regression analysis. Nomograms predicting OS were built using variables from multivariable Cox models. Finally, Kaplan-Meier curve and Log-rank test were also conducted to analyze the 1-yr, 3-yr and 5-yr OS to validate the efficiency of risk stratification of the nomogram.

RESULTS

A total of 366 GC patients were included. After univariate and multivariate Cox regression analysis, age (HR = 1.52, 95% CI = 1.01-2.30, P = 0.044), CA50 (HR = 1.90, 95% CI = 1.12-3.21, P = 0.017), PNI (HR = 1.65, 95% CI = 1.13-2.39, P = 0.009), SII (HR = 1.46, 95% CI = 1.03-2.08, P = 0.036), T stage (HR = 2.26, 95% CI = 1.01-5.05, P = 0.048; HR = 7.24, 95% CI = 3.64-14.40, P < 0.001) were independent influencing factors on the survival time of GC patients. Five factors including CEA, prognostic nutritional index (PNI), systemic immune-inflammation index (SII), ln (tumor size), T stage, and N stage were identified and entered the nomogram, which showed good discrimination and calibration in both sets. On internal validation, 1-yr, 3-yr and 5-yr nomogram demonstrated a good discrimination with an area under the ROC curve (AUC) of 0.77, 0.84 and 0.86, respectively. The AUC for 1-yr, 3-yr and 5-yr nomogram in validation set was 0.77, 0.79 and 0.81, respectively. The OS in low risk group of training cohort and validation cohort was significantly higher than that of intermediate risk group and high risk group, respectively.

CONCLUSIONS

We established a nomogram based on PNI, SII and pathological factors for predicting OS in GC patients. In addition, its efficiency was validated by validation set and stratified analysis.

Comprehensive multi-omics analysis of tryptophan metabolism-related gene expression signature to predict prognosis in gastric cancer

Introduction: The 5-year survival of gastric cancer (GC) patients with advanced stage remains poor. Some evidence has indicated that tryptophan metabolism may induce cancer progression through immunosuppressive responses and promote the malignancy of cancer cells. The role of tryptophan and its metabolism should be explored for an in-depth understanding of molecular mechanisms during GC development. Material and methods: We utilized the Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) dataset to screen tryptophan metabolism-associated genes via single sample gene set enrichment analysis (ssGSEA) and correlation analysis. Consensus clustering analysis was employed to construct different molecular subtypes. Most common differentially expressed genes (DEGs) were determined from the molecular subtypes. Univariate cox analysis as well as lasso were performed to establish a tryptophan metabolism-associated gene signature. Gene Set Enrichment Analysis (GSEA) was utilized to evaluate signaling pathways. ESTIMATE, ssGSEA, and TIDE were used for the evaluation of the gastric tumor microenvironment. Results: Two tryptophan metabolism-associated gene molecular subtypes were constructed. Compared to the C2 subtype, the C1 subtype showed better prognosis with increased CD4 positive memory T cells as well as activated dendritic cells (DCs) infiltration and suppressed M2-phenotype macrophages inside the tumor microenvironment. The immune checkpoint was downregulated in the C1 subtype. A total of eight key genes, EFNA3, GPX3, RGS2, CXCR4, SGCE, ADH4, CST2, and GPC3, were screened for the establishment of a prognostic risk model. Conclusion: This study concluded that the tryptophan metabolism-associated genes can be applied in GC prognostic prediction. The risk model established in the current study was highly accurate in GC survival prediction.

Preoperative Radiotherapy Is Associated With Significant Survival Benefits for Patients With Gastric Signet Ring Cell Carcinoma: A SEER-Based Approach

Objective:

To explore the clinical and pathological features of gastric signet ring cell carcinoma, and evaluate the survival impact of preoperative radiotherapy on these patients.

Methods:

The Surveillance, Epidemiology, and End Results database was used to extract eligible patients from 2004 to 2015. The patients were divided into those with and without preoperative radiotherapy. The categorical variables were described by chi-square tests. The patients’ survival was compared between the 2 groups by Kaplan-Meier method with log-rank tests. Cox proportional hazard model was adopted to identify prognostic factors of cancer-specific survival.

Results:

Totally 4771 patients were recruited, of whom 218(4.6%) patients received preoperative radiotherapy, while 4553(95.4%) patients didn’t receive this treatment. Survival analysis of the entire cohort demonstrated that preoperative radiotherapy improved both cancer-specific survival and overall survival (p < 0.001) of the patients. Cox proportional hazard models identified age >60, tumor size >50 mm, TNM stage II-IV as independent risk factors for poor prognosis (HR > 1, p < 0.05). Notably, preoperative radiotherapy was identified as an independent protective factor for favorable prognosis (HR < 1, p < 0.05). Subgroup survival analysis showed that preoperative radiotherapy exerted significant survival benefits for the stages III and IV patients.

Conclusions:

In this population-based study, preoperative radiotherapy is associated with significant survival benefits for the patients with advanced gastric signet ring cell carcinoma. Hence preoperative radiotherapy is feasible for these patients.

DNA methylation data-based molecular subtype classification and prediction in patients with gastric cancer

Background

Genetic and epigenetic alterations have been indicated to be closely correlated with the carcinogenesis, DNA methylation is one of most frequently occurring molecular behavior that take place early during this complicated process in gastric cancer (GC).

Methods

In this study, 398 samples were collected from the cancer genome atlas (TCGA) database and were analyzed, so as to mine the specific DNA methylation sites that affected the prognosis for GC patients. Moreover, the 23,588 selected CpGs that were markedly correlated with patient prognosis were used for consistent clustering of the samples into 6 subgroups, and samples in each subgroup varied in terms of M, Stage, Grade, and Age. In addition, the levels of methylation sites in each subgroup were calculated, and 347 methylation sites (corresponding to 271 genes) were screened as the intrasubgroup specific methylation sites. Meanwhile, genes in the corresponding promoter regions that the above specific methylation sites were located were performed signaling pathway enrichment analysis.

Results

The specific genes were enriched to the biological pathways that were reported to be closely correlated with GC; moreover, the subsequent transcription factor enrichment analysis discovered that, these genes were mainly enriched into the cell response to transcription factor B, regulation of MAPK signaling pathways, and regulation of cell proliferation and metastasis. Eventually, the prognosis prediction model for GC patients was constructed using the Random Forest Classifier model, and the training set and test set data were carried out independent verification and test.

Conclusions

Such specific classification based on specific DNA methylation sites can well reflect the heterogeneity of GC tissues, which contributes to developing the individualized treatment and accurately predicting patient prognosis.

The Predictive Value of Low Muscle Mass as Measured on CT Scans for Postoperative Complications and Mortality in Gastric Cancer Patients: A Systematic Review and Meta-Analysis

Risk assessment is relevant to predict outcomes in patients with gastric cancer. This systematic review aimed to investigate the predictive value of low muscle mass for postoperative complications in gastric cancer patients. A systematic literature search was performed to identify all articles reporting on muscle mass as measured on computed tomography (CT) scans in patients with gastric cancer. After full text screening, 15 articles reporting on 4887 patients were included. Meta-analysis demonstrated that patients with low muscle mass had significantly higher odds of postoperative complications (odds ratio (OR): 2.09, 95% confidence interval (CI): 1.55–2.83) and severe postoperative complications (Clavien–Dindo grade ≥III, OR: 1.73, 95% CI: 1.14–2.63). Moreover, patients with low muscle mass had a significantly higher overall mortality (hazard ratio (HR): 1.81, 95% CI: 1.52–2.14) and disease-specific mortality (HR: 1.58, 95% CI: 1.36–1.84). In conclusion, assessment of muscle mass on CT scans is a potential relevant clinical tool for risk prediction in gastric cancer patients. Considering the heterogeneity in definitions applied for low muscle mass on CT scans in the included studies, a universal cutoff value of CT-based low muscle mass is required for more reliable conclusions.

Tumor Size Improves the Accuracy of the Prognostic Prediction of Lymph Node-Negative Gastric Cancer

BACKGROUND

Tumor size has been regarded as the "T" stage of many solid tumors because of its effect on prognosis. However, the prognostic impact of tumor size in gastric cancer (GC) is still controversial.

MATERIALS AND METHODS

A total of 436 patients with curatively resected GC and those without lymph node metastasis in our center were retrospectively enrolled. The appropriate cutoff points for tumor size were determined. Potential prognostic factors were analyzed. In addition, a pathological tumor-size (pTS) classification system was proposed to evaluate the superiority of its prognostic prediction of node-negative GC patients compared with that of the pT staging system.

RESULTS

The ideal cutoff points for tumor size were 4 and 8 cm. In the multivariate analysis, tumor size was identified as an independent prognostic factor for node-negative GC patients after surgery, as was pT stage. The pTS classification was found to be more appropriate for predicting the overall survival of node-negative GC patients after curative surgery than pT stage, and the -2 log-likelihood of the pTS classification (1680.782) was smaller than the value of pT (1695.239).

CONCLUSIONS

As an independent prognostic factor, tumor size should be incorporated into the pT staging system to enhance the accuracy of the prognostic prediction of node-negative GC patients.

microRNA-203 suppresses invasion of gastric cancer cells by targeting ERK1/2/Slug/ E-cadherin signaling

BACKGROUND AND AIMS

Growing evidence suggests that microRNA plays an essential role in the development and metastasis of many tumors, including gastric cancer (GC). Expression of microRNA-203 (miR-203) has been reported to decrease in GC. In addition, overexpression of miR-203 inhibits grow of GC cells in vitro and in vivo. However, whether miR-203 affects cell migration and invasion of GC remains unclear. This study aimed to reveal the role of miR-203 on migration and invasion of GC, and its potential mechanisms.

METHODS

Synthetic pre-miR-203 (miR-203), anti-miR-203 and scrambled negative control RNAs was transfected into the gastric cancer SGC7901 cells to generate miR-203 or anti-miR-203-transfected stable clones. The roles of miR-203 on cell invasion and motility were then analyzed by Transwell migration assay and Wound healing assay in vitro. Using siRNA to targeting ERK1/2, Slug, and E-cadherin or Slug cDNA transfection (to increase Slug expression) to examine the miR-203 signaling pathway. We also examined the efficacies of miR-203 or anti-miR-203 on peritoneal metastasis of SGC7901 cells in the nude mouse model.

RESULTS

Overexpression of miR-203 inhibits SGC7901 cell invasion and motility, followed by decreased phospho-ERK1/2 (pERK1/2) and Slug expression, as well as increased E-cadherin expression. Re-expression of Slug in miR-203/SGC7901cells decreased E-cadherin expression and restored the invasive phenotypes. Targeting E-cadherin in miR-203/SGC7901cells also restored the invasive phenotypes. Inhibition of miR-203 promotes SGC7901 cell invasion and motility, followed by increased phospho-ERK1/2 (pERK1/2) and Slug expression, as well as decreased E-cadherin expression. Targeting ERK1/2 or Slug in anti-miR-203/SGC7901cells increased E-cadherin expression and reversed the invasive phenotypes. In addition, targeting ERK1/2 decreased Slug and increased the E-cadherin expression. Significantly, we found that miR-203 could exert marked inhibition of the peritoneal metastasis of SGC7901 in nude mice in vivo. Targeting miR-203 could exert marked promotion of the peritoneal metastasis of SGC7901 in nude mice in vivo.

CONCLUSIONS

miR-203/ERK1/2/Slug/E-cadherin signaling pathway plays an essential role on SGC7901 cell invasion and motility. miR-203 can be novel modalities to prevent peritoneal metastasis of invasive cancers such as gastric cancer.

Parametric Model to Analyse the Survival of Gastric Cancer in the Presence of Interval Censoring

Aims and background

The objective of the study was to assess the impact of prognostic factors on survival of patients with gastric cancer in the presence of interval censoring using parametric models.

Methods and study design

In a retrospective cohort study, 178 patients with gastric cancer were studied from February 2003 to January 2008. Gender, age at diagnosis, distant metastasis, tumor size, histology type, tumor grade, lymph node metastasis and pathologic stage were selected as prognostic and entered in the models. Weibull, exponential, log-logistic and log-normal analyses with interval censoring were performed as parametric models, and Akaike Information Criterion (AIC) was used to compare the efficiency of models.

Results

The risk of death for patients at an older age, with tumor size greater than 35 mm, distant metastasis and advanced stage of disease was statistically higher. Other clinical and demographic factors were not significant. According to AIC, the log logistic model is the most efficient of all the models in multivariable analysis.

Conclusions

The results indicated that the early detection of a cancer at a young patient age and in primary stages is important to increase survival from gastric cancer. According to statistical criteria, a parametric model can also be a useful statistical model to find prognostic factors in the presence of interval censoring. Although it seems that all models in this analysis fit well, AIC supported the log logistic regression as the best option.

Should Splenic Hilar Lymph Nodes be Dissected for Siewert Type II and III Esophagogastric Junction Carcinoma Based on Tumor Diameter?: A Retrospective Database Analysis

The aim of the study is to identify the value of a spleen-preserving No. 10 lymphadenectomy (SPL) for Siewert type II/III adenocarcinoma of the esophagogastric junction (AEG).From January 2007 to June 2014, 694 patients undergoing radical total gastrectomy for Siewert type II/III AEG were analyzed. Oncologic outcomes were compared between SPL and no SPL (No. 10D+ and No. 10D-) groups.The incidence of No. 10 lymph node metastasis (LNM) was 12.3%. No significant differences in the incidence of No. 10 LNM were found between Siewert type II AEG with tumor diameters of <4 cm and ≥4 cm (P = 0.071). However, Siewert type III AEG with a tumor diameter ≥4 cm showed a significantly higher frequency of No. 10 LNM compared with a tumor diameter <4 cm (P < 0.001). The No. 10D+ group had superior 3-year overall survival (OS) and disease-free survival (DFS) rates compared with the No. 10D- group (P = 0.030 and P = 0.005, respectively). For patients with Siewert type II and type III AEG with a tumor diameter <4 cm, the 3-year OS and DFS rates were similar between the 2 groups. However, the No. 10D+ group had better 3-year OS (66.6% vs 51.1%, P = 0.019) and DFS (63.2% vs 45.9%, P = 0.007) rates for Siewert type III AEG with a tumor diameter ≥4 cm. A multivariate Cox regression showed that SPL was an independent prognostic factor in Siewert type III AEG with a tumor diameter ≥4 cm.SPL may improve the prognosis of Siewert type III AEG with a tumor diameter ≥4 cm, whereas SPL may be omitted without decreasing survival in patients with Siewert type II or type III AEG with a tumor diameter <4 cm.

Prognostic Significance of Tumor Size in 2405 Patients With Gastric Cancer: A Retrospective Cohort Study

The clinical prognostic significance of tumor size (Ts) in gastric cancer remains under debate. This study aims to evaluate the prognostic value of Ts in gastric cancer patients undergoing gastrectomy. A total of 2405 patients with gastric cancer, all having received radical resection, were enrolled in this retrospective study from 2000 to 2011. Patients were categorized by minimum P value from log-rank χ2 statistics using X-tile. The relationships between Ts and other clinicopathologic characteristics were analyzed, and the survival prediction accuracy was also compared between Ts and T stage. Patients were divided into 5 groups, according to which Ts stage and TsNM stage system were proposed. Ts, an independent prognostic factor identified by univariate and multivariate survival analysis, was significantly associated with sex, age, tumor location, macroscopic type, tumor diffferentiation, vessel invasion, perineural invasion, T stage, N stage, and TNM stage. Compared with T stage system, Ts stage system was found no superiorities in survival prediction. However, for patients with lymph node metastasis and patients with age ≥60, Ts stage system revealed a significant improvement of predictive accuracy in subgroup survival analysis. Furthermore, TsNM stage (c-index = 0.783) system was found to be superior to TNM stage (c-index = 0.743) system in prognostic prediction accuracy (P < 0.05). Ts is significantly correlated with gastric cancer progression, which can be regarded as a reliable prognostic factor, and the TsNM stage system may improve the prognostic prediction accuracy in gastric cancer patients.

Does tumor size improve the accuracy of prognostic predictions in node-negative gastric cancer (pT1-4aN0M0 stage)?

Background

The prognostic importance of tumor size in gastric cancer is unclear. This study investigated whether the inclusion of tumor size could improve prognostic accuracy in node-negative gastric cancer.

Methods

Clinical and pathological data of 492 patients with node-negative gastric cancer who underwent radical surgery in our department from January 1995 to December 2008 were analyzed. The prognostic accuracy of T stage was compared with that of T stage plus tumor size. The ability of tumor size to improve the 95% confidence interval (CI) of postoperative 5-year survival rate in gastric cancer patients was assessed. Different T stages plus tumor size were further analyzed to assess improvements in prognosis.

Results

Mean tumor size was 3.79±1.98 cm with a normal distribution. Multivariate analysis showed that tumor size and T stage were independent prognostic factors. Postoperative 5-year survival rate tended to decrease as tumor size increased in 1 cm increments. The addition of tumor size to T stage improved accuracy in predicting 5-year survival by 4.2% (P<0.05), as well as improving the 95% CI of postoperative 5-year survival rate by 3.2–5.1%. The addition of tumor size improved the predictive accuracy of postoperative 5-year survival rate by 3.9% (95% CI 70.4%–91.1%, P = 0.033) in patients with stage T3N0M0 tumors and by 6.5% (95% CI 68.7%–88.4%, P = 0.014) in patients with stage T4aN0M0 tumors.

Conclusions

Tumor size is an independent prognostic factor for survival in patients with node-negative gastric cancer, as well as improving prognostic accuracy in stage T3/4aN0M0 tumors.

Is tumor size a predictor of preoperative N staging in T2-T4a stage advanced gastric cancer?

BACKGROUND

The aim of this study was to assess the relationship between tumor size and preoperative N staging in patients with T2-T4a stage advanced gastric cancer.

METHODS

A total of 697 patients with gastric cancer were analyzed. The correlations between the number of metastatic lymph nodes (LNs) and other clinicopathologic factors were investigated. The Kappa consistency test was used to test the agreement between predicted and pathologic N staging.

RESULTS

Multivariate analysis showed that tumor size was independently (r = 0.987, P < 0.05) and linearly (R(2) = 0.940, P < 0.05) correlated with the number of metastatic LNs. The numbers of predicted metastatic LNs in patients with primary tumors <2.02 cm, 2.02-4.07 cm, 4.07-6.80 cm, and ≥ 6.80 cm in size were 0 (Stage N0), 1-2 (Stage N1), 3-6 (Stage N2), and ≥ 7 (Stage N3), respectively. There was good agreement between N staging predicted by tumor size and pathologic N staging (Kappa value = 0.531, P < 0.05). The overall accuracy of tumor size for preoperative N staging was 82.13%. The 5-year survival rates of patients with predicted Stages N0, N1, N2, and N3 were 80.0%, 71.1%, 56.8%, and 39.8%, respectively (P < 0.05). There were no significant differences in the survival rates of patients with predicted N staging and the corresponding pathologic N staging.

CONCLUSIONS

Tumor size is correlated with the number of LN metastases in patients with stage T2-T4a advanced gastric cancer. The measurements of tumor size can predict preoperative N staging.

Minimally invasive surgery for serosa-positive gastric cancer (pT4a) in patients with preoperative diagnosis of cancer without serosal invasion

BACKGROUND

Although surgeons normally use minimally invasive surgery (MIS) for patients with early gastric cancer, in Korea and Japan the procedure is also indicated for serosa-negative tumors. Serosal invasion is regarded to be a potential risk factor for peritoneal dissemination as a result of the effect of pneumoperitoneum and tumor manipulation during the operation. We compared operative outcomes between MIS and conventional open surgery for serosa-involved advanced gastric cancer patients who had a preoperative diagnosis of cancer without serosal invasion.

METHODS

A total of 61 patients (39 patients treated by MIS and 22 by open surgery) treated between 2003 and 2009 who were first diagnosed preoperatively as serosa negative on the basis of computed tomography, endoscopy, and endoscopic ultrasound but then diagnosed as serosa positive upon final pathology were studied. We retrospectively compared recurrence and survival between the two treatment groups.

RESULTS

Clinicopathologic characteristics, clinical stage, extent of surgery, and short-term operative outcome did not differ between the groups. 5-year overall survival (73.5 vs. 67.5 %, p = 0.518, respectively) and disease-free survival (67.8 vs. 54.2 %, p = 0.296, respectively) were comparable between the MIS and open surgery groups. There were recurrences in 12 patients in the MIS group and 11 patients in the open surgery group, with a median follow-up period of 64 months. Recurrence patterns did not differ between the groups; moreover, MIS did not increase peritoneal recurrences compared to open surgery (42.0 vs. 54.5 %, p = 0.537, respectively). In multivariate analyses, the type of surgery was not an independent prognostic factor.

CONCLUSIONS

Similar survival and recurrence patterns were observed in advanced gastric cancer patients preoperatively diagnosed as serosa negative who were treated either by MIS or open surgery. MIS may be safely applied in patients with serosa-positive tumors.

Baseline tumour measurements predict survival in advanced non-small cell lung cancer

BACKGROUND

The association between tumour measurements and survival has been studied extensively in early-stage and locally advanced non-small cell lung cancer (NSCLC). We analysed these factors in patients with advanced NSCLC.

METHODS

Data were derived from the E4599 trial of paclitaxel-carboplatin±bevacizumab. Associations between the Response Evaluation Criteria in Solid Tumors (RECIST) baseline sum longest diameter (BSLD), response rate, progression-free survival (PFS) and overall survival (OS) were evaluated using univariate and multivariable Cox regression models.

RESULTS

A total of 759 of the 850 patients (89%) in the E4599 trial had measurable diseases and were included in this analysis. The median BSLD was 7.5 cm. BSLD predicted OS (hazard ratio (HR) 1.41; P<0.001) and had a trend towards association with PFS (HR 1.14; P=0.08). The median OS was 12.6 months for patients with BSLD <7.5 cm compared with 9.5 months for BSLD ≥ 7.5 cm. This association persisted in a multivariable model controlling multiple prognostic factors, including the presence and sites of extrathoracic disease (HR 1.24; P=0.01). There was no association between BSLD and response rate.

CONCLUSION

Tumour measurements are associated with survival in the E4599 trial. If validated in other populations, this parameter may provide important prognostic information to patients and clinicians.

Consideration of tumor size improves the accuracy of TNM predictions in patients with gastric cancer after curative gastrectomy

OBJECTIVE

To investigate whether addition of tumor size improves the prognostic accuracy of the UICC 7th TNM staging system in gastric cancer patients who underwent radical surgery (R0 resection).

METHODS

The clinical and pathological data and postoperative 5-year survival rate of 507 patients with gastric cancer who underwent radical surgery (R0 resection) in our department from January 2004 to June 2006 were evaluated retrospectively. The prognostic accuracy of conventional UICC 7th TNM staging was compared with that of UICC 7th TNM staging plus tumor size. The ability of tumor size to improve the 95% confidence interval (CI) of postoperative 5-year survival rate in gastric cancer patients was assessed.

RESULTS

Of the 507 patients, 470 (92.7%) were followed up. The five-year survival rate of these patients was 50.4%. The survival rates of patients with pT1, pT2, pT3, and pT4 stage tumors were 89.3%, 72.4%, 36.9%, and 23.7%, respectively (P < 0.05), and the survival rates of patients with pN0, pN1, pN2, and pN3 stage tumors were 75.2%, 68.8%, 46.7%, and 21.3% (P < 0.05). Depth of invasion, lymph node metastasis stage, metastatic lymph node ratio (MLR), lymphatic invasion and tumor size were independent predictors of patient prognosis. The accuracy of UICC 7th TNM staging in predicting 5-year survival was 75.4% and the accuracy of tumor size plus the UICC 7th TNM staging was 77.9% (P < 0.05). This combination improved the 95% CI of postoperative 5-year survival rate in gastric cancer patients.

CONCLUSION

Tumor size can improve the accuracy of UICC 7th TNM staging in predicting survival in gastric cancer patients following radical surgery (R0 resection). Tumor size is likely to be another important indicator in future UICC-TNM staging systems for gastric cancer patients.

Application of smoothing methods for determining of the effecting factors on the survival rate of gastric cancer patients

Background

Smoothing methods are widely used to analyze epidemiologic data, particularly in the area of environmental health where non-linear relationships are not uncommon. This study focused on three different smoothing methods in Cox models: penalized splines, restricted cubic splines and fractional polynomials.

Objectives

The aim of this study was to assess the effects of prognostic factors on survival of patients with gastric cancer using the smoothing methods in Cox model and Cox proportional hazards. Also, all models were compared to each other in order to find the best one.

Materials and Methods

We retrospectively studied 216 patients with gastric cancer who were registered in one referral cancer registry center in Tehran, Iran. Age at diagnosis, sex, presence of metastasis, tumor size, histology type, lymph node metastasis, and pathologic stages were entered in to analysis using the Cox proportional hazards model and smoothing methods in Cox model. The SPSS version 18.0 and R version 2.14.1 were used for data analysis. These models compared with Akaike information criterion.

Results

In this study, The 5 year survival rate was 30%. The Cox proportional hazards, penalized spline and fractional polynomial models let to similar results and Akaike information criterion showed a better performance for these three models comparing to the restricted cubic spline. Also, P-value and likelihood ratio test in restricted cubic spline was greater than other models. Note that the best model is indicated by the lowest Akaike information criterion.

Conclusions

The use of smoothing methods helps us to eliminate non-linear effects but it is more appropriate to use Cox proportional hazards model in medical data because of its’ ease of interpretation and capability of modeling both continuous and discrete covariates. Also, Cox proportional hazards model and smoothing methods analysis identified that age at diagnosis and tumor size were independent prognostic factors for the survival of patients with gastric cancer (P < 0.05). According to these results the early detection of patients at younger age and in primary stages may be important to increase survival.

Stage-stratified analysis of prognostic significance of tumor size in patients with gastric cancer

Background

The prognostic significance of tumor size in gastric cancer is not well defined. The objective of this study was to identify the prognostic value of tumor size in patients with gastric cancer.

Methods

We retrospectively reviewed a total of 1800 patients with gastric cancer admitted to our hospital between 1997 and 2007. These patients were divided into two groups according to tumor size: small size group (SSG, tumor ≤5 cm) and large size group (LSG, tumor >5 cm). We compared clinico-pathologic features of the two groups and investigated the prognostic factors by performing univariate, multivariate, and stage- stratified analyses according to tumor size.

Results

LSG had more aggressive clinico-pathologic features than SSG. Tumor size was an independent prognostic indicator in patients with gastric cancer. In a stratified-pT, pN, and pTNM analysis, survival of patients with LSG was significantly worse than that of patients with SSG and advanced stage. Tumor size was not a significant predictor of survival in patients with early stage tumors. Large tumor size was associated with shorter survival in patients with stages N0, N1, N2, and N3, and stages I, II, III, and IV.

Conclusions

Tumor size is a simple and practical prognostic factor in patients with gastric cancer. Tumor size could supplement clinical staging in the future.

Prognostic value of tumor size in gastric cancer: an analysis of 2,379 patients

Tumor size has been included into the staging systems of many solid tumors, such as lung and breast. However, tumor size is not integrated in the staging of gastric cancer, and its prognostic value for gastric cancer needs to be reappraised. A total of 2,379 patients who received radical resection for histopathologically confirmed gastric adenocarcinoma were enrolled in the present study. Tumor size, originally presented as continuous variable, was categorized into small gastric cancer (SGC) group and large gastric cancer (LGC) group using an optimal cutoff point determined by Cox proportional hazards model. The associations between tumor size and other clinicopathological factors were checked using Chi-square test. Survival of gastric cancer patients was estimated by using univariate Kaplan-Meier method, and the survival difference was checked by using the log-rank test. The significant clinicopathological factors were included into the Cox proportional hazards model to determine the independent prognostic factors, and their hazard ratios were calculated. With the optimal cutoff point of 4 cm, tumor size was categorized into SGC group (≤ 4 cm) and LGC group (>4 cm). Tumor size closely correlated with age, tumor location, macroscopic type, Lauren classification, and lymphatic vessel invasion. Moreover, tumor size was also significantly associated with depth of tumor invasion and status of regional lymph nodes. The 5-year survival rate was 68.7 % for SGC group which was much higher than 40.2 % for LGC group. Univariate analysis showed that SGC had a better survival than LGC, mainly for patients with IIA, IIB, and IIIA stage. Multivariate analysis revealed that tumor size as well as age, tumor location, macroscopic type, Lauren classification, lymphatic vessel invasion, depth of tumor invasion, and status of regional lymph nodes were independent prognostic factors for gastric cancer. Tumor size is a reliable prognostic factor for patients with gastric cancer, and the measurement of tumor size would be helpful to the staging and management of gastric cancer.

Tumor size as a prognostic factor in patients with advanced gastric cancer in the lower third of the stomach

AIM: To explore the impact of tumor size on outcomes in patients with advanced gastric cancer in the lower third of the stomach.

METHODS: We retrospectively analyzed the clinical records of 430 patients with advanced gastric cancer in the lower third of the stomach who underwent distal subtotal gastrectomy and D2 lymphadenectomy in our hospital from January 1998 to June 2004. Receiver-operating characteristic (ROC) curve analysis was used to determine the appropriate cutoff value for tumor size, which was measured as maximum tumor diameter. Based on this cutoff value, patients were divided into two groups: those with large-sized tumors (LSTs) and those with small-sized tumors (SSTs). The correlations between other clinicopathologic factors and tumor size were investigated, and the 5-year overall survival (OS) rate was compared between the two groups. Potential prognostic factors were evaluated by univariate Kaplan-Meier survival analysis and multivariate Cox’s proportional hazard model analysis. The 5-year OS rates in the two groups were compared according to pT stage and pN stage.

RESULTS: The 5-year OS rate in the 430 patients with advanced gastric cancer in the lower third of the stomach was 53.7%. The mean ± SD tumor size was 4.9 ± 1.9 cm, and the median tumor size was 5.0 cm. ROC analysis indicated that the sensitivity and specificity results for the appropriate tumor size cutoff value of 4.8 cm were 80.0% and 68.2%, respectively (AUC = 0.795, 95%CI: 0.751-0.839, P = 0.000). Using this cutoff value, 222 patients (51.6%) had LSTs (tumor size ≥ 4.8 cm) and 208 (48.4%) had SSTs (tumor size < 4.8 cm). Tumor size was significantly correlated with histological type (P = 0.039), Borrmann type (P = 0.000), depth of tumor invasion (P = 0.000), lymph node metastasis (P = 0.000), tumor-nodes metastasis stage (P = 0.000), mean number of metastatic lymph nodes (P = 0.000) and metastatic lymph node ratio (P = 0.000). Patients with LSTs had a significantly lower 5-year OS rate than those with SSTs (37.1% vs 63.3%, P = 0.000). Univariate analysis showed that depth of tumor invasion (χ² = 69.581, P = 0.000), lymph node metastasis (χ² = 138.815, P = 0.000), tumor size (χ² = 78.184, P = 0.000) and metastatic lymph node ratio (χ² = 139.034, P = 0.000) were significantly associated with 5-year OS rate. Multivariate analysis revealed that depth of tumor invasion (P = 0.000), lymph node metastasis (P = 0.019) and tumor size (P = 0.000) were independent prognostic factors. Gastric cancers were divided into 12 subgroups: pT2N0; pT2N1; pT2N2; pT2N3; pT3N0; pT3N1; pT3N2; pT3N3; pT4aN0; pT4aN1; pT4aN2; and pT4aN3. In patients with pT2-3N3 stage tumors and patients with pT4a stage tumors, 5-year OS rates were significantly lower for LSTs than for SSTs (P < 0.05 each), but there were no significant differences in the 5-year OS rates in LST and SST patients with pT2-3N0-2 stage tumors (P > 0.05).

CONCLUSION: Using a tumor size cutoff value of 4.8 cm, tumor size is a prognostic factor in patients with pN3 stage or pT4a stage advanced gastric cancer located in the lower third of the stomach.

Tumor size as a prognostic factor in gastric cancer patient

PURPOSE

The purpose of this study is to investigate the prognostic significance of tumor size for 5-year survival rate in patients with gastric cancer.

MATERIALS AND METHODS

A total of 1,697 patients with gastric cancer, who underwent potentially curative gastrectomy, were evaluated. Patients were divided into 4 groups as follows, according to the median size of early and advanced gastric cancer, respectively: small early gastric cancer (tumor size ≤3 cm), large early gastric cancer (tumor size >3 cm), small advanced gastric cancer (tumor size ≤6 cm), and large advanced gastric cancer (tumor size >6 cm). The prognostic value of tumor size for 5-year survival rate was investigated.

RESULTS

In a univariate analysis, tumor size is a significant prognostic factor in advanced gastric cancer, but not in early gastric cancer. Multivariate analysis showed that tumor size is an independent prognostic factor for 5-year survival rate in advanced gastric cancer (P=0.003, hazard ratio=1.372, 95% confidence interval=1.115~1.690). When advanced gastric cancer is subdivided into 2 groups, according to serosa invasion: Group 1; serosa negative (T2 and T3, 7th AJCC), and Group 2; serosa positive (T4a and T4b, 7th AJCC), tumor size is an independent prognostic factor in Group 1 (P=0.011, hazard ratio=1.810, 95% confidence interval=1.149~2.852) and in Group 2 (P=0.033, hazard ratio=1.288, 95% confidence interval=1.020~1.627), respectively.

CONCLUSIONS

Tumor size is an independent prognostic factor in advanced gastric cancer irrespective of the serosa invasion, but not in early gastric cancer.

Efficacy of hydrogastric sonography and spiral Computed Tomography in staging of gastric carcinoma--a comparative study

OBJECTIVE

Accurate preoperative diagnosis and staging of patients with gastric cancer is essential for optimal treatment. The standard of care for staging gastric carcinoma is helical CT. This study was conducted to compare the efficacy of hydrogastric sonography (HGS) with that of helical CT in the staging of patients with gastric carcinoma.

METHODS

A total of 42 consecutive patients (29 men and 13 women) diagnosed with gastric carcinoma after endoscopy and biopsy were staged on the basis of TNM classification, preoperatively with HGS and helical CT and postoperatively with histopathologic examination (HPE). The findings of HGS and helical CT were compared with those on HPE with respect to TNM stage.

RESULTS

Regarding T stage, the accuracy of HGS was 78.6% (kappa = 0.68) and that of helical CT was 66.7% (kappa = 0.48). In evaluating the nodal status, the accuracy of HGS was 66.7% (kappa = 0.52) and that of helical CT was 54.6% (kappa = 0.39). Regarding distant metastases, accuracy was the same with HGS and helical CT (accuracy 95.2%, kappa = 0.89).

CONCLUSIONS

When compared with HPE, HGS was found to be more accurate than helical CT for assessment of T and N staging. Sonographic and helical CT were equally accurate for the assessment of M stage.

Abnormal expression of early growth response 1 in gastric cancer: association with tumor invasion, metastasis and heparanase transcription

Given that previous studies indicated that early growth response 1 (EGR1) exerts pro-tumorigenic effects through regulating heparanase (HPA) transcription, it was hypothesized that EGR1 may correlate with the progression of gastric cancer. One hundred and fifteen patients with gastric cancer were evaluated for the protein and transcript expression of EGR1 and HPA on immunohistochemistry and real-time quantitative polymerase chain reaction (PCR). In normal gastric mucosa, EGR1 protein expression was absent or weak, whereas gastric cancer was positive for EGR1. Seventy gastric cancer patients (60.9%) were positive for cytoplasmic EGR1 expression, and 26 (22.6%) had nuclear expression of EGR1. In the gastric cancer examined, the transcripts of EGR1 were enhanced compared to that of normal gastric mucosa, and positively correlated with EGR1 protein expression. The cytoplasmic or nuclear expression of EGR1 and its transcripts in gastric cancer was positively correlated with tumor infiltration (P < 0.05), lymph node and distant metastasis (P < 0.05), tumor node metastasis (TNM) stages (P < 0.05), but not with age, gender, tumor location and size, histological types or differentiation. Moreover, the protein and transcript expression of EGR1 was correlated with that of HPA in gastric cancer. These results indicate that aberrant expression of EGR1 in gastric cancer is associated with tumor invasion and metastasis, and HPA transcription.

Role of tumor size in the pre-operative management of rectal cancer patients

Background

Clinical management of rectal cancer patients relies on pre-operative staging. Studies however continue to report moderate degrees of over/understaging as well as inter-observer variability. The aim of this study was to determine the sensitivity, specificity and accuracy of tumor size for predicting T and N stages in pre-operatively untreated rectal cancers.

Methods

We examined a test cohort of 418 well-documented patients with pre-operatively untreated rectal cancer admitted to the University Hospital of Basel between 1987 and 1996. Classification and regression tree (CART) and logistic regression analysis were carried out to determine the ability of tumor size to discriminate between early (pT1-2) and late (pT3-4) T stages and between node-negative (pN0) and node-positive (pN1-2) patients. Results were validated by an external patient cohort (n = 28).

Results

A tumor diameter threshold of 34 mm was identified from the test cohort resulting in a sensitivity and specificity for late T stage of 76.3%, and 67.4%, respectively and an odds ratio (OR) of 6.67 (95%CI:3.4-12.9). At a threshold value of 29 mm, sensitivity and specificity for node-positive disease were 94% and 15.5%, respectively with an OR of 3.02 (95%CI:1.5-6.1). Applying these threshold values to the validation cohort, sensitivity and specificity for T stage were 73.7% and 77.8% and for N stage 50% and 75%, respectively.

Conclusions

Tumor size at a threshold value of 34 mm is a reproducible predictive factor for late T stage in rectal cancers. Tumor size may help to complement clinical staging and further optimize the pre-operative management of patients with rectal cancer.

Small RNA interference-mediated gene silencing of heparanase abolishes the invasion, metastasis and angiogenesis of gastric cancer cells

Background

Heparanase facilitates the invasion and metastasis of cancer cells, and is over-expressed in many kinds of malignancies. Our studies indicated that heparanase was frequently expressed in advanced gastric cancers. The aim of this study is to determine whether silencing of heparanase expression can abolish the malignant characteristics of gastric cancer cells.

Methods

Three heparanase-specific small interfering RNA (siRNAs) were designed, synthesized, and transfected into cultured gastric cancer cell line SGC-7901. Heparanase expression was measured by RT-PCR, real-time quantitative PCR and Western blot. Cell proliferation was detected by MTT colorimetry and colony formation assay. The in vitro invasion and metastasis of cancer cells were measured by cell adhesion assay, scratch assay and matrigel invasion assay. The angiogenesis capabilities of cancer cells were measured by tube formation of endothelial cells.

Results

Transfection of siRNA against 1496-1514 bp of encoding regions resulted in reduced expression of heparanase, which started at 24 hrs and lasted for 120 hrs post-transfection. The siRNA-mediated silencing of heparanase suppressed the cellular proliferation of SGC-7901 cells. In addition, the in vitro invasion and metastasis of cancer cells were attenuated after knock-down of heparanase. Moreover, transfection of heparanase-specific siRNA attenuated the in vitro angiogenesis of cancer cells in a dose-dependent manner.

Conclusions

These results demonstrated that gene silencing of heparanase can efficiently abolish the proliferation, invasion, metastasis and angiogenesis of human gastric cancer cells in vitro, suggesting that heparanase-specific siRNA is of potential values as a novel therapeutic agent for human gastric cancer.

miR-199a regulates the tumor suppressor mitogen-activated protein kinase kinase kinase 11 in gastric cancer

Small noncoding microRNAs (miRNAs) have been shown to play an important role in tumor proliferation and metastasis. However, their function and mechanism in the proliferation and metastasis of gastric cancer has not yet been elucidated. Here, we investigated the relationship between miRNA-199a and gastric cancer proliferation and metastasis. Using real-time reverse-transcriptase (RT)-polymerase chain reaction, we found that miR-199a is highly expressed in gastric cancer compared to normal gastric tissues and in metastatic, compared to non-metastatic gastric cancer tissues. MiR-199a positively regulated gastric cancer cell proliferation, migration and invasion. Further studies showed that mitogen-activated protein kinase kinase kinase 11 was significantly down-regulated by miR-199a at the post-transcriptional level and, the level of miR-199a expression in gastric cancer significantly correlated with clinical progression. These findings suggested miR-199a promoted proliferation and metastasis of gastric cancer cells through a regulatory pathway in gastric cancer that has yet to be described. miR-199a may be useful as a new potential therapeutic target for gastric cancer.

Stable knockdown of heparanase expression in gastric cancer cells in vitro

AIM: To develop short hairpin RNA (shRNA) against heparanase, and to determine its effects on heparanase expression and the malignant characteristics of gastric cancer cells.

METHODS: Heparanase-specific shRNA was constructed and transferred into cultured the gastric cancer cell line SGC-7901. Stable subclonal cells were screened by G418 selection. Heparanase expression was measured by reverse transcriptase-polymerase chain reaction (RT-PCR), real-time quantitative PCR and Western blotting. Cell proliferation was detected by 2-(4,5-dimethyltriazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) colorimetry and colony formation assay. The in vitro invasiveness and metastasis of cancer cells were measured by cell adhesion assay, wound healing assay and matrigel invasion assay. The angiogenesis capabilities of cancer cells were measured by tube formation of endothelial cells.

RESULTS: Stable transfection of heparanase-specific shRNA, but not of scrambled shRNA and mock vector, resulted in reduced mRNA and protein levels of heparanase. The shRNA-mediated knockdown of heparanase did not affect the cellular proliferation of SGC-7901 cells. However, the in vitro invasiveness and metastasis of cancer cells were decreased after knockdown of heparanase. Moreover, transfection of heparanase-specific shRNA decreased the in vitro angiogenesis capabilities of SGC-7901 cells.

CONCLUSION: Stable knockdown of heparanase can efficiently decrease the invasiveness, metastasis and angiogenesis of human gastric cancer cells. In contrast, stable knockdown of heparanase does not affect the cell proliferation.