Pathological prognostic factors in the second British Stomach Cancer Group trial of adjuvant therapy in resectable gastric cancer

Association between Helicobacter pylori infection, mismatch repair, HER2 and tumor-infiltrating lymphocytes in gastric cancer

BACKGROUND

The influence of Helicobacter-pylori (H. pylori) infection and the characteristics of gastric cancer (GC) on tumor-infiltrating lymphocyte (TIL) levels has not been extensively studied. Analysis of infiltrating-immune-cell subtypes as well as survival is necessary to obtain comprehensive information.

AIM

To determine the rates of deficient mismatch-repair (dMMR), HER2-status and H. pylori infection and their association with TIL levels in GC.

METHODS

Samples from 503 resected GC tumors were included and TIL levels were evaluated following the international-TILs-working-group recommendations with assessment of the intratumoral (IT), stromal (ST) and invasive-border (IB) compartments. The density of CD3, CD8 and CD163 immune cells, and dMMR and HER2-status were determined by immunohistochemistry (IHC). H. pylori infection was evaluated by routine histology and quantitative PCR (qPCR) in a subset of samples.

RESULTS

dMMR was found in 34.4%, HER2+ in 5% and H. pylori-positive in 55.7% of samples. High IT-TIL was associated with grade-3 (P = 0.038), while ST-TIL with grade-1 (P < 0.001), intestinal-histology (P < 0.001) and no-recurrence (P = 0.003). dMMR was associated with high TIL levels in the ST (P = 0.019) and IB (P = 0.01) compartments, and ST-CD3 (P = 0.049) and ST-CD8 (P = 0.05) densities. HER2- was associated with high IT-CD8 (P = 0.009). H. pylori-negative was associated with high IT-TIL levels (P = 0.009) when assessed by routine-histology, and with high TIL levels in the 3 compartments (P = 0.002-0.047) and CD8 density in the IT and ST compartments (P = 0.001) when assessed by qPCR. A longer overall survival was associated with low IT-CD163 (P = 0.003) and CD8/CD3 (P = 0.001 in IT and P = 0.002 in ST) and high IT-CD3 (P = 0.021), ST-CD3 (P = 0.003) and CD3/CD163 (P = 0.002).

CONCLUSION

TIL levels were related to dMMR and H. pylori-negativity. Low CD8/CD3 and high CD163/CD3 were associated with lower recurrence and longer survival.

Association between Helicobacter pylori infection, mismatch repair, HER2 and tumor-infiltrating lymphocytes in gastric cancer

BACKGROUND

The influence of Helicobacter-pylori (H. pylori) infection and the characteristics of gastric cancer (GC) on tumor-infiltrating lymphocyte (TIL) levels has not been extensively studied. Analysis of infiltrating-immune-cell subtypes as well as survival is necessary to obtain comprehensive information.

AIM

To determine the rates of deficient mismatch-repair (dMMR), HER2-status and H. pylori infection and their association with TIL levels in GC.

METHODS

Samples from 503 resected GC tumors were included and TIL levels were evaluated following the international-TILs-working-group recommendations with assessment of the intratumoral (IT), stromal (ST) and invasive-border (IB) compartments. The density of CD3, CD8 and CD163 immune cells, and dMMR and HER2-status were determined by immunohistochemistry (IHC). H. pylori infection was evaluated by routine histology and quantitative PCR (qPCR) in a subset of samples.

RESULTS

dMMR was found in 34.4%, HER2+ in 5% and H. pylori-positive in 55.7% of samples. High IT-TIL was associated with grade-3 (P = 0.038), while ST-TIL with grade-1 (P < 0.001), intestinal-histology (P < 0.001) and no-recurrence (P = 0.003). dMMR was associated with high TIL levels in the ST (P = 0.019) and IB (P = 0.01) compartments, and ST-CD3 (P = 0.049) and ST-CD8 (P = 0.05) densities. HER2- was associated with high IT-CD8 (P = 0.009). H. pylori-negative was associated with high IT-TIL levels (P = 0.009) when assessed by routine-histology, and with high TIL levels in the 3 compartments (P = 0.002-0.047) and CD8 density in the IT and ST compartments (P = 0.001) when assessed by qPCR. A longer overall survival was associated with low IT-CD163 (P = 0.003) and CD8/CD3 (P = 0.001 in IT and P = 0.002 in ST) and high IT-CD3 (P = 0.021), ST-CD3 (P = 0.003) and CD3/CD163 (P = 0.002).

CONCLUSION

TIL levels were related to dMMR and H. pylori-negativity. Low CD8/CD3 and high CD163/CD3 were associated with lower recurrence and longer survival.

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.

Prognostic Analysis of Prophylactic Hyperthermic Intraperitoneal Chemotherapy for Advanced Gastric Cancer: a Propensity Score-Matched Analysis

PURPOSE

To investigate the efficacy of prophylactic hyperthermic intraperitoneal chemotherapy (HIPEC) for advanced gastric cancer (AGC).

METHODS

We included 198 patients treated from December 2016 to January 2019; of these patients, the 132 who had clinical T4 gastric cancer were divided into a hyperthermic intraperitoneal chemotherapy group (HIPEC group) and a radical gastrectomy and D2 lymph node dissection group (control group). Because this study was retrospective, we used propensity score matching (PSM) to reduce selectivity bias; we then assessed risk factors for recurrence and compared prognosis in terms of survival in the gastrectomy and prophylactic HIPEC groups.

RESULTS

Prophylactic HIPEC reduced the risk of postoperative peritoneal metastasis (PM: 27.5% vs. 10.5%, P = 0.015) and did not increase the risk of postoperative complications, but there was no significant difference in the effect on hepatic metastases or other distant metastases. Risk factors for recurrence included pT4 staging and positive lymph node metastases. Both disease-free survival (DFS: HR 0.592; 95% CI 0.354-0.990; P = 0.042) and peritoneal recurrence-free survival (PFS: HR 0.314; 95% CI 0.127-0.774; P = 0.008) were better in the prophylactic HIPEC group than in the gastrectomy-only group. In addition, there was no difference in the prognosis of patients between the two groups of raltitrexed (RT) and paclitaxel (PTX) for perfusion dosing.

CONCLUSION

Our study showed that prophylactic HIPEC could prevent postoperative PM in patients with AGC and did not increase the incidence of postoperative complications. However, it was not found to be effective in the prevention of other metastases, such as hepatic metastases.

Combined Prophylactic Hyperthermic Intraperitoneal Chemotherapy and Intraoperative Radiotherapy for Localized Gastroesophageal Junction and Gastric Cancer: A Comparative Nonrandomized Study

BACKGROUND

The peritoneum frequently is the only recurrence site after radical resection of gastric cancer. Data suggest that hyperthermic intraperitoneal chemotherapy (HIPEC) and intraoperative radiotherapy (IORT) reduce peritoneal recurrence and possibly improve survival for patients with resected gastric and serosal involvement. This study aimed to evaluate the efficacy of combining prophylactic HIPEC and IORT after radical resection of localized gastric cancer.

METHODS

In this retrospective study, the medical records of adult patients with histologically proven gastric/gastroesophageal adenocarcinoma who underwent radical resection with curative intent were evaluated for recurrence and survival according to whether they received prophylactic HIPEC and IORT.

RESULTS

The eligibility criteria were met by 58 patients, 33 of whom underwent prophylactic HIPEC and IORT after radical surgery. Overall, 91% the HIPEC/IORT group and 72% of the surgery-only group had ≤pT3 disease. The median follow-up period was 26.6 months for the HIPEC/IORT group and 50.6 months for the surgery group. Locoregional recurrence occurred for six patients (18.1%) in the HIPEC/IORT group and five patients (20%) in the surgery-only group, with peritoneal metastasis (PM) occurring in respectively three (9%) and six (24%) patients. The median recurrence-free survival (RFS) duration was 23.2 months (95% confidence interval [CI] 6.5-39.9 months) for the HIPEC/IORT group versus 24.8 months (95% CI 0.0-51.1 months) for the surgery-only group (p = 0.88), and the corresponding 5-year overall survival (OS) estimates were 69% and 58%.

CONCLUSION

Prophylactic HIPEC and IORT after radical surgery for localized gastric or gastroesophageal cancer did not improve RFS or OS for an unselected group of patients at risk for peritoneal recurrence.

Methylation statuses of NCOR2, PARK2, and ZSCAN12 signify densities of tumor-infiltrating lymphocytes in gastric carcinoma

Individual cell types of human tissues have their own CpG site methylation profiles, which might be utilized for the development of methylation markers to denote tumor-infiltrating lymphocytes (TILs). We aimed to develop DNA methylation markers that recapitulate the densities of TILs in gastric carcinoma (GC). Through genome-wide methylation profiling, NCOR2, PARK2, and ZSCAN12 were found to be highly methylated in CD3-positive and CD8-positive cells and rarely methylated in tumor cells. Scores of the three methylation markers were analyzed for their relationship with the overall survival and recurrence-free survival of patients with advanced GC (n = 471). The scores of three methylation markers were closely associated with densities of CD3-positive or CD8-positive cells at the tumor center or invasive front of GCs and found to be a significant prognostic factor in univariate analysis of overall survival and recurrence-free survival. In multivariate analysis, the highest score showed hazard ratios of 0.513 (CI 0.306–0.857) and 0.434 (CI 0.261–0.720) for overall survival and recurrence-free survival, respectively. The findings suggest that methylation markers signifying TILs might be utilized for the recapitulation of TIL density in GCs and serve as biomarkers for predicting prognosis in patients with GC.

Hyperthermic intraperitoneal chemotherapy in prevention of gastric cancer metachronous peritoneal metastases: a systematic review

Gastric cancer progression resulting in metachronous peritoneal metastasizing is almost always associated with an adverse prognosis. This review discusses various options of preventing metachronous peritoneal metastases in radically operated gastric cancer patients. Also examined are different hyperthermic intraperitoneal chemotherapy (HIPEC) regimens employed in gastric cancer treatment, postoperative morbidity and mortality rates and long-term treatment outcomes. The authors also review their own experience of using HIPEC based on the combination of cisplatin and doxorubicin in doses of 50 mg/m² at 42 °C for 1 h to prevent gastric cancer peritoneal dissemination. As a result, progression-free survival rose from 19.6%±5.6% to 47.1%±6.3% (P_log-rank <0.001) and dissemination-free survival-from 22.7%±6.0% to 51.9%±6.3% (P_log-rank <0.001). It is noted that the combination of the described HIPEC regimen with systemic chemotherapy helped raise metastases-free 3-year survival rate to up to 91.0%±9.0% (P_log-rank =0.025) compared with 48.6%±6.4% for patients who underwent only a combined surgery/HIPEC treatment. HIPEC is a promising combined treatment strategy for radically operated gastric cancer patients that can improve patient survival and decrease peritoneal dissemination rate. However, the number of randomized studies on adjuvant HIPEC are still insufficient for a subgroup assessment of efficacy of the given chemotherapy regimens and generation of evidence-based recommendations on the individual use of chemotherapy agents and their combinations, and HIPEC procedural techniques. Further prospective randomized studies are needed to assess the practicability of complementing HIPEC with adjuvant systemic chemotherapies.

Prediction of Survival and Recurrence Patterns by Machine Learning in Gastric Cancer Cases Undergoing Radiation Therapy and Chemotherapy

Purpose

Radical surgery is the most important treatment modality in gastric cancer. Preoperative or postoperative radiation therapy (RT) and perioperative chemotherapy are the treatment options that should be added to surgery. This study aimed to evaluate the overall survival (OS) and recurrence patterns by machine learning in gastric cancer cases undergoing RT.

Methods and Materials

Between 2012 and 2019, the OS and recurrence patterns of 75 gastric cancer cases receiving RT ± chemotherapy at the Department of Radiation Oncology were evaluated by machine learning. Logistic regression, multilayer perceptron, XGBoost, support vector classification, random forest, and Gaussian Naive Bayes (GNB) algorithms were used to predict OS, hematogenous distant metastases, and peritoneal metastases. After the correlation analysis, the backward feature selection was performed as the variable selection method, and the variables with P values less than .005 were selected.

Results

Over the median 23-month follow-up, recurrence was seen in 33 cases, and 36 patients died. The median OS was 23 (min: 7; max: 82) months, and the disease-free survival was 18 (min: 5, max: 80) months. The most common recurrence pattern was hematogenous distant metastasis, followed by peritoneal metastasis. In this study, the most successful algorithms in the prediction of OS, distant metastases, and peritoneal metastases were found to be GNB with an accuracy of 81% (95% confidence interval [CI], 0.65-0.97, area under the curve [AUC]: 0.89), XGBoost with 86% accuracy (95% CI, 0.74-0.97, AUC: 0.86), and random forest with 97% accuracy (95% CI, 0.92-1.00, AUC: 0.97), respectively.

Conclusions

In gastric cancer, GNB, XGBoost, and random forest algorithms were determined to be the most successful algorithms for predicting OS, distant metastases, and peritoneal metastases, respectively. To determine the most accurate algorithm and perhaps make personalized treatments applicable, more precise machine learning studies are needed with an increased number of cases in the coming years.

Prediction of Survival and Recurrence Patterns by Machine Learning in Gastric Cancer Cases Undergoing Radiation Therapy and Chemotherapy

Purpose

Radical surgery is the most important treatment modality in gastric cancer. Preoperative or postoperative radiation therapy (RT) and perioperative chemotherapy are the treatment options that should be added to surgery. This study aimed to evaluate the overall survival (OS) and recurrence patterns by machine learning in gastric cancer cases undergoing RT.

Methods and Materials

Between 2012 and 2019, the OS and recurrence patterns of 75 gastric cancer cases receiving RT ± chemotherapy at the Department of Radiation Oncology were evaluated by machine learning. Logistic regression, multilayer perceptron, XGBoost, support vector classification, random forest, and Gaussian Naive Bayes (GNB) algorithms were used to predict OS, hematogenous distant metastases, and peritoneal metastases. After the correlation analysis, the backward feature selection was performed as the variable selection method, and the variables with P values less than .005 were selected.

Results

Over the median 23-month follow-up, recurrence was seen in 33 cases, and 36 patients died. The median OS was 23 (min: 7; max: 82) months, and the disease-free survival was 18 (min: 5, max: 80) months. The most common recurrence pattern was hematogenous distant metastasis, followed by peritoneal metastasis. In this study, the most successful algorithms in the prediction of OS, distant metastases, and peritoneal metastases were found to be GNB with an accuracy of 81% (95% confidence interval [CI], 0.65-0.97, area under the curve [AUC]: 0.89), XGBoost with 86% accuracy (95% CI, 0.74-0.97, AUC: 0.86), and random forest with 97% accuracy (95% CI, 0.92-1.00, AUC: 0.97), respectively.

Conclusions

In gastric cancer, GNB, XGBoost, and random forest algorithms were determined to be the most successful algorithms for predicting OS, distant metastases, and peritoneal metastases, respectively. To determine the most accurate algorithm and perhaps make personalized treatments applicable, more precise machine learning studies are needed with an increased number of cases in the coming years.

Clinicopathological risk factors for gastric cancer: a retrospective cohort study in China

OBJECTIVE

To examine the potential clinicopathological factors affecting the prognosis of patients with gastric cancer after surgical treatment in China.

METHODS

Between 1 January 2001 and 31 December 2012, a total of 716 patients aged 22-84 years with gastric cancer were enrolled in the study. Survival analysis techniques including log rank test and Cox proportional hazard regression model were applied to evaluate the prognostic significance of clinicopathological characteristics in terms of survival time.

RESULTS

Of the 24 demographic and pathological variables collected in the data, 16 prognostic factors of gastric cancer were found to have statistically significant influences on survival time from the unadjusted analyses. The adjusted analysis furtherly revealed that age, age square, lymph node metastasis rate group, tumour size group, surgical type II, number of cancer nodules, invasion depth group and the interaction between surgical type II and tumour size group were important prognosis and clinicopathological factors for gastric cancer in Chinese.

CONCLUSION

Our study with relatively large sample size and many potential risk factors enable us to identify independent risk factors associated with the prognosis of gastric cancer. Findings from the current study can be used to assist clinical decision-making, and serve as a benchmark for the planning of future prognosis and therapy for patients with gastric carcinoma.

Prognostic value and association of Lauren classification with VEGF and VEGFR-2 expression in gastric cancer

Gastric cancer (GC) is one of the most common malignant tumors in the world. As anti-angiogenic therapy shows efficacy in the treatment of GC, but only works in certain patients, the identification of potential beneficiaries are urgently required in order to apply appropriate treatments. The Lauren classification demonstrates numerous differences in etiology, epidemiology and pathology; however, the association between Lauren classification and pro-angiogenic factors remains unclear. The present study aimed to investigate the clinicopathological factors associated with Lauren classification and the prognostic significance of Lauren classification and vascular endothelial growth factor (VEGF) and VEGF receptor-2 (VEGFR-2) expression in GC. Paraffin-embedded GC tissues and clinical information of 255 patients with GC were collected. The clinicopathological factors associated with Lauren classification were evaluated by Logistic regression analysis. Kaplan-Meier survival and Cox regression analyses were used to examine the prognostic significance of Lauren classification and of VEGF and VEGFR-2 expression in patients with GC. The results demonstrated that there was no association between Lauren classification and VEGF and VEGFR-2 expression. Furthermore, results from survival analysis demonstrated that Lauren classification (P=0.001) and Tumor-Node-Metastasis stage (stage II, P=0.002; stage III, P<0.001) were independent prognostic factors in GC. Following subgroup analysis based on Tumor-Node-Metastasis stage, Lauren classification was demonstrated to be an independent prognostic factor in patients with stage III GC (P=0.010) but not in patients with stage I or II GC. Furthermore, VEGFR-2 overexpression was an independent predictor of survival in intestinal-type GC (P=0.040) but not in diffuse-type GC. Taken together, these results indicate that Lauren classification may serve as an independent prognostic factor for patients with GC. In addition, although the expression of VEGF and VEGFR-2 was not associated with Lauren classification, VEGFR-2 overexpression may be considered as an independent prognostic factor in intestinal-type GC.

Mucin phenotype of differentiated early gastric cancer: an immunohistochemistry study supporting therapeutic decision making

Introduction: Endoscopic submucosal dissection is widely employed in early gastric cancer (EGC). Foveolar phenotypes should be distinguished from the other differentiated EGC (DEGC) types because of their increased malignant potential. The phenotypic classification could be useful not only for investigating EGC tumorigenesis but also for evaluating the tumor aggressiveness to guide treatment decision making. Methods: On surgical tissue specimens, we studied the mucin phenotype of EGC to distinguish cases with a worse prognosis dictating different therapeutic options or a very close surveillance program. DEGC in our series were classified as mucin foveolar (51%) or mucin intestinal (49%) phenotype. We evaluated correlations among foveolar and intestinal phenotypic markers, tumor patterns, clinicopathologic features and prognostic and therapeutic implications. Immunohistochemistry (IHC) for MUC5AC and CDX2 was performed on 63 EGC patient specimens. MUCA5C was employed as gastric foveolar phenotypic marker and CDX2 as intestinal phenotypic marker. Results: Foveolar DEGC was significantly associated with larger tumor size (p=0.01), high grade (G2-G3) (p=0.001), vessel permeation (p=0.05), lymph node metastasis (p=0.001) and ulceration (p=0.001), whereas intestinal type DEGC was associated with low grade (p=0.001). Conclusion: IHC determination of the mucin phenotype is an easy, inexpensive method that can provide useful, sensitive markers distinguishing the foveolar or intestinal phenotype in DEGC. The precise identification of the foveolar type, featuring a poorer prognosis, should sound a warning bell mandating very close study of the lesion before endoscopic treatment or contraindicating endoscopic resection in favor of the open surgery option.

Prognostic and Predictive Factors for the Curative Treatment of Esophageal and Gastric Cancer in Randomized Controlled Trials: A Systematic Review and Meta-Analysis

BACKGROUND

An overview of promising prognostic variables and predictive subgroups concerning the curative treatment of esophageal and gastric cancer from randomized controlled trials (RCTs) is lacking. Therefore, we conducted a systematic review and meta-analysis.

METHODS

PubMed, EMBASE, CENTRAL, and ASCO/ESMO conferences were searched up to March 2019 for RCTs on the curative treatment of esophageal or gastric cancer with data on prognostic and/or predictive factors for overall survival. Prognostic factors were deemed potentially clinically relevant according to the following criteria; (1) statistically significant (p < 0.05) in a multivariate analysis, (2) reported in at least 250 patients, and (3) p < 0.05, in ≥ 33% of the total number of patients in RCTs reporting this factor. Predictive factors were potentially clinically-relevant if (1) the p-value for interaction between subgroups was <0.20 and (2) the hazard ratio in one of the subgroups was significant (p < 0.05).

RESULTS

For gastric cancer, 39 RCTs were identified (n = 13,530 patients) and, for esophageal cancer, 33 RCTs were identified (n = 8618 patients). In total, we identified 23 potentially clinically relevant prognostic factors for gastric cancer and 16 for esophageal cancer. There were 15 potentially clinically relevant predictive factors for gastric cancer and 10 for esophageal cancer.

CONCLUSION

The identified prognostic and predictive factors can be included and analyzed in future RCTs and be of guidance for nomograms. Further validation should be performed in large patient cohorts.

Extra-capsular growth of lymph node metastasis correlates with poor prognosis and high SOX9 expression in gastric cancer

BACKGROUND

Extra-capsular growth (ECG) describes the extension of neoplastic cells beyond the lymph node capsule. Aim of this study was to investigate the prognostic value of ECG and its association with a stem cell like phenotype indicated by expression of the transcription factor SOX9 in gastric cancer.

METHODS

By histological evaluation, 199 patients with nodal positive gastric cancer or adeoncarcinoma of the esophageal-gastric junction (AEG) were divided into two groups according to the presence (ECG) or absence (ICG) of extracapsular growth in at least one nodal metastasis. Of these, 194 patients were stained for SOX9 and SOX2 using immunohistochemistry. Seventeen nodal negative patients (pT3/4, pN0, pM0) served as controls.

RESULTS

Seventy-three patients (36.7%) showed ECG. ECG was associated with lower overall survival (p < 0.0001), advanced pT- (p = 0.03) and pN- category (p < 0.0001) and lymphovascular invasion (p = 0.014). In multivariate analysis, ECG was found to be an independent prognostic factor (HR = 2.1; 95% CI 1.7-3.4; p = 0.001). SOX9 expression correlated significantly with ECG (96% SOX9 high in ECG patients vs. 79% SOX9 high in patients with ICG; p = 0.002). Controls showed significantly reduced SOX9 expression compared to nodal positive carcinomas (59% vs. 85% high SOX9 expression; p = 0.006). No significant correlation of ECG and SOX2 (59% SOX2 negative in ECG patients vs. 64% in patients with ICG, p = 0.48) could be obtained.

CONCLUSIONS

Patients with ECG exhibit poorer prognosis and ECG was found to be an independent prognostic factor. Thus, ECG turns out to be a morphological biomarker for a more aggressive phenotype in gastric cancer. This is supported by the fact that ECG correlates with the expression of SOX9, which has been described in the context of pro-oncogenic properties of tumours. However, the fact that SOX2 failed to show significant results indicate that ECG is not associated with a distinct cancer stem cell phenotype in gastric cancer.

Validation of the Memorial Sloan Kettering Cancer Center nomogram to predict disease-specific survival in a Chinese gastric cancer population receiving postoperative chemoradiotherapy after an R0 resection

The widely validated Memorial Sloan Kettering Cancer Center (MSKCC) nomogram for gastric carcinoma (GC) was developed based on patients who received R0 resection only. The purpose of the current study was to assess the performance of this nomogram in Chinese patients who received postoperative chemoradiotherapy (CRT) after an R0 resection for GC. From 2006 to 2015, the clinical data of 150 eligible patients were retrospectively collected from the Fudan University Shanghai Cancer Center (FUSCC) and used for external validation. The nomogram was validated by means of the concordance index (CI) and a calibration plot. The CI for the nomogram was 0.657, which was lower than the CI of the nomogram for patients who received surgery alone (0.80). In the calibration plot, the gap between the observed and the predicted survival gradually increased as the predicted 5-year disease-specific survival (DSS) decreased. Thus the MSKCC nomogram for GC significantly underestimated the survival of patients in the FUSCC cohort, especially the survival of patients whose predicted 5-year DSS was less than 50%. The current study indicates the potential for the nomogram to be developed as an ideal tool to identify target patients for postoperative CRT.

Hyperthermic intraperitoneal chemotherapy (HIPEC) and neoadjuvant chemotherapy as prophylaxis of peritoneal carcinosis from advanced gastric cancer-effects on overall and disease free survival

BACKGROUND

The possibility to enlarge criteria for intra-peritoneal chemotherapy (IPC) to all patients at high-risk to develop peritoneal carcinosis (i.e., with serosal invasion) is still discussed.

METHODS

Retrospective case-control study. Three-groups: advanced-gastric-cancer (AGC) (pT4) without proven carcinosis: prophylactic group (PG), those with PC: treatment group (TG), AGC (pT3-pT4) operated without hyperthermic intraperitoneal chemotherapy (HIPEC), surgery alone group (SG T3, SG T4).

RESULTS

Forty four patients. 26 (59.1%) were male. Sixteen (36%) patients underwent 16 HIPEC: 6 (38%) had AGC (pT4) without PC (PG), 10 (62%) had carcinosis (TG), 28 were operated without HIPEC (SG T3, SG T4). The mean disease free survival (DFS): TG: 7.7 months, SG T4: 21.6 months, SG T3: 27.7 months, PG: 34.5 months. DFS was significantly different for TG (P=0.03, P=0.021, P=0.013 respectively). The mean OS TG: 10 months, SG T4: 27.1 months, SG T3: 28.2 months, PG: 34.6 months. OS was significantly different for TG (P=0.04, P=0.04, P=0.045 respectively). Severe complication rate: TG: 60%, PG: 16.7%, SG T3: 7.7% and SG T4: 25% (P=0.035). Length-of-stay differs significantly (P=0.003); overall length-of-stay: 19.41 days [standard deviation (SD) ±15.03]; TG: 33.01 (SD ±23.08), PG: 20.17 (SD ±6.21), SG T3: 11.33 (SD ±3.22), SG T4: 15.36 (SD ±5.48).

CONCLUSIONS

Prophylactic intraperitoneal chemotherapy associated to neoadjuvant chemotherapy increases the DFS and OS in patients with AGC without carcinosis. More data are needed in order to confirm these results.

Effectiveness of plasma treatment on gastric cancer cells

BACKGROUND

Treatment of peritoneal carcinomatosis arising from gastric cancer remains a considerable challenge. In recent years, the anticancer effect of nonequilibrium atmospheric pressure plasma (NEAPP) has been reported in several cancer cell lines. Use of NEAPP may develop into a new class of anticancer therapy that augments surgery, chemotherapy, and radiotherapy.

METHOD

Gastric cancer cells were assessed for changes in cell morphology and rate of proliferation after treatment with NEAPP-exposed medium (PAM). To explore the functional mechanism, caspase 3/7, annexin V, and uptake of reactive oxygen species (ROS) were evaluated, along with the effect of the ROS scavenger N-acetylcysteine (NAC).

RESULTS

PAM treatment for 24 h affected cell morphology, suggestive of induction of apoptosis. PAM cytotoxicity was influenced by the time of exposure to PAM, the type of cell line, and the number of cells seeded. Cells treated with PAM for 2 h demonstrated activated caspase 3/7 and an increased proportion of annexin V-positive cells compared with untreated cells. Additionally, ROS uptake was observed in PAM-treated cells, whereas NAC reduced the cytotoxicity induced by PAM presumably through reduction of ROS uptake. Furthermore, CD44 variant 9, which reportedly leads to glutathione synthesis and suppresses stress signaling of ROS, was overexpressed in PAM-resistant cells.

CONCLUSIONS

PAM treatment induced apoptosis of gastric cancer cells through generation and uptake of ROS. Local administration of PAM could develop into an option to treat peritoneal carcinomatosis.

Peritoneal carcinomatosis

Several gastrointestinal and gynecological malignancies have the potential to disseminate and grow in the peritoneal cavity. The occurrence of peritoneal carcinomatosis (PC) has been shown to significantly decrease overall survival in patients with liver and/or extraperitoneal metastases from gastrointestinal cancer. During the last three decades, the understanding of the biology and pathways of dissemination of tumors with intraperitoneal spread, and the understanding of the protective function of the peritoneal barrier against tumoral seeding, has prompted the concept that PC is a loco-regional disease: in absence of other systemic metastases, multimodal approaches combining aggressive cytoreductive surgery, intraperitoneal hyperthermic chemotherapy and systemic chemotherapy have been proposed and are actually considered promising methods to improve loco-regional control of the disease, and ultimately to increase survival. The aim of this review article is to present the evidence on treatment of PC in different tumors, in order to provide patients with a proper surgical and multidisciplinary treatment focused on optimal control of their locoregional disease.

Intraperitoneal chemotherapy in advanced gastric cancer. Meta-analysis of randomized trials

INTRODUCTION

An important component of treatment failure in gastric cancer (GC) is cancer dissemination within the peritoneal cavity and nodal metastasis. Intraperitoneal chemotherapy (IPC) is considered to give a fundamental contribute in treating advanced GC. The purpose of the study is to investigate the effects of IPC in patients with advanced GC.

MATERIAL AND METHODS

A systematic review with meta-analysis of randomized controlled trials (RCTs) of IPC + surgery vs. control in patients with advanced GC was performed.

RESULTS

Twenty prospective RCTs have been included (2145 patients: 1152 into surgery + IPC arm and 993 into control arm). Surgery + IPC improves: 1, 2 and 3-year mortality (OR = 0.31, 0.27, 0.29 respectively), 2 and 3-year mortality in patients with loco-regional nodal metastasis (OR = 0.28, 0.16 respectively), 1 and 2-year mortality rate in patients with serosal infiltration (OR = 0.33, 0.27 respectively). Morbidity rate was increased by surgery + IPC (OR = 1.82). The overall recurrence and the peritoneal recurrence rates were improved by surgery + IPC (OR = 0.46 and 0.47 respectively). There was no statistically significant difference in lymph-nodal recurrence rate. The rate of haematogenous metastasis was improved by surgery + IPC (OR = 0.63).

CONCLUSIONS

1, 2 and 3-year overall survival is incremented by the IPC. No differences have been found at 5-year in overall survival rate. 2 and 3-year mortality rates in patients with nodal invasion and 1 and 2-year mortality rates in patients with serosal infiltration are improved by the use of IPC. IPC has positive effect on peritoneal recurrence and distant metastasis. Morbidity rate is incremented by IPC. Loco-regional lymph-nodes invasion in patients affected by advanced gastric cancer is not a contraindication to IPC.

Post-surgical chemotherapy versus surgery alone for resectable gastric cancer

BACKGROUND

For gastric cancer surgery is the mainstay treatment. Chemotherapy seems to improve the survival results. But chemotherapy is not a complication-free therapy and its role has been questioned by some trials.

OBJECTIVES

To determine whether post-surgical chemotherapy should be used routinely in resectable gastric cancer.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) in The Cochrane Library, MEDLINE, EMBASE, and Science Citation Index Expanded (July 2013).

SELECTION CRITERIA

Randomised controlled trials (RCT) comparing post-surgical chemotherapy versus surgery alone for resectable gastric cancer.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed trials for inclusion and independently extracted the data. We analysed the data with both the fixed-effect and the random-effects models using the RevMan analysis software. We calculated the hazard ratio (HR) with 95% confidence interval (CI) based on intention-to-treat or available case analysis.

MAIN RESULTS

The authors identified 34 studies (7824 patients) reporting overall survival (OS) and only 15 reporting disease free survival (DFS) as well. Post-surgical chemotherapy showed an improvement in OS (HR 0.85; 95% CI 0.80 to 0.90) and an improvement in DFS (HR 0.79; 95% CI 0.72 to 0.87), although all the trials had a high risk of bias.The planned analysis of quality of life, return to work, and number of hospital admissions was impossible to complete as the outcome data for the analysis were not available from any trials.

AUTHORS' CONCLUSIONS

Post-surgical chemotherapy should be used routinely for resectable gastric cancer where possible. Further RCTs are needed to determine the role at each stage of disease.

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.

Can adjuvant chemoradiotherapy replace extended lymph node dissection in gastric cancer?

Surgical resection remains the essential part in the curative treatment of gastric cancer. However, with surgery only, long-term survival is poor (5-year survival <25 % in Europe). Randomized studies, which compared limited (D1) lymph node dissection with more extended (D2) resections in the Western world, failed to show a survival benefit for more extensive surgery. A substantial increase in survival was found with perioperative chemotherapy in the MAGIC study. In addition, the SWOG/Intergroup 0116 study showed that postoperative chemoradiotherapy (CRT) prolonged 5-year overall survival compared to surgery only. However, it has been argued that surgical undertreatment undermined survival in this trial. In a randomized Korean study, patients with advanced stage gastric cancer who received postoperative CRT had better outcome after a D2 dissection. At our institute phase I-II studies with adjuvant cisplatin and capecitabine-based CRT have been performed in over 120 patients with resected gastric cancer. Retrospective comparison of patients treated in these studies with those that had surgery only in the D1D2 study, demonstrated that postoperative CRT was associated with better outcome, especially after D1 or a R1 resection. For daily practice, it remains unclear whether patients after optimal (D2) gastric surgery will benefit from postoperative CRT. This is currently being tested in prospective randomized phase III trials (CRITICS; TOPGEAR).

Adjuvant chemotherapy for elderly patients with gastric cancer after D2 gastrectomy

BACKGROUND

A phase III clinical trial has already shown the survival benefits of postoperative chemotherapy in gastric cancer. However, there are limited published data concerning the elderly. This study aims to investigate the use of adjuvant chemotherapy for gastric cancer after D2 gastrectomy among the elderly and identify its impact on survival.

METHODS

We retrospectively reviewed 360 patients who had undergone D2 gastrectomy, aged 65 years or older, with non-metastatic gastric cancer in a single institution. We analyzed the predictors and survival benefits of adjuvant chemotherapy use in the elderly. Further, we analyzed the survival benefits of adjuvant chemotherapy by dividing the patients into groups according to disease stages and chemotherapeutic regimens.

RESULTS

Among the 360 patients, only 34.7% of patients received adjuvant chemotherapy. Age, tumor location, lymph node involvement and tumor invasion were associated with the receipt of adjuvant chemotherapy. Adjuvant chemotherapy improved the overall survival for non-metastatic elderly patients (HR 0.60, 95%CI 0.42-0.83, P = 0.003). Significant survival benefits were found with adjuvant chemotherapy in stage III patients (HR 0.67, 95%CI 0.47-0.97, P = 0.033), but not in stage I patients or in stage II patients (HR 0.52, 95%CI 0.21-1.30 P = 0.161). Compared to adjuvant chemotherapy without platinum, no significant survival benefits were observed with platinum-containing chemotherapy (HR 0.84, 95%CI 0.49-1.45, P = 0.530). Besides adjuvant chemotherapy, other independent prognostic factors of survival included tumor location, tumor size, histologic grade, depth of tumor invasion, and lymph node status.

CONCLUSIONS

This study demonstrated the survival benefits of adjuvant fluoropyrimidine-based chemotherapy among the elderly patients with non-metastatic gastric cancer after D2 gastrectomy. However, due to the limitations of this study, further well-designed prospective studies with large populations are needed to confirm these findings and identify the patients that can tolerate and benefit from adjuvant chemotherapy.

Quality of care indicators for the surgical treatment of gastric cancer: a systematic review

BACKGROUND

Quality assurance is increasingly acknowledged as a crucial factor for the (surgical) treatment of gastric cancer. The purpose of the current study was to define a minimum set of evidence-based quality of care indicators for the surgical treatment of locally advanced gastric cancer.

METHODS

A systematic review of the literature published between January 1990 and May 2011 was performed, using search terms on gastric cancer, treatment, and quality of care. Studies were selected based on predefined selection criteria. Potential quality of care indicators were assessed based on their level of evidence and were grouped into structure, process, and outcome indicators.

RESULTS

A total of 173 articles were included in the current study. For structural measures, evidence was found for the inverse relationship between hospital volume and postoperative mortality as well as overall survival. Regarding process measures, the most common indicators concerned surgical technique, perioperative care, and multimodality treatment. The only outcome indicator with supporting evidence was a microscopically radical resection.

CONCLUSIONS

Although specific literature on quality of care indicators for the surgical treatment of locally advanced gastric cancer is limited, several quality of care indicators could be identified. These indicators can be used in clinical audits and other quality assurance programs.

Prognostic significance of host- and tumor-related factors in patients with gastric cancer

BACKGROUND

Various factors regarding the biological state of tumors or the nutritional status of patients have been reported individually to correlate with prognosis. Identification of defined patient groups based on a prognostic score may improve the prediction of survival and individualization of therapy. The aim of the present study was to identify clinically useful parameters obtainable before treatment that could be used for predicting clinical outcomes in patients with gastric cancer.

METHODS

In 357 consecutive patients who had been treated for potentially curable gastric cancer, we retrospectively analyzed the following clinicopathological factors: sex, age, body mass index, body weight changes, hemoglobin, white blood cell count, neutrophil to lymphocyte (N/L) ratio, serum C-reactive protein (CRP), serum albumin, serum cholinesterase, tumor location, tumor size, histology, and clinical tumor node metastasis (TNM) stage. Factors related to prognosis were evaluated by univariate and multivariate analysis.

RESULTS

From univariate analysis, significant differences in survival were found for age, hemoglobin, N/L ratio, serum CRP, serum albumin, serum cholinesterase, tumor size, and clinical T and N grouping. N/L ratio, tumor size, and clinical T grouping were identified as independent prognostic indicators in multivariate analysis. A prognostic score was constructed using these variables to estimate the probability of death. The model gave an area under the receiver operating characteristic curve of 0.85 for prediction of death at 5 years.

CONCLUSIONS

This model based on N/L ratio, tumor size, and clinical T grouping before treatment offers a very informative scoring system for predicting prognosis of gastric cancer.

Expression of thymidylate synthase determines the response of gastric cancer patients undergoing gastrectomy to 5-fluorouracil-based adjuvant chemotherapy

PURPOSE

We investigated whether the intensity of thymidylate synthase (TS) staining in tissue samples obtained from gastric cancer (GC) patients undergoing gastrectomy could predict response to 5-FU-based adjuvant chemotherapy after gastrectomy.

METHOD AND MATERIALS

Clinicopathological features of 124 patients with histologically proven GC who underwent radical gastrectomy were retrospectively reviewed. Tissue samples obtained from these patients were immunohistochemically stained for assessing TS expression. We arbitrarily classified the TS staining results as low (<20% cytoplasmic immunostaining) and high (> or =20% cytoplasmic immunostaining) TS expression.

RESULTS

The clinicopathological features of the low TS expression group patients were typically similar to those of the high TS expression group patients. However, multivariate forward stepwise logistic regression analysis revealed that low TS expression was independently associated with females and responders to 5-FU-based adjuvant chemotherapy. The median follow-up duration for the 124 GC patients who had undergone curative resection was 41.3 months. The GC patients who showed poor tumor differentiation and high TS expression had short disease-free survival (DFS) and overall survival (OS).

CONCLUSIONS

Low TS expression is significantly associated with female GC patients and responders to 5-FU-based adjuvant chemotherapy. It predicts longer DFS and OS in selected GC patients treated with 5-FU-based adjuvant chemotherapy after curative resection. The results suggest that prospective assessment of TS staining intensity in tissue samples obtained from GC patients undergoing gastrectomy would be useful to predict the patients who would be benefited from 5-FU-based adjuvant chemotherapy after gastrectomy.

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

BACKGROUND

The purpose of this study was to clarify the clinical significance of tumor size in advanced gastric cancer and to evaluate the risk factors of survival in advanced gastric cancer with large tumor size.

METHODS

The cut-off point for tumor size, 90th percentile value of tumor size in advanced gastric cancer, was determined to be 10 cm. We retrospectively studied the clinicopathological features and prognosis of 406 patients with advanced gastric tumors measuring 10 cm or more.

RESULTS

Large tumors had a propensity for the following: Borrmann type IV, adjacent organ invasion, lymph node and distant metastasis, and stage IV classification. Tumor size was an independent risk factor for lymph node metastasis and survival in advanced gastric cancer. In patients with large advanced gastric cancer, Borrmann type IV, adjacent organ invasion, and N2-3 nodal involvement were independent factors associated with a poorer prognosis. The 5-year survival rate in large gastric cancer patients without any risk factors (65.5%) was similar with those in small gastric cancer patients (59.3%, P = 0.123).

CONCLUSION

Tumor size was a simple predictor for lymph node metastasis and survival in advanced gastric cancer. Radical surgery should be recommended for large advanced gastric cancer patients without risk factors, while large gastric cancer with risk factors may not be a surgically treatable disease.

Abnormal expression of pRb, p16, and cyclin D1 in gastric adenocarcinoma and its lymph node metastases: relationship with pathological features and survival

The retinoblastoma (Rb) pathway controls the G1-S checkpoint of the cell cycle. Inactivating mutations and deletions of p16 and Rb and up-regulation of cyclin D1 disrupt this pathway and occur in many cancers. However, the concurrent expression of these genes in primary and metastatic gastric cancer is unknown, and the prognostic value of their expression is unclear. In this study, the expression of cyclin D1, retinoblastoma protein (pRb), and p16 in 67 resected gastric adenocarcinomas, and of pRb and p16 in 40 associated lymph node metastases, was determined using a streptavidin-biotin-peroxidase immunohistochemical method. Relationships with clinical and pathological features were analyzed. Cyclin D1 overexpression (>/=5% expression) was seen in 55% of cancers; pRb loss (<20% expression), in 33%; p16 loss (<10% expression), in 49%; and at least 1 of these abnormalities, in 92.5%. Cyclin D1 overexpression was associated with poor differentiation (P = 0.027) and signet ring cell type (P = 0.029). pRb expression was lower in lymph node metastases than in the corresponding primary tumors (P <0.001). Univariate and multivariate survival analysis (minimum follow-up 72 months or until death) revealed that <20% pRb expression, <30% pRb expression, and International Union Against Cancer stage >2 were associated with worse overall survival. The results suggest that Rb pathway disturbances play an important role in gastric carcinogenesis. The poor prognosis of cancers with low pRb expression and the reduced pRb expression in lymph node metastases raise the possibility that Rb and related genes also influence progression.

Curative treatment of gastric cancer: towards a multidisciplinary approach?

Despite marked decreases in incidence over the last century, particularly in developed countries, gastric cancer is still the second-most common tumor worldwide. Surgery remains the gold standard for the cure of locoregional disease. However, in most countries, the diagnosis is made at an advanced stage, and the 5-year survival for surgically resectable disease stays far below 50%. The efficacy of chemotherapy and/or radiation therapy in addition to surgery has been actively studied over the last 30 years. Unfortunately, with few exceptions, most studies of adjuvant therapy in gastric cancer have given deceiving results. The purpose of this review is to address the reasons for our failure to objectivate an improvement in the cure of gastric cancer with adjuvant treatment in most trials, and to consider potential solutions. The low efficacy of chemotherapy regimens available up to now may have hampered our progress. In addition, many previous studies suffered limitations of design or methodology (e.g. low accrual, inadequate disease stage selection, inadequate surgical treatment) that may have obscured a treatment effect. Furthermore, the reduced treatment tolerance of post-gastrectomy patients, perhaps due to their poor nutritional status, results in decreased or delayed adjuvant systemic therapy, with potential adverse consequences in its efficacy. Among potential solutions, the arrival of new drugs, taxanes and topoisomerase I inhibitors in particular, which have shown encouraging results in metastatic disease, may increase the impact of chemotherapy in a multidisciplinary treatment approach. Pre-treatment with chemotherapy and/or radiation therapy prior to surgery may also be advantageous, averting the problems associated with post-surgical treatment. Such an approach has been shown to be feasible in phase II studies, and is relatively well tolerated by patients. Several carefully designed randomized phase III trials are underway to answer this question.

Intravenous chemotherapy for resected gastric cancer: meta-analysis of randomized controlled trials

AIM: To assess the safety and efficacy of different intravenous chemotherapeutic regimens in patients with gastric carcinomas who had undergone gastrectomy.

METHODS: A meta-analysis of all the relevant randomized controlled trials (RCTs) was performed. Language was restricted to Chinese and English. RCTs were identified from Medline and Embase (1980-2001/4), and Chinese Bio-medicine Database (1990-2001/1). Literature references were checked at the same time. We included randomized and quasi-randomized trials comparing the efficacy of intravenous chemotherapy after gastrectomy with that of surgery alone in patients with confirmed gastric carcinomas who had undergone gastrectomy. Selection criteria were: randomized or quasi-randomized trials with following-up results; Trials could be double-blind, single-blind or not blind; Chemotherapy groups were given intravenous chemotherapy after gastrectomy without neo-adjuvant chemotherapy, intraperitoneal hyperthermic perfusion, radiotherapy or chemoimmunotherapy; Controlled group included those receiving gastrectomy alone. The following data were extracted: the number of survival and death by the end of the follow-up; the different agents and doses of the intravenous chemotherapy; the baseline of the chemotherapy group and the controlled arm; the serious adverse events; the statistical consideration; cost-effectiveness analysis. The statistical analysis was performed by RevMan4.1 software which was provided by the Cochrane Collaboration. A P value of < 0.05 was considered statistically significant. Meta-analysis was done with random effects model. Heterogeneity was checked by chi-square test. Sensitivity analysis was performed by excluding the trials in which Jadad-scale was only 1 score. The result was expressed with odds ratio (OR) for the categorical variable.

RESULTS: Fourteen trials involving 4543 patients were included. Meta-analysis was done with random effects model Heterogeneity and sensitivity analysis were performed also. The effect of intravenous chemotherapy after gastrectomy was better than surgery alone (odds ratio 0.56, 95%CI 0.40-0.79). There was a significant difference between the two groups by u-test (P = 0.0008). Sensitivity analysis revealed the same difference (odds ratio 0.81, 95%CI 0.70-0.94). Of fourteen trials, only three studies were of high quality according to the Jadad-scale (with three score). There was one meta-analysis trial and the others, about ten trials, were of low quality. There was no trial which mentioned sample-size calculation, allocation concealment, intention-to-treat analysis. Most of the trials didn’t describe the blind-procedure. There were five trials which detailed the side-effects according to the toxicity grade by WHO standard. The side-effects halting treatment were haematologic and biochemical toxicity, debilitating nausea and vomiting. There were two patients died of chemotherapy toxicity.

CONCLUSION: Based on the review, intravenous chemotherapy after gastrectomy may have positive treatment effect on gastric cancer. However, the evidence is not strong because of the general low methodologic quality of the RCTs. Therefore, we can’t make the conclusion that intravenous chemotherapy after gastrectomy may have better treatment effect on gastric cancer than that of surgery alone. Rigorously designed, randomised, double-blind, placebo-controlled trials are required.

Histopathological grading does not affect survival after R0 surgery for gastric cancer

AIM

It is unclear whether Histopathological Grading (UICC, TNM Classification) affects survival after resection for gastric cancer.

METHODS

To investigate the prognostic significance of Histopathological Grading after gastrectomy, 1455 patients who underwent gastric resection for gastric adenocarcinoma were reviewed.

RESULTS

The R0 (UICC, R Classification) resection rate was inversely correlated with the grade (86.5% for Grade 1, 79.7% for Grade 2 and 69.2% for Grade 3) and the R1 and R2 resection rates increased with the grade. The Histopathological Grading did not influence survival in the 1119 patients who underwent R0 resection (71.0% for Grade 1, 65.7% for Grade 2 and 66.7% for Grade 3). When multivariate analysis was performed for the 1119 cases undergoing R0 resection, the Histopathological Grading was not a determinant prognostic factor.

CONCLUSION

We conclude that the UICC Histopathological Grading affects R0 resection rates, but does not affect survival independently.

Influence of pathological tumour variables on long-term survival in resectable gastric cancer

Although tumour stage and nodal status are established prognostic factors for resectable gastric cancer, the relative importance of other pathological characteristics remains unclear. This study reports univariate and multivariate analyses of the prognostic value of various pathological and staging factors based on 324 patients entered into the MRC randomised surgical trial for gastric cancer. In the univariate analysis tumour stage, nodal status, UICC clinical stage, number of involved nodes, WHO predominant type, mixed Lauren type, Ming type, tumour differentiation, lymphocytic and tumour stromal eosinophilic infiltration were all found to have a significant impact on survival (logrank test, 5% level). In the multivariate analysis, UICC clinical stage and eosinophilic infiltration were found to have a significant influence. Risk of death increased for UICC stage II and III patients (Hazard Ratio for stage II compared to stage I=2.0, 95% Confidence Interval (CI) 1.4-2.9; Hazard Ratio for stage III compared to stage I=3.5, 95% CI 2.5-4.8). Patients with numerous eosinophils had a lower risk of death than those with none (Hazard Ratio=0.5, 95% CI 0.3-0.8). This association between survival and eosinophilic infiltration merits further study.

[Target volume in radiotherapy of gastric adenocarcinoma]

The spread of gastric adenocarcinoma may follow three main patterns: hematogenic, lymphatic and intraperitoneal. A GTV should be considered in preoperative or exclusive radiation therapy. After non-radical surgery, a "residual GTV" will be defined with the help of the surgeon. The CTV encompasses three intricated volumes. a) A "tumor bed" volume. After radical surgery, local recurrences appear as frequent as distant metastases. The risk depends upon the depth of parietal invasion and the nodal status. Parietal infiltration may extend beyond macroscopic limits of the tumor, especially in "linitis plastica". Therefore this volume will include: the tumor and the remaining stomach or their "bed of resection", a part of the transverse colon, the duodenum, the pancreas and the truncus of the portal vein. In postoperative RT, this CTV also includes the jejuno-gastric or jejuno-esophageal anastomosis. b) A peritoneal volume. For practical purposes, two degrees of spread must be considered: (1) contiguous microscopic extension from deeply invasive T3 and T4 tumors, that remain amenable to local sterilization with doses of 45-50 Gy, delivered in a CTV including the peritoneal cavity at the level of the gastric bed, and under the parietal incision; (2) true "peritoneal carcinomatosis", with widespread seeds, where chemotherapy (systemic or intraperitoneal) is more appropriate. c) A lymphatic volume including the lymph node groups 1 to 16 of the Japanese classification. This volume must encompass the hepatic pedicle and the splenic hilum. In proximal tumors, it is possible to restrict the lower part of the CTV to the lymphatic volume, and therefore to avoid irradiation of large intestinal and renal volumes. In distal and proximal tumors, involvement of resection margins is of poor prognosis--a radiation boost must be delivered at this level. The CTV in tumors of the cardia should encompass the lower part of the thoracic esophagus and the corresponding posterior mediastinum. In tumors invading the distal esophagus, a more complete coverage of mediastinal lymph nodes should be considered, especially in patients in good general condition. In tumors of the gastric fundus, most of the left hemidiaphragm should be included, as well as the spleen and its hilum (or their resection bed). In proximal tumors without involvement of the lesser curvature, a full coverage of the hepatic pedicle is not necessary. In contrast, for distal tumors, the hepatic pedicle and the hepatoduodenal ligament should be included whereas the splenic area could be spared.

CONCLUSION

Planning the treatment of gastric cancer remains difficult; target volumes must be customized by experienced radiation oncologists according to tumoral and clinical situation.

Expression of thymidylate synthase in gastric cancer patients treated with 5-fluorouracil and doxorubicin-based adjuvant chemotherapy after curative resection

We evaluated the expression of thymidylate synthase (TS) in locally advanced gastric cancer patients treated with adjuvant chemotherapy after curative resection and investigated the association between TS expression and clinicopathologic characteristics including prognosis of the patients. TS expression was evaluated by immunohistochemical staining using TS106 monoclonal antibody in 103 locally advanced gastric cancer patients (stage IB-IV) who underwent 5-fluorouracil (5-FU) and doxorubicin-based adjuvant chemotherapy after curative resection. 65 patients (63%) had primary tumours with high TS expression (> or = 25% of tumour cells positive), and 38 patients (37%) demonstrated low TS expression (< 25% of tumour cells positive or no staining). High TS expression was associated with male gender (P = 0.002), poorly differentiated histology (P = 0.015), and mixed type in Lauren's classification (P = 0.027). There were no statistically significant differences in 4-year disease-free survival (60.0% vs. 57.2%, P = 0.548) and overall survival (59.6% vs. 59.3%, P = 0.792) between high-TS group and low-TS group. In conclusion, although high TS expression was associated with poorly differentiated histology and mixed type in Lauren's classification, it did not predict poor disease-free and overall survival in gastric cancer patients treated with 5-FU and doxorubicin-based adjuvant chemotherapy after curative resection. Further prospective studies including the evaluation of other biological markers associated with the resistance to 5-FU and doxorubicin are necessary.

Problems with intraoperative hyperthermic peritoneal chemotherapy for advanced gastric cancer

BACKGROUND

Intraoperative hyperthermic peritoneal chemotherapy (IHPC) after total gastrectomy for advanced, serosa-penetrating gastric cancer has been demonstrated in several studies to reduce the incidence of peritoneal carcinosis and to prolong survival.

METHODS

In a prospective pilot study, nine patients with advanced gastric cancer were selected to receive IHPC with Mitomycin and Cisplatin after total gastrectomy and systematic lymphadenectomy.

RESULTS

All patients had nodal, and four patients distant, metastases. Six patients (66%) suffered from post-operative complications including renal failure, pancreatitis, pancreatic fistula and anastomotic dehiscence. Thirty-day mortality was zero. Six patients died within 3-10 months after surgery. Five of these deaths were related to peritoneal carcinosis and one patient died from cardiac failure 3 months after surgery. Three patients, respectively, have been alive for 12, 20 and 24 months at present, with suspected peritoneal tumour in the last patient. The 2-year probability of survival among our patients receiving IHPC is 29%.

CONCLUSION

Intraoperative hyperthermic peritoneal chemotherapy carries a high risk of peri-operative complications and was not able to prevent or delay peritoneal tumour recurrence in patients with advanced gastric cancer.

Surgical results in gastric cancer

Although the therapeutic results for gastric cancer have markedly improved, it remains the most common cause of cancer death in Korea. Annually, at Seoul National University Hospital, over 700 gastric cancer patients are surgically treated, and, between the years from 1970 and 1997, a total of 11,491 such patients were treated. We will review the principles of surgery for gastric cancer and our comparative studies of immunochemosurgery and postoperative chemotherapy. Further, we will review our evaluation of the survival rate and prognostic factors for 9,262 patients from 1981 to 1996. We conclude that the most important factors for improvement of the postoperative survival of these patients are early diagnosis and curative resection with radical lymph node dissection, followed by postoperative immunochemotherapy. This should be recommended as the standard treatment for patients with gastric cancer, especially patients with Stage III gastric cancer.

Expression of oncoproteins and the amount of eosinophilic and lymphocytic infiltrates can be used as prognostic factors in gastric cancer. Dutch Gastric Cancer Group (DGCG)

Preoperative staging of gastric cancer is difficult. Several molecular markers associated with initiation and progression of cancer seem promising for obtaining preoperative prognostic information. To investigate whether these markers are indicative especially for the presence of lymph node metastases in patients with gastric cancer, we have examined primary tumour specimens from 105 patients with primary adenocarcinoma of the stomach entered in a surgical trial. In this trial, lymph node status was determined by strictly quality-controlled lymph node dissection and examination. The selected markers were growth regulators (p53, Rb and myc), metastasis-suppressor gene product (nm23), adhesion molecules (Ep-CAM, E-cadherin, CD44v5 and CD44v6) and urokinase-type plasminogen activator (u-PA). Also, the amount of eosinophilic and lymphocytic infiltrates available post-operatively was analysed with respect to its prognostic value for lymph node status. Moreover, the association of these parameters with survival and disease-free period (DFP) was evaluated. Of all molecular markers investigated, only Rb expression had a significant association with the presence of lymph node metastasis in both univariate and multivariate analysis. For curative resectability, a significant association was found with Rb and E-cadherin expression, while in multivariate analysis Rb and myc were selected as the combination with additional independent prognostic value, and E-cadherin had no additional independent value. For overall survival in univariate analysis, the amount of both eosinophilic and lymphocytic infiltrates and Rb and myc expression were of significant prognostic value. Only the amount of lymphocytic infiltrate had a prognostic significance for DFP. In stepwise multivariate analysis, TNM stage (I + II) and marked lymphocytic infiltrate were associated with better overall survival and longer DFP. We conclude that, if these results are confirmed in a larger series of patients, molecular markers can provide useful prognostic information.

Prognostic factors in gastric cancer: the value of vascular invasion, mitotic rate and lymphoplasmacytic infiltration

A retrospective analysis of 321 gastric cancer patients was made to assess the prognostic value of TNM classification, tumour differentiation, Laurén classification, proliferative rate, inflammatory reaction and tumour invasion in vascular or neural structures of the gastric wall. The TNM classification showed the strongest correlation with survival in univariate and multivariate analyses (P < 0.0001). The invasion in lymphatic or vascular system and Laurén classification were also independent prognosticators in multivariate analysis (P < 0.05). In univariate analysis, the WHO-grade, the size and the location of the tumour and perinueral invasion were significant prognostic factors (P < 0.01), as were the infiltration of lymphocytes and plasma cells in the tumour (P < 0.05). On the other hand, the mitotic indices reflecting the proliferative activity of the tumour cells showed no significant correlation with the prognosis. The results indicate that the prognostic power of the TNM classification can be further increased by assessment of the above special histological features in gastric cancer.