Surgical approaches and outcomes in the treatment of gastric cancer

KRAS G12V Mutation is an Adverse Prognostic Factor of Chinese Gastric Cancer Patients

This study aims to investigate the molecular characteristics of Chinese gastric cancer patients. In our study, the KRAS, BRAF, and PIK3CA mutation status of 485 GC patients were analyzed by Sanger sequencing. Kaplan-Meier analysis was used to plot survival curves according to different genotypes. The results show that the frequency of KRAS, BRAF and PIK3CA mutations were 4.1%, 1.2% and 3.5%, respectively. BRAF mutations were significantly concentrated in stage III and IV gastric cancer (P=0.009). KRAS G12V mutation carriers have much shorter OS than other mutation carriers and wild-type group patients (P=0.013). In conclusion, only the KRAS G12V mutation has an adverse effect on patient survival.

Kidney-Sparing Radiotherapy by Multiple-Field Three-Dimensional Technique in the Postoperative Management of Patients with Gastric Cancer: Comparison with Standard Two-Field Conformal Technique

AIMS AND BACKGROUND

The opposed two-field technique is the standard approach for delivering adjuvant radiotherapy to patients with resected gastric cancer. Since a considerable radiation dose may reach both kidneys with this beam arrangement, with a potential risk of late effects, we investigated whether the CT-based multiple-field (M-F) approach was superior in terms of sparing critical organs at risk.

METHODS

From March 2001 to March 2004, 19 patients with radically resected gastric cancer entered the study. They were treated with adjuvant chemoradiotherapy according to the INT 0116 protocol. For each patient dose-volume histograms were calculated and the volume values of both kidneys and liver receiving 25 Gy (V25), 30 Gy (V30) and 40 Gy (V40) individually estimated with the M-F and two-field techniques were compared in detail.

RESULTS

Right kidney median V25, V30 and V40 values for the two-field and M-F techniques were 1.50%, 0%, 0% and 0%, 0% and 0%, respectively (P < 0.005, P < 0.01, P < 0.05). Left kidney median V25, V30 and V40 values for the M-F and two-field technique were 16%, 9.80%, 0.90% and 33.20%, 30.20%, 21.40% (P < 0.001, P < 0.0005, P < 0.0005). Liver median V25, V30 and V40 values for the M-F and two-field techniques were 51.30%, 22.30%, 8.90% and 13.30%, 11.60%, 8.10%, respectively (P < 0.0001, P < 0.0005 and P = 0.18).

CONCLUSIONS

Our comparison revealed that with the multiple-field technique the right kidney may be largely spared from irradiation; with respect to the two-field technique, the left kidney may receive a significantly reduced dose; however, the liver receives an increased dose that warrants careful long-term monitoring of hepatic function.

Site-specific Hypermethylation of RUNX3 Predicts Poor Prognosis in Gastric Cancer

BACKGROUND AND AIMS

Methylation status of RUNX3 remains largely unknown in gastric cancer (GC). The aim of this study was to prognostically evaluate the methylation level of CpG sites within RUNX3 promoter region in GC.

METHODS

Using pyrosequencing, we quantitatively explored the methylation status of 8 CpG sites within RUNX3 promoter region for 76 gastric cancer and 24 normal gastric tissues. We then analyzed the association between methylation level of each CpG site and clinicopathological characteristics and outcomes in the cohort.

RESULTS

Methylation of RUNX3 promoter was significantly higher in GC than normal subjects. Overall methylation level was closely associated with tumor invasion and TNM stage. Positive associations were found between hypermethylation of the following concerned sites and variables: site -1392, -1397, -1403, -1415 and tumor invasion, as well as TNM stage; site -1392 and lymph node metastasis along with number of lymph node metastases; site -1415 and cancer recurrence; site -1403, -1415 and cancer-related deaths. In multivariate analysis, tumor invasion was correlated with sites -1392 and -1397. Lymph node metastasis was associated with site -1392. Most importantly, methylation of site -1415 was associated with poor survival by using Cox survival regression.

CONCLUSION

Analysis of RUNX3 gene promoter by quantitative pyrosequencing suggested methylation status of RUNX3 is different in normal and tumor tissues. RUNX3 methylation level is associated with GC, especially the methylation at site -1415 contributes to the poor prognosis in GC. Thus, RUNX3 methylation may serve as a valuable diagnostic and prognostic biomarker in GC.

P53 and Protein Phosphorylation Regulate the Oncogenic Role of Epithelial Cell Transforming 2 (ECT2)

BACKGROUND Gastric cancer (GC) is the second leading cause of cancer-related death worldwide, but little progress has been achieved in the treatment of advanced or metastatic GC. GC is highly heterogeneous and more studies are needed to elucidate the metastatic mechanisms. Epithelial cell transforming 2 (ECT2) has been reported to be up-regulated in GC tissues, but its signaling mechanisms remain unclear. MATERIAL AND METHODS In this study, we used Western blot analysis to compare the expression level of ECT2 in 2 GC cell lines: MKN1 and MKN45. Mutagenesis and transfections were conducted to investigate the oncogenic mechanisms of ECT2 in GC cells. RESULTS ECT2 was expressed at higher levels in MKN1 than in MKN45. Immunoblotting results showed that MKN1 expression was suppressed by p53-WT but was enhanced by p53-mutant. In addition, in vitro experiments showed that ECT2 positively regulated the proliferation and invasion of GC cells. To better explore the mechanisms of ECT2 in promoting GC progression, we introduced site-directed mutants of ECT2, and found that the phosphor-mimic mutant T359D enhanced its oncogenic activity. In contrast, activation of RhoA was inhibited in cells transfected with ECT2 phosphor-deficient mutant T359A. We found that the epithelial cell biomarker E-cadherin was down-regulated by ECT2-T359D, highlighting the role of phosphorylation in regulating epithelial-mesenchymal transition. CONCLUSIONS Our results identified p53 as a novel up-stream signaling molecule of ECT2 in GC cells, and the post-translational modifications of ECT2 play important roles in regulating cancer development and progression.

High expression of CD11c indicates favorable prognosis in patients with gastric cancer

AIM: To determine the relationship between CD11c expression level and prognosis in patients with gastric cancer (GC).

METHODS: This retrospective survival study was performed from July 31, 2008 to June 30, 2014. Our study inclusion criteria included all the patients with GC who underwent surgical resection between January 1998 and December 2009 in the Third Affiliated Hospital of Soochow University. CD11c expression levels in 140 patients with GC at different UICC stages were evaluated using immunohistochemistry, and GC tissues from 16 cases were further verified by qRT-PCR. The χ² test was used to compare the patient- and disease-related factors between the low CD11c expression group and the high expression group. Univariate probabilities of overall survival (OS) and disease-free survival (DFS) were assessed using the Kaplan-Meier method. The log rank test was used to compare survival curves. Different multivariate COX models were used to estimate the association between CD11c expression and both death and recurrence risk in GC patients.

RESULTS: The average CD11c expression level was 5.1 ± 1.8/high power field (HPF) in 10 gastritis samples, 4.5 ± 2.3/HPF in 10 gastric polyp samples and 9.7 ± 6.3/HPF in 140 gastric cancer samples, respectively. The CD11c expression level was significantly decreased from UICC stage I to stage IV (stage I: 16.0 ± 7.4, stage II: 10.4 ± 5.5, stage III: 9.4 ± 6.1, stage IV: 5.3 ± 3.2, P < 0.001). Patients in the high CD11c expression group had a greater 3- and 5-year OS probability and longer median survival time compared with the low CD11c expression group, (67.7% vs 39.2%; 51.4% vs 29.0%; 67.0 mo vs 28.0 mo; χ² = 6.80, P = 0.009), and had a greater 3- and 5-year DFS probability and longer median DFS time (63.7% vs 24.0%; 49.1% vs 11.9%; 64.0 mo vs 18.0 mo; χ² = 15.39, P < 0.001). Patients with high CD11c high expression had a reduced risk of death (HR = 0.56, 95%CI: 0.33-0.98, P < 0.05) and relapse (HR = 0.39, 95%CI: 0.23-0.67, P < 0.01) compared with patients with low CD11c expression after adjustment of potential confounders, with the exception of tumor size. However, the protective effect related to death (HR = 0.90, 95%CI: 0.49-1.67, P = 0.749) and relapse (HR = 0.65, 95%CI: 0.36-1.19, P = 0.160) disappeared when tumor size was incorporated into the model.

CONCLUSION: High expression of CD11c decreased the risk of death and relapse, and may be regarded as an alternative indicator of favorable prognosis in patients with GC.

Role of hMLH1 and E-cadherin promoter methylation in gastric cancer progression

INTRODUCTION

Gastric cancer (GC) is one of the leading causes of cancer-related death in Iran. Genome stability is one of the main genetic issues in cancer biology which is governed via the different repair systems such as DNA mismatch repair (MMR). A clear correlation between MMR defects and tumor progression has been shown. Beside the genetic mutations, epigenetic changes also have a noticeable role in MMR defects.

METHODS

Here, we assessed promoter methylation status and the level of hMLH1mRNA expression as the main component of MMR system in 51 GC patients using the methylation-specific PCR and real-time PCR, respectively. Moreover, we performed a promoter methylation study of the E-cadherin gene promoter.

RESULTS

It was observed that, 12 out of 39 cases (23.5%) had hMLH1 overexpression. Hypermethylation of hMLH1 and E-cadherin promoter regions were observed in 25.5 and 36.4%, respectively. Although, there was no significant correlation between hMLH1 mRNA expression and clinicopathological features, there are significant correlations between E-cadherin promoter methylation and tumor stage (p = 0.028) and location (p = 0.025). The rate of hMLH1 promoter methylation in this study was lower than that in the other population, showing the importance of the other mechanisms, in gastric tumorigenesis.

CONCLUSION

The results of this study indicate that DNA repair system is adversely affected by hypermethylation of hMLH1 in a fraction of gastric cancer patients. Additionally, E-cadherin hypermethylation seen in a subset of our gastric cancer patients is consistent with other reports showing correlation with aggressiveness and metastasis of gastric cancer.

KRC-408, a novel c-Met inhibitor, suppresses cell proliferation and angiogenesis of gastric cancer

Among many cancer therapeutic targets, c-Met receptor tyrosine kinase has recently given particular attention. This kinase and its ligand, hepatocyte growth factor (HGF), play a central role in cell proliferation and the survival of several human cancers. Thus, we developed KRC-408 as a novel c-Met inhibitor and investigated its anti-cancer effects on human gastric cancer. KRC-408 inhibited the phosphorylation of c-Met and its constitutive downstream effectors such as phosphatidylinositol 3-kinase (PI3K), Akt, Mek, and Erk. This compound was found to exert anti-cancer effects stronger than those of 5-fluorouracil (5-FU) on gastric cancer cells, especially cell lines that overexpressed c-Met. Interestingly, cytotoxicity of KRC-408 was lower than that of 5-FU in normal gastric cells. Apoptosis induced by KRC-408 was accompanied by increased levels of cleaved caspase-3 and PARP as well as DNA condensation and fragmentation. Flow cytometry analysis showed an accumulation of gastric cancer cells in the G2/M phase with concomitant loss of cells in the S phase following treatment with this drug. In the angiogenesis studies, KRC-408 inhibited tube formation and migration of human umbilical vein endothelial cells (HUVECs), and suppressed microvessel sprouting from rat aortic rings ex vivo along with blood vessel formation in a Matrigel plug assay in mice. Results of an in vivo mouse xenograft experiment showed that the administration of KRC-408 significantly delayed tumor growth in a dose-dependent manner, and suppressed Akt and Erk phosphorylation as well CD34 expression in tumor tissues. These findings indicate that KCR-408 may exert anti-tumor effects by directly affecting tumor cell growth or survival via the c-Met receptor tyrosine kinase pathway. We therefore suggest that KRC-408 is a novel therapeutic candidate effective against gastric cancers that overexpress c-Met.

Frequent gene amplification predicts poor prognosis in gastric cancer

Gastric cancer is one of the most common malignancies worldwide. However, genetic alterations leading to this disease are largely unknown. Gene amplification is one of the most frequent genetic alterations, which is believed to play a major role in the development and progression of gastric cancer. In the present study, we identified three frequently amplified genes from 30 candidate genes using real-time quantitative PCR method, including ERBB4, C-MET and CD44, and further explored their association with clinicopathological characteristics and poor survival in a cohort of gastric cancers. Our data showed amplification of these genes was significantly associated with certain clinicopathological characteristics, particularly tumor differentiation and cancer-related death. More importantly, amplification of these genes was significantly related to worse survival, suggesting that these amplified genes may be significant predictors of poor prognosis and potential therapeutic targets in gastric cancer. Targeting these genes may thus provide new possibilities in the treatment of gastric cancer.

Highly frequent PIK3CA amplification is associated with poor prognosis in gastric cancer

Background

The phosphoinositide 3-kinase (PI3K)/Akt pathway plays a fundamental role in cell proliferation and survival in human tumorigenesis, including gastric cancer. PIK3CA mutations and amplification are two major causes of overactivation of this pathway in human cancers. However, until this work, there was no sound investigation on the association of PIK3CA mutations and amplification with clinical outcome in gastric cancer, particularly the latter.

Methods

Using direct sequencing and real-time quantitative PCR, we examined PIK3CA mutations and amplification, and their association with clinicopathological characteristics and clinical outcome of gastric cancer patients.

Results

PIK3CA mutations and amplification were found in 8/113 (7.1%) and 88/131 (67%) gastric cancer patients, respectively. PIK3CA amplification was closely associated with increased phosphorylated Akt (p-Akt) level. No relationship was found between PIK3CA mutations and clinicopathological characteristics and clinical outcome in gastric cancer. PIK3CA amplification was significantly positively associated with cancer-related death. Importantly, Kaplan-Meier survival curves revealed that the patients with PIK3CA amplification had significantly shorter survival times than the patients without PIK3CA amplification.

Conclusions

Our data showed that PIK3CA mutations were not common, but its amplification was very common in gastric cancer and may be a major mechanism in activating the PI3K/Akt pathway in gastric cancer. Importantly, Kaplan-Meier survival curves revealed that PIK3CA amplification was significantly positively associated with poor survival of gastric cancer patients. Collectively, the PI3K/Akt signaling pathway may be an effective therapeutic target in gastric cancer.

Quantitative assessment of gene methylation and their impact on clinical outcome in gastric cancer

BACKGROUND

Promoter methylation is an alternative mechanism of gene silencing in human tumorigenesis. Although a number of methylated genes have been found in gastric cancer, useful methylation markers for early diagnosis and prognostic evaluation of this cancer remain largely unknown.

METHODS

Using quantitative methylation-specific PCR (Q-MSP), we examined promoter methylation of 6 genes, including CALCA, DAPK1, RARbeta, RASSF1A, TIMP3, and PAX6, and explored their association with clinical outcome in gastric cancer.

RESULTS

We found that most of the genes investigated in the present study had significantly higher methylation level in tumor tissues than normal gastric tissues, including CALCA, RARbeta, RASSF1A, TIMP3, and PAX6. With more focus on specificity compared to sensitivity, all genes were hypermethylated in gastric cancer, ranging from 12.8% to 36.9%. Methylation of TIMP3 and PAX6 was strongly associated with differentiation and lymph node metastasis, respectively. Importantly, most of gene methylation, except for DAPK1, was closely associated with poor survival in gastric cancer.

CONCLUSION

We found that a panel of genes was specifically methylated in gastric cancer, and demonstrated the effect of promoter methylation of some genes on clinical outcome in gastric cancer, indicating these methylated genes may be useful biomarkers for prognostic evaluation in this cancer.

The analysis of PIK3CA mutations in gastric carcinoma and metanalysis of literature suggest that exon-selectivity is a signature of cancer type

BACKGROUND

PIK3CA is one of the genes most frequently mutated in human cancers and it is a potential target for personalized therapy. The aim of this study was to assess the frequency and type of PIK3CA mutations in gastric carcinoma and compare them with their clinical pathological correlates.

METHODS

We analysed 264 gastric cancers, including 39 with microsatellite instability (MSI), for mutations in the two PIK3CA hotspots in exons 9 and 20 by direct sequencing of DNA obtained from microdissected cancer cells.

RESULTS

The cases harbouring mutations were 42 (16%). All were heterozygous missense single base substitutions; the most common was H1047R (26/42; 62%) in exon 20 and the second was Q546K (4/42; 9.5%) in exon 9. All the mutated MSI cases (8/39) carried the H1047R mutation. No other association between PI3KCA mutations and their clinical pathological covariates was found. A metanalysis of the mutations occurring in the same regions presented in 27 publications showed that ratio between exon 20 and exon 9 prevalences was 0.6 (95% CI: 0.5 -0.8) for colon, 1.6 (95% CI: 1.1 -2.3) for breast, 2.7 (95% CI: 1.6 -4.9) for gastric and 4.1 (95% CI: 1.9 -10.3) for endometrial cancer.

CONCLUSIONS

The overall prevalence of PIK3CA mutations implies an important role for PIK3CA in gastric cancer. The lack of association with any clinical-pathological condition suggests that mutations in PIK3CA occur early in the development of cancer. The metanalysis showed that exon-selectivity is an important signature of cancer type reflecting different contexts in which tumours arise.

Microsatellite instability in gastric cancer is associated with better prognosis in only stage II cancers

BACKGROUND

The assessment of microsatellite instability (MSI) is not included yet in the routine evaluation of patients with gastric cancer, as controversial data exist regarding its prognostic value.

METHODS

We determined the clinical significance of MSI in 510 sporadic gastric cancers, using the mononucleotide markers BAT25 and BAT26. The results were compared with the immunohistochemical expression of the mismatch repair proteins Mlh1 and Msh2.

RESULTS

MSI was present in 83 (16%) cancers and correlated with better survival (P < .001). Multivariate analysis showed that the MSI phenotype was an independent factor (P = .005) and added prognostic information to TNM stage, location, and age. The relative risk of death for MSI cancer patients was 0.6 (95% confidence interval [CI], 0.4-0.8). Moreover, when grouped according to stage, only stage II cancers showed a significant effect of MSI status on survival (P = .011; hazard ratio = 0.3; 95% CI, 0.1-0.8). MSI also correlated with older age (P = .002), female gender (P < .001), intestinal histotype (P = .011), lower T stage (P = .018), and less lymph node involvement (P < .001). Finally, comparison of the results of immunohistochemical expression of the mismatch repair proteins Mlh1 and Msh2 with microsatellite analysis showed concordant results in 95% of neoplasms, with a sensitivity of 82% and specificity of 98%.

CONCLUSIONS

Microsatellite analysis of gastric cancer has clinical utility in determination of prognosis, but should be determined in only stage II neoplasms in a routine clinical setting. Immunohistochemistry may be considered sufficient, although microsatellite analysis is preferable.

Role of radiation therapy in gastric adenocarcinoma

Outcomes in patients with gastric cancer in the United States remain disappointing, with a five-year overall survival rate of approximately 23%. Given high rates of local-regional control following surgery, a strong rationale exists for the use of adjuvant radiation therapy. Randomized trials have shown superior local control with adjuvant radiotherapy and improved overall survival with adjuvant chemoradiation. The benefit of adjuvant chemoradiation in patients who have undergone D2 lymph node dissection by an experienced surgeon is not known, and the benefit of adjuvant radiation therapy in addition to adjuvant chemotherapy continues to be defined.

In unresectable disease, chemoradiation allows long-term survival in a small number of patients and provides effective palliation. Most trials show a benefit to combined modality therapy compared to chemotherapy or radiation therapy alone.

The use of pre-operative, intra-operative, 3D conformal, and intensity modulated radiation therapy in gastric cancer is promising but requires further study.

The current article reviews the role of radiation therapy in the treatment of resectable and unresectable gastric carcinoma, focusing on current recommendations in the United States.

Assessment of lymph node metastases using 18F-FDG PET in patients with advanced gastric cancer

PURPOSE

The aim of this study was to assess the diagnostic accuracy of (18)F-fluoro-2-deoxyglucose (FDG) positron emission tomography (PET) with respect to lymph node (LN) metastasis in patients with advanced gastric cancer, and to ascertain the factors that affect this accuracy.

METHODS

Seventy-three patients with advanced gastric cancer, verified in all cases by endoscopic biopsy, were enrolled in this prospective study. We conducted FDG PET and other routine preoperative studies, including abdominal computed tomography (CT). Patients underwent either curative-intent gastrectomy and lymphadenectomy (n = 67) or exploratory laparotomy. The Japanese system for the classification of gastric cancer was used for LN assessment.

RESULTS

FDG PET was able to detect primary lesions in 70 of the 73 cases. The sensitivity, specificity, positive predictive value (PPV) and negative predictive value of FDG PET for LN metastasis were 40%, 95%, 91% and 56%, respectively. Signet-ring cell carcinoma was associated with the lowest sensitivity (15%), whereas other cell types could be detected with moderate sensitivity (30-71%) and high specificity (93-100%). According to multiple logistic regression, the standardised uptake value for primary tumours was the only independent variable to be significantly related to sensitivity for LN metastasis (p = 0.02, odds ratio = 1.14). CT was superior to PET in terms of sensitivity (p < 0.0001), and PET was superior to CT in terms of specificity (p < 0.0001) and PPV (p = 0.05).

CONCLUSION

FDG PET exhibits good specificity for LN staging of gastric cancer, and FDG uptake in the primary tumour is significantly related to the accuracy of FDG PET. Despite some clear limitations, FDG PET proved useful in the LN staging of FDG-avid gastric cancer.

Over-DI dissection may question the value of radiotherapy as a part of an adjuvant programme in high-risk radically resected gastric cancer patients

The aim of our analysis was to assess retrospectively the effect on local relapse, overall survival (OS) and disease-free survival (DFS) of a limited or an extended lymphadenectomy in radically resected gastric cancer patients. This study was performed in order to identify a subgroup of patients possibly not benefiting from a therapeutic approach such as chemoradiation therapy. We divided our patients into two groups according to lymphadenectomy type: group A for limited (<25 resected lymph nodes) and group B for extended (>25 resected lymph nodes) lymph nodes resection. A total of 418 patients were analysed: tumour stage at diagnosis was pT2–3 pN1–3 M0 in 339 patients and pT3 N0 M0 in 79 patients. Median age at diagnosis was 68 years (range 30–92 years). A total of 306 patients (73.2%) were in group A and 112 (26.8%) in group B. The median survival time (OS) for patients in groups A and B was 58.8 and 84.8 months, respectively (P=0.0371); median DFS was 28.8 months in group A and 59.9 months in group B (P=0.0027). At multivariate analysis, extension within the gastric wall, nodal involvement and the number of resected lymph nodes appeared to affect both OS and DFS. An inadequate lymph nodes resection can affect survival and result in a higher incidence of local relapse, making the latter group of patients optimal candidates for adjuvant chemoradiation.

Changing gastric cancer treatment in the United States and the pursuit of quality

The low incidence of gastric cancer in the US presents various quality challenges. For most US practitioners, individual experience is inadequate. Accrual to clinical trials testing new treatments can be daunting. However, through the use of nationally available clinical trials sponsored by many trial groups working in concert, and the use of national registries for treatment and outcome surveillance, a path to increased gastric cancer survival has been charted. Moreover, systems for continuous quality improvement at the institutional level are in place. Quality assurance is an increasing concern of both private and governmental groups. In this article, we summarize recent national US clinical trial findings concerning gastric cancer treatment, highlight national assessment systems for cancer outcomes, and describe what these systems tell us about the current status of gastric cancer care in the US, highlighting challenges and areas for potential improvement.

Clinicopathological features, surgical management, and disease outcome of perforated gastric cancer

BACKGROUND AND OBJECTIVES

Perforated gastric cancer is rare and generally not diagnosed preoperatively or intraoperatively, if a frozen section is unavailable. Therefore, the elucidation of its clinicopathological features and disease outcomes will help surgeons manage perforated gastric cancer.

PATIENTS AND METHODS

The clinicopathological features, surgical management, and disease outcomes of 13 patients with perforated gastric cancer from March 1989 to May 2003 were retrospectively analyzed. Disease outcomes were analyzed in-depth based on tumor stage, depth of tumor invasion, operative curability, and three treatment groups.

RESULTS

All 13 patients (median age of 72 years) received emergent laparotomy. Malignant gastric perforation was diagnosed intraoperatively in eight (61.5%) patients. Four patients whose frozen sections exhibited perforated gastric cancer underwent radical surgery with curative intent and were assigned to Group 1. Another four patients with overt distal metastases underwent palliative surgery and were assigned to Group 2. The remaining five patients were misdiagnosed as having benign gastric perforation and underwent local surgery; these patients were assigned to Group 3. All patients received follow-up for a median of 26 months. The survival rates for Stage I disease (P = 0.0342), T1/T2 tumors (P = 0.0342), and curative resection (P = 0.0012) significantly exceeded those of Stage III/IV, T3/T4 tumors, and non-curative resection. Additionally, the survival rates of Group 1 (P = 0.0067) and Group 3 (P = 0.0067) significantly exceeded those of Group 2. Stepwise logistic regression analysis revealed no significant predictor of prognosis.

CONCLUSIONS

In resectable cases, one-stage radical gastrectomy with possible extensive lymphadenectomy should be encouraged if conditions allow. In cases of misdiagnosis, non-radical local surgery with curative resection is sufficient to treat early-stage cancer.

Preoperative staging of gastric adenocarcinoma: comparison of helical CT and endoscopic US

PURPOSE

To compare the performance of helical computed tomography (CT) and endoscopic ultrasonography (US) in the preoperative staging of gastric cancer.

MATERIALS AND METHODS

Fifty-one consecutive patients with a primary malignant gastric tumor (stage T2-T4) were preoperatively evaluated with both helical CT and endoscopic US within 3 days. Each tumor was staged according to the TNM classification system with both modalities. All patients subsequently underwent surgery. Results of CT and endoscopic US were compared with histologic staging of tumor invasion depth and regional lymph node metastasis. For comparison of CT and endoscopic US data, the marginal homogeneity test was used, and a P value of less than.05 was determined to indicate statistical significance.

RESULTS

In comparison with histologic results, CT achieved correct T staging in 39 patients (76%) and correct N staging in 35 patients (70%). The corresponding results for endoscopic US achieved correct T staging in 44 patients (86%) and correct N staging in 45 patients (90%). There was no significant difference between T staging (P =.55) and N staging (P >.99). Because of challenging detection of wall layers, correct T staging was difficult for CT and endoscopic US in the differentiation of T2 and T3 lesions.

CONCLUSION

Compared with endoscopic US, helical CT focused on the stomach provides valuable results regarding T and N staging in patients with gastric cancer.