Prognostic indicators for survival after curative resection for patients with carcinoma of the stomach

Higher Risk of Lymph Node Metastasis in Young Patients with Early Gastric Cancer

Objective: Whether age affects lymph node metastasis (LNM) in patients with gastric cancer (GC) is currently inconclusive. This study investigates the effect of age on LNM in patients with GC. Methods: From January 1988 to December 2013, 22,808 GC patients underwent gastrectomy at the Surveillance, Epidemiology, and End Results database were included. The relationship between age and LNM was analyzed. Results: The median number of examined lymph nodes (ELNs) was 12 (interquartile range [IQR], 7-20) among the 22,808 patients with GC, and the median numbers of ELNs were 10 (IQR, 5-18), 12 (IQR, 6-19), 13 (IQR, 7-21) and 13 (IQR, 7-21) in patients with T1 to T4 disease, respectively. A total of 13,780 (60.4%) patients presented with LNM. The LNM rates were 69.6%, 66.1%, 64.7%, 61.8%, 57.8% and 55.6% for patients in the 20-39, 40-49, 50-59, 60-69, 70-79 and ≥ 80 age groups, respectively (P < 0.001). The LNM rates and the number of positive lymph nodes were correlated with age among patients whose diseases were of the same T stage (all P < 0.01). Multivariate analysis showed that age was an independent predictor for LNM in patients with early gastric cancer (EGC) (P < 0.05), and linear regression analysis showed that the LNM rate was higher in young patients with EGC (P < 0.05). Conclusions: Age is an independent predictor for LNM in EGC. Moreover, LNM is more common in young patients with EGC than in other age groups, which indicates that limited lymph node dissection may not be appropriate for young patients with EGC.

Preoperative Anemia or Low Hemoglobin Predicts Poor Prognosis in Gastric Cancer Patients: A Meta-Analysis

Background

The prognostic value of preoperative anemia in gastric cancer remains unclear. Therefore, the purpose of the present study is to evaluate the prognostic value of preoperative anemia in gastric cancer.

Methods

We searched Embase and PubMed databases for relevant studies from inception to March 2018. The prognostic value of preoperative anemia in gastric cancer was determined by calculating the hazard ratio (HR) and the corresponding 95% confidence interval (CI) as effect measures. A random effect model was used in cases in which there was significant heterogeneity; otherwise, a fixed effect model was used. Statistical analyses were performed using Stata software.

Results

Seventeen studies involving 13,154 gastric cancer patients were included. The estimated rate of preoperative anemia was 36% (95%CI = 27-44%). The overall survival of preoperative anemia was poor (HR = 1.33, 95%CI = 1.21-1.45). Moreover, disease-free survival was significantly lower in patients with preoperative anemia compared with those without this condition (HR = 1.62, 95%CI = 1.13-2.32). These findings were corroborated by the results of subgroup analyses.

Conclusions

The results indicate that preoperative anemia predicts poor prognosis in gastric cancer, including overall survival and disease-free survival. Therefore, preoperative anemia may be a convenient and cost-effective blood-derived prognostic marker for gastric cancer.

Implications of clinical research on adjuvant chemotherapy for gastric cancer: Where to go next?

Postoperative adjuvant chemotherapy (ACT) confers superior gastric cancer (GC) survival in the Eastern cohort. However, is the current standard of ACT already excessive, or is it still necessary to increase its intensity for specific subgroups? Tailored ACT strategies for GC depend on gradual exploration by clinical trials in selected patients. Thus, understanding the implications of previous and current research can help us respond wisely and design effective, rational trials, save medical resources and make better decisions in clinical practice. After reviewing and analyzing studies on ACT for GC patients undergoing curative resection, we found that research strategies for conducting “addition” ACT for specific stages of the disease have achieved great progress in making ACT more tailored and personalized in consideration of pathology stages. Furthermore, trials indicate that “addition” ACT strategies for GC patient subgroups based on histological characteristics might be helpful to move toward a more specific tailored and personalized management approach. Designing ACT research focused on different node statuses should also be conducted according to the biological specificity of lymph node (LN) metastasis. Therefore, future trials designed to determine tailored treatment based on histological and biological characteristics for specific subgroups are urgently needed and conducted as the theme of the 2019 American Society of Clinical Oncology (ASCO): Caring for Every Patient, Learning from Every Patient.

Adjuvant Therapy is Associated with Improved Survival in pT1N1 Gastric Cancer in a Heterogeneous Western Patient Population

BACKGROUND

Two recent South Korean studies showed adjuvant therapy (AT) was not associated with improved survival in pT1N1 gastric adenocarcinoma (GAC). We established the prognostic utility of lymph node status, determined the pattern of use of AT, and compared survival stratified by type of AT in pT1N1 GAC in a Western patient population.

METHODS

We identified patients with pT1N0 and pT1N1 GAC using the National Cancer Database from 2004 to 2012. Clinicopathologic variables, treatment regimens, and overall survival (OS) were compared.

RESULTS

We compared 4516 (86.6%) pT1N0 to 696 (13.4%) pT1N1 patients. pT1N1 tumors were larger (median size 2.5 vs. 1.8 cm, p < 0.001), more often poorly differentiated (56.2% vs. 39.6%, p < 0.001), and had higher median retrieved lymph nodes (RLN) (14 vs. 12, p < 0.001) compared with pT1N0. pT1N1 was associated with worse median overall survival (OS) (6.9 vs. 9.9 years for pT1N0, p < 0.001). pN1 was independently associated with worse OS (hazard ratio [HR] 2.17, 95% confidence interval [CI] 1.84-2.56). Increased RLN was associated with improved OS (HR 0.73, 95% CI 0.65-0.83). Among pT1N1 patients, 330 (47.4%) had observation (OBS), 77 (11.1%) received adjuvant chemotherapy (ACT), 68 (9.8%) received adjuvant radiation therapy (ART), and 221 (31.8%) received adjuvant chemoradiation therapy (ACRT). ACT and ACRT were independently associated with improved OS (HR 0.37, 95% CI 0.22-0.65 and HR 0.40, 95% CI 0.28-0.57).

CONCLUSIONS

pN1 was associated with worse survival and RLN ≥ 15 was associated with improved survival in pT1 GAC. ACT and ACRT were independently associated with improved survival in pT1N1 gastric cancer suggesting a valuable role in Western patients.

The Benefits of Resection for Gastric Carcinoma Patients with Non-curative Factors

The benefits of resection for gastric carcinoma patients with non-curative factors remain controversial. Thus, we evaluated the survival benefits of resection in these gastric carcinoma patients. We reviewed the hospital records of 467 gastric carcinoma patients with non-curative factors who had resection (n=305) and compared their clinicopathological findings with individuals (n=162) who underwent bypass or exploration from 1996 to 2010. The 3-year survival rate of patients who had resection was higher than was that of patients who did not (13.2 vs. 7.2%, respectively p<0.001). Cox's proportional hazard regression analysis revealed that only one factor was an independent, statistically significant prognostic parameter: the presence of peritoneal dissemination (risk ratio, 1.37; 95% confidence interval, 1.04–1.79; p<0.05). The 3-year survival rate of patients with peritoneal dissemination was higher in individuals who underwent resection compared with those who did not (9.5 vs. 4.7%, respectively; p<0.001). The current results highlight the improved survival rates of gastric carcinoma patients with non-curative factors who underwent surgery compared with those who did not. Although resection is not curative in this group of patients, we still recommend performing the procedure.

A clinical prognostic scoring system for resectable gastric cancer to predict survival and benefit from paclitaxel- or oxaliplatin-based adjuvant chemotherapy

Background

Gastrectomy with D2 lymphadenectomy is a standard procedure of curative resection for gastric cancer (GC). The aim of this study was to develop a simple and reliable prognostic scoring system for GC treated with D2 gastrectomy combined with adjuvant chemotherapy.

Methods

A prognostic scoring system was established based on clinical and laboratory data from 579 patients with localized GC without distant metastasis treated with D2 gastrectomy and adjuvant chemotherapy.

Results

From the multivariate model for overall survival (OS), five factors were selected for the scoring system: ≥50% metastatic lymph node rate, positive lymphovascular invasion, pathologic TNM Stage II or III, ≥5 ng/mL preoperative carcinoembryonic antigen level, and <110 g/L preoperative hemoglobin. Two models were derived using different methods. Model A identified low- and high-risk patients for OS (P<0.001), while Model B differentiated low-, intermediate-, and high-risk patients for OS (P<0.001). Stage III patients in the low-risk group had higher survival probabilities than Stage II patients. Both Model A (area under the curve [AUC]: 0.74, 95% confidence interval [CI]: 0.69–0.78) and Model B (AUC: 0.79, 95% CI: 0.72–0.83) were better predictors compared with the pathologic TNM classification (AUC: 0.62, 95% CI: 0.59–0.71, P<0.001). Adjuvant paclitaxel- or oxaliplatin-based or triple chemotherapy showed significantly better outcomes in patients classified as high risk, but not in those with low and intermediate risk.

Conclusion

A clinical three-tier prognostic risk scoring system was established to predict OS of GC treated with D2 gastrectomy and adjuvant chemotherapy. The potential advantage of this scoring system is that it can identify high-risk patients in Stage II or III who may benefit from paclitaxel- or oxaliplatin-based regimens. Prospective studies are needed to confirm these results before they are applied clinically.

Factors Associated With Recurrence and Survival in Lymph Node-negative Gastric Adenocarcinoma: A 7-Institution Study of the US Gastric Cancer Collaborative

OBJECTIVES

To determine pathologic features associated with recurrence and survival in patients with lymph node-negative gastric adenocarcinoma.

STUDY DESIGN

Multi-institutional retrospective analysis.

BACKGROUND

Lymph node status is among the most important predictors of recurrence after gastrectomy for gastric adenocarcinoma. Pathologic features predictive of recurrence in patients with node-negative disease are less well established.

METHODS

Patients who underwent curative resection for gastric adenocarcinoma between 2000 and 2012 from 7 institutions of the US Gastric Cancer Collaborative were analyzed, excluding 30-day mortalities and stage IV disease. Competing risks regression and multivariate Cox regression were used to determine pathologic features associated with time to recurrence and overall survival. Differences in cumulative incidence of recurrence were assessed using the Gray method (for univariate nonparametric analyses) and the Fine and Gray method (for multivariate analyses) and shown as subhazard ratios (SHRs) and adjusted subhazard ratios (aSHRs), respectively.

RESULTS

Of 805 patients who met inclusion criteria, 317 (39%) had node-negative disease, of which 54 (17%) recurred. By 2 and 5 years, 66% and 88% of patients, respectively, experienced recurrence. On multivariate competing risks regression, only T-stage 3 or higher was associated with shorter time to recurrence [aSHR = 2.7; 95% confidence interval (CI), 1.5-5.2]. Multivariate Cox regression showed T-stage 3 or higher [hazard ratio (HR) = 1.8; 95% CI, 1.2-2.8], lymphovascular invasion (HR = 2.2; 95% CI, 1.4-3.4), and signet ring histology (HR = 2.1; 95% CI, 1.2-3.6) to be associated with decreased overall survival.

CONCLUSIONS

Despite absence of lymph node involvement, patients with T-stage 3 or higher have a significantly shorter time to recurrence. These patients may benefit from more aggressive adjuvant therapy and postoperative surveillance regimens.

Survival after Gastrectomy in Node-Negative Gastric Cancer: A Review and Meta-Analysis of Prognostic Factors

Background

Lymph node metastasis is one of the most important prognostic factors for survival of patients with gastric cancer (GC) after surgical resection. Nevertheless, a considerable number of patients have node-negative disease. We performed the present systematic review to evaluate survival and identify prognostic factors in node-negative GC patients undergoing curative intent resection.

Material/Methods

Relevant studies published between January 2000 and January 2015 were identified by searching the PubMed database and reviewed systematically. Summary relative risks (RR) and 95% confidence intervals (95% CI) were estimated using random-effects models.

Results

Thirty observational studies involving 12 504 patients were included in the review. Median 5-year overall survival was 84.3% (range, 53–96.3%). Pooled analysis showed that old age (RR, 1.26; 95%CI, 1.13–1.42), <D2 lymph node dissection (1.28; 1.05–1.55), larger tumor (1.18; 1.10–1.26), serosal invasion (2.03; 1.68–2.44), lymphatic invasion (1.25; 1.00–1.57), vascular invasion (1.67; 1.19–2.34), and lymphovascular invasion (1.93; 1.20–3.10) were significant association with decreased survival.

Conclusions

Surgical resection offers good overall survival for patients with node-negative GC. Tumor-related factors seem to have most prognostic significance.

Impact of pre-existing type-2 diabetes on patient outcomes after radical resection for gastric cancer: a retrospective cohort study

BACKGROUND

The aim of this study was to evaluate the impact of pre-existing type-2 diabetes on postoperative recovery and prognosis in gastric cancer (GC) patients who underwent radical gastrectomy.

RESEARCH DESIGN AND METHODS

From June 2001 to June 2011, a total of 1,014 eligible patients were enrolled. Among them, 67 patients were diagnosed with type-2 diabetes. The clinicopathologic features and prognostic data were compared between patients with type-2 diabetes (the DM group) and without diabetes (the non-DM group).

RESULTS

Median survival was 68.3 months. The 5-year overall survival in the DM group was similar to that in the non-DM group (52.1 vs. 53.0 %, p = 0.411). Propensity score matching analysis demonstrated that the hazard ratio of death in the DM group was 1.191 (95 % confidential index 0.693-2.072; p = 0.531) compared to the-non DM group. Incidence of postoperative complications was higher in the DM group than in the non-DM group (17.9 vs. 8.1 %, p = 0.006). The DM remission rate was 46 % among patients who received Roux-en-Y reconstruction, and 13 % among patients who received Billroth II anastomosis (p = 0.009). The 5-year overall survival rate was 62.1 % for patients with cured or improved DM and 23.4 % for patients with worse or same DM status (p = 0.003).

CONCLUSION

Type-2 diabetes can be cured by radical gastrectomy plus Roux-en-Y reconstruction in some GC patients. Pre-existing diabetes is associated with increased postoperative complications and decreased survival when it becomes worse after curative dissection for GC.

Does D2 plus para-aortic nodal dissection surgery offer a better survival outcome compared to D2 surgery only for gastric cancer consistently? A definite result based on a hospital population of nearly two decades

BACKGROUND AND AIMS

Curative resection is the treatment of choice for gastric cancer. Although it has been concluded that D2 lymphadenectomy plus para-aortic nodal dissection does not improve survival rate in curable gastric cancer, it is unclear whether D2 plus para-aortic nodal dissection has a benefit in some groups of patients. We conducted a retrospective study in our hospital, in which we compared D2 with D2 plus para-aortic nodal dissection lymphadenectomy for gastric cancer in subgroups of each clinical characteristic in terms of long-term survival after surgery.

MATERIAL AND METHODS

We selected 1792 patients who had undergone the treatment with curative intent between 1990 and 2007, 1344 in the D2 group and 448 in the D2 plus para-aortic nodal dissection group. Each procedure was verified by pathological analyses. The primary end points were 5-year overall survival.

RESULTS AND CONCLUSIONS

Median follow-up periods were 50 months for patients assigned to D2 group and 54 months for patients assigned to D2 plus para-aortic nodal dissection group. Overall 5-year survival was not significantly higher in patients assigned to D2 plus para-aortic nodal dissection surgery compared to those assigned to D2 surgery (31.2% (95% confidence interval: 19.8%-42.6%) vs 26.6% (95% confidence interval: 20.3%-32.9%); log-rank p = 0.433). D2 plus para-aortic nodal dissection surgery should only be used for curable gastric cancer of T3-4 and N2 stage and should not be used for T1 disease and total gastrectomy.

Cancer spheres from gastric cancer patients provide an ideal model system for cancer stem cell research

Cancer stem cells have been hypothesized to drive the growth and metastasis of tumors. Because they need to be targeted for cancer treatment, they have been isolated from many solid cancers. However, cancer stem cells from primary human gastric cancer tissues have not been isolated as yet. For the isolation, we used two cell surface markers: the epithelial cell adhesion molecule (EpCAM) and CD44. When analyzed by flow cytometry, the EpCAM(+)/CD44(+) population accounts for 4.5% of tumor cells. EpCAM(+)/CD44(+) gastric cancer cells formed tumors in immunocompromised mice; however, EpCAM(-)/CD44(-), EpCAM(+)/CD44(-) and EpCAM(-)/CD44(+) cells failed to do so. Xenografts of EpCAM(+)/CD44(+) gastric cancer cells maintained a differentiated phenotype and reproduced the morphological and phenotypical heterogeneity of the original gastric tumor tissues. The tumorigenic subpopulation was serially passaged for several generations without significant phenotypic alterations. Moreover, EpCAM(+)/CD44(+), but not EpCAM(-)/CD44(-), EpCAM(+)/CD44(-) or EpCAM(-)/CD44(+) cells grew exponentially in vitro as cancer spheres in serum-free medium, maintaining the tumorigenicity. Interestingly, a single cancer stem cell generated a cancer sphere that contained various differentiated cells, supporting multi-potency and self-renewal of a cancer stem cell. EpCAM(+)/CD44(+) cells had greater resistance to anti-cancer drugs than other subpopulation cells. The above in vivo and in vitro results suggest that cancer stem cells, which are enriched in the EpCAM(+)/CD44(+) subpopulation of gastric cancer cells, provide an ideal model system for cancer stem cell research.

Downregulation of metastasis suppressor 1(MTSS1) is associated with nodal metastasis and poor outcome in Chinese patients with gastric cancer

Background

The putative tumor metastasis suppressor 1(MTSS1) is an actin-binding scaffold protein that has been implicated to play an important role in carcinogenesis and cancer metastasis, yet its role in the development of gastric cancer has not been well illustrated. In this study, we detected MTSS1 expression and explored its clinical significance in gastric cancer.

Methods

Immunohistochemistry was performed using tissue microarrays containing gastric adenocarcinoma specimens from 1,072 Chinese patients with normal adjacent mucosa, primary gastric cancer and lymph node (LN) metastasis and specific antibody against MTSS1. MTSS1 mRNA and protein expression were detected by reverse transcription-polymerase chain reaction and Western blotting. The clinical follow-up was done in the 669 patients living in Shanghai that was chose from the 1072 cases.

Results

Complete loss of MTSS1 expression was observed in 751 cases (70.1%) of the 1,072 primary tumors and 103 (88%) of 117 nodal metastases; and loss of MTSS1 expression was significantly associated with poorly differentiated tumors, large tumor size, deep invasion level, the presence of nodal metastases and advanced disease stage. Moreover, multivariate analysis demonstrated that loss of MTSS1 expression correlated significantly with poor survival rates (RR = 0.194, 95% CI = 0.144-0.261, P < 0.001).

Conclusions

MTSS1 expression decreased significantly as gastric cancer progressed and metastasized, suggesting MTSS1 may serve as a useful biomarker for the prediction of outcome of gastric cancer.

R0 resection in the treatment of gastric cancer: Room for improvement

Gastric carcinoma is one of the most frequent malignancies in the world and its clinical behavior especially depends on the metastatic potential of the tumor. In particular, lymphatic metastasis is one of the main predictors of tumor recurrence and survival, and current pathological staging systems reflect the concept that lymphatic spread is the most relevant prognostic factor in patients undergoing curative resection. This is compounded by the observation that two-thirds of gastric cancer in the Western world presents at an advanced stage, with lymph node metastasis at diagnosis. All current therapeutic efforts in gastric cancer are directed toward individualization of therapeutic protocols, tailoring the extent of resection and the administration of preoperative and postoperative treatment. The goals of all these strategies are to improve prognosis towards the achievement of a curative resection (R0 resection) with minimal morbidity and mortality, and better postoperative quality of life.

Does D3 surgery offer a better survival outcome compared to D1 surgery for gastric cancer? A result based on a hospital population of two decades as taking D2 surgery for reference

Background

We conducted a retrospective study in our hospital in which we compared D1 with D3 through D2 lymphadenectomy for gastric cancer in terms of morbidity, postoperative mortality, long-term survival after surgery.

Methods

567 patients who were performed curative intent between 1980 and 2003 were enrolled. 187 in the D1 group, 189 in the D2 group and 191 in the D3 group. Every procedure was verified by pathological analyses. The primary endpoints were 5-year overall survival.

Results

Median follow-up periods were 36 months and 60 months for D1 group and D3 group. Overall 5-year survival rate was significantly higher in patients underwent D3 surgery than in those performed D1 surgery (37.4% vs 48.7%; log-rank, p = 0.027). For the cases followed up to 120 months, the 10-year overall survival rate was 29% (95% CI, 22.1% to 35.9%) for the D1 group and 33.7% (95% CI, 26.6% to 40.8%) for the D3 group (log-rank, p = 0.005).

Conclusions

D1 surgery should be operated only for patients with Borrmann I disease. As D3 gastrectomy is associated with low mortality and adequate survival times when performed in selected institutions that have had sufficient experience with the operation and with postoperative management, we recommend D3 lymphadenectomy for patients with curable gastric cancer.

Effective reduction of gastric cancer risk with regular use of nonsteroidal anti-inflammatory drugs in Helicobacter pylori-infected patients

PURPOSE

Nonsteroidal anti-inflammatory drugs (NSAIDs) play protective roles in gastric carcinogenesis. However, the interaction between NSAIDs and Helicobacter pylori (H pylori) infection and the number needed to treat to prevent gastric cancer remains unclear.

PATIENTS AND METHODS

We conducted a nationwide retrospective cohort study based on data from the Taiwan National Health Insurance Database. Hospitalized patients with a primary diagnosis of peptic ulcer disease were selected. Overall, 52,161 patients were divided into non-NSAID user and regular NSAID user cohorts. Standardized incidence ratios (SIRs), cumulative incidences, and hazard ratios (HRs) were calculated.

RESULTS

Patients with peptic ulcers who never used NSAIDs had higher risk of gastric cancer compared with the general population (SIR, 2.11; 95% CI, 2.07 to 2.15), but regular NSAID use conferred lower risk (SIR, 0.79; 95% CI, 0.77 to 0.81). The protective role of NSAID use was observed in patients with gastric ulcer, but not in patients with non-H pylori-associated duodenal ulcer. On multivariate analysis, regular NSAID use was an independent protective factor for gastric cancer development (HR, 0.79 for each incremental year; P < .001), especially in H pylori-associated patients (HR, 0.52 for each incremental year; P < .001). Among patients with H pylori-infected gastric ulcers, the NNT to prevent a gastric cancer was 50.

CONCLUSION

Regular NSAID use may be a feasible way to prevent gastric cancer, at least in patients with gastric ulcers, and especially in H pylori-infected subjects.

Should direct mesocolon invasion be included in T4 for the staging of gastric cancer?

BACKGROUND AND OBJECTIVES

One of the sites most frequently invaded by gastric cancer is the mesocolon; however, the UICC does not mention this anatomical site as an adjacent structure involved in gastric cancer. The purpose of this study was to characterize and classify mesocolon invasion from gastric cancer.

METHODS

We examined 806 patients who underwent surgery for advanced gastric carcinoma from 1992 to 2007 at the Department of Surgery, Gangnam Severance Hospital, Korea. Among these, patients who showed macroscopically direct invasion into the mesocolon were compared to other patients with advanced gastric cancer.

RESULTS

The curability, number and extent of nodal metastasis, and the survival of the mesocolon invasion group were significantly worse than these factors in the T3 group. However, the survival of the mesocolon invasion group after curative resection was much better than that of patients who had incurable factors.

CONCLUSIONS

Mesocolon invasion should be included in T4 for the staging of gastric cancer.

Overexpression of stathmin1 in the diffuse type of gastric cancer and its roles in proliferation and migration of gastric cancer cells

BACKGROUND

Stathmin1 is a microtubule-regulating protein that has an important role in the assembly and disassembly of the mitotic spindle. The roles of stathmin1 in carcinogenesis of various cancers, including prostate and breast cancer, have been explored. However, its expression and roles in gastric cancer have not yet been described.

METHODS

Stathmin1 expression in paraffin-embedded tissue sections from 226 patients was analysed by immunohistochemistry. Roles of stathmin1 were studied using a specific small interfering RNA (siRNA).

RESULTS

The expression of stathmin1 was positively correlated with lymph node metastasis, TNM stages and vascular invasion, and negatively with recurrence-free survival, in the diffuse type of gastric cancer. The median recurrence-free survival in patients with a negative and positive expression of stathmin1 was 17.0 and 7.0 months, respectively (P=0.009). When the expression of stathmin1 was knocked down using siRNA, the proliferation, migration and invasion of poorly differentiated gastric cancer cells in vitro were significantly inhibited. Moreover, stathmin1 siRNA transfection significantly slowed the growth of xenografts in nude mice.

CONCLUSION

These results suggest that stathmin1 can be a good prognostic factor for recurrence-free survival rate and is a therapeutic target in diffuse-type gastric cancer.

Surgical outcomes and prognostic factors for T4 gastric cancers

PURPOSE

In locally advanced gastric carcinomas that have invaded adjacent organs, the prognosis is poor. When combined resections are performed in T4 gastric cancers, a high morbidity rate is reported and it is inconclusive as to whether or not there is an improvement in the survival rate. We investigated surgical outcomes and analysed the prognostic factors for T4 gastric cancers.

PATIENTS AND METHODS

Between January 1992 and December 2000, 132 patients underwent surgery for T4 gastric cancer; they were divided into three groups: combined resections in group I, gastrectomy alone in group II, and resections not performed but palliative gastrojejunostomy or intraperitoneal chemotherapy in group III. Surgical outcomes and clinicopathologic factors were compared and prognostic factors were evaluated.

RESULTS

Among the three groups, statistically significantly different factors were tumour location, Borrmann type, tumour size, distant metastasis and peritoneal metastasis. The most commonly resected organ was the transverse colon, and 14 post-operative morbidities developed. In the multivariate analysis, the treatment group and curability were proved to be independent prognostic factors.

CONCLUSION

In patients with T4 gastric carcinoma, an aggressive surgical approach can be beneficial when curative resection is performed. If curative resection is not possible, palliative resection can be performed for a better quality of life.

Early Helicobacter pylori eradication decreases risk of gastric cancer in patients with peptic ulcer disease

BACKGROUND & AIMS

Helicobacter pylori (H pylori) is a risk factor for gastric cancer. We investigated whether early H pylori eradication is associated with gastric cancer risk in patients with peptic ulcer diseases.

METHODS

This nationwide cohort study was based on the Taiwan National Health Insurance Database (NHID), which provided data on 80,255 patients who were hospitalized for the first time between 1997 and 2004 with a primary diagnosis of peptic ulcer diseases and received H pylori eradication therapy. The patient population was divided into early (within 1 year) and late (after 1 year) eradication cohorts; standardized incidence ratios (SIRs) and hazards ratios (HRs) were determined.

RESULTS

There was no significant difference in gastric cancer risk between patients who received early H pylori eradication and the general population (SIR, 1.05; 95% confidence interval [CI]: 0.96-1.14), but late eradication was associated with an increased risk (SIR, 1.36; 95% CI: 1.24-1.49). In gastric ulcer patients who received early eradication, SIRs of gastric cancer decreased from 1.60 at 3-4 years to 1.05 at 7-10 years after hospitalization; the SIRs decreased from 0.57 to 0.33 for duodenal ulcer patients over the same period. Among patients who received late eradication, SIRs decreased from 2.14 to 1.32 for those with gastric ulcers and from 0.90 to 0.66 for those with duodenal ulcers. Early H pylori eradication (HR, 0.77) and frequent aspirin or nonsteroidal anti-inflammatory drug use (HR, 0.65) were independent protective factors for gastric cancer.

CONCLUSIONS

Early H pylori eradication is associated with decreased risk of gastric cancer in patients with peptic ulcer diseases.

Factors affecting recurrence in node-negative advanced gastric cancer

BACKGROUND AND AIM

Prognostic factors of lymph node-negative gastric adenocarcinoma after curative resection have been discussed. Recurrent pattern of advanced lymph node-negative gastric cancer after curative resection has rarely been described.

METHODS

Recurrent sites and correlated clinicopathological factors of 372 patients with lymph node-negative advanced gastric adenocarcinoma that underwent R0 resection from 1988 to 2005 were analyzed.

RESULTS

Recurrence was noted in 51 (13.7%) patients. Recurrent rates according to site of recurrence were 26 peritoneal seeding (51.0%), 26 locoregional (51.0%), 17 hematogenous (33.3%), and 4 lymph node metastasis (7.8%). Clinicopathological factors to predict peritoneal seeding were serosal exposure, lymphovascular invasion, Lauren's diffuse type differentiation and scirrhous stromal reaction. Serosal exposure, tumor size, microscopic infiltrating growth type predicts locoregional recurrence. Tumor had only lymphovascular invasion predict hematogenous spreading.

CONCLUSION

Node-negative advanced gastric cancer has more peritoneal seeding and locoregional recurrence. Aggressive cell behavior predicted the route of tumor cell spreading.

Hedgehog signaling regulates the survival of gastric cancer cells by regulating the expression of Bcl-2

Gastric cancer is the second most common cause of cancer deaths worldwide. The underlying molecular mechanisms of its carcinogenesis are relatively poorly characterized. Hedgehog (Hh) signaling, which is critical for development of various organs including the gastrointestinal tract, has been associated with gastric cancer. The present study was undertaken to reveal the underlying mechanism by which Hh signaling controls gastric cancer cell proliferation. Treatment of gastric cancer cells with cyclopamine, a specific inhibitor of Hh signaling pathway, reduced proliferation and induced apoptosis of gastric cancer cells. Cyclopamine treatment induced cytochrome c release from mitochondria and cleavage of caspase 9. Moreover, Bcl-2 expression was significantly reduced by cyclopamine treatment. These results suggest that Hh signaling regulates the survival of gastric cancer cells by regulating the expression of Bcl-2.

Tissue microarray analysis reveals strong clinical evidence for a close association between loss of annexin A1 expression and nodal metastasis in gastric cancer

AIMS

Annexin A1 (ANXA1) is a calcium- and phospholipid-binding protein that has been implicated in the regulation of inflammation, cell proliferation, and apoptosis. Its role in tumor development and progression is controversial, whereas its role in gastric cancer is unknown. We investigated ANXA1 expression and determined its clinical significance in gastric cancer.

METHODS AND RESULTS

Tissue microarray blocks containing primary gastric cancer, lymph node metastasis, and adjacent normal mucosa specimens obtained from 1,072 Chinese patients were constructed. Expression of ANXA1 in these specimens was analyzed using immunohistochemistry. Complete loss of ANXA1 expression was observed in 691 (64%) of the 1,072 primary tumors and 146 (86%) of 169 nodal metastases. Loss of ANXA1 expression was significantly associated with advanced T stage, lymph node metastasis, advanced disease stage, and poor histological differentiation. Loss of ANXA1 expression correlated significantly with poor survival rates in both univariate and multivariate analyses.

CONCLUSIONS

ANXA1 expression decreased significantly as gastric cancer progressed and metastasized, suggesting the importance of ANXA1 as a negative biomarker for gastric cancer development and progression.

Role of symptoms in diagnosis and outcome of gastric cancer

Gastric cancer is one of the most common cancers and the second most common cause of cancer deaths worldwide. Apart from Japan, where screening programmes have resulted in early diagnosis in asymptomatic patients, in most countries the diagnosis of gastric cancers is invariably made on account on dyspeptic and alarm symptoms, which may also be of prognostic significance when reported by the patient at diagnosis. However, their use as selection criteria for endoscopy seems to be inconsistent since alarm symptoms are not sufficiently sensitive to detect malignancies. In fact, the overall prevalence of these symptoms in dyspeptic patients is high, while the prevalence of gastro-intestinal cancer is very low. Moreover, symptoms of early stage cancer may be indistinguishable from those of benign dyspepsia, while the presence of alarm symptoms may imply an advanced and often inoperable disease. The features of dyspeptic and alarm symptoms may reflect the pathology of the tumour and be of prognostic value in suggesting site, stage and aggressiveness of cancer. Alarm symptoms in gastric cancer are independently related to survival and an increased number, as well as specific alarm symptoms, are closely correlated to the risk of death.Dysphagia, weight loss and a palpable abdominal mass appear to be major independent prognostic factors in gastric cancer, while gastro-intestinal bleeding, vomiting and also duration of symptoms, do not seem to have a relevant prognostic impact on survival in gastric cancer.

Quality of life after curative gastrectomy for gastric cancer in a randomised controlled trial

Quality of life (QOL) was studied in gastric cancer patients treated on a randomised, controlled trial comparing D1 (level 1) with D3 (levels 1, 2 and 3) lymphadenectomy. A total of 221 patients were randomly assigned to D1 (n=110) and D3 (n=111) surgery. Quality-of-life assessments included functional outcomes (a 14-item survey about treatment-specific symptoms) and health perception (Spitzer QOL Index) was performed before and after surgery at disease-free status. Patients suffered from irrelative events such as loss of partners was excluded thereafter. Main analyses were done by intention-to-treat. Thus, 214 D1 (106/110=96.4%) and D3 (108/111=97.3%) R0 patients were assessed. Longitudinal analysis showed that functional outcomes decreased at 6 months after surgery and increased over time thereafter, while health perceptions increased over time in general. On the basis of linear mixed model analyses, patients having total gastrectomy, advanced cancer and hemipancreaticosplenectomy, but not complications had poorer QOL than those without. D1 and D3 patients showed no significant difference in QOL. The results suggest that changes of QOL were largely due to scope of gastric resection, disease status and distal pancreaticosplenectomy, rather than the extent of lymph node dissection. This indicates that nodal dissection can be performed for a potentially curable gastric cancer.

Ratio of metastatic lymph nodes: impact on staging and survival of gastric cancer

AIMS

No consensus exists on the level and number of lymph nodes to be dissected and examined for accurate staging of patients with resectable gastric cancer. The aim of this study was to examine the prognostic value and staging accuracy of the metastatic lymph nodes ratio (NR).

METHODS

The postoperative survival of 247 patients with gastric cancer who underwent gastrectomy was analyzed. Lymph nodes status was assigned according to three different classifications: 6th UICC/AJCC TNM; JGCA; NR (NR0: 0%; NR1: < or =20%; NR2: >20%). Staging accuracy of the three classifications was compared according to patients survival.

RESULTS

A significant difference in survival was observed in patients with NR1 versus NR2. At multivariate analysis only NR along with pT and grading were found to be independent prognostic factors. Stage migration was present in 84 cases (51%) with JGCA classification, in 30 (19%) with 6th UICC/AJCC TNM classification and in only 18 cases (11%) when NR was applied.

CONCLUSIONS

Our data showed that NR is a simply reproducible and highly reliable staging system with a strong ability to predict patients' outcome. Compared to other nodal staging classifications, NR is less influenced from the number of the lymph nodes dissected and examined, reducing the stage migration phenomenon.

Survival predictors in patients with node-negative gastric carcinoma

BACKGROUND

Presence or absence of nodal metastasis influences outcome of gastric cancer patients. This study gives insight into survival predictors and clinicopathological features of node-negative gastric adenocarcinoma.

METHODS

Between 1988 and 1999, 689 gastric cancer patients without other cancer or gastrectomy for benign disease who underwent curative resection were enrolled in this study. Clinicopathological data in patients with node metastasis were compared with those without.

RESULTS

The survival rate at 5 and 10 years for node-negative cases was 91.7% and 89.7%, respectively. On univariate analysis, node-negative patients were characterized by frequent location in the lower two-thirds of the stomach (84.9%), tumor size less than 4 cm (63.5%), grossly superficial type (71.6%), more medullary stromal reaction (50.5%) and intestinal type (67.7%), tumor invasion confined to serosa (78.4%), less poorly differentiated cell type (43.2%), and less lymphovascular invasion (33.4%). Multivariate analysis demonstrated that lymphovascular invasion (relative risk: 5.036) and depth of cancer invasion (relative risk: 4.404) were independent poor prognostic factors. However, lymphovascular invasion and serosal invasion were also correlated (P < 0.001).

CONCLUSION

Patients with node-negative gastric adenocarcinoma had less disease progression and a favorable survival. Lymphovascular invasion and depth of cancer invasion were two independent but correlated survival predictors.

Outcome of distal gastric cancer with pyloric stenosis after curative resection

AIMS

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Results following resection for stage IV gastric cancer; are better outcomes observed in selected patient subgroups?

BACKGROUND

Patients who present with stage IV gastric cancer are not commonly managed with surgical resection as effective palliation can usually be accomplished with systemic chemotherapy, endoscopic stenting, or surgical bypass procedures. Given the inherent morbidity and mortality associated with gastrectomy, palliative resection for stage IV gastric cancer should be reserved for ideal surgical candidates who are most likely to benefit from the procedure. The purpose of this study is to review outcomes following resection for stage IV gastric cancer, and to identify criteria predictive of improved outcomes following gastrectomy in this setting.

METHODS

A retrospective review of a prospective GI oncology database was conducted. Sixty-three patients with stage IV gastric cancer managed with surgical resection between 1989 and 2001 were identified. Variables including demographic data, patterns of distant spread (ex: peritoneal, lymphatic, hematogenous), location of tumor, and type of gastrectomy were utilized to conduct survival analyses.

RESULTS

Actuarial survival for all patients at one and 3-year intervals was 52% and 12%, respectively. Improved survival was observed for patients of East Asian race (median survival 20 vs. 12 months, P < 0.05, students t-test) and age less than 60 years (median survival 15 vs. 12 months, P < 0.05). This trend was also illustrated by Kaplan-Meier survival analysis. Other variables including pattern of distant spread, location of tumor, and type of gastrectomy were not associated with a significant difference in survival. Both East Asian race and age less than 60 years were statistically significant predictors of improved survival when assessed by univariate regression analysis. When variables were analyzed in a multivariate regression analysis, Asian race and age <60 both lost their statistical significance as independent predictors of improved survival.

CONCLUSIONS

Long-term survival for patients with stage IV gastric cancer who are managed with surgical resection is achievable. Patient specific variables including East Asian race and age less than 60 years appear to be associated with prolonged survival when assessed by comparison of means, Kaplan-Meier analysis, and univariate regression analysis. However, multivariate regression analysis failed to demonstrate these factors as independent predictors of improved outcome. In conclusion, highly selected acceptable risk surgical candidates with stage IV gastric cancer should be considered for management with surgical resection in clinically appropriate scenarios.

T4 gastric carcinoma: the benefit of non-curative resection

BACKGROUND

The prognosis of patients with gastric carcinoma with invasion of the adjacent organs (T4 gastric carcinoma) is very poor. We evaluated the survival benefit of resection in this group of patients.

METHOD

We retrospectively reviewed the hospital records of 288 patients with T4 gastric carcinoma to compare the clinicopathological results in patients with curative resection (n = 95) with patients with non-curative resection (n = 193) during the period 1986-2000.

RESULTS

With a 33% curative resectability in patients with T4 gastric carcinoma, patients with tumour resection (curative and non-curative) had a significantly improved survival rate. The overall survival rate was higher for patients who underwent resection (11.6%) than for patients who were not resected (2.5%), regardless of curability (P < 0.001). Using Cox's proportional hazard regression model, lymph node invasion and curability were independent statistically significant prognostic parameters. The prognosis of patients with invasion to the peritoneum and adrenal glands was significantly poorer than that of patients in whom there was no such invasion. But, the number of organs invaded had no effect on patient survival.

CONCLUSIONS

Patients with T4 gastric carcinoma might be benefited from curative resection. The results also emphasize the improved survivorship of T4 gastric carcinoma patients with resection compared with those who did not undergo resection. Although curative resection cannot be undertaken in patients with T4 gastric carcinoma, we recommend performing resection in patients with locally advanced gastric carcinoma, regardless of curability.

Surgical outcomes in patients with T4 gastric carcinoma

BACKGROUND

There is controversy about the best therapeutic surgical approach for treatment of patients with T4 gastric cancer.

STUDY DESIGN

We used univariate and multivariate analyses to review the surgical outcomes and prognostic factors of 117 patients who underwent surgery for T4 gastric carcinoma.

RESULTS

Curative resection was performed in 38 (32.4%) patients, with the pancreas being the most frequently resected organ. The 5-year survival rate was 16.0% and the median survival time (MST) was 11 months for all 117 registered patients. The 5-year survival rates and MSTs in patients after curative and noncurative resection were 32.2% versus 9.5% and 20 months versus 8 months, respectively. These values differed considerably between the two groups (p < 0.0001). Curability was an independent prognostic factor among all registered patients, including those who underwent noncurative resection. A relatively small tumor diameter (< 100 mm) and few lymph node metastases (six or fewer metastatic lymph nodes) were independent prognostic factors when curative resection could be performed. Postoperative morbidity and mortality were acceptable after curative combined resection.

CONCLUSIONS

We recommend the use of aggressive combined resection of adjacent organs, with extended lymph node dissection, for patients with T4 gastric carcinoma in whom curative resection can be used; that is, those with few metastatic lymph nodes (six or less) and a relatively small tumor diameter (100 mm). But noncurative resection should be avoided in patients with T4 gastric cancer.

[Tumor volume in advanced gastric cancer as a prognostic factor correlating with lymph node involvement]

INTRODUCTION

It has been established that measurement of tumor volume, rather than its diameter, is a better indicator of the depth of tumor invasion and lymph node involvement. The present study evaluates the significance of tumor volume as a prognostic factor in gastric cancer.

MATERIAL AND METHODS

This prospective clinical trail included 87 patients with gastric cacncer admitted to Surgery Clinic "Dr. Dragisa Misović" in Belgrade from 1998 to 2003. All patients were evaluated by standard diagnostic procedures, and after that underwent radical surgical treatment. Oncologic-surgical principles recommended by Japanese Research Society for Gastric Cancer were respected. Tumor volume was determined by measurement of specimens that had been obtained during surgery and by histopathological analysis. These criteria were analyzed and correlated with the lymph node status and clinicopathological factors.

RESULTS

Single-factor analysis showed that lymph node metastases correlated with larger tumor diameter, larger tumor volume, depth of tumor invasion, diffuse and low-grade differentiation of the intestinal type of gastric carcinoma. Using a linear correlation coefficient, it was found that there was a highly significant correlation of tumor volume and number of metastatic nodes in groups between lymph nodes r = 0.567; p < 0.0001 in drainage group 1, r = 0.511; p < 0.0001 in drainage group II, r = 0.579; p < 0.0001 in drainage group III. Also, there was highly significant correlation with the total number of metastatic nodes (r = 0.577; p < 0.0001) and significant correlation with the depth of tumor invasion and tumor diameter (p < 0.05). With 97% sensitivity and 88% specificity, "cut off" point was established by determining the tumor volume above which there were metastases into lymph nodes. In this study that volume was 2750 cmm.

CONCLUSION

Tumor volume can be used as a valuable prognostic factor for advanced gastric cancer, and hopefully it will be calculated preoperatively by 3D-EUS volumetric analysis.

Mitochondrial DNA mutations and mitochondrial DNA depletion in gastric cancer

Gastric carcinoma is one of the most common types of cancer in Taiwan. Somatic mitochondrial DNA (mtDNA) alteration in gastric carcinoma and its association with clinicopathologic features remain unclear. When we used polymerase chain reaction (PCR) and direct sequencing, 15 of the 31 (48%) gastric carcinomas displayed somatic mutations in the D-loop region, a hot spot for mutations in mtDNA of human cancers. Ten (67%) cancers with the somatic mutations in the D-loop had insertion or deletion mutations in nucleotide position (np) 303-309 in the mononucleotide repeat region. One carcinoma carried tandem duplication and triplication flanked by mononucleotide repeats starting at np 311 and 568, respectively, in the D-loop. We also detected the common 4,977-bp deletion in 17 (55%) of the noncancerous tissue samples, but only in three (9%) carcinomas. Moreover, we quantified the mtDNA content using a competitive PCR technique and found that mtDNA depletion occurred in 17 (55%) of the gastric carcinomas. Although no significant association was found between clinicopathologic features and the mtDNA mutations in the D-loop, mtDNA depletion was observed significantly in the ulcerated, infiltrating (Borrmann's type III) and diffusely thick (Borrmann's type IV) types of gastric carcinomas (P = 0.018). Our results suggest that somatic mtDNA mutations and mtDNA depletion occur in gastric cancer and that mtDNA depletion is involved in carcinogenesis and/or cancer progression of gastric carcinoma.

Pretreatment anemia is associated with poorer survival in patients with stage I and II gastric cancer

BACKGROUND AND OBJECTIVES

A negative correlation between anemia and outcome has been demonstrated in various cancers treated with radiotherapy. However, it is rarely studied whether this correlation may exist in surgical setting. Our aim was to investigate the relationship between pretreatment anemia and survival in surgically treated patients with gastric cancer.

METHODS

A total of 1,688 patients who had undergone curative resection for gastric cancer between 1991 and 1995 were reviewed. Anemia was defined as a hemoglobin level <12.0 g/dl. The influence of anemia on patient overall survival was evaluated by univariate and multivariate analysis.

RESULTS

Pretreatment anemia was present in 39.9% of the patients. The 10-year overall survival rate in anemic patients was 48.2% as compared with 62.6% in nonanemic patients (P < 0.001). In subgroup analysis according to the stage, the significant difference in 10-year overall survival rate between anemic and nonanemic patients was found in stage I and II gastric cancer (76.1% vs. 83.5% in stage I, P = 0.030; 55.1% vs. 67.2% in stage II, P = 0.043). On multivariate analysis, anemia was an independent prognostic predictor in patients with stage I and II disease (P = 0.007; RR, 1.466; 95% CI, 1.109-1.937).

CONCLUSIONS

Pretreatment anemia was found to have an independent relationship to the long-term survival of patients with stage I and II gastric cancer.

Identifying patterns of DNA for tumor diagnosis using capillary electrophoresis-amplified fragment length polymorphism (CE-AFLP) screening

Amplified Fragment Length Polymorphism (AFLP) screening is a genome-wide genotyping strategy that has been widely used in plants and bacteria, but little has been reported concerning its use in humans. We investigated if the AFLP procedure could be coupled with high-throughput capillary electrophoresis (CE) for use in tumor diagnosis and classification. Using CE-AFLP, a series of molecular 'fingerprints' were generated for a set of gastric tumor and normal genomic DNA samples. The CE-AFLP procedure was qualitatively and quantitatively robust, and a variety of clustering tools were used to identify a specific DNA marker 'pattern' of 20 features that classified the tumor and normal samples to reasonable degrees of accuracy (Sensitivity 95%, Specificity 80%). The CE-AFLP-based approach also correctly classified 16 tumor samples, which in a previous study had exhibited no detectable genomic aberrations by comparative genome hybridization (CGH). This is the first reported application of CE-AFLP screening in tumor diagnosis. As the procedure is relatively inexpensive and requires minimal prior sequence knowledge and biological material, we suggest that CE-AFLP-based protocols may represent a promising new approach for DNA-based cancer screening and diagnosis.

Overexpression of rho effector rhotekin confers increased survival in gastric adenocarcinoma

Like many epithelial-derived cancers, gastric cancer (GC) results from a multistep tumorigenic process. However, the detailed mechanisms involved in GC formation are poorly characterized. Using an ordered differential display method, we have identified rhotekin (RTKN), the gene coding for the Rho effector, RTKN, as one of the genes differentially expressed in human GC. Northern analysis using human multiple tissue blots showed that RTKN is predominantly expressed in the kidney and spinal cord, and, to a lesser degree, in the thyroid, tongue, liver, brain, prostate, trachea, and stomach. RT-PCR analysis confirmed that RTKN was overexpressed in most (5/7; 71%) GC examined. By analyzing the Stanford Microarray Database for the expression profiles of gastric tissues, we also found a progressional increase in RTKN expression in nonneoplastic mucosa, GC, and then lymph node metastases (p < 0.005 by Jonckheere-Terpstra test), suggesting that RTKN expression correlates with GC progression. The role of RTKN in the pathogenic development of GC was investigated by transfection and expression of RTKN in AGS gastric cells, which express endogenous RTKN at a low basal level. Flow-cytometric analysis showed that RTKN-transfected AGS cells were significantly more resistant than vector-transfected cells to apoptosis upon treatment with sodium butyrate. To explore the mechanisms underlying RTKN-mediated cell survival, a reporter assay was performed. Since the NF-kappaB activation is known to promote cell survival and Rho GTPase may lead to NF-kappaB activation, we transfected AGS cells with the RTKN expression vector along with a pNF-kappaB-Luc reporter plasmid. Our results showed that overexpression of RTKN induced robust activation of NF-kappaB, and RTKN-mediated NF-kappaB activation was suppressed significantly by C3 transferase, an inhibitor of the small GTPase Rho. We conclude that Rho/RTKN-mediated NF-kappaB activation leading to cell survival may play a key role in gastric tumorigenesis. This study provides original documentation for the overrepresentation of the Rho GTPase effector rhotekin in human cancer and its links to cancer formation.

The increase of MICA gene A9 allele associated with gastric cancer and less schirrous change

Since surgical resection is the principal treatment of gastric cancer, early detection is the only effective strategy against this disease at present. Recently, a new polymorphic gene family, the major histocompatibility complex class I chain-related (MIC) genes located about 40 kb centromeric to HLA-B gene has been proposed. This family consists of five genes (A, B, C, D and E). Among them, MICA has five various alleles (A4, A5, A5.1, A6 and A9), which can be used as a polymorphic marker for genetic mapping and for disease susceptibility. The MICA polymorphism was studied in our gastric cancer patients to see if there is any possible correlation with genetic predisposition and clinicopathological factors. Genomic DNA was extracted from fresh or frozen peripheral blood leukocytes in 107 patients with gastric adenocarcinoma who underwent gastrectomy in our hospital and 351 noncancer controls. MICA polymorphism was analysed by using PCR-based technique. The results showed both phenotypic and allele frequencies of allele A9 in patients with gastric cancer were significantly higher than controls (33 vs 17.6%, P=0.005; 17 vs 9.9%, P=0.02). Gastric adenocarcinoma with allele A9 was associated with less schirrous change than those without (P=0.014). MICA gene A9 allele might confer the risk of gastric cancer and associate with less schirrous change. The mechanisms among them deserve further investigation.

Aggressive surgical treatment for T4 gastric cancer

Surgical treatment for locally advanced gastric cancer remains controversial, and many still question the benefits of extended resection. The aim of this study was to evaluate the effectiveness of combined resection of the involved organs with regard to survival in patients with gastric cancer. Between 1993 and 2000, among the 1638 patients with gastric cancer who underwent gastrectomy, 82 were found to have evidence of adjacent organ spread at laparotomy. A retrospective analysis of these patients was performed. Curative resections were carried out in 50 patients, whereas noncurative resections were performed in 32 patients. The 5-year survival rate in the group undergoing curative resection was 36.9%. The survival rate in the R0 group was significantly higher than the survival rate for patients undergoing noncurative resections. There was no significant difference in survival rates between patients with pT3 cancer and those with pT4 cancer. Seventy-one patients were pathologically proved to have lymph node metastasis, and the survival rate for patients with a lymph node ratio greater than 0.2 was lower than that in other groups. In multivariate analysis, peritoneal dissemination, lymph node ratio, and histologic findings were the predictors of survival. Patients with T4 gastric carcinoma, even with lymph node metastasis, might have benefited from aggressive surgery with curative intent.

Clinical implications of chromosomal abnormalities in gastric adenocarcinomas

Gastric carcinoma (GC) is one of the most common malignancies worldwide and has a very poor prognosis. Genetic imbalances in 62 primary gastric adenocarcinomas of various histopathologic types and pathologic stages and six gastric cancer-derived cell lines were analyzed by comparative genomic hybridization, and the relationship of genomic abnormalities to clinical features in primary GC was evaluated at a genome-wide level. Eighty-four percent of the tumors and all six cell lines showed DNA copy number changes. The recurrent chromosomal abnormalities including gains at 15 regions and losses at 8 regions were identified. Statistical analyses revealed that gains at 17q24-qter (53%), 20q13-qter (48%), 1p32-p36 (42%), 22q12-qter (27%), 17p13-pter (24%), 16p13-pter (21%), 6p21-pter (19%), 20p12-pter (19%), 7p21-pter (18%), 3q28-qter (8%), and 13q13-q14 (8%), and losses at 18q12-qter (11%), 3p12 (8%), 3p25-pter (8%), 5q14-q23 (8%), and 9p21-p23 (5%), are associated with unique patient or tumor-related features. GCs of differing histopathologic features were shown to be associated with distinct patterns of genetic alterations, supporting the notion that they evolve through distinct genetic pathways. Metastatic tumors were also associated with specific genetic changes. These regions may harbor candidate genes involved in the pathogenesis of this malignancy.

T cell receptor Vbeta repertoire expression reflects gastric carcinoma progression

Analysis of TCR beta-chain complementarity-determining region size gives an indication of the T cell immune response. We examined CD4+ and CD8+ subgroups of T cells in the peripheral blood (PBL), benign gastric mucosa, and tumor (TIL) lymphocytes of 12 patients with primary gastric carcinomas of both intestinal and diffuse types. The average number of expanded clones in each compartment, expressed by the 24 families of the TCRVbeta repertoire, was analyzed according to tumor histological type, maximal invasive depth, and lymph node metastases. Fewer clones were expressed by the PBL in the cases with lymph node metastases than in those without (CD4+ P = 0.00017, CD8+ P = 0.016). Fewer CD8+ clones were expressed by the PBL in the cases with full thickness tumor infiltration than in those involving only the mucosa and submucosa (P = 0.05). The CD8+ TIL showed significantly fewer clones in the diffuse-type carcinoma than in the intestinal type (P = 0.046).

A genome-wide study of microsatellite instability in advanced gastric carcinoma

BACKGROUND

Microsatellite instability (MSI) has been described in many human carcinomas, including gastric carcinomas (GCs). There are inconsistent findings regarding the association of MSI with various subsets of GC with specific clinicopathologic features. The objective of this study was to define MSI in advanced GC at a genome-wide level and to evaluate the clinical relevance of MSI in these patients.

METHODS

Forty-one gastric adenocarcinomas with serosa invasion (T3) were analyzed at 59 loci that detected at least one site per arm of each autosome in human genome. The expression patterns of mismatch repair proteins hMLH1 and hMSH2 were examined by immunohistochemistry. Comparisons were made by categorizing tumors into three groups: tumors with MSI at multiple loci (at more than three loci), tumors with MSI at low level (at one to three loci), and microsatellite-stable (MSS) tumors. Clinical significance of MSI in advanced GC was evaluated. The relative rates of hypermutability of the 59 markers also were determined.

RESULTS

A significant association was found between tumors with MSI at multiple loci and the expanding type of tumor growth by Ming's histologic classification (P = 0.001), whereas tumors with MSI at low level and MSS tumors are clinicopathologically indistinguishable. The 59 dinucleotide repeat markers displayed varying degrees of susceptibility toward genetic instability. The relative rates of hypermutability of these markers were consistent with a normal distribution pattern in which the frequency of unstable tumors detected at different chromosomal loci varied from 0% to 20%.

CONCLUSIONS

The authors' results showed that advanced GC with MSI at multiple loci progress preferentially in an expanding mode, supporting the notion that high MSI tumors and low MSI/MSS tumors evolve through different genetic pathways. Thus, microsatellite testing may have clinical utility as a favorable prognostic marker.

Prognosis of T4 gastric carcinoma patients: an appraisal of aggressive surgical treatment

BACKGROUND AND OBJECTIVES

Despite precipitous drop in the incidence of gastric carcinoma in Japan, it is still one of the leading causes of death associated with malignant disease. Once the contiguous organs are involved the prognosis becomes dismal. Prognostic factors governing the survival of patients with T4 gastric carcinoma remain unclear.

METHODS

Between 1980 and 1998, 150 patients were treated for T4 gastric carcinoma. Results and prognostic factors were evaluated by univariate and multivariate analyses.

RESULTS

With a 73% resectability, patients with tumor resection had a significantly (P < 0.0001) improved survival rate. Within an acceptable operative mortality (2.6%), apparently curative cases had survival benefit (P < 0.0001) over noncurative cases. In the multivariate analysis, the death risk increased by 2.18 (relative risk) when splenectomy was spared from the operative procedure (P < 0.0071). Presence of esophageal invasion was the other independent prognostic factor in T4 gastric carcinoma patients (relative risk 2.11). Conventional prognostic factors along with the type of organs invaded by the carcinoma had no impact on prognosis.

CONCLUSIONS

Patients with T4 gastric carcinoma might be benefited from aggressive surgery with a curative intent. Whenever possible, splenectomy should be done along with invaded organ resection.

Human gastric cancer kinase profile and prognostic significance of MKK4 kinase

Alterations of protein tyrosine kinase are often associated with uncontrolled cell growth and tumor progression. Knowledge of the overall expression pattern of tyrosine kinases should prove beneficial in understanding the signaling pathways involved in gastric cancer oncogenesis and in providing possible biomarkers for gastric cancer progression. To establish a general tyrosine-kinase expression profile, degenerated polymerase chain reaction primers designed from the consensus catalytic kinase motifs were used to amplify protein tyrosine kinase molecules from gastric cancer tissues. We observed more than 50 tyrosine and serine/threonine kinases from matching pairs of gastric cancer tissue and normal mucosa. Based on this new kinase profile information, we selected the MKK4 gene for further immunohistochemical studies. Statistical analysis of MKK4 protein expression and clinicopathological features indicated that MKK4 kinase expression could serve as a significant prognostic factor for relapse-free survival and for overall survival. We demonstrated a simple and sensitive method for establishing protein tyrosine-kinase expression profiles of human gastric cancer tissues as well as for discovering novel and useful clinical biomarkers from such kinase expression profiles.

Evaluation of the New American Joint Committee on Cancer/International Union against cancer classification of lymph node metastasis from gastric carcinoma in comparison with the Japanese classification

BACKGROUND

A new system for the classification of gastric carcinoma, based on the number of metastatic lymph nodes, has been adopted by the current American Joint Committee on Cancer/International Union Against Cancer (AJCC/UICC) TNM system (1997). The purpose of this study was to evaluate the rationality of this classification in comparison with the Japanese classification, which is based on the location of positive lymph nodes.

METHODS

The authors analyzed 587 patients who underwent clinically curative gastrectomy with D2 lymphadenectomy for gastric carcinoma and each had 15 or more lymph nodes histologically examined from 1982 to 1992. Multivariate analysis with the Cox proportional hazards model was carried out to determine which classification was more effective.

RESULTS

Within the pN1 or pN2 category of the new AJCC/UICC system, no significant difference in the survival rates existed between n1 patients and n2 patients of the Japanese classification. On the other hand, the survival rates significantly decreased, in the order of pN1, pN2, and pN3 (from greatest to smallest decrease), within the n1 and n2 categories. In multivariate analysis, lymph node involvement by the AJCC/UICC classification was selected as the most significant prognostic determinant, whereas the Japanese lymph node classification was not significantly prognostic. When survival rates were calculated within the pT1, pT2, and pT3-4 categories, no differences existed between pN0 and pN1. There was some discrepancy between the survival rate for each pT and pN category and the corresponding stage.

CONCLUSIONS

The new AJCC/UICC classification for lymph node involvement of gastric carcinoma is basically acceptable and considered superior to the Japanese classification. Further analysis involving a greater number of cases may be necessary to confirm the applicability of this staging system.

Serum anti-p53 antibodies in gastric adenocarcinoma patients are associated with poor prognosis, lymph node metastasis and poorly differentiated nuclear grade

Mutation of the p53 tumour suppressor gene often leads to the accumulation of mutant p53 protein in tumour cells. Many cancer patients develop antibodies that recognize the overexpressed p53 protein. The presence of these antibodies is, in some tumour types, associated with poor prognosis. Gastric cancer is a highly prevalent disease associated with a high rate of mortality, there is a need for improved clinical and biological markers for disease behaviour. To investigate the clinical relevance of serum anti-p53 antibodies in patients with gastric adenocarcinoma, we have examined the sera of 501 gastric cancer patients for the presence of serum antibodies against the p53 protein. By immunoblotting analysis using a cell lysate containing overexpressed p53 protein as well as affinity-purified recombinant p53 protein as antigens, we have detected anti-p53 antibodies in 11.2% (61 of 501) of gastric cancer patients, but in none of 46 cancer-free individuals. The presence of anti-p53 antibodies was tightly associated with tumours of higher nuclear grade and lymph node metastasis, and a negative association was found between the presence of anti-p53 antibodies and survival. These results suggest that a preoperative test of serum anti-p53 antibodies in gastric cancer patients can be useful to identify subset of patients who may need gastrectomy with lymph node dissection and post-operative adjuvant therapy.

Factors correlated with number of metastatic lymph nodes in gastric cancer

OBJECTIVE

We had previously reported a reasonable categorization of the number of positive lymph nodes (LN: 0, 1-4, 5-8, and > 8) as a prognostic indicator. This study was an extension, to see which factors correlated with number of positive lymph nodes.

METHODS

A total of 533 patients with gastric adenocarcinoma, who underwent curative surgery between January 1988 and December 1995, were entered into this study. Patients were divided into four groups according to metastatic LN number (0, 1-4, 5-8, and > 8). Their survival and clinicopathological factors were analyzed.

RESULTS

A total of 16,457 LNs, with an average of 30.9 per specimen, were removed, of which 1686 (10.2%) showed metastases. The 5-yr cumulative survival rate decreased as the number of metastatic LNs increased, ie., 91.3% for LN 0; 67.4% for LN 1-4; 37.2 for LN 5-8, and 14.1% for LN > 8. Multivariate analyses showed that depth of cancer invasion (odds ratio: 2.4), gross appearance (odds ratio: 1.9), size (odds ratio: 1.9), and location (odds ratio: 1.4) of tumor were four independent factors correlated with the number of metastatic LNs. Number of metastatic LNs increased with advanced Japanese nodal stage and UICC-TNM stage.

CONCLUSIONS

Depth of tumor invasion, and gross appearance, size, and location of tumor were four pathological factors independently correlated with number of metastatic LNs in gastric cancer.