Survival after surgical treatment of early gastric cancer: surgical techniques and long-term survival

Equal short-term outcomes of intracorporeal mechanical gastrogastrostomy in laparoscopic pylorus-preserving gastrectomy for cT1N0 gastric cancer in the middle stomach compared with the extracorporeal hand-sewing method

BACKGROUND

Intracorporeal mechanical gastrogastrostomy (IMG) techniques have recently been developed and their short-term safety was presented in their initial evaluation. However, whether they are comparable to extracorporeal hand-sewing gastrogastrostomy (EHG) remains unclear. The aim of the study is to establish the safety of IMG in totally laparoscopic pylorus-preserving gastrectomy (TLPPG) compared to EHG in laparoscopy-assisted pylorus-preserving gastrectomy (LAPPG).

METHODS

We retrospectively analyzed the short-term outcomes of patients with middle-third early gastric cancer who underwent LAPPG or TLPPG between 2005 and 2022. The primary objective of this study was to evaluate the non-inferiority of IMG to EHG in terms of safety, with the primary endpoint being the risk difference in anastomosis-related complications (ARCs). The sample size required to achieve a statistical power of 80% for the non-inferiority test was 971 with a one-sided alpha level of 5% and non-inferiority of 5%.

RESULTS

The analysis included a total of 1,021 patients who underwent LAPPG or TLPPG during the study period. Among them, 488 patients underwent EHG, while 533 underwent IMG. The incidences of ARCs were 11.3% and 11.4% in EHG and IMG, respectively. The observed difference in incidence was 0.0017 (90% confidence interval - 0.0313 to 0.0345), which statistically demonstrated the non-inferiority of IMG to EHG in the incidence of ARCs. Among other complications, the incidence of wound infection in IMG was lower than that in EHG.

CONCLUSION

IMG is safe regarding ARCs compared with EHG. These results will encourage surgeons to introduce IMG for patients with early middle gastric cancer.

Development and validation of LightGBM algorithm for optimizing of Helicobacter pylori antibody during the minimum living guarantee crowd based gastric cancer screening program in Taizhou, China

Gastric cancer continues to be a significant health concern in China, with a high incidence rate. To mitigate its impact, early detection and treatment is key. However, conducting large-scale endoscopic gastric cancer screening is not feasible in China. Instead, a more appropriate approach would be to initially screen high-risk groups and follow up with endoscopic testing as needed. We conducted a study on 25,622 asymptomatic participants aged 45-70 years from a free gastric cancer screening program in the Taizhou city government's Minimum Living Guarantee Crowd (MLGC) initiative. Participants completed questionnaires, blood tests, and underwent gastrin-17 (G-17), pepsinogen I and II (PGI and PGII), and H. pylori IgG antibody (IgG) assessments. Using the light gradient boosting machine (lightGBM) algorithm, we developed a predictive model for gastric cancer risk. In the full model, F1 score was 2.66%, precision was 1.36%, and recall was 58.14%. In the high-risk model, F1 score was 2.51%, precision was 1.27%, and recall was 94.55%. Excluding IgG, the F1 score was 2.73%, precision was 1.40%, and recall was 68.62%. We conclude that H. pylori IgG appears to be able to be excluded from the prediction model without significantly affecting its performance, which is important from a health economic point of view. It suggests that screening indicators can be optimized, and expenditures reduced. These findings can have important implications for policymakers, as we can focus resources on other important aspects of gastric cancer prevention and control.

Comparing artificial intelligence to humans for endoscopic diagnosis of gastric neoplasia: An external validation study

OBJECTIVES

Artificial intelligence (AI) uses deep learning functionalities that may enhance the detection of early gastric cancer during endoscopy. An AI-based endoscopic system for upper endoscopy was recently developed in Japan. We aim to validate this AI-based system in a Singaporean cohort.

METHODS

There were 300 de-identified still images prepared from endoscopy video files obtained from subjects that underwent gastroscopy in National University Hospital (NUH). Five specialists and 6 non-specialists (trainees) from NUH were assigned to read and categorize the images into "neoplastic" or "non-neoplastic." Results were then compared with the readings performed by the endoscopic AI system.

RESULTS

The mean accuracy, sensitivity, and specificity for the 11 endoscopists were 0.847, 0.525, and 0.872, respectively. These values for the AI-based system were 0.777, 0.591, and 0.791, respectively. While AI in general did not perform better than endoscopists on the whole, in the subgroup of high-grade dysplastic lesions, only 29.1% were picked up by the endoscopist rating, but 80% were classified as neoplastic by AI (P = 0.0011). The average diagnostic time was also faster in AI compared with endoscopists (677.1 s vs 42.02 s (P < 0.001).

CONCLUSION

We demonstrated that an AI system developed in another health system was comparable in diagnostic accuracy in the evaluation of static images. AI systems are faster and not fatigable and may have a role in augmenting human diagnosis during endoscopy. With more advances in AI and larger studies to support its efficacy it would likely play a larger role in screening endoscopy in future.

Serum Pepsinogen as a Biomarker for Gastric Cancer in the United States: A Nested Case-Control Study Using the PLCO Cancer Screening Trial Data

BACKGROUND

Gastric cancer lacks specific symptoms, resulting in diagnosis at later stages and high mortality. Serum pepsinogen is a biomarker for atrophic gastritis, a gastric cancer precursor, and may be useful to detect persons at increased risk of gastric cancer.

METHODS

The Prostate, Lung, Colorectal and Ovarian (PLCO) Cancer Screening Trial was conducted in the United States between 1993 and 2001. ELISA-based pepsinogen tests were conducted on prediagnostic serum samples of 105 PLCO participants who developed gastric cancer and 209 age, sex, and race-matched controls. Pepsinogen positive (PG+) was defined as pepsinogen I ≤ 70 μg/L and pepsinogen I/II ratio ≤3.0. Results of conditional logistic regression models, and sensitivity and specificity, of PG+ for gastric cancer are reported.

RESULTS

Gastric cancer cases were more likely to be PG+ (31.4% vs. 5.5%, P < 0.001) at baseline than controls. Compared to PG-, PG+ was associated with an 8.5-fold increased risk for gastric cancer [95% confidence interval (CI) = 3.8-19.4]. This risk remained significant after adjusting for Helicobacter pylori, family history of gastric cancer, education, smoking, and BMI (aOR, 10.6; 95% CI, 4.3-26.2). In subgroup analysis, PG+ individuals were 11-fold more like to develop non-cardia gastric cancer (OR, 11.1; 95% CI, 4.3-28.8); conversely, they were not significantly more likely to develop cardia gastric cancer (OR, 2.0; 95% CI = 0.3-14.2). PG+ status yielded low sensitivity but high specificity for both noncardia (44.3%; 93.6%) and cardia gastric cancer (5.7%; 97.2%).

CONCLUSIONS

Prediagnostic serum pepsinogen levels from a large, prospective cohort study were associated with risk of gastric cancer, particularly noncardia gastric cancer.

IMPACT

PG status may identify individuals at higher risk of noncardia gastric cancer for targeted screening or interventions. See related commentary by Zhou and Huang, p. 1257.

The Feasibility of Applying Artificial Intelligence to Gastrointestinal Endoscopy to Improve the Detection Rate of Early Gastric Cancer Screening

Convolutional neural networks in the field of artificial intelligence show great potential in image recognition. It assisted endoscopy to improve the detection rate of early gastric cancer. The 5-year survival rate for advanced gastric cancer is less than 30%, while the 5-year survival rate for early gastric cancer is more than 90%. Therefore, earlier screening for gastric cancer can lead to a better prognosis. However, the detection rate of early gastric cancer in China has been extremely low due to many factors, such as the presence of gastric cancer without obvious symptoms, difficulty identifying lesions by the naked eye, and a lack of experience among endoscopists. The introduction of artificial intelligence can help mitigate these shortcomings and greatly improve the accuracy of screening. According to relevant reports, the sensitivity and accuracy of artificial intelligence trained on deep cirrocumulus neural networks are better than those of endoscopists, and evaluations also take less time, which can greatly reduce the burden on endoscopists. In addition, artificial intelligence can also perform real-time detection and feedback on the inspection process of the endoscopist to standardize the operation of the endoscopist. AI has also shown great potential in training novice endoscopists. With the maturity of AI technology, AI has the ability to improve the detection rate of early gastric cancer in China and reduce the death rate of gastric cancer related diseases in China.

Self-preparation system using glucose oxidase-inspired nitroreductase amplification for cascade-responsive drug release and multidrug resistance reversion

Early antitumor therapy is an important determinant of survival in patients with cancer. Utilization of specific pathological states, such as hypoxia, greatly promotes the development of intelligent drug delivery systems (DDSs) for targeted antitumor therapy. However, a slight decrease in oxygen levels in early-stage tumors is not sufficient to trigger hypoxia-responsive drug release. Nitroreductase (NTR) is overexpressed in bioreductive hypoxic cancers, and its expression level has been verified to be directly related to hypoxic status. Herein, using glucose oxidase (GOx) as an O₂-consuming agent to exacerbate hypoxia, a cascade strategy of GOx-induced overexpression of NTR and amplified NTR-catalyzed release was proposed for early antitumor therapy. Briefly, NTR-sensitive p-nitrobenzyl chloroformate (PNZ-Cl) was adopted to conjugate with the polysaccharide chitosan (CS) and self-assemble into CS-PNZ-Cl micelles. These polymer micelles possess the dual abilities to specifically immobilize GOx and load mitoxantrone (MIT) to form the NTR-responsive nanocascade reactor GOx/MIT@CS-PNZ-Cl. First, as a "key", tumor hypoxia triggers the initial release of GOx, which serves as the O₂-consuming agent when catalyzing its reaction with glucose, which is accompanied by H₂O₂ production. Depleted oxygen levels facilitate the expression of NTR, which in turn amplifies the capacity of the nanocascade reactor to decompose into secondary micelles for enhanced intratumoral permeation. GOx-inspired NTR amplification further elicits MIT release, realizing a synergistic "domino effect" cascade. In addition, upregulated H₂O₂ has been shown to effectively reverse GSH-mediated MIT resistance, reaching the superior tumor inhibition rate of 93.08%. This GOx-based NTR-responsive nanocascade reactor provides amplification of the bioreductive hypoxic tumor microenvironment for early antitumor therapy.

Common Locations of Gastric Cancer: Review of Research from the Endoscopic Submucosal Dissection Era

Detection of early-stage gastric cancer improves the prognosis of patients. Endoscopic submucosal dissection (ESD) is a curative and stomach-preserving treatment for early gastric cancer (EGC) associated with a low risk of lymph node metastasis. However, several studies have reported missed diagnosis of gastric cancer. Therefore, endoscopists are required to learn accurate diagnostic skills to eliminate endoscopic blind spots. A systematic screening protocol to map the entire stomach without blind spots reduces the risk of missed lesions. Knowledge of the features of EGC or dysplasia is essential to identify suspicious lesion. Information of the common sites of occurrence of EGC can also enable a detailed endoscopic examination to improve detection rates. Previous reports investigating the location of gastric cancers resected by ESD or surgery showed that the antrum and lesser curvature of stomach were predominantly affected. Helicobacter pylori-induced atrophic changes advance from the antrum to the corpus along the lesser curvature, predominantly affecting these areas. Gastric cancers in the antrum and the lower corpus are also commonly missed during screening examination. Therefore, a careful examination of the lower third stomach is warranted to avoid missing synchronous and metachronous gastric lesions. Knowledge of the location of EGC enables accurate endoscopic examination and detection of EGC in early stage.

Postoperative Serum C-Reactive Protein Level Predicts Long-term Outcomes in Stage I Gastric Cancer

BACKGROUND

The aim of this study was to investigate the prognostic impact of postoperative systemic inflammation in patients with stage I gastric cancer.

METHODS

This study reviewed the medical records of 470 patients with stage I gastric cancer who underwent gastrectomy. The postoperative serum C-reactive protein (CRP) level on postoperative days (PODs) 1 and 3 and its peak value were evaluated as prognostic factors. A receiver operating characteristics curve analysis was performed to determine their cut-off values.

RESULTS

The CRP level on POD 3 (P = 0.001) and the peak CRP level (P = 0.007) were significantly associated with the overall survival rate. In the multivariate analysis, the CRP level on POD 3 (P = 0.002) and the peak CRP level (P = 0.008) were identified as independent predictors of the overall survival. The high CRP on POD3 group had significantly higher mortality rate from relapse of gastric cancer (P = 0.001) and infectious disease (P = 0.003) than the low CRP on POD 3 group. The CRP level on POD 3 was significantly associated with the patient sex, surgical procedure, duration of the operation, amount of blood loss, postoperative infectious complication, and peak CRP level.

CONCLUSIONS

The serum CRP level during the early postoperative period predicts the long-term outcomes in stage I gastric cancer. The present study suggests a significant influence of postoperative systemic inflammation on the survival of patients with stage I gastric cancer.

Is endoscopic surveillance necessary for patients who undergo total gastrectomy for gastric cancer?

There have been only a few reports investigating the clinical efficacy of follow-up endoscopy for detection of recurrent gastric cancer after total gastrectomy (TG). We reviewed the records of 747 patients undergoing TG from 2003 to 2012 and enrolled 267 patients (70 with early gastric cancer (EGC) and 197 with advanced gastric cancer (AGC)), who received one or more follow-up endoscopy and contrast abdominal computed tomography (CT) scan. We found no tumor recurrence in the 70 EGC patients during the mean follow-up periods of 42.1 ± 18 and 43.2 ± 19 months by endoscopy and contrast abdominal CT scan. In 197 AGC patients, 59 patients (29.8%) had confirmed tumor recurrence during mean follow-up periods of 40.5 ± 21 and 45.3 ± 22 months. The most common pattern of tumor recurrence was distant metastasis (n = 35) followed by peritoneal metastasis (n = 11). Among the other 13 cases with loco-regional recurrence, seven cases were regional lymph node metastases, four were anastomosis site recurrences, and two were duodenal stump and jejunal loop site recurrences. Three of the four cases of anastomosis site recurrence were found by both endoscopy and contrast abdominal CT scan; one case was missed by contrast abdominal CT scan. However, the two cases with duodenal stump and jejunal loop recurrences were detected by contrast abdominal CT scan only. An annual follow-up endoscopy for gastric cancer after TG might have a limited role in the detection of tumor recurrence, especially in patients with EGC. Contrast abdominal CT scan may be sufficient as a follow-up method for recurrent gastric cancer after TG.

National Trend in Laparoscopic Gastrectomy for Gastric Cancer: Analysis of the National Register in Chile

INTRODUCTION

The laparoscopic approach for the treatment of gastric cancer has many advantages. However, outside Asia there are few large case series.

AIM

To evaluate postoperative morbidity, long-term survival, changes in indication, and the results of laparoscopic gastrectomy.

METHODS

We included all patients treated with a laparoscopic gastrectomy from 2005 to 2014. We compared results across 2 time periods: 2005-2011 and 2012-2014. Median follow-up was 39 months.

RESULTS

Two hundred and eleven patients underwent a laparoscopic gastrectomy (median age 64 years, 55% male patients). In 135 (64%) patients, a total gastrectomy was performed. Postoperative morbidity occurred in 29%. A significant increase in the indication of laparoscopic surgery for stages II-III (32 vs. 45%; p = 0.04) and higher lymph node count (27 vs. 33; p = 0.002) were observed between the 2 periods. The 5-year overall survival was 72%. According to the stage, the 5-year overall survival was 85, 63, and 54% for stage I, II, and III respectively (p < 0.001).

CONCLUSIONS

There was an acceptable rate of postoperative complications and the long-term survival was in accordance with the disease stage. There was a higher indication of laparoscopic surgery in stages II-III disease, and higher lymph node count in the latter period of this study.

Gastric cancer treated by endoscopic submucosal dissection or endoscopic mucosal resection in Japan from 2004 through 2006: JGCA nationwide registry conducted in 2013

BACKGROUND

The Japanese Gastric Cancer Association (JGCA) initiated a new nationwide gastric cancer registry in 2008 and reported the treatment outcomes of patients with primary gastric cancer who underwent surgical therapy in 2001 and 2003. However, the outcomes of endoscopic therapy have not been reported yet.

METHODS

The JGCA conducted a retrospective nationwide registry in 2013 to investigate the short-term and long-term outcomes of endoscopic mucosal resection or endoscopic submucosal dissection in patients with gastric cancer treated from January 2004 through December 2006. This registry used a computerized database with terminology in accordance with the JGCA classification (13th and 14th editions) and the Japanese Gastric Cancer Treatment Guidelines from 2010.

RESULTS

Accurate data on 12,647 patients were collected from 126 participating hospitals and analyzed. The treatment procedure was endoscopic submucosal dissection in 81% of the patients and endoscopic mucosal resection in 19%. En bloc and R0 resections were achieved in 89% and 79% of the patients respectively. The total proportion of patients who underwent curative resection was 69.2%; 43.8% of patients underwent curative resection for absolute indication lesions, and 25.4% underwent curative resection for expanded indication lesions. Emergency surgery was performed to treat bleeding or perforation in very few patients (0.3% and 0.4% respectively). The 5-year follow-up rate after endoscopic resection was 70%. The 5-year overall survival rate was 91.6% in patients with absolute indications and 90.3% in patients with expanded indications after curative resection and 86.5% in patients who underwent noncurative resection. The 5-year disease-specific survival rates were 99.9%, 99.7%, and 98.7% in patients with absolute indications who underwent curative resection, patients with expanded indications who underwent curative resection, and patients who underwent noncurative resection respectively.

CONCLUSION

Endoscopic resection of gastric cancer resulted in favorable short-term and long-term outcomes nationwide in Japan. Further efforts to increase the follow-up rate are needed.

Long-term outcomes of endoscopic submucosal dissection for early gastric cancer: a multicenter collaborative study

OBJECTIVE

The indications for endoscopic submucosal dissection (ESD) in patients with early gastric cancer (EGC) have been expanded. However, the long-term outcomes of ESD remain unclear. We retrospectively investigated the long-term outcomes of ESD in patients with EGC.

METHODS

We retrospectively studied patients with EGC who underwent ESD at 11 institutions between January 2003 and December 2010. A total of 6456 patients (7979 lesions) who met the absolute indications for ESD and 4202 patients (5781 lesions) who met the expanded indications for ESD were studied. Clinicopathological features, clinical course, and outcomes were studied in 67 patients in whom local recurrence or metastatic recurrence was diagnosed as of March 31, 2014. The median follow-up period was 56 months.

RESULTS

Local recurrence was diagnosed in 14 patients (0.22%) who met the absolute indications and 53 patients (1.26%) who met the expanded indications. The rate of local recurrence was significantly higher in patients with expanded-indication lesions (p < 0.05). As additional treatment for recurrence, most patients received endoscopic treatment. Metastatic recurrence did not develop in any patient with absolute-indication lesions, but was diagnosed in 6 patients (0.14%) with expanded-indication lesions (p < 0.05). The histological type was undifferentiated mixed type in half the patients. Three patients died of primary gastric cancer.

CONCLUSIONS

ESD for expanded-indication lesions of EGC is considered an effective therapy associated with an extremely low rate of metastatic recurrence on long-term follow-up. However, fully informed consent concerning the risk of metastatic recurrence should be obtained before ESD, and close postoperative follow-up is essential.

How to improve endoscopic diagnosis of early gastric cancer?

Gastric cancer is the third leading cause of cancer death worldwide. The detection of early-stage gastric neoplastic lesions may improve survival. The gold standard for diagnosing gastric cancer remains endoscopy and histology of biopsy specimens. On one hand, we should administer the optimum preparation to patients, including an antiperistaltic agent. On the other hand, in order to detect the entire stomach, we need to follow a standardized protocol, and we should be aware of the diagnostic criteria for a suspicious lesion. Chromoendoscopy, narrow band imaging and magnifying endoscopy are promising image-enhanced endoscopic techniques for characterization. The criteria for diagnosing a cancerous lesion by narrow-band imaging with magnifying endoscopy are as follows: irregular microvascular pattern with a demarcation line or irregular microsurface pattern with a demarcation line. This paper gives a brief review of these methods.

Early Gastric Cancer: Trends in Incidence, Management, and Survival in a Well-Defined French Population

BACKGROUND

Little is known about the epidemiology of early gastric cancer (EGC) in Western countries. The aim of this study was to analyze trends in the incidence, management, and survival of EGC in a well-defined population over a 30 year period.

METHODS

Data were obtained from the population-based cancer Registry of Burgundy (France). Incidence rates were calculated by sex, age, and 10 year period of diagnosis. Net survival rates were calculated and a multivariate relative survival analysis performed.

RESULTS

EGC represented 6.7 % of gastric cancer diagnosed between 1982 and 2011. Age-standardized incidence rates were higher in men (0.79/100,000) than in women (0.40/100,000). Between the periods 1982-1991 and 2002-2011, it decreased from 0.97 to 0.53 per 100,000 in men and from 0.44 to 0.30 per 100,000 in women. Overall, 19 % of the tumors were limited to the mucosa, 69 % to the submucosa, and 15 % invaded lymph nodes. Node invasion and male sex were the only significant prognostic factors. Five-year net survival was 50 % in node-positive patients and 85 % in node-negative patients (p < 0.001). In multivariate analysis, the relative risk of death in men compared to women was 2.3 and was 10.4 in patients with positive nodes compared to patients with negative nodes.

CONCLUSIONS

EGCs are rare in France. The prognosis is favorable, except for node-positive cancers, which may benefit from the recently developed adjuvant chemotherapy for gastric cancer.

A New Statistical Model Identified Two-thirds of Clinical T1 Gastric Cancers as Possible Candidates for Endoscopic Treatment

BACKGROUND

Clinical T1 gastric cancer has low metastatic potential to lymph nodes and is generally curable by local treatment. Endoscopic resection can preserve the whole stomach and does not impair the patient's quality of life; however, its indication is strictly limited to the subset of patients without nodal metastasis. The study was designed to predict reliably the patients without nodal metastasis based only on the clinical information.

METHODS

We examined patients with clinical T1 disease who were treated with surgery. The clinically available information was evaluated for its ability to predict nodal metastasis by logistic regression model. Then, the predictive ability of the logistic regression model using the risk factors for nodal metastasis was evaluated by a receiver operating characteristic curve.

RESULTS

A total of 511 patients were entered into this study. The clinical depth (cT1a or cT1b), maximal tumor diameter, and pathological type were confirmed to be significantly different between patients with and without nodal metastasis. The cutoff value of the tumor diameter differed depending on the histology and clinical depth: 79 mm for differentiated type and 48 mm for undifferentiated type in cT1a tumors, and 43 mm for differentiated type and 11 mm for undifferentiated type in cT1b tumors. According to these criteria, 348 of the 511 patients (68.1 %) were classified to have predictive N0 status. The negative predictive value was 95.7 % (95 % confidence interval 94.0-97.5 %).

CONCLUSIONS

The predictive criteria based on the multivariate logistic model identified that almost two-thirds of the patients with clinical T1 gastric cancer were possible candidates for endoscopic treatment.

Helicobacter pylori-negative Differentiated Adenocarcinoma of the Stomach

A 58-year-old Japanese man was diagnosed with differentiated adenocarcinoma of the stomach. Histological findings of the resected specimen revealed well- to moderately-differentiated tubular adenocarcinoma (tub1, tub2), 13 mm in diameter, which invaded into the submucosa (SM1, 300 μm) and lymphovascular lumen (ly1). Serum antibody against Helicobacter pylori (Hp) and the (13)C-urea breath test were negative, and there were no atrophic changes in the tumor-adjacent mucosa. The immunohistochemical analysis showed that gastric mucin (MUC5AC) was strongly positive and intestinal mucin (MUC2) was weakly and partially positive. According to these results, the final diagnosis of Hp-negative well-differentiated early gastric cancer was made.

Prognostic role of lymph node metastasis in early gastric cancer

OBJECTIVE

To clarify the relationship between clinicopathological features and lymph node metastasis and to propose the potential indications of lymph node metastasis for prognosis in early gastric cancer (EGC) patients.

METHODS

We retrospectively observed 226 EGC patients with lymph node resection, and analyzed the associations between lymph node metastasis and clinicopathological parameters using the chi-square test in univariate analysis and logistic regression analysis in multivariate analysis. Overall survival analysis was determined using the Kaplan-Meier and log-rank test. We conducted multivariate prognosis analysis using the Cox proportional hazards model.

RESULTS

Of all the EGC patients, 7.5% (17/226) were histologically shown to have lymph node metastasis. The differentiation, lymphovascular invasion and depth of invasion were independent risk factors for lymph node metastasis in EGC. The 5- and 10-year survival rates were significantly lower in patients with lymph node metastasis than in those without and the patients also had shorter progress-free survival time. Lymph node metastasis and tumor size were independent prognostic factors for EGC. The status of the lymph nodes was a significant factor in predicting recurrence or metastasis after surgery.

CONCLUSIONS

The undifferentiated carcinoma and lymphovascular and/or submucosal invasion were associated with a higher incidence of lymph node metastasis in EGC patients, whom need to perform subsequent D2 lymphadenectomy or laparoscopic lymph node dissection and more rigorous follow-up or additional chemotherapy/radiation after D2 gastrectomy for poor prognosis and high recurrence/metastasis rate.

Diagnostic value of computed tomography for staging of clinical T1 gastric cancer

BACKGROUND

T1 gastric cancer can be diagnosed only by endoscopy and is almost curable by local treatment. It has been unclear how a multidetector-row computed tomography (CT) evaluation is valuable for clinical T1 patients.

METHODS

Patients with clinical T1 disease, as diagnosed by endoscopy and treated with endoscopic submucosal dissection (ESD) or surgery between October 2000 and October 2007, were examined. The efficacy of CT was evaluated by the reversal rate of endoscopic T1 by CT, the incidence of clinical M1 disease, and the accuracy of diagnosing pathological N+ disease in patients who received surgery. To confirm metachronous distant and nodal metastases, the disease-free survival (DFS) also was evaluated.

RESULTS

A total of 761 patients, 236 treated by ESD and 525 treated with surgery, were examined. None of the patients had an endoscopic diagnosis of clinical T1 reversed by CT. No clinical M1 disease was found. Among the 525 patients who underwent surgery, 8 showed clinical N+ disease (1.5 %), while 47 demonstrated pathological N+ disease (8.9 %). The accuracy, sensitivity, specificity, positive predictive value, and negative predictive values were 90.3, 4.3, 98.7, 25, and 91.3 %, respectively. The 5-year DFS rate was 93.6 % (95 % confidence interval 91.4-95.8 %).

CONCLUSIONS

The present study suggests that diagnostic value of CT is limited for staging of clinical T1 gastric cancer patients, because the reversal rate of endoscopic T1 by CT was very low, clinical M1 disease was rare, the diagnosis of N+ status was unreliable, and metachronous M1 and N+ findings were rare.

Serum antibody against Helicobacter pylori FlaA and risk of gastric cancer

BACKGROUND

Helicobacter pylori (H. pylori) infection is a major risk factor for gastric cancer (GC); however, only a minority of infected individuals develops GC. We aim to assess the association between serostatus of antibody against H. pylori flagellin A (FlaA) and risk of GC and to evaluate the value of serum FlaA antibody as a novel screening biomarker for GC risk.

METHODS

A hospital-based case-control study including 232 cases and 264 controls was conducted. Logistic regression was adopted to analyze the association between the serostatus of FlaA antibody and risk of GC. Serum FlaA antibody was measured by an enzyme-linked immunosorbent assay (ELISA). Receiver operating characteristic (ROC) curve was used to evaluate the screening efficacy and to identify a cutoff point of serum FlaA antibody level.

RESULTS

Helicobacter pylori infection was associated with an increased risk of GC (p = .007). A positive association between serum FlaA antibody and GC risk was observed in overall subjects and H. pylori-positive subjects (OR [95% CI]: 6.8 [4.3-10.7] and 6.9 [3.6-13.4], respectively; p < .001). The seropositivity of FlaA antibody was strongly related to GC risk in a dose-dependent manner (p for trend < .001). The optimal cutoff value (OD) was 0.1403, providing a sensitivity of 74.1% and a specificity of 64.4%. The area under the ROC curve (AUC) was 0.74 in overall subjects and 0.73 in H. pylori-positive subjects, respectively.

CONCLUSIONS

FlaA was an independent risk factor for H. pylori-related GC. Serum FlaA antibody may serve as a novel noninvasive biomarker for early detection of GC.

Meta-analysis of laparoscopy assisted distal gastrectomy and conventional open distal gastrectomy for EGC

In recent decades, laparoscopy assisted distal gastrectomy (LADG) has been introduced to treat early gastric cancer (EGC). This study evaluated the safety and efficacy of laparoscopy assisted and conventional open distal gastrectomy for EGC. Comprehensive searches of PubMed, EmBase, Cochrane Controlled Trials Register and Chinese Biomedical Database (CBM) were performed. Included literature was evaluated using the Newcastle-Ottawa Scale. Original data were extracted, pooled odds ratio (OR) and 95% confidence intervals (CI) were calculated using RevMan 5.0. Eight RCTs of 734 patients were included in the study. Compared to CODG, LADG increases the operation time (weighted mean difference [WMD]: 63.35; 95% confidence interval [CI]: 57.96, 68.74; P<0.01), reduces intraoperative blood loss (WMD: -127.95; 95% CI: -147.97, -107.93; P<0.01), decreases number of harvested lymph nodes (WMD: -4.21; 95% CI: -6.10, -2.31; P<0.01), forwards oral intake time (WMD:-0.43; 95% CI: -0.61, -0.24; P<0.01), and shortens hospital stay(WMD: -1.29; 95% CI: -1.76, -0.83; P<0.01). There is no significant difference in postoperative complications(OR: 0.70; 95% CI: 0.46, 1.06; P=0.09). All these findings indicate that LADG for EGC is feasible and safe.

Health economic assessment for screening of gastric cancer in a high risk population in northeastern china

OBJECTIVE

To assess economic cost-effects for the screening programs of gastric cancer in a high risk population in northeastern China.

METHODS

The data were collected from November 2001 to December 2003. The multi-stage sampling to define the screening group and the control group was applied in this study. Two stage screening programs were used in the study. An epidemiological survey and serum PG test were carried out in the first stage. The endoscopy and pathological examination were performed in the second stage screening. Effectiveness was assessed by the increased quality adjusted life-year (QALY) because of reduced gastric cancer deaths in screening.

RESULTS

A total of 27,970 participants (n=7,128 screening group, n=20,842 control group) were enrolled in the survey. Twenty nine gastric cancer cases were detected in the screening group with 20 cases in the early stage and 9 cases in the advanced stage, respectively. Eighty six gastric cancer cases were detected in the control group, all of whom were in the advanced stage and had died before the study finished. The screening and treatment of 29 cases cost $152,227 and $5,249 per each case, respectively. The costs were $459 to gain per QALY.

CONCLUSION

The screening program of gastric cancer used in our study is an economic and society-beneficial measure to detect gastric cancer in high risk area. The methods fit China's present economic development level.

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

Background

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

Methods

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

Results

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

Conclusions

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

Laparoscopy versus open distal gastrectomy by expert surgeons for early gastric cancer in Japanese patients: short-term clinical outcomes of a randomized clinical trial

BACKGROUND

Short-term outcomes of laparoscopy-assisted distal gastrectomy (LADG) and open DG (ODG) have been investigated in previous clinical trials, but operative techniques and concomitant treatments have evolved, and up-to-date evidence produced by expert surgeons is required to provide an accurate image of the relative efficacies of the treatments. The purpose of this study was to compare laparoscopic versus ODG with respect to specific primary and secondary short-term outcomes.

METHODS

From October 2005 to February 2008, a total of 64 patients with early gastric cancer were randomly assigned to the LADG or the ODG group. One patient was excluded due to concurrent illness unrelated to the intervention, so the data from 63 patients were analyzed. The primary short-term outcome was the 4-day postoperative use of analgesics. Secondary short-term outcomes were postoperative residual pain, complications, days hospitalized, blood data, days with fever, and days to first flatus.

RESULTS

There was a significant difference in favor of LADG for postoperative use of analgesics (P = 0.022). Unexpectedly, there was no significant difference in degree of pain in the immediate postoperative period, putatively due to the optimal use of analgesics. Of the secondary outcomes, residual pain at postoperative day 7 (P = 0.003) and days to first flatus (P = 0.001) were significantly better with LADG. Postoperative complications, number of days hospitalized, and number of days with fever were also better with LADG, but the differences were not significant. Blood data representing inflammation (WBC and CRP) showed marked differences, especially on postoperative day 7 (P = 0.0016 and P = 0.0061, respectively).

CONCLUSIONS

LADG performed by expert surgeons results in less postoperative pain accompanied by decreased surgical invasiveness and is associated with fewer postoperative inconveniences. No preliminary suggestions of changes in long-term curability were observed. LADG for early gastric cancer is a feasible and safe procedure with short-term clinical results superior to those of ODG.

Metachronous liver metastasis from early gastric cancer

INTRODUCTION

Early gastric cancer (EGC) has an excellent prognosis, but tumors recur in some patients even after apparently successful treatment. Among recurrent sites, the liver is one of the most common. In this study, we investigated clinicopathological features and factors predicting the development of liver metastasis from EGC.

PATIENTS AND METHODS

We examined the medical records of 2,707 consecutive patients who underwent open gastrectomy for EGC (pT1; m, sm) between 1991 and 2005. We assessed clinicopathological features and predictive factors for EGC metastasis in the liver.

RESULTS

Fifteen (0.6%) of the 2,707 patients developed liver metastasis. All primary gastric tumors of patients with liver recurrence demonstrated invasion to the submucosal layer. Macroscopically, nine patients had elevated-type and six depressed-type. Nodal metastasis was documented in seven patients (47%). Lymphatic and vascular involvements were seen in 11 (73%) and 7 (47%) patients, respectively. Multivariate analysis of patients with submucosal invasion revealed macroscopic elevated type and vascular involvement to be independent risk factors for liver metastasis.

CONCLUSIONS

With submucosal cancer, the macroscopic elevated type and vascular involvement are significant predictive factors for EGC recurrence in the liver.

Advances in research and diagnosis of early gastric cancer

The overall prognosis of gastric cancer is generally poor due to late presentation and diagnosis. When detected early, the prognosis of gastric cancer is excellent, and curative endoscopic resection may be possible, without the need for surgery. Careful endoscopic examination is important so as to avoid missed lesions. Besides the endoscopic screening for gastric cancer, other screening methods are also used in different countries and areas. This also provides us different avenues for the diagnosis of early gastric cancer.

Meta-analysis on the relationship between nonsteroidal anti-inflammatory drug use and gastric cancer

Although nonsteroidal anti-inflammatory drugs (NSAIDs), including aspirin, show chemopreventive effects on several types of cancer, their role in the development of gastric cancer remains controversial. The objective of this study is to assess the quantitative association between NSAIDs and gastric cancer by meta-analysis using both crude data and adjusted data. A search of Medline, Embase, Web of science, and citations from relevant articles was conducted for eligible articles published up to March 2009. A meta-analysis was developed. Pooled risk ratio and odds ratio with 95% confidence intervals were calculated, based on both crude and adjusted data from the selected studies and using random or fixed effects models based on heterogeneity analysis. Overall, 21 individual epidemiological studies (13 case-control studies with 29 560 participants and 8 cohort studies with 2 199 227 participants) were examined. The summary crude and adjusted risk ratios were 0.89 (0.83-0.97) and 0.81 (0.73-0.89) when the case-control and cohort studies were pooled, respectively. Significant protective effects of NSAIDs against gastric cancer appeared in all subgroups (study design, type of drug, site of cancer, and sample source), but only the site of cancer and sample source can substantially influence the estimate of effect. The chemopreventive effect of NSAIDs in gastric cancer was stronger based on the adjusted data than that based on crude data. Therefore, we conclude that NSAID use is associated with a decrease in the development of gastric cancer. The associations were more obvious after we adjusted for several risk factors that are known to contribute to the development of gastric cancer.

Overt bone metastasis and bone marrow micrometastasis of early gastric cancer

Recently we encountered two cases of early gastric cancer (EGC) with bone metastasis after surgery. As they were not accompanied by overt liver, lung, or peritoneal metastasis, we examined the clinical significance of bone metastasis in EGC and its mechanisms by a review of the literature. We found only 10 cases of EGC complicated with overt bone metastasis in the English literature, so we also examined the Japanese reports of such cases. The main histologic type of cases of bone metastasis from EGC was the diffuse type, and there were long intervals between surgery and overt bone metastasis. One reason for such long intervals may have been the tumor dormancy. Two types of dormancy, dynamic and static, and two types of postoperative overt metastases, that of micrometastatic origin (normograde metastatic process) and that of bone marrow origin (retrograde metastatic process), were considered. We speculated that there may be specific routes by which the cancer cells infiltrate the bone marrow directly from EGC or lymph node metastasis. The procedures for diagnosing bone micrometastasis using monoclonal antibodies have recently been improved, but their accuracy rates are still not universally accepted. New, more reliable examinations are required to improve the survival rates of EGC.

Predictive factors for lymph node metastasis in early gastric cancer

AIM: To analyze the predictive factors for lymph node metastasis (LNM) in early gastric cancer (EGC).

METHODS: Data from patients surgically treated for gastric cancers between January 1994 and December 2007 were retrospectively collected. Clinicopathological factors were analyzed to identify predictive factors for LNM.

RESULTS: Of the 2936 patients who underwent gastrectomy and lymph node dissection, 556 were diagnosed with EGC and included in this study. Among these, 4.1% of patients had mucosal tumors (T1a) with LNM while 24.3% of patients had submucosal tumors with LNM. Univariate analysis found that female gender, tumors ≥ 2 cm, tumor invasion to the submucosa, vascular and lymphatic involvement were significantly associated with a higher rate of LNM. On multivariate analysis, tumor size, lymphatic involvement, and tumor with submucosal invasion were associated with LNM.

CONCLUSION: Tumor with submucosal invasion, size ≥ 2 cm, and presence of lymphatic involvement are predictive factors for LNM in EGC.

The role of serum pepsinogen in the detection of gastric cancer

The incidence of gastric cancer is very high in Japan, Korea, and China. Reducing the morbidity and mortality associated with gastric cancer requires early diagnosis, which can be facilitated by applying gastroscopy more frequently in high-risk groups. A strategy of population screening for gastric cancer is currently being adopted in Korea, Japan, and the Matsu region of Taiwan, but using different screening methods. In addition, the history of pepsinogen (PG) in research as a gastric cancer biomarker has varied, in that the use of serum levels of PGI and PGII and the PGI/PGII ratio as gastric cancer screening tools was introduced in Japan before 1990, but in Korea the first research results were only reported in 2008. This review first evaluates the physiology of PG, followed by the usefulness or limitations of serum PG testing with regard to the detection of gastric cancer. Finally, the factors affecting the efficacy of PG tests as a gastric cancer biomarker (i.e., Helicobacter pylori infection status, gender, histopathologic features, and cancer location and depth) are evaluated. It was found that the strategies used to increase the efficacy of PG tests should be individualized in each country according to the seroprevalence of H. pylori.

Correlation between the length of the pyloric cuff and postoperative evaluation after pylorus-preserving gastrectomy

BACKGROUND

Recent years have seen the preserved pyloric cuff being lengthened in pylorus-preserving gastrectomy for early gastric cancer. We performed clinical assessment of the symptoms after pylorus-preserving gastrectomy in patients treated at the National Cancer Center Hospital in Japan during the past 9 years.

METHODS

Four hundred and fifty-six patients who had undergone pylorus-preserving gastrectomy and been followed up for at least 3 years were studied. We classified the patients into two groups according to the length of the pyloric cuff (group A, within 3.0 cm; group B, more than 3.0 cm). Medical records were reviewed for further histological and follow-up data. A questionnaire regarding dumping syndrome and gastric stasis was also completed by the patients.

RESULTS

Our results showed no statistically significant differences in symptoms, such as dumping syndrome or emptying disturbances, between the two groups.

CONCLUSION

Our study revealed that the differences in several functions and symptom scales were not pronounced between the two groups. Regardless of the length of the pyloric cuff, pylorus-preserving gastrectomy can be utilized for the treatment of early gastric cancer even if the tumor is located proximal to the middle body.

Recurrence after curative resection of early gastric cancer

BACKGROUND

Few studies have evaluated the recurrence of EGC after curative gastrectomy, due to its relatively low incidence. This study evaluated recurrence patterns and independent predictive factors for recurrence in order to determine appropriate follow-up and early detection of recurrence.

METHODS

We reviewed the medical records of 3,883 consecutive patients who underwent curative gastrectomy for EGC at Samsung Medical Center between February 1995 and January 2006 and were followed up until January 2008. The clinical and pathological characteristics and the predictive factors for recurrence were evaluated retrospectively.

RESULTS

Eighty-five (2.2%) patients had recurrence, and liver was the most common site of recurrence (45.9%). The recurrence rates within 2, 3, and 5 years were 43.5%, 67.1%, and 85.6%, respectively. There were 106 overall recurrences, with 86 (81.1%) being detected by computed tomography (CT). Second primary cancer was the primary cause of death after gastrectomy, followed by recurrence. Old age (>60 years), tumor size (>3 cm), multiple tumor, N category, and N2 station metastasis were significant factors for recurrence by multivariate analysis, but depth of invasion was not a significant factor.

CONCLUSIONS

Age, tumor size, number of tumors, N category, and N2 station metastasis were predictive factors for recurrence, with lymph node metastasis being the most significant factor. After curative gastrectomy, follow-up programs should be applied for more than 5 years for EGC patients, and computed tomography could be an essential diagnostic tool.

STAT3 expression in gastric cancer indicates a poor prognosis

BACKGROUND AND AIM

Signal transducers and activators of transcription (STAT) behave as signal transducers in the cytoplasm and as transcription factors in the nucleus. In the current study, we analyzed the immunohistochemical staining patterns of gastrectomy tissue specimens. We investigated the expression of STAT3 and STAT5 and estimated the relationship between STAT and cancer prognosis.

METHODS

One hundred patients who underwent gastrectomy due to gastric adenocarcinoma at Bundang CHA hospital between January 2000 and May 2005 were studied. Immunohistochemistry was carried out using antibodies against STAT3 and STAT5. The interpretation of the immunohistochemical staining was based on the proportion of stained cells in the field: positive, > 10% stained cells; and negative, < 10% stained cells.

RESULTS

The longest diameter of tumor was 4.67 cm in the positive group and 3.76 cm in the negative group, and these results were not statistically different (P-value = 0.112). Higher T (primary tumor) value (P-value = 0.05), more regional lymph node invasion (P-value = 0.008) and higher TNM staging (P-value = 0.069) were significantly related to STAT3 positivity, but Helicobacter pylori infection or atrophic gastritis were not related. A lower survival rate was observed in the STAT3-positive group (P-value = 0.001). The results of STAT5 were not statistically different with respect to TNM staging and survival (P-value = 0.958). We thus report that the immunohistochemical results of STAT3 revealed a significant association with TNM staging and survival.

CONCLUSION

We anticipate that STAT3 may be used as a molecular staging biomarker predicting poor prognosis of gastric cancer.

Recurrence in early gastric cancer with lymph node metastasis

BACKGROUND

Early gastric cancer (EGC) has an excellent prognosis, but some patients with lymph node-positive disease will develop recurrence. In this study we investigated the risk factors for recurrence in this selected group of patients.

METHODS

The clinical and pathological records of 2368 patients who underwent gastrectomy for solitary EGC between 1980 and 1999 at the National Cancer Center Hospital, Tokyo, were examined. Two hundred and thirty-eight patients (10%) were lymph node-positive (positive for lymph node metastasis) and form the population of this study.

RESULTS

Nineteen (8%) of the 238 patients with lymph node-positive disease developed recurrence. The most common site of recurrence was lymph node (37%), followed by liver (21%). The interval between surgery and the detection of recurrence ranged from 3 to 98 months, with a median of 26 months. Multivariate analysis demonstrated that the number of metastatic nodes was an independent risk factor for recurrence. Patients with seven or more metastatic nodes had the highest rate of recurrence, at 38%.

CONCLUSION

The number of nodes positive for metastasis was the only independent risk factor for recurrence after curative surgery in patients with lymph node-positive early gastric cancer. These high-risk patients may obtain additional survival benefit if targeted with adjuvant chemotherapy.

Asia-Pacific consensus guidelines on gastric cancer prevention

BACKGROUND AND AIM

Gastric cancer is a major health burden in the Asia-Pacific region but consensus on prevention strategies has been lacking. We aimed to critically evaluate strategies for preventing gastric cancer.

METHODS

A multidisciplinary group developed consensus statements using a Delphi approach. Relevant data were presented, and the quality of evidence, strength of recommendation, and level of consensus were graded.

RESULTS

Helicobacter pylori infection is a necessary but not sufficient causal factor for non-cardia gastric adenocarcinoma. A high intake of salt is strongly associated with gastric cancer. Fresh fruits and vegetables are protective but the use of vitamins and other dietary supplements does not prevent gastric cancer. Host-bacterial interaction in H. pylori infection results in different patterns of gastritis and differences in gastric acid secretion which determine disease outcome. A positive family history of gastric cancer is an important risk factor. Low serum pepsinogens reflect gastric atrophy and may be useful as a marker to identify populations at high risk for gastric cancer. H. pylori screening and treatment is a recommended gastric cancer risk reduction strategy in high-risk populations. H. pylori screening and treatment is most effective before atrophic gastritis has developed. It does not exclude the existing practice of gastric cancer surveillance in high-risk populations. In populations at low risk for gastric cancer, H. pylori screening is not recommended. First-line treatment of H. pylori infection should be in accordance with national treatment guidelines.

CONCLUSION

A strategy of H. pylori screening and eradication in high-risk populations will probably reduce gastric cancer incidence, and based on current evidence is recommended by consensus.

Lymph node metastasis in submucosal gastric cancer and reduction surgery

Although the concept of early gastric cancer (EGC) has been accepted, lymph node metastasis is the most important prognostic factor for EGC. Submucosal gastric cancer is greatly concerned because of its high lymph node metastasis incidence accounting for about 20% of all lymph node metastases. Many researchers suggest that reduction surgery should be performed for submucosal gastric cancer patients at a lower risk of developing lymph node metastasis. Submucosal gastric cancer can be divided into 3 levels (Sm1, Sm2, Sm3) based on its depth of invasion, which has been proven useful for predicting lymph node metastasis, directing treatment and evaluating prognosis. Recently, with the advances in clinical pathology and molecular biology, the risk factor for lymph node metastasis of submucosal gastric cancer can be accurately evaluated and its treatment has become rather rational. This paper reviews the relative factors for lymph node metastasis of submucosal gastric cancer and advances in its rational surgical treatment.

Optimal band imaging system can facilitate detection of changes in depressed-type early gastric cancer

BACKGROUND

The endoscopic diagnosis of depressed-type early gastric cancers is difficult because these cancers manifest as subtle changes in color and shape. The newly developed optimal band imaging (OBI) system can reconstruct the best spectral images derived from ordinary endoscopic images and enhances the mucosal surface without the use of dyes. This imaging technique is based on narrowing the bandwidth of conventional image arithmetically by using spectral estimation technology.

OBJECTIVE

Evaluation of the usefulness of the OBI system for identifying the demarcation line of depressed-type early gastric cancers.

DESIGN

Prospective study.

SETTING

Jichi Medical University in Japan.

PATIENTS

Twenty-seven cases with depressed-type early gastric cancer.

MAIN OUTCOME MEASUREMENT

Comparative study for the success rate of identifying the demarcation line of depressed-type early gastric cancer by using optimal band images and conventional endoscopic images.

RESULTS

Demarcation of the depressed-type early gastric cancer was easily identified by optimal band images without magnification in 26 of 27 cases (96%), because distinct demarcation was observed endoscopically between the reddish images of the cancerous lesion and the yellowish images of the surrounding noncancerous area. With 40-fold magnification of optimal band images, the demarcation was also clearly recognized in all cases. Medical students could point out the demarcation line with significantly greater accuracy by observing the new nonmagnified optimal band images than by the conventional images (P< .0001).

LIMITATION

Small sample size.

CONCLUSIONS

The new contrasting images of the OBI system can delineate the depressed-type early gastric cancer more easily than conventional endoscopy.

Features of Gastric Neoplasm Detected during the Screening Examination

BACKGROUND/AIMS

Gastric cancer is the leading malignancy in Korea and early detection through the health screening seems to be important. The aims of this study were to investigate the features of gastric neoplasms detected during screening, and to figure out the risk factors of these lesions.

METHODS

From October 2003 to September 2005, subjects who visited Seoul National University Hospital Healthcare System Gangnam Center for health check-up were included in the study. The program included a questionnaire and tests including anti-Helicobacter pylori (H. pylori) antibody, esophagogastroduodenoscopy or double contrast upper gastrointestinal study. To figure out the risk factors, an age and gender-matched, four-fold sized control group was selected from the subjects.

RESULTS

Of 25, 432 subjects, 122 cases of gastric neoplasms were detected including 61 adenocarcinoma (45 early gastric cancers), 53 adenoma, 7 mucosa-associated lymphoid tissue lymphoma, and one metastatic cancer. There was no significant statistical difference in basal characteristics of the subjects between gastric adenocarcinoma and adenoma. When comparing with the control group those without gastric neoplasms, smoking history, family history of stomach cancer, and H. pylori seropositivity were found to be significant risk factors for gastric neoplasms. Metabolic syndrome was more prevalent in adenoma than in the control (p<0.05).

CONCLUSIONS

The health screening may be beneficial in early detection of gastric cancer. In addition, metabolic syndrome might be related with gastric adenoma.

Early diagnosis of early gastric cancer

The prognosis of gastric cancer is closely related to the stage of disease at diagnosis. Early gastric cancer, whereby disease is limited to mucosa and submucosa, confers a survival rate of greater than 90% in 5 years in many centres. Gastric cancer is still a major cause of cancer mortality worldwide. In high incidence areas such as Japan, screening of asymptomatic population has been advocated. However, in Western countries, mass screening is not cost-effective. Hence, strategy has been directed to screen symptomatic individuals who are at higher risk of gastric cancer. Most patients with early gastric cancer present with symptoms indistinguishable from benign peptic ulcer disease. Screening for this group of patients improves detection rate of early gastric cancer and therefore its prognosis. Endoscopy for surveillance of premalignant lesions has been explored with this objective in mind. Serology testing for biomarkers such as pepsinogen, anti-Helicobacter pylori antibody and gastrin has been studied as an alternative to endoscopy. There is compelling evidence for the role of H. pylori in the initiation of Correa's cascade (stepwise progression from chronic active gastritis, atrophic gastritis, intestinal metaplasia, dysplasia and finally adenocarcinoma). Regression of premalignant lesions has been demonstrated with H. pylori eradication. However, it is not known whether this might effectively prevent gastric cancer in either low or high-risk population.

Prognostic factors for advanced gastric cancer: stage-stratified analysis of patients who underwent curative resection

PURPOSE

Advanced gastric cancer patients have a poorer prognosis as compared to the patients with early gastric cancer. This study was conducted to define the prognostic factors for advanced gastric cancer.

MATERIALS AND METHODS

606 patients with advanced gastric cancer who underwent curative gastric resection at our hospital were retrospectively examined. The patients were divided into two groups: group 1 was comprised of patients with a survival time <5 years, and group 2 patients had a survival time >or=5 years. We compared clinicopathological characteristics of the two groups by performing univariate and multivariate analysis. We also investigated the prognostic factors according to the stage.

RESULTS

On univariate analysis, 7 factors (age, tumor size, Borrmann type, resection type, distal resection margin, depth of invasion and lymph node status) were found to be different, and multivariate analysis revealed that patient age, depth of invasion and lymph node metastasis were the only significantly differences between the two groups. On the other hand, age and the Borrmann type for stage I b patients, age and the number of retrieved lymph nodes for stage II patients, tumor size for stage III patients, and the type of resection for stage IV patients were found to be the independent prognostic factors.

CONCLUSION

The age of patients had prognostic value in the early stages of advanced gastric cancers such as stage I b or II. The number greater than 20 retrieved lymph nodes affected the survival, particularly for the patients with stage II disease, and the tumor size was a significant prognostic factor for patients with stage III disease. Therefore, physicians are advised to pay special attention to lymph node dissection for those patients with stage II or III disease.

Laparoscopy-assisted distal gastrectomy for early gastric cancer: experience with 111 consecutive patients

BACKGROUND

Laparoscopy-assisted distal gastrectomy (LADG) is gaining wider acceptance for the treatment of early gastric cancer. However, firm evidence supporting its safety and usefulness is scant, and no study has compared the outcomes of various procedures for LADG. We examined the surgical outcomes of LADG performed using different methods for lymph node dissection.

METHODS

Between September 1998 and January 2005, we performed LADG in 111 patients with early gastric cancer. In the 55 patients treated initially, group 2 lymph node dissection was performed through a small, 7-cm-long incision (minilaparotomy). In 43 of these patients, hand-assisted laparoscopic surgery (HALS) was done. In the 56 patients treated more recently, lymph node dissection was performed laparoscopically. In 31 of these patients, the celiac branches of the vagus nerve were preserved. Clinical outcomes of these procedures were compared.

RESULTS

In the first 55 patients, HALS significantly shortened the operation time (277 vs 243 min, p < 0.05). In the latter 56 patients, LADG with preservation of the celiac branches of the vagus nerve was associated with a longer operation time (283 vs 228 min, p < 0.01) and higher blood loss (150 vs 92 g, p < 0.05) than with LADG without celiac branch preservation. There were no differences among the various operative procedures in postoperative course, including the length of the postoperative hospital stay or the rate of complications.

CONCLUSIONS

LADG is a safe and technically feasible procedure for the treatment of early gastric cancer. Laparoscopic lymph node dissection provided a good visual field and was easier to perform and required less time when the celiac branches of the vagus nerve were not preserved, with no negative effect on outcome.

Minimally invasive and local treatment for mucosal early gastric cancer

BACKGROUND

Early gastric cancer (EGC) can present an indication for local resection procedures under pertain circumstances. Especially endoscopic mucosal resections (EMRs) and laparoscopic resections or those combined with endoscopy have been made possible in recent years.

METHODS

From 1996 to 2004, of a total of 425 patients with gastric cancer, 58 patients with EGC (13.6%) were prospectively analyzed and observed. Of these, 35 patients had preoperatively diagnosed submucosal infiltration and subsequently underwent gastrectomy and standard lymphnodectomy. Of the 23 patients with intramucosal EGC, 22 underwent local resection. One patient displayed lymph node and liver metastasis at the time of diagnosis and received chemotherapy following staging laparoscopy.

RESULTS

Among the 23 patients with intramucosal EGC, 13 were female and 10 male. The average age of the patients was 77.4 years (range: 69-86). The rate of lymph node metastasis was 12.5% (n = 35) for submucosal EGC and 4.3% (n = 23) for intramucosal EGC. Twenty-two patients with intramucosal EGC underwent local resection (four EMR, six laparoscopic intragastric resection, 12 laparoscopic wedge resection). The average tumor size was 1.2 cm (range 0.3-2.3). The definitive histological findings yielded in all patients tumor-free resection margins without venous or lymphangic infiltration. In 10 of 18 patients undergoing laparoscopic resection a simultaneous sentinel lymph node sampling (4 +/- 3 LN) was performed. There were no metastases detected. Method-specific complications did not occur. The morbidity of this patient group was 13.6% (three of 22). Mortality was zero. The average postoperative hospital stay was 6.5 days (range 2-12). In the median follow-up of 30.3 months (range 1-86) no recurrences have yet been diagnosed. Four patients died within the observation period of non-cancer-related causes.

CONCLUSIONS

Minimally invasive local resection of intramucosal EGC represents a favorable option when strict determination of indication has taken place.

Is a lymph node detected by the dye-guided method a true sentinel node in gastric cancer?

PURPOSE

A sentinel node is defined as the initial lymph node, to which cancer cells metastasize from a primary tumor. Recently, sentinel node navigation surgery has been done using the dye-guided method. However, no study has shown that a lymph node detected by the dye-guided method is the true sentinel node from the viewpoint of micrometastasis. Micrometastases of lymph nodes, in which no metastasis was found by H&E staining, were examined to establish whether a lymph node detected by the dye-guided method is the true sentinel node.

EXPERIMENTAL DESIGN

Isosulfan blue was injected endoscopically as the dye-guided method at a submucosal lesion of early gastric cancer. Total 345 lymph nodes, including 150 blue-dyed lymph nodes and 195 nondyed lymph nodes were collected from 57 patients and each was quartered. Two quarters were examined histologically by H&E staining and cytokeratin staining. The other specimens were used for quantitative reverse transcription-PCR of CEA and CK20 mRNAs.

RESULTS

Lymph node disease was not found in any of 345 lymph nodes from the 57 patients by routine H&E staining. By contrast, either CEA or CK20 mRNA expression was detected in 21 of 345 lymph nodes obtained from the 10 (18%) of 57 patients by quantitative reverse transcription-PCR. Eight of the 21 micrometastasis-positive lymph nodes were confirmed to be positive for cytokeratin staining. Although micrometastasis of nondyed lymph nodes was found in three cases, these were included in the 10 cases with micrometastasis of blue-dyed nodes, such that there was no patient who only had micrometastasis in nondyed nodes. Six of 10 cases were micrometastasis-positive in a single node; all six were blue-dyed nodes.

CONCLUSION

A lymph node detected by the dye-guided method should be a true sentinel node to which cancer cells metastasize initially.