Gastric cancer detected by mass survey. Comparison between mass survey and outpatient detection

Risk factors and clinical outcomes of gastric cancer identified by screening endoscopy: a case-control study

BACKGROUND AND AIM

A customized screening program for gastric cancer would optimize the benefits of screening endoscopy. This study investigated the risk factors for gastric cancer detected during screening and factors affecting clinical outcomes.

METHODS

From April 2000 to December 2010, subjects who underwent screening endoscopy at Asan Medical Center were included. To investigate risk factors, age- and sex-matched control group was selected. The clinical outcomes of gastric cancer identified during screening (screening group) were compared with age, sex, and date of diagnosis-matched subjects who were diagnosed with gastric cancer in the outpatient clinic (outpatient group).

RESULTS

Of 109 530 subjects, 327 were diagnosed with gastric cancer. The median age of the screening group was 63.6 years (interquartile range 56-71 years), and the male-to-female ratio was 2.4:1. When comparing with the control group, Helicobacter pylori seropositivity (odds ratio [OR] 2.933, P < 0.001), carcinoembryonic antigen (OR 8.633, P = 0.004), family history of gastric cancer (OR 2.254, P = 0.007), and drinking (OR 3.312, P < 0.001) were independent positive risk factors, and the use of aspirin a negative risk factor for gastric cancer (OR 0.445, P = 0.012) in multivariate analysis. Low-density lipoprotein cholesterol (hazard ratio [HR] 0.987, P = 0.005), cancer antigen 19-9 (HR 21.713, P < 0.001), resectability (HR 59.833, P < 0.001), and family history (HR 0.308, P = 0.009) were independent risk factors for death. The 5-year survival rate was significantly higher in the screening group than in the outpatient group (P < 0.001).

CONCLUSIONS

Early detection of gastric cancer by screening endoscopy while asymptomatic enhances patient outcomes, especially in high-risk groups.

Converting a microarray signature into a diagnostic test: a trial of custom 74 gene array for clarification and prediction the prognosis of gastric cancer

Background

Gastric cancer (GC) is associated with high mortality rates and an unfavorable prognosis at advanced stages. In addition, there are no effective methods for diagnosing gastric cancer at an early stage or for predicting the outcome for the purpose of selecting patient-specific treatment options. Therefore, it is important to investigate new methods for GC diagnosis.

Methodology/Principal Findings

To facilitate its use in a diagnostic setting, a group of 74 genes with diagnostic and prognostic information was translated into a customized microarray containing a reduced set of 1,042 probes suitable for high throughput processing. In this report, we demonstrate for the first time that the custom mini-array can be used as a reliable diagnostic tool in gastric cancer. With an AUC value of 0.565 (95% CI 0.305-0.825) indicating a perfect test, the sensitivity and specificity of diagnosis from the ROC curve were calculated to be 70% and 80%, respectively.

Conclusions/Significance

The data clearly demonstrate the reproducibility and robustness of the small custom-made microarray. The array is an excellent tool for classifying and predicting the outcome of disease in gastric cancer patients.

Gastric precancerous lesions are associated with gene variants in Helicobacter pylori-susceptible ethnic Malays

AIM: To identify genes associated with gastric precancerous lesions in Helicobacter pylori (H. pylori)-susceptible ethnic Malays.

METHODS: Twenty-three Malay subjects with H. pylori infection and gastric precancerous lesions identified during endoscopy were included as “cases”. Thirty-seven Malay subjects who were H. pylori negative and had no precancerous lesions were included as “controls”. Venous blood was collected for genotyping with Affymetrix 50K Xba1 kit. Genotypes with call rates < 90% for autosomal single nucleotide polymorphisms (SNPs) were excluded. For each precancerous lesion, associated SNPs were identified from Manhattan plots, and only SNPs with a χ²P value < 0.05 and Hardy Weinberg Equilibrium P value > 0.5 was considered as significant markers.

RESULTS: Of the 23 H. pylori-positive subjects recruited, one sample was excluded from further analysis due to a low genotyping call rate. Of the 22 H. pylori-positive samples, atrophic gastritis only was present in 50.0%, complete intestinal metaplasia was present in 18.25%, both incomplete intestinal metaplasia and dysplasia was present in 22.7%, and dysplasia only was present in 9.1%. SNPs rs9315542 (UFM1 gene), rs6878265 (THBS4 gene), rs1042194 (CYP2C19 gene) and rs10505799 (MGST1 gene) were significantly associated with atrophic gastritis, complete intestinal metaplasia, incomplete metaplasia with foci of dysplasia and dysplasia, respectively. Allele frequencies in “cases”vs“controls” for rs9315542, rs6878265, rs1042194 and rs10505799 were 0.4 vs 0.06, 0.6 vs 0.01, 0.6 vs 0.01 and 0.5 vs 0.02, respectively.

CONCLUSION: Genetic variants possibly related to gastric precancerous lesions in ethnic Malays susceptible to H. pylori infection were identified for testing in subsequent trials.

Epidemiological features of gastric cancer detected by gastroscopy in Qinghai between 1979 and 2008

AIM: To investigate the prevalence of gastric cancer since the use of gastroscopy in Qinghai province, China.

METHODS: The clinical data for patients with gastric cancer detected by gastroscopy between 1979 and 2008 in Qinghai province was analyzed retrospectively. The detection rates of gastric cancer by gastroscopy were compared by ethnicity, gender, and time period, and the prevalence of gastric cancer in this region was calculated.

RESULTS: A total of 6 362 cases of gastric cancer were detected between 1979 and 2008, with an overall detection rate of 6.228%. The male to female ratio was 3.594:1. The detection rates of gastric cancer by gastroscopy in Han, Hui, Tibetan, Salar, Tu, and Mongolian people were 5.959%, 8.519%, 6.128%, 6.868%, 6.492%, and 3.876%, respectively. The mean age of patients with gastric cancer was 55.40 years old (men, 56.19 years; women, 52.65 years). The predilection site of gastric cancer is the antrum. Although the overall detection rate of gastric cancer tended to decrease in recent years, an increase in the detection rate was note in Tu and Mongolian people. Age of onset of gastric cancer has gradually increased in recent years. There was an upward trend in the incidence of cardia cancer in recent years.

CONCLUSION: There are several features of gastric cancer detected in Qinghai between 1979 and 2008, including high detection rate, young average patient age, high proportion of male patients, and low degree of differentiation. Overall, the detection rate of gastric cancer decreased and average age of onset increased in recent years.

Statistical analysis of serum pepsinogen I (PG I) and II (PG II) levels, PG I/PG II ratios and serum gastrin levels in a general population

To allow adoption of serum pepsinogen as a screening indicator of gastric cancer, serum pepsinogen I & II levels, the ratios of PG I / PG II and the serum gastrin levels in a general population were studied using 850 samples selected at random from a rural area in Japan. The collected data were analyzed statistically to determine the distribution characteristics by various categories of sex and age. The following results were obtained:1. The distributions of PG I and PG II, the ratios of PG I/PG II and serum gastrin values largely deviated from the normal distribution. Therefore, the use of non-parametrical methods was recommended for analysis of these data.2. Although no significant difference between all selected men and all selected women was observed in any of the three parameters of PG I and PG II levels and the ratios of PG I / PG II, a significant difference between men and women was observed for PG I levels in under-fifty age groups. On the other hand, the median serum gastrin value (92.0 pg/ml) in all selected men was significantly lower than that (101.0 pg/ml) in all selected women. A statistically significant difference between men and women was observed in serum gastrin levels both in the under-forty age group and in the sixty and over age group.3. No significant difference was observed in the pattern of changes in PG I levels with increasing age in either men or women. While PG II levels in men varied irregularly with advancing age, PG II levels in women showed obvious increases with advancing age. The ratios of PG I / PG II showed a tendency to decrease with advancing age in both men and women. Conversely, serum gastrin levels increased with advancing age in both men and women.

MicroRNAs as diagnostic biomarkers in gastric cancer

Considering the high mortality rates and the unfavorable prognosis of gastric cancer (GC) as well as the lack of a clinical predictive marker, which is sufficiently sensitive to GC, it is of great significance to investigate new sensitive and specific markers for GC diagnosis. MicroRNAs (miRNAs) could be a practical form of potential biomarkers in the diagnosis of human disease, and they are confirmed to be closely associated with GC. In this review, we discuss the recent research results that indicate the feasibility and clinical applications of miRNAs in GC. Although several challenges remain to be addressed, miRNAs have the potential to be applied in the diagnosis of GC.

Experienced versus inexperienced confocal endoscopists in the diagnosis of gastric adenocarcinoma and intestinal metaplasia on confocal images

BACKGROUND

Confocal laser endomicroscopy (CLE) may be used to diagnose gastric cancer and intestinal metaplasia, but the impact of CLE experience on the accuracy of confocal diagnosis of gastric cancer and intestinal metaplasia is not clear.

OBJECTIVE

To establish the sensitivity, specificity, and intragroup interobserver agreement of CLE image interpretation by 3 experienced (group 1) and 3 inexperienced (group 2) CLE endoscopists for diagnosing gastric intestinal metaplasia (GIM) and adenocarcinoma.

DESIGN

Blinded review of CLE images for the diagnosis of gastric cancer or intestinal metaplasia.

SETTING

Tertiary care hospital.

PATIENTS

CLE images obtained ex vivo from gastrectomy specimens with proven gastric cancer and CLE images obtained in vivo from Chinese subjects older than 50 years of age by using matched biopsy specimens as reference standards.

MAIN OUTCOME MEASUREMENTS

Sensitivity, specificity, and intragroup interobserver agreement of CLE image interpretation.

RESULTS

Interpretation of in vivo images by group 1 was associated with higher sensitivity (95.2% vs 61.9%, P = .039) and higher specificity (93.3% vs 62.2%, P < .001) for GIM than interpretation by group 2. The agreement between interpretation by group 1 and histology for GIM was higher than that for group 2 (κ = 0.864 vs 0.217). The sensitivity (93.3% for group 1 vs 86.7% for group 2, P = 1.000) and specificity (87.7% for group 1 vs 80.7% for group 2, P = .344) of interpretation of ex vivo CLE images for the diagnosis of gastric adenocarcinoma was similar for groups 1 and 2.

LIMITATIONS

Single-center study.

CONCLUSIONS

Experience in CLE was associated with greater accuracy in the diagnosis of intestinal metaplasia.

Detection of gastric carcinoma-associated MG7-Ag by serum immuno-PCR assay in a high-risk Chinese population, with implication for screening

To evaluate gastric carcinoma-associated antigen, MG7-Ag, for detection of gastric cancer in a high-risk population, a population-based screening of gastric cancer was conducted in Linqu County, Shandong Province, China. In 2002 and 2003, a total of 2,710 participants aged 35-65 years received an endoscopic examination with 5 biopsies taken from standard sites with pathological diagnosis, and serum samples were collected to detect MG7-Ag by serum-based Immunopolymerase chain reaction (PCR) assay. The sensitivity and specificity of MG7-Ag Immuno-PCR assay in detecting of gastric cancer were assessed. Of 2,710 participants, 148 (5.46%) were determined to be MG7-Ag positive. The sensitivity of MG7-Ag Immuno-PCR assay for the detection of gastric cancer was 77.5% (31 of 40 gastric cancer cases), the specificity was 95.62% (2,553 of 2,670 nongastric cancer subjects) and the accuracy was 73.12%. A total of 24 gastric cancer cases were in Stage I or II, of which 17 (70.8%) were MG7-Ag positive. However, the proportion of MG7-Ag positivity in subjects with superficial gastritis, chronic atrophic gastritis, intestinal metaplasia, indefinite dysplasia or dysplasia was ranged from 3.00% to 5.61% in comparison with 77.5% in those with gastric cancer. Our findings suggest that MG7-Ag was a sensitive and specific serum biomarker and may have a potential for gastric cancer screening in the high-risk population.

Detection of early gastric cancer: misunderstanding the role of mass screening

BACKGROUND

The proportion of early gastric cancer (EGC) increased from 15% during the 1960s to 50% recently, leading to a remarkable improvement of the 5-year survival rate of gastric cancer patients from 40% to 70%. This has been attributed to mass screening together with extended lymphadenectomy. However, more and more patients with EGC are diagnosed outside of mass screening. The aim of this study was to determine whether patients are symptomatic at the time of early detection and the method of tumor detection.

METHODS

From 2001 to 2003, a total of 1226 patients (male/female 2.2 : 1.0, age 26-95 years) with EGC were treated at the National Cancer Center Hospital, Tokyo. We reviewed their medical records.

RESULTS

Of these 1226 patients, 512 (41.8%) were symptomatic, and 714 (58.2%) reported no symptoms. Among the symptomatic patients, 468 (91.4%) were examined at outpatient clinics, 39 (7.6%) by private health assessment clinics, and 5 (1.0%) by mass screening. In total, 91.6% of the symptomatic patients directly underwent esophagogastro-duodenoscopy (EGD). Of the asymptomatic patients, 320 (44.8%) were examined at outpatient clinics, 306 (42.9%) by private health assessment clinics, and 88 (12.3%) by mass screening. EGD was the initial assessment in 67.8% and radiography in 32.2% of asymptomatic patients.

CONCLUSION

Most patients with EGC were detected outside of mass screening. This suggests that the Japanese public and physicians are well aware of the risk of gastric cancer and the importance of early detection. The effect of mass screening is misunderstood.

Comparing mass screening techniques for gastric cancer in Japan

AIM: To discuss the efficacy of endoscopic mass screening for gastric cancer.

METHODS: The data used in this study were the results of mass screening programs for gastric cancer in Niigata City from 2002 to 2004. The number of participants was 35 089 in 2002, 34 557 in 2003 and 36 600 in 2004. The finding ratio referred to the final diagnosis of gastric cancer after a double check of endoscopic files and histological findings. The costs of identifying one case of gastric cancer were calculated based on the total expense for each screening program and additional close examinations.

RESULTS: From the analysis of individual screening program with endoscopy, individual screening program with X-ray (ISX) and mass screening program with photofluorography (MSP) in reference to the finding ratio of gastric cancer, endoscopic examination was the best for detecting early gastric cancer, the finding ratio was 0.87% in 2004, approximately 2.7 and 4.6 times higher than those of the ISX and MSP groups. In addition, this novel method was the cheapest means regarding the cost of identifying one case of gastric cancer, which was estimated to be 1 608 000 Japanese yen in 2004.

CONCLUSION: Endoscopic mass screening is a promising method and can be effectively applied if a sufficient number of skilled endoscopists become available to staff the system and if city offices support it.

Status of extended lymph node dissection: Locoregional control is the only way to survive gastric cancer

There are many factors that are of influence on gastric cancer treatment. The only way to survive is complete locoregional control. More extended dissections should lead to better outcome, but increased morbidity and mortality probably offset its long-term effect in survival in randomised studies. In this article the factors of influence on outcome of gastric cancer treatment such as the extent of lymph node dissection, splenectomy, pancreatectomy, age, volume and additional treatments are discussed. A literature review of these factors in relation to the latest results of the Dutch Gastric Cancer Trials are presented. If morbidity and mortality can be reduced there might be an advantage of extended lymph node dissection. Splenectomy and pancreatectomy should be performed only in case of direct in growth from the tumour into these organs. Centralisation of gastric cancer treatment should be achieved in order to improve results and to facilitate research. By refining selection criteria in the treatment of gastric cancer further improvements are to be expected.

Quality assurance of surgery in gastric and rectal cancer

Multimodality and quality controlled treatment result in improved treatment outcome in patients with solid tumours. Quality assurance focuses on identifying and reducing variations in treatment strategy. Treatment outcome is subsequently improved through the introduction of programs that reduce treatment variations to an acceptable level and implement standardised treatment. In chemotherapy and radiotherapy, such programmes have been introduced successfully. In surgery however, there has been little attention for quality assurance so far. Surgery is the mainstay in the treatment of patients with gastric and rectal cancer. In gastric cancer, the extent of surgery is continuously being debated. In Japan, extended lymph node dissection is favoured whereas in the West this type of surgery is not routinely performed with two large European trials concluding that there is no survival benefit from regional lymph node clearance. Post-operative chemoradiation is part of the standard treatment in the United States, although its role in combination with adequate surgery has not been established yet. These global differences in treatment policy clearly relate to the extent and quality of surgical treatment. As for gastric cancer, surgical treatment of rectal cancer patients determines patient's prognosis to a large extent. With the introduction of total mesorectal excision, local control and survival have improved substantially. Most rectal cancer patients receive adjuvant treatment, either pre- or post-operatively. The efficacy of many adjuvant treatment regimens has been investigated in combination with conventional suboptimal surgery. Traditional indications of adjuvant treatment might have to be re-examined, considering the substantial changes in surgical practise. Quality assurance programs enable the introduction of standardised and quality controlled surgery. Promising adjuvant regimens should be investigated in combination with optimal surgery.

The epidemiology of gastric cancer

Gastric cancer mortality has declined markedly around the world. In South Australia, the reduction approximated 40% over the last 20 years. Possible reasons include: better refrigeration; reduced consumption of salted, smoked, and chemically preserved foods; increased intake of fruit and vegetables; and improved living standards and a greater use of antibiotics, which may have reduced Helicobacter pylori infection. Reductions generally have been greater for intestinal than diffuse histopathologies. Gastric cancer remains the second leading cause of cancer death worldwide, probably accounting for about 10% of newly diagnosed cancers. High rates apply to Japan, China. Central and South America, Eastern Europe, and parts of the Middle East, and low rates to North America, Australia and New Zealand, Northern Europe, and India. Rates usually are higher in lower socioeconomic groups. Five-year relative survivals of around 20% or less are frequently reported. A figure of 50% or more has been cited for Japan, where there has been radiological screening, although this exceptional figure could have been affected artificially by lead-time and related effects. Male-to-female incidence ratios generally are in the 1.5-2.5 range, with higher ratios for intestinal than diffuse cancers and higher-risk populations. In South Australia, the ratio has been 1.8 to one, although higher at 4.6 to one for cardia lesions. Recent increases in cardia cancers, especially in males in populations of European extraction, often are accompanied by increases for esophageal adenocarcinoma. It is estimated that the global burden of gastric cancer could be reduced by up to 50% by dietary changes that included an increased intake of fruit and vegetables.

Cancer surgery: the last 25 years

Surgery is, and always has been, the main treatment modality of solid tumours. For a long period, it consisted of a number of surgical procedures dictated by basic oncologic principles, most of which are still adhered to. Over the last few decades, increased understanding of the disease, new or improved diagnostic facilities, novel and perfected adjuvant treatments, improved surgical techniques and daring challenges to established dogmas have all contributed to the development of surgical oncology. The heritage from the past came under close scrutiny, and the fruits of basic and clinical science were added to an ever expanding body of knowledge. It is impossible to review all developments in surgical oncology of the last 25 years in one comprehensive paper. Therefore we have restricted ourselves to those items that appear most representative for the changes that have taken place, and those diseases that have the greatest numerical impact.

A clinicopathological study of asymptomatic gastric cancer

The clinicopathological profiles of 419 patients with asymptomatic gastric cancer (AGC) first detected by gastric screening, were reviewed and compared with those of the 1727 patients with symptomatic gastric cancer (SGC). The incidence of AGC increased gradually and has amounted to 30% of the total resected cases in recent years. About 75% of AGC cases were of early cancer and 84% were negative for lymph node metastases. In contrast, only 33% of SGC cases were of early cancer and 57% were node positive. Curative resection was done in 97% of AGC and 75% of SGC. The cumulative 5 and 10 year survival rates of patients with curatively resected AGC were 85.2% and 72.2%, respectively, while those for patients with SGC were 66.8% and 55.4%. These data demonstrated that most patients with asymptomatic gastric cancers could expect a curative resection, i.e. have a better clinical outcome, than those with symptomatic cancer.

Comparison of factors influencing the prognosis of Japanese, German, and Dutch gastric cancer patients

As a result of Japanese reports of improved survival of gastric cancer patients after extended lymph node dissection, a study was undertaken to evaluate factors that might influence these results. The influence of staging was evaluated by stratifying 1085 patients of the National Cancer Center of Japan and grouping them according to the three commonly used systems; UICC's old and new TNM systems (fourth edition) and the system of the Japanese Research Society for the study of Gastric Cancer (JRSGC). No survival difference was found between the stages of the three systems, except for stage II, where the new TNM and the JRSGC differed (p < 0.05). In a second analysis, the incidence of the most important prognostic factors for advanced gastric cancer was compared among three institutions: the National Cancer Center Tokyo, Japan (NCC), the University Hospital Erlangen, Germany (UHE) and the University Hospital Maastricht in The Netherlands (UHM). Japanese patients were on average 3 years younger than the German patients and 8 years younger than the Dutch patients, and had a higher proportion of advanced (T4) carcinomas. Male-female distribution, histology, and lymph node invasion were comparable in the three groups. From these data a rather worse prognosis for Japanese advanced gastric cancer patients could be expected. However, the observed 5-year survival rates show a marked advantage for the Japanese patients: 57% (NCC) versus 34% (UHE) and 31% (UHM). The survival difference for stage II patients between the new TNM and the JRSGC staging systems is not sufficient to explain this advantage. This result underlines the importance of the Japanese therapeutic approach.(ABSTRACT TRUNCATED AT 250 WORDS)

Early gastric cancer

Early gastric cancer is a unique form of gastric carcinoma with an excellent prognosis. Now recognized worldwide, this tumor is most commonly diagnosed in Japan secondary to aggressive screening practices. Early detection is dependent on a low threshold for esophagogastroduodenoscopy with biopsies, because specific symptoms and physical findings or diagnostic laboratory tests are rarely present with early gastric cancer. Once the disease is diagnosed, subtotal gastrectomy achieves survival rates equivalent to those of age-matched controls. Consideration of total gastrectomy is warranted with proximal tumor location or multicentric carcinoma. Radical lymphadenectomy should be undertaken in patients with regional nodal metastasis. After operative resection, patient outcome is usually excellent. Large submucosal tumors with an aneuploid DNA pattern and nodal involvement denote a more ominous outlook. Close patient follow-up is necessary to detect both the uncommon recurrence and the more common nongastric malignancy.

Surgical treatment of carcinoma of the gastric stump

To evaluate retrospectively the surgical treatment of patients with gastric stump cancer following gastrectomy for benign disease, we reviewed 52 patients operated on at the National Cancer Centre, Tokyo, between 1962 and 1988. Resection was carried out in 47 patients (90 per cent) and with curative intent in 36 (69 per cent). Stage distribution was: stage 1, 15 patients; stage 2, 5; stage 3, 9; stage 4, 23. In 36 cases curatively resected, 32 had completion total gastrectomy and four had subtotal resection. An R1 resection was performed in 11 patients and an R2 in 25. We had two hospital deaths and a 5-year survival rate excluding hospital deaths of 39 per cent. The 5-year survival rates of resected cases, curative cases and those having metastatic nodes were 43 per cent, 57 per cent and 29 per cent respectively. Radical resection is a reasonable treatment for gastric stump cancer as it is for primary cancer of the stomach.