Cancer of the gastric cardia is rising in incidence in an Asian population and is associated with adverse outcome

Structural characterization and biological properties of human gastrokine 1

Gastrokine-1 (GKN1), a protein expressed in normal gastric tissue, but absent in gastric cancer tissues and derived cell lines, has recently emerged as a potential biomarker for gastric cancer. To better establish the molecular properties of GKN1, the first protocol for the production of mature human GKN1 in the expression system of Pichia pastoris was settled. The recombinant protein showed anti-proliferative properties specifically on gastric cancer cell lines thus indicating that it was properly folded. Characterization of structural and biochemical properties of recombinant GKN1 was achieved by limited proteolysis analysis, circular dichroism and fluorescence spectroscopy. The analysis of GKN1 primary structure coupled to proteolytic experiments highlighted that GKN1 was essentially resistant to proteolytic enzymes and showed the presence of at least a disulphide bond between Cys61 and one of the other three Cys (Cys122, Cys145 and Cys159) of the molecule. The secondary structure analysis revealed a prevailing β-structure. Spectroscopic and calorimetric investigations on GKN1 thermal denaturation pointed out its high thermal stability and suggested a more complex than a two-state unfolding process. The resulting protein was endowed with a globular structure characterized by domains showing different stabilities toward chemical and physical denaturants. These results are in agreement with the prediction of GKN1 secondary structure and a three-dimensional structure model. Our findings provide the basis for the development of new pharmaceutical compounds of potential use for gastric cancer therapy.

Lymphadenectomy around the left renal vein in Siewert type II adenocarcinoma of the oesophagogastric junction

BACKGROUND

The extent of lymphadenectomy in patients with Siewert type II adenocarcinoma of the oesophagogastric junction is controversial. The aim of this study was to investigate lymph node involvement around the left renal vein.

METHODS

Lymph node involvement and prognosis in patients with Siewert type II cancers treated by R0-1 surgical resection were investigated, with regard to lymphadenectomy around the left renal vein. Based on the incidence of involvement at each node, the node stations were divided into three tiers (first tier, more than 20 per cent involvement; second tier, 10-20 per cent involvement; third tier, less than 10 per cent involvement).

RESULTS

Of 150 patients with type II oesophagogastric adenocarcinoma, 94 had left renal vein lymphadenectomy. The first lymph node tier included nodes along the lesser curvature, right cardia, left cardia and left gastric artery, with involvement of 28·0-46·0 per cent and a 5-year survival rate of 42-53 per cent in patients with positive nodes. The nodes around the lower mediastinum, left renal vein, splenic artery and coeliac axis constituted the second tier, with involvement of 12·7-18 per cent and a 5-year survival rate of 11-35 per cent. With regard to the left renal vein, the incidence of involvement was 17 per cent and the 5-year rate survival rate was 19 per cent. Multivariable analysis showed that left renal vein lymphadenectomy was an independent prognostic factor in patients with pathological tumour category pathological T3-4 disease (hazard ratio 0·51, 95 per cent confidence interval 0·26 to 0·99; P = 0·048).

CONCLUSION

Left renal vein nodal involvement is similar to that seen along the splenic artery, in the lower mediastinum and coeliac axis, with similar impact on patient survival.

Different expression pattern and significance of p14ARF-Mdm2-p53 pathway and Bmi-1 exist between gastric cardia and distal gastric adenocarcinoma

Recent studies have suggested that adenocarcinoma of gastric cardia (GCA) is distinct from distal stomach, with different risk factors, tumor characteristics, and biological behavior. The aim of this study is to evaluate the possible difference in the expressions of p14ARF, Mdm2, p53, and Bmi-1 by immunohistochemical staining on paraffin-embedded tissues of gastric cardia adenocarcinoma (GCA; n = 74) and distal gastric adenocarcinoma (DGA; n = 41). The results showed that the percentage of p14ARF-negative expression, Mdm2 overexpression, p53-positive expression, and p53 pathway abnormality (p14ARF(-)/Mdm2(+)/p53(+)) were all significantly higher in GCA than those in DGA (P < .05). Further analysis showed that in GCA, the negative expression of p14ARF was significantly associated with poor differentiation, Mdm2 overexpression with tumor stage and lymph node metastasis, and positive p53 expression with tumor stage (P < .05), whereas in DGA, only Mdm2 overexpression was related with well/moderate differentiation (P < .05). Abnormality of the p53 pathway was significantly correlated with poorer differentiation only in GCA (P < .05). The positive expression of Bmi-1 in all cases of GCA and DGA was significantly higher than normal gastric mucosa epithelium, but no difference was found between GCA and DGA (P > .05). Thus, the results in this study confirmed that different expression pattern and clinicopathologic significance of the p14ARF-Mdm2-p53 pathway did exist between GCA and DGA. The results further support the hypothesis that different mechanisms may be involved in the development and progression of adenocarcinoma from cardia and distal portion of stomach.

Higher prevalence of obesity in gastric cardia adenocarcinoma compared to gastric non-cardia adenocarcinoma

BACKGROUND AND AIMS

Obesity is one of the main risk factors for gastric cardia adenocarcinoma (GCA) in the West. Also, recent studies have suggested that GCA is distinct from distal stomach tumor, with differing risk factors, tumor characteristics, and biological behavior. The objective of our research was to evaluate the relationship between obesity and GCA compared to non-cardia adenocarcinoma.

MATERIALS AND METHODS

A total of 298 patients who were diagnosed with gastric adenocarcinoma and underwent surgery at Seoul National University Bundang Hospital were evaluated. Ninety-one cases were GCA, and 207 cases were non-cardiac adenocarcinoma. Obesity was estimated by body mass index (BMI, kg/m(2)). The degree of obesity was determined by using BMI <18.5, 18.5-23.9, 24-27.9, and ≥ 28 (kg/m(2)) as the cut-off points for underweight, normal weight, overweight, and obese, respectively. Association with obesity was estimated by odds ratio (OR) and 95% confidence interval (CI).

RESULTS

Obesity was more prevalent in patients with GCA at the time of diagnosis for gastric cancer. Among obese persons with a BMI of 28 kg/m(2) or higher, the OR was 3.937 (95% CI, 1.492-10.389; p = 0.006) for GCA compared to non-cardia adenocarcinoma. For overweight individuals, the OR was 2.194 (95% CI, 1.118-4.305; p = 0.022). Multivariate analysis of age, Helicobacter pylori infection, smoking, stage, and BMI with logistic regression was performed. BMI was an independent risk factor for GCA (OR, 1.123; 95% CI, 1.037-1.217; p = 0.004).

CONCLUSION

Obesity was more prevalent in patients with GCA compared to that in patients with gastric non-cardia adenocarcinoma. Also, BMI was an independent risk factor for GCA.

Prevalence and clinicopathologic characteristics of gastric cardia cancer in South Korea

BACKGROUND AND AIM

Western reports have suggested that the prevalence of gastric cardia cancer (GCC) has been increasing, and indicated some differences between GCC and gastric noncardia cancer (GNCC). However, few studies have been conducted in Asia. The aims of this study were to estimate the prevalence of GCC and to evaluate differences of clinicopathologic characteristics between GCC and GNCC in South Korea.

METHODS

This study was single-center case-control study. A total of 829 patients with gastric cancer and 270 controls were enrolled between 2003 and 2011. Baseline characteristics, Helicobacter pylori (H. pylori) infection status, and histologic characteristics were compared among three groups (GCC, GNCC, and control).

RESULTS

Sixty cases (7.2%) of gastric cancer were located in cardia. Multivariate analysis showed that male odds ratio (OR, 5.72; 95% CI, 1.72-19.07; p = .005) and cigarette smoking (OR, 5.38; 95% CI, 1.39-20.90; p = .015) were risk factors of GCC in comparison with control group, but H. pylori infection rate was not significant. In the case of GNCC, cigarette smoking (OR, 3.87; 95% CI, 1.81-8.29; p < .001), past alcohol intake (OR, 2.82; 95% CI, 1.28-6.20; p = .010), intestinal metaplasia (OR, 3.22; 95% CI, 2.00-5.17; p < .001), and H. pylori infection (OR, 3.06; 95% CI, 1.90-4.93; p < .001) were risk factors of GNCC. Gastroesophageal reflux disease symptoms were higher in the GNCC (21.2%) than control group (13.5%) (p = .008). However, in the case of GCC, they were similar between the GCC (12.7%) and control group (p = .872). According to multivariate analysis, history of H. pylori eradication (OR, 0.34; 95% CI, 0.19-0.61; p < .001) was associated with a protective effect on GNCC. GCC showed higher depth of invasion (p = .038) and frequent distant metastasis (p = .012) than GNCC.

CONCLUSION

In this referral center based study, the prevalence of GCC was 7.2% in South Korea. Risk factors and clinicopathologic characteristics for GCC and GNCC were different, supporting that the pathophysiology is different in the development of GCC and GNCC.

Comparative Study on the Difference in Functional Outcomes at Discharge between Proximal and Total Gastrectomy

Several studies have regarded proximal gastrectomy (PG) as optimal compared to total gastrectomy (TG) for upper stomach cancer. In addition to the traditional outcomes of complication and mortality, change in functional status should be considered as another relevant outcome in aging generations. However, there has been no community-based appraisal of functional outcomes between PG and TG. Using an administrative database, we compared functional outcomes between PG and TG. Among 12,508 patients who survived for ≥15 years and underwent open gastrectomy between 2008 and 2010, we examined patient characteristics, comorbidities, functional status estimated by the Barthel index (BI) at admission and discharge, complications, ICU care, ventilation administration, blood transfusion, operating room time, resumption of oral intake, length of stay and total charges. With reference to distal gastrectomy (DG), we performed multivariate analyses to assess the impacts of PG and TG on complications and BI deterioration. A total of 434 PGs and 4,941 TGs were observed in 148 and 295 hospitals, respectively. Patient characteristics, care process, resumption of oral intake, operating room time, length of stay and total charges were also significantly different among the three gastrectomy types. PG, TG and DG were not associated with complications or functional deterioration. Patient characteristics, preoperative blood transfusion and longer operating room time were significantly associated with more complications and BI deterioration. Since patient case mix and longer operating room time were associated with poor outcomes, physicians should recognize the role of PG and might optimally challenge and complete gastrectomies within the appropriate indications.