Is gastric carcinoma different between Japan and the United States?

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.

Clinical significance of expression of protein tyrosine kinase 7 in gastric adenocarcinoma

AIM: To explore the role of protein tyrosine kinase 7 (PTK7) in gastric adenocarcinoma (GAC).

METHODS: A total of 210 GAC tissue samples and 30 normal gastric mucosal tissues were obtained from patients who underwent D2/D3 lymphadenectomy. Immunohistochemical method was used to detect the expression of PTK7 in GAC tissues and normal gastric mucosa tissues. The correlations of expression of PTK7 in GAC with clinical characteristics and 3-year survival rate in GAC patients were analyzed.

RESULTS: In GAC tissues and normal gastric mucosa tissues, the expression of PTK7 differed significantly (87.14% vs 22.86%, P < 0.05). In GAC tissues, the expression of PTK7 has no significant correlation with gender, age, tumor location or size (P > 0.05), but was significantly correlated with Lauren classification (P = 0.011), differentiation (P = 0.039), invasion depth (P = 0.025) and distant metastasis (P = 0.034), In GAC patients, positive expression of PTK7 was associated with a poorer 3-year survival rate compared with patients with negative expression of PTK7 (39.89% vs 62.96%, P < 0.05).

CONCLUSION: The expression of PTK7 in GAC is higher than that in normal gastric mucosa tissues, and high expression of PTK7 is related to clinical pathological characteristics. PTK7 may be a useful biomarker to predict the prognosis for patients with GAC. PTK7 might be a potential therapeutic target for GAC.

Trial of a novel endoscopic tattooing biopsy forceps on animal model

AIM: To tattoo gastric mucosa with a novel medical device which could be used to monitor and follow-up gastric mucosal lesions.

METHODS: Combining endoscopic biopsy with sclerotherapy injection, we designed a new device that could perform biopsy and injection simultaneously. We performed endoscopies on a pig by using a novel endoscope tattoo biopsy forceps for 15 mo. At the same time, we used two-step method combining sclerotherapy injection needle with endoscopic biopsy. The acuity, inflammation and duration of endoscopy were compared between two methods.

RESULTS: Compared with the old two-step method, although the inflammation induced by our new device was similar, the duration of procedure was markedly decreased and the acuity of tattooing was better than the old two-step method. All characteristics of the novel device complied with national safety guidelines. Follow-up gastroscopy after 15 mo showed the stained site with injection of 1:100 0.5 mL of India ink was still markedly visible with little inflammatory reaction.

CONCLUSION: Endoscopic tattooing biopsy forceps can be widely used in monitoring precancerous lesions. Its safety and effectiveness has been established in animals.

Prognostic significance of expression of cyclooxygenase-2 and vascular endothelial growth factor in human gastric carcinoma

AIM: To investigate the role of cyclooxygenase-2(COX-2) and vascular endothelial growth factor (VEGF) in the development of gastric carcinoma and correlation between expression of COX-2 and VEGF and clinicopathologic features in tissues from patients with gastric carcinoma.

METHODS: 281 patients with gastric carcinoma who underwent surgical resection between 1990 and 1999 at the First Affiliated Hospital, Anhui Medical University, PRC, were followed up. Expression of COX-2 and VEGF was investigated retrospectively in 232 gastric carcinoma tissues and 60 noncancerous specimens by using immunohistochemistry.

RESULTS: The 5-year survival rates of early gastric carcinoma (EGC) and advanced gastric carcinoma (AGC) were 93.4% and 59.0%, respectively. Survival time was highly correlated with lymph node metastasis, vascular invasion, depth of invasion and treatment with chemotherapy. Compared with paired noncancerous tissues, expression of COX-2 and VEGF and microvessel density (MVD) value in carcinoma tissue were significantly higher. The MVD value was much higher in COX-2-positive group and VEGF-positive group than that in COX-2-negative group and VEGF-negative group. Expression of COX-2 and VEGF, as well as MVD value were highly correlated with lymph node metastasis and vascular invasion. The 5-year survival rate of patients with expression of COX-2 or VEGF was significantly lower than that of patients without COX-2 or VEGF expression. Multivariate analysis revealed that VEGF overexpression, lymph node metastasis, COX-2 overexpression, depth of invasion and vascular invasion were all independent prognostic factors of gastric carcinoma.

CONCLUSION: Overexpression of COX-2 and VEGF in patients with gastric carcinoma can enhance the possibility of invasion and metastasis, implicating a poor prognosis. They may serve as the fairly good prognostic factors to indicate biologic behaviors of gastric carcinoma.