Gastric Cancer

Opinion statement  

Gastric Cancer Chemoprevention

In 1996, approximately one million new cases of gastric cancer were found. It is the second most common cancer in the world, and seventy five percent of the new cases are found in Asia. It is therefore an important issue in Asian countries. Like most malignancies, the etiology of gastric cancer is still unclear. It is generally agreed that the pathogenesis is multifactorial, which may include dietary factors, environmental factors, bacterial and viral infections. The role of Helicobacter pylori infection in gastric carcinogenesis is certainly very important.     

胃癌的化学预防

当前对胃癌化学预防的研究主要集中在根除幽门螺杆菌(H.pylori)﹑抗氧化剂﹑叶酸、选择性环氧合酶(COX)-2抑制剂上。动物实验和临床研究均发现,根除H.pylori能够预防胃癌的发生,在癌前病变形成前根除效果更佳。某些抗氧化剂(β-胡萝卜素、维生素A、C、E,绿茶、硒等)和叶酸通过保护DNA免受氧化损害和提高DNA甲基化水平预防胃癌的发生。选择性COX-2抑制剂在动物实验中能显著降低胃癌发生率和癌前病变发生率,目前已正式用于肿瘤的预防,其预防效果有待于大规模临床研究。     

Gastric Myeloid Sarcoma Mimicking a Scirrhous Gastric Cancer

Myeloid sarcoma (MS) is a relatively rare manifestation of myeloid neoplasms at sites other than the bone marrow. The rarity of gastrointestinal (GI) MS is attributed to certain factors, such as misdetection due to insufficient endoscopic assessments at the initial presentation with acute myeloid leukemia (AML) as well as the difficulty of making a histologic assessment of leukemic involvement of the GI tract. We herein report a case of AML with gastric involvement and discuss the importance of screening examinations and therapies considering the location of MS and the data of cytogenetic and molecular mutation.     

Early Gastric Cancer in Japan

In Japan the mortality rate of gastric cancer is very high, 57.3 per cent in males. Because of such a high mortality our clinicians and investigators have been making efforts to detect the early gastric cancer cases. We experienced a remarkable increase in diagnosed cases in these years, which was attributed to the spread of endoscopic and cytologic diagnosis.

The roentgenologic signs of early gastric cancer are so minute in many instances that they can only be detected by a careful and skillful roentgenologic examination team.

The double contrast method employs the proper ratio of barium to air and changes the position of the patient in order to obtain the best view of the mucous fold.

Surgical intervention in the detected early gastric cancer cases in Japan has been greatly improved, as indicated in Table VI. We have in fact achieved the excellent five-year survival rate of 98 per cent.     

幽门螺杆菌与胃癌的关系

本文报道1994年在福建长乐进行的大规模胃癌防治计划,通过胃镜、血液检查及问卷检查,发现30例胃癌及214例消化性溃疡,幽门螺杆菌的感染率在各类人群中为67％至94％不等。在年龄36岁至65岁组中,长乐地区幽门螺杆菌的感染率明显高于香港,无论是幽门螺杆菌的感染者或非感染者,胃窦肠上皮化生发现率在长乐都高于香港,在长乐,胃窦肠上皮化生发现率高于胃体肠上皮化生。长乐及香港的Cag-A阳性菌株与各种胃疾病有明显关系,在无症状组中,Cag-A阳性菌株在长乐占72％,明显高于香港的29％。Cag-A阳性菌株与胃炎、粘膜萎缩、肠上皮化生、不典型增生和胃癌有明显关系。问卷发现多喝茶及多进食蔬菜有保护作用,而抽烟及饮酒人群或进食咸鱼有较多机会形成胃癌。     

Antiulcer Drugs and Gastric Cancer

Inhibitors of gastric acid secretion are efficient drugs in the treatment of acid-related diseases. However, by reducing gastric acidity, hypergastrinemia develops. Gastrin regulates its target cell, the enterochromaffin (ECL) cell, both functionally and trophically. Long-term hypergastrinemia in whatever species studied, has been shown to induce tumors originating from the ECL cell. In man, at least 10 years of hypergastrinemia, accompanied by high or reduced gastric acidity is necessary to induce ECL cell carcinoids. There are reports indicating development of ECL cell carcinoids after long-term treatment with proton pump inhibitors. Moreover, the ECL cell may give rise to gastric carcinomas of diffuse type, which have increased during the last decades. Furthermore, most of the carcinomas developing in patients with long-lasting hypergastrinemia are of ECL cell origin. Therefore, long-lasting iatrogenic hypergastrinemia induced by potent inhibitors of acid secretion may be expected to increase the occurrence of gastric carcinomas in the future.     

胃癌相关基因及其在治疗中应用的研究进展

胃癌是我国最常见的恶性肿瘤之一,发病率和死亡率均较高。胃癌的发生由遗传和环境等诸多因素相互作用所致,是一个多因素、多基因、多步骤参与的癌变过程,涉及大量相关基因的结构和表达异常,其中c-met、Bmi-1、HER-2/neu和基质金属蛋白酶（MMP）-9等的活化在胃癌的发生、发展中起重要作用。本文就近年胃癌相关基因及其在胃癌治疗中的研究进展作一综述,旨在帮助理解胃癌发生、发展的分子机制,并为其基因靶向治疗提供一定的理论依据。     

Gastric Ulcer and Risk of Cancer

Abstract In 1976, 121 patients with benign gastric ulcer and 13 with gastric carcinoma were diagnosed in our department by endoscopy, cytology and directed biopsies. At a 5-year follow-up, 78 of these patients were re-examined with endoscopy and biopsies. None had developed gastric cancer during the observation time. Of the 78 patients who underwent endoscopy, 16 had gastric ulcer, 2 duodenal ulcer and 27 atrophic gastritis, including 3 with moderate dysplasia of the gastric mucosa. The patients with ulcer had remarkably few symptoms. Only few data are available concerning the postulated link between gastric ulcer disease and gastric malignancy. The cancer-ex-ulcere hypothesis seems to be a medical dogma. However, well planned prospective studies with endoscopic follow-up of gastric ulcers are needed to elucidate the question properly     

Gastric Cancer in a Young Adult

We report a case of gastric adenocarcinoma in a 23-yr-old white man. Since only 1% of gastric cancers occur in patients under 35 yr or age, the diagnosis is often overlooked. The presence of persistent pain, weight loss, early satiety, anemia, and vomiting are clues to the underlying disorder. Endoscopy is the best means of diagnosis. All ulcers or other suspicious lesions should be biopsied. Prognosis is poor, related to the failure to suspect the diagnosis and to the aggressive nature of the disease. This case points out the importance of the thorough investigation of all patients with suggestive findings regardless of the patient's age.