International variation in Helicobacter pylori infection and rates of oesophageal cancer

Quality of life in patients with esophageal stenting for the palliation of malignant dysphagia

Incidence of esophageal cancer (EC) is rising more rapidly in the Western world than that of any other cancer. Despite advances in therapy, more than 50% of patients have incurable disease at the time of presentation. This precludes curative treatment and makes palliative treatment a more realistic option for most of these patients. Dysphagia is the predominant symptom in more than 70% of patients with EC and although several management options have been developed in recent years to palliate this symptom, the optimum management is not established. Self-expanding metal stents (SEMS) are a well-established palliation modality for dysphagia in such patients. Health-related quality of life (HRQoL) is becoming a major issue in the evaluation of any therapeutic or palliative intervention. To date, only a few published studies can be found on Medline examining HRQoL in patients with advanced EC treated with SEMS implantation. The aim of this study was to review the impact on HRQoL of SEMS implantation as palliative treatment in patients with EC. All Medline articles regarding HRQoL in patients with advanced EC, particularly those related to SEMS, were reviewed. In most studies, relief of dysphagia was the only aspect of HRQoL being measured and SEMS implantation was compared with other palliative treatments such as brachytherapy and laser therapy. SEMS insertion provides a swift palliation of dysphagia compared to brachytherapy and no evidence was found to suggest that stent implantation is different to laser treatment in terms of improving dysphagia, recurrent dysphagia and better HRQoL, although SEMS insertion has a better technical success rate and also reduces the number of repeat interventions.

Helicobacter pylori infection may be implicated in the topography and geographic variation of upper gastrointestinal cancers in the Taihang Mountain high-risk region in northern China

BACKGROUNDS

Helicobacter pylori infection is prevalent in China. Chronic infection of the bacterial not only causes distal stomach cancer, but also confers risk to gastric cardia adenocarcinoma. Because H. pylori infection is inversely associated with esophageal adenocarcinoma, globally the infection rate is significantly correlated with the ratio of squamous carcinoma to adenocarcinoma of the esophagus. These agree with the topography of upper gastrointestinal cancer observed in the Taihang Mountain high-risk region where both gastric cardia and non-cardia adenocarcinoma coincide with esophageal squamous cancer, but with almost no distal esophageal adenocarcinoma. Moreover, as altitude increases from plain to mountains, we observed progressively increasing incidence rates of gastric adenocarcinomas in recent years in the region. Because H. pylori infection is a definite carcinogen to gastric adenocarcinoma and is more prevalent in the mountain than in plain areas due to undeveloped living conditions, the observation gives the impression as though H. pylori infection is implicated.

AIMS

This article aims to note the role of H. pylori infection in upper gastrointestinal cancer in the Taihang Mountain high-risk region in northern China.

MATERIALS AND METHODS

First the unique topography and geographic variation of upper gastrointestinal cancer in the region is described to indicate a possible role of H. pylori infection, then we review studies on prevalence of H. pylori infection in the high-risk region and describe difference in socioeconomic development and water hygiene between the plains and the mountains as related to the prevalence of H. pylori infection.

RESULTS

  Coincidence of gastric cancer in the region and a progressively increasing rate of the cancer from the plain towards the mountains indicate H. pylori infection may be implicated in upper gastrointestinal cancer.

CONCLUSION

International collaboration is needed to study H. pylori and upper gastrointestinal cancer in the region when rapid industrialization is just beginning.

Northwestern China: a place to learn more on oesophageal cancer. Part one: behavioural and environmental risk factors

Oesophageal squamous cell carcinoma (OSCC) remains a public health problem in many countries, especially in emerging and developing countries. Epidemiology of OSCC is characterized by marked differences in prevalence between countries/regions/ethnical groups. The highest incidence in the world is reached by populations living in specific areas of northwestern Xinjiang, China where age-adjusted mortality may reach 150 of 100 000. In fact, there are also marked differences among the various geographical areas and the various ethnic groups within the region, which suggests specific risk factors. Behavioural factors include those factors which are common to all 'high-risk populations', such as tobacco smoking and alcohol drinking. However, the very unusual sex ratio (1.2 : 1.0) and young age range of OSCC occurrence suggests the involvement of additional early risk factors shared by males and females, and which are different from those studied in other 'high-risk' areas of the world, including China, such as LinXian area. These include drinking very hot and salted tea, boiled with milk; a diet rich in meat, especially salted, dry and/or smoked meat, and dairy products; and a diet poor in fresh fruit and vegetables. The combination of hot drinks (such as milk, tea and soups) and high-degree spirit drinks, and hard food (bread, meat and cheese), together with poor oral hygiene and tooth loss, is likely to add mechanical injury of the oesophagus to other factors linked to climate characteristics of the area (drought) and dietary habits, which promote a sodium and nitrosamine-rich diet. Association of early and severe hypertension in the same populations at high risk of OSCC might likely raise more attention. Human papilloma virus (HPV) infection, and especially HPV 16/18 E6/E7, with gene mutations and association with p53 overexpression, may contribute to the extremely high incidence of OSCC observed in Xinjiang, and could be accessible to prevention. Infection may especially be a crucial additional factor in the Uygur population in which not only HPV infection but also infection with other oncogenic viruses, such as HHV8, are highly prevalent. Genetic polymorphism might interact with viruses and/or viral products to promote carcinogenesis. These observations in northwestern China suggest that usually neglected factors, such as sodium excess and viral infection, could be taken into more account when studying OSCC risk factors in other parts of the world, especially Europe.

Oesophageal cancer in Golestan Province, a high-incidence area in northern Iran - a review

Golestan Province, located in the south-east littoral of the Caspian Sea in northern Iran, has one of the highest rates of oesophageal cancer (OC) in the world. We review the epidemiologic studies that have investigated the epidemiologic patterns and causes of OC in this area and provide some suggestions for further studies. Oesophageal squamous cell carcinoma (OSCC) constitutes over 90% of all OC cases in Golestan. In retrospective studies, cigarettes and hookah smoking, nass use (a chewing tobacco product), opium consumption, hot tea drinking, poor oral health, low intake of fresh fruit and vegetables, and low socioeconomic status have been associated with higher risk of OSCC in Golestan. However, the association of tobacco with OSCC in this area is not as strong as that seen in Western countries. Alcohol is consumed by a very small percentage of the population and is not a risk factor for OSCC in this area. Other factors, such as polycyclic aromatic hydrocarbons, N-nitroso compounds, drinking water contaminants, infections, food contamination with mycotoxins, and genetic factors merit further investigation as risk factors for OSCC in Golestan. An ongoing cohort study in this area is an important resource for studying some of these factors and also for confirming the previously found associations.