Mass Eradication of Helicobacter pylori to Prevent Gastric Cancer: Theoretical and Practical Considerations

Although the age-adjusted incidence of gastric cancer is declining, the absolute number of new cases of gastric cancer is increasing due to population growth and aging. An effective strategy is needed to prevent this deadly cancer. Among the available strategies, screen-and-treat for Helicobacter pylori infection appears to be the best approach to decrease cancer risk; however, implementation of this strategy on the population level requires a systematic approach. The program also must be integrated into national healthcare priorities to allow the limited resources to be most effectively allocated. Implementation will require adoption of an appropriate screening strategy, an efficient delivery system with a timely referral for a positive test, and standardized treatment regimens based on clinical efficacy, side effects, simplicity, duration, and cost. Within the population, there are subpopulations that vary in risk such that a "one size fits all" approach is unlikely to be ideal. Sensitivity analyses will be required to identify whether the programs can be utilized by heterogeneous populations and will likely require adjustments to accommodate the needs of subpopulations.

Roadmap for elimination of gastric cancer in Korea

Most gastric cancers are caused by infection with the common human bacterial pathogen, Helicobacter pylori. It is now accepted that gastric cancer can be prevented and virtually eliminated by H. pylori eradication and this knowledge was responsible for country-wide H. pylori eradication combined with secondary cancer prevention for those with residual risk that was introduced in Japan in 2013. Korea is a high H. pylori prevalence and high gastric cancer incidence country and a good candidate for a gastric cancer elimination program. The presence of an H. pylori infection is now considered as an indication for treatment of the infection. However, antimicrobial drug resistance is common among H. pylori in Korea making effective therapy problematic. Country-wide studies of the local and regional antimicrobial resistance patterns are needed to choose the most appropriate therapies. H. pylori and gastric cancer eradication can be both efficient and cost effective making it possible and practical to make Korea H. pylori and gastric cancer free. There is no reason to delay.

The Role of CD44 in the Pathogenesis, Diagnosis, and Therapy of Gastric Cancer

CD44 is a transmembrane glycoprotein and surface receptor for hyaluronan that is involved in the response of cells to their microenvironment. CD44 splice variants play roles in carcinogenesis, differentiation, and lymph node metastasis and are predictive of the prognosis for various carcinomas, including gastric cancer. Current data suggest that gastric tissue stem cells and gastric cancer stem cells both express the splice variant, CD44v9. Overall, the data regarding the alterations that occur in CD44 and its splice variants in response to acute and chronic infection with Helicobacter pylori are scant and poorly elucidated in terms of possible changes in expression that occur in gastric cancer precursor lesions, such as chronic atrophic gastritis, pyloric metaplasia and intestinal metaplasia. In this study, we discuss the available data and suggest which new data would likely be useful in clinical practice. We also discuss the potential for CD44-targeted therapeutic strategies in gastric cancer. CD44 and its splice variants are positively associated with the initiation and progression of gastric cancer and may also play important roles in diagnosis, therapy and prognosis. CD44 research has been active but fragmented, and it may offer new therapeutic approaches to gastric cancer.

Palliative treatment of esophageal cancer: new role of endoprosthesis?

Esophageal endoprostheses are very useful in management of patients with esophageal cancer and are the primary therapy for patients with esophagorespiratory fistula. In addition, patients with tumors, poorly responsive to dilatation or other therapies, will have long-lasting symptomatic relief when an endoprosthesis is placed. The available prostheses are discussed, as well as the methods of insertion and the relative merits of each. The self- expanding metal stents may have advantages over plastic stents