| [ Summary ] |
To develop appropriate strategies for cancer chemoprevention in clinical and public health settings, it is essential to obtain evidence regarding relative risk reduction. It is also necessary to examine dose-response relationships and target populations, such as high risk groups, to strike a balance between absolute benefits and possible harm. There is currently some evidence related to gastric cancer prevention through nutritional supplementation or eradication of Helicobacter pylori. Prevention of colorectal adenoma recurrence with non-steroidal anti-inflammatory drugs is also being investigated. However, there is no practical or readily applicable chemoprevention modality which can provide sufficient benefits, which outweigh side effects. In Japan, tens of millions of people are infected with Helicobacter pylori and have atrophic gastritis. Several million are also infected with hepatitis viruses. They are important public health targets for cancer prevention. The development of effective chemoprevention agents with minimum side effects and evidence of positive risk-benefit rations, developed from large-scale clinical trials is warranted. |