OBJECTIVETo evaluate the long-time effect on allitridum and selenium in preventing cancer of digestive system.

METHODSPersons who were recruited into the intervention group and took allitridum and selenium to prevent gastric cancer in Qixia county of China from 1989-1991 were followed up to 2001 and data of deaths was collected. The long effect on allitridum and selenium in preventing cancer of digestive system was analysed.

RESULTSData were compared to placebo group five years (1992-1996) after the termination of intervention to have found that the accumulative mortality rate of all cancer, digestive system cancer and gastric cancer had decreased 45.5%, 41.2% and 63.3% in the intervention group respectively. By stratum analysis, accumulative mortality rate of all cancer, digestive system cancer and gastric cancer had decreased 51.5%, 51.5% and 67.7% in males of the intervention group, respectively. Relative risks for males in the intervention group were 0.48, 0.47 and 0.30 times more than the placebo group, respectively. All of them were statistically significant. Relative risks for females in the intervention group were 0.74, 0.92 and 0.70 times more than placebo group. Six to ten years later after the termination of intervention, the accumulative mortality rate and relative risk of all cancers in two groups became similar.

CONCLUSIONAllitridum and selenium had the effect of decreasing the incidence risk of digestive cancer with a protective rate more than 50% for five years after the termination of intervention program.