[Sister chromatid exchange in gastric cancer, chronic atrophic gastritis and normal control].

The frequencies of sister chromatid exchange (SCE) in proven cases of 10 chronic atrophic gastritis and 9 gastric cancer were observed together with 10 cases of normal control. They were (1) chronic atrophic gastritis 6.98 +/- 0.89, (2) gastric cancer 7.49 +/- 0.42 and (3) normal control 5.89 +/- 0.57. Statistically, there was a very significant difference in the SCE frequencies between the gastric cancer and normal control groups (P less than 0.001) and a significant difference between the chronic atrophic gastritis and normal control groups (P less than 0.05). However, the difference between the gastric cancer and the chronic atrophic gastritis was not significant (P greater than 0.05). The similarity in the incidence of SCE may offer an evidence for the close relationship theory between gastric cancer and chronic atrophic gastritis.