Gastric Cancer in Japan

To the Editor: In their Perspective article (July 31 issue), 1 Forman and Pisani ask, “Why does gastric cancer occur so frequently in Japan?” One answer was proposed more than 30 years ago by Matsudo et al., 2 who detected talc in the normal gastric mucosa and in gastric cancers in Japanese patients and suggested a causal relationship. Talc is used in Japan to polish rice, and it is customary to wash off the talc before cooking the rice. However, if the washing is insufficient, talc is ingested. Talc is a hydrated magnesium silicate with the chemical formula H 2 Mg 3 . . .