[Mastocytes in the process of cancerogenesis. I. Study of experimental model systems]

Changing numbers of mast cells were observed in precancerous and cancerous lesions of the gut in mice treated by 1, 2-dimethylhydrazine dihydrochloride. The study included 18 samples of abnormal and atypical epithelium, 14 samples of preinvasive carcinoma, 15 samples of infiltrative carcinoma, and 12 control samples from untreated mice. Carcinogenesis was accompanied by a significant increase of mast cell numbers culminating in preinvasive carcinoma. A decrease of mast cells followed in fully developed adenocarcinomas up to numbers comparable to but more variable than those found in abnormal and atypical epithelium.