Histochemical detection of lipid peroxidation in human gastrointestinal, mammary and renal carcinomas

Constitutional lipid peroxidation in randomly selected 32 cases of clinically advanced carcinoma from human gastrointestinal tract (20 cases), breast (8 cases) and kidney (4 cases) was examined histochemically in frozen sections using cold Schiff's reagent. Only two cases of gastrointestinal carcinoma were positive by the reagent. Non-cancerous parenchymal cells were negative. These findings suggest that detectable constitutional lipid peroxidation seldom occurs in either cancerous or normal tissues. The capacity for normal and neoplastic tissues to undergo lipid peroxidation was also studied by incubation with an iron-NADPH pro-oxidant system. Normal parenchymal cells showed, to various degrees, a positive reactivity. In gastrointestinal carcinoma, 6 out of 7 cases of well differentiated adenocarcinoma reacted positively, whereas 2 out of 8 cases of moderately to poorly differentiated adenocarcinoma disclosed weakly positive reactions. Mucinous adenocarcinomas (4 cases) were all negative. Signet-ring cell carcinoma (1 case) was positive. One out of 8 cases of breast cancer also showed positive reaction. Four renal cell carcinomas were all negative. Cancer cells have lower capacity to undergo lipid peroxidation than normal cells, when the iron-NADPH pro-oxidant system was employed. In gastrointestinal carcinoma, the ability to undergo lipid peroxidation by the iron-NADPH pro-oxidant seems to be correlated with their histological differentiation. This fact may suggest that differences in lipid composition or the NADPH enzyme system exist between well differentiated and poorly differentiated gastrointestinal malignancies.