Liver zinc in carcinoma

Abstract

IN contrast to the important role of zinc in wound healing1,2 comparatively little attention has been paid to the metal in relation to tissue reaction to malignant disease3-8. In this study samples of liver tissue from fifty necropsies were divided into four series (excluding malignant tissue itself): "normal" liver (series I), fatty liver (series II), apparently uninvaded liver from organs containing secondary malignant deposits (series III) and livers from patients with malignant disease but no obvious liver secondaries (series IV). The selection, preliminary processing and preparation of the specimens will be described elsewhere9. All specimens were analysed in duplicate. One set of samples was wet-digested and used for the measurement of zinc concentration by atomic-absorption spectroscopy. The other set of samples was ashed and used for the determination of the wet-weight/ash ratio. Closely adjacent specimens were examined microscopically to exclude histological evidence of local malignant invasion. Zinc concentrations were finally expressed in terms of ash weight tissue. (In this context this is a more meaningful reference datum than "dry" weight, wet weight or protein or nitrogen concentration.) The results are summarized in Table 1. "Normal" liver (series I) refers to organs which had been removed from subjects who showed no evidence of malignant disease anywhere, and whose liver showed only mild terminal changes. The range of zinc concentrations in this series was comparatively narrow and is in fairly close agreement with the findings of other workers3,11-15. The difference between normal liver zinc and liver zinc from subjects with malignant disease (series III and IV) was highly significant (PT< 0.005 and P< 0.0025 respectively). The difference between the two malignant-disease series was insignificant compared to the difference between the two malignant-disease series combined on the one hand and the two non-malignant series combined on the other. © 1972 Nature Publishing Group.