Nuclear changes in blood, early liver anomalies and hepatocellular cancers in flounder (Platichthys flesus L.) as prognostic indicator for a higher cancer risk?

Nuclear changes (micronuclei) in blood are a well-established biomarker of toxic injury and related genotoxicity in mussel, fish and humans, as well. Yet, the relationship between the frequencies of micronuclei in blood and nuclear changes in liver cells itself and the higher potential risk to develop liver cancer is not yet fully implemented. We analysed and diagnosed macroscopic liver changes and H&E and Feulgen stained histological liver sections (2 μm of thickness) together with blood smears (stained with Sytox Green) from same individuals in flounder caught along a well-known contaminant gradient in the North Sea. Results showed an increase in micronuclei frequencies in blood at the more contaminated sites and higher frequencies of macroscopically visible neoplastic liver changes. In livers of the same individuals, nuclear changes were diagnosed in early to degenerative liver lesion, extra-focal tissue surrounding neoplastic lesion and various stages during cancer progression from early neoplastic foci, benign adenomas and malignant carcinomas. The aim of this approach is to expand diagnostic criteria, well-established in the frame of BEQUALM to nuclear changes which might help diagnosis of malignancies in doubtful cases.