Metabolic state of perifocal zone and resection line of skin melanoma.

Abstract

e19049 Background: The state of metabolism in perifocal zone and morphologically intact skin along resection line is of importance for the processes of neoplasm metastasizing and relapse, including skin melanoma. Normalization of the state of free-radical processes, first of all along resection line, and then in neoplasm perifocal zone, should be a characteristic of pathogenically substantiated neoadjuvant influence. Methods: to study activity of free-radical processes in tissue of skin melanoma relapse, its perifocal zone (PZ) (1 cm from tumour edge) and in skin along resection line (3-5 cm from tumour edge) we investigated concentration of vitamins E and A, activity of superoxide dismutase (SOD), catalase, summary peroxidase activity (SPA), and malonic dialdehyde level (MDA) in patients with skin melanoma (pT2-3N1-2M0). The study group included 54 samples after treatment (chemotherapy and radiation). Control groups: 45 samples before treatment (CG1) and 27 samples of intact skin after plastic operations (CG2). Results: After treatment MDA concentration in tumour tissue increased by 33.4% in comparison with the CG1, but remained 17.7% lower than in CG2. Average increase in concentration of vitamins E and A was equal to 1.8 times, catalase activity decreased by 30.3% in comparison with parameters before treatment (p<0.05). SOD/catalase coefficient was 1.3 times higher than in the CG1, but 3.4 times lower than CG2.More manifested changes in activity of free-radical processes were observed in PZ: MDA concentration level after treatment increased by 30% in comparison with the CG1, and differed from the one in CG2 only by 10% (p<0.05). Catalase activity decreased by 1.5 times and didn’t significantly differ from the corresponding parameter in tumour tissue after treatment. Normalization of concentration level of vitamins A and E without change of their ratio was observed. There was 1.6-fold increase of SOD/SPA coefficient in comparison with the CG1, however it was 2.4 times lower than CG2 (p<0.05). All parameters under study along resection line after treatment didn’t significantly differ from parameters in CG2. Conclusions: The performed treatment completely restores broken metabolism in skin along resection line, partially–in tumour perifocal zone.