[Oxidative stress after anthracycline therapy in patients with solid tumors]

Anthracyclines are regarded as some of the most potent oxidative stress inductors. Despite the fact that oxidative stress induction by anthracyclines is believed to be the key factor in anthracycline-related cardiotoxicity, the precise timeline of oxidative stress changes after anthracycline treatment remains unknown. The aim of the present study is to assess the level of oxidative stress after anthracycline therapy in patients with solid tumors.

The study population consists of 128 adult patients (14 males, 114 females, mean age 56 ± 10 years) receiving anthracycline chemotherapy for solid tumors. The control group consists of 38 patients (4 males, 34 females, mean age 59 ± 11 years) receiving anthracycline-free chemotherapy for solid tumors.

The main activities of antioxidant enzymes (catalase, glutathione peroxidase-1, superoxide dismutase, and paraoxonase-1) and concentrations of conjugated dienes, surrogate markers of oxidative stress level, were established at the baseline and after anthracycline therapy (median 45; IQR 27-69 days after the end of anthracycline therapy) in all patients. By comparing the activities of antioxidant enzymes and the concentrations of conjugated dienes, before and after therapy, changes in oxidative stress level within the time period were established for both study groups. Differences between the study groups, with regard to changes in the activities of antioxidant enzymes and the concentrations of conjugated dienes, were also evaluated.

An increase in oxidative stress was observed after the end of anthracycline therapy in patients with solid tumors. However, our study shows that this persistent elevation of oxidative stress after the end of anthracycline therapy is probably not caused by anthracyclines.