ORIGINAL ARTICLE Potential survival markers in cancer patients undergoing chemotherapy Krzysztof Roszkowski • Jan Filipiak • Magdalena Wisniewska • Anna Mucha-Malecka • Pawel Basta Received: 1 July 2014 / Accepted: 15 September 2014 Ó Springer-Verlag Italia 2014 Abstract Due to the importance of the identification of chemotherapy outcome prognostic factors, we attempted to establish the potential of oxidative stress/DNA damage parameters such as prognostic markers. The aim of the study was to determine whether platinum derivative-based chemotherapy in cancer patients (n = 66) is responsible for systemic oxidatively damaged DNA and whether damage biomarkers, such as 8-oxo-7,8-dihydro-2 0 -deoxyguanosine (8-oxo-dG) and the modified base 8-oxo-7,8-dihydrogua- nine (8-oxo-Gua), in urine and DNA may be used as a prognostic factor for the outcome of chemotherapy. All the aforementioned modifications were analyzed using tech- niques involving high-performance liquid chromatography/ electrochemical detection (HPLC/EC) or HPLC/gas chro- matography–mass spectrometry (GC–MS). Among all the analyzed parameters, the significantly decreased levels of 8-oxo-Gua in urine collected from a subgroup of patients 24 h after the first infusion of the drug, as compared with the baseline levels, correlated with a significantly longer overall survival (OS) (60 months after therapy) than in the subgroup without any decrease of this parameter after therapy (median OS = 24 months, p = 0.007). Moreover, a significantly longer OS was also observed in a group with increased urine levels of 8-oxo-dG after chemotherapy (38.6 vs. 20.5 months, p = 0.03). The results of our study suggest that patients with decreased 8-oxo-Gua levels and increased 8-oxo-dG levels in urine 24 h after the first dose should be considered as better responders to the adminis- tered chemotherapy, with a lower risk of death. The con- clusion may permit the use of these parameters as markers for predicting the clinical outcome of platinum derivative- based chemotherapy. Keywords Molecular biomarkers Á Oxidatively damaged DNA Á Survival markers Á 8-Oxo-Gua Á 8-Oxo-dG Á Chemotherapy Á Cancer patients Introduction In the course of some essential metabolic processes occurring in cells, reactive oxygen species (ROS) with potentially genotoxic and mutagenic properties are formed [1]. ROS, such as superoxide, hydrogen peroxide and hydroxyl radical are by-products of cellular respiration, but they may also be generated during inflammatory processes [2, 3]. Similarly, reactive nitrogen species (RNS) generate toxic products in their reactions with cells and free mole- cules [4]. Normal cells are equipped with enzymatic and nonen- zymatic mechanisms limiting the production of ROS; however, abnormally functioning cells are often subjected K. Roszkowski Department of Clinical Biochemistry, Collegium Medicum, Nicolaus Copernicus University, Torun, Poland K. Roszkowski (&) Department of Radiotherapy, The F. Lukaszczyk Oncology Center, Bydgoszcz, Poland e-mail: roszkowskik@co.bydgoszcz.pl J. Filipiak Á M. Wisniewska Department of Chemotherapy, The F. Lukaszczyk Oncology Center, Bydgoszcz, Poland A. Mucha-Malecka Department of Radiotherapy, Center of Oncology – Maria Sklodowska-Curie Memorial Institute, Krakow, Poland P. Basta I Department of Surgery, Medical College, Jagiellonian University, Krakow, Poland 123 Clin Exp Med DOI 10.1007/s10238-014-0313-6