Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Cisplatin is a chemotherapeutic agent widely used in the treatment of several solid tumours. For patients with advanced head and neck squamous cell carcinoma in whom surgery is contraindicated, treatment with high-dose cisplatin administered every 21 days for 3 cycles concomitantly with conventional radiotherapy is recommended [1-3]. Its anticancer mechanism is mediated by DNA binding, which leads to the formation of inter-and intrastrand crosslinks and results in defective DNA templates, arrest of DNA synthesis and replication, DNA damage and, finally, cell death [4]. In addition, cisplatin accumulates in human cells (normal and tumour cells) resulting in enhanced production of reactive oxygen species (ROS) and reactive nitrogen species (RNS), which leads to mitochondrial damage and dysfunction [5,6]. In addition, there is a decrease in the antioxidant defence system mediated primarily by links formed between cisplatin and glutathione, which culminates in the depletion of glutathione [7]. The excessive generation of ROS and RNS damages biomolecules, resulting in lipid, protein and DNA/RNA oxidation and causing toxicities including nephrotoxicity, neurotoxicity, ototoxicity and hepatotoxicity [8-11]. The intensity of biomolecular damage can be determined by oxidative/nitrosative stress biomarkers. In this study, we used malondialdehyde (MDA) and lipid hydroperoxides, which are indicators of lipid peroxidation/oxidative stress biomarkers and nitrite, a nitrosative stress biomarker. Therefore, the aim of this study was to determine the effects of high-dose cisplatin chemotherapy and conventional radiotherapy on urinary levels of MDA, lipid hydroperoxides and nitrite biomarkers in patients with head and neck1181 8386Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)