Background Both diabetes mellitus and cancer are characterised by elevated levels of oxidative stress and the production of free radicals, which further complicates the control and outcomes of these diseases.

Purpose To assess the level of urinary 8-hydroxydeoxyguanosine in diabetic cancer patients as a biomarker of both disease progression and chemotherapy administration.

Material and methods A controlled prospective observational study was carried out in 100 diabetic patients newly diagnosed with diverse cancer types and eligible for different chemotherapeutic protocols at the oncology unit. Urinary 8-hydroxydeoxyguanosine levels were assessed at baseline (before the required chemotherapy protocol schedule) and at a second reading (at the end of the required chemotherapy protocol schedule). The main outcome measure was urinary 8-hydroxydeoxyguanosine levels as a biomarker of cellular oxidative stress in diabetic patients with cancer.

Results There was a significant (p<0.05) increase in urinary 8-hydroxydeoxyguanosine levels between baseline and the second readings (27.04±4.33 ng/dL vs 30.77±4.63 ng/dL), and between the baseline and second readings after a 7 day course (25.96±4.21 ng/dL vs 28.16±5.27 ng/dL), a 14 day course (27.76±5.33 ng/dL vs 31.56±4.47 ng/dL) and a 21 day course (27.22±4.16 ng/dL vs 31.40±4.24 ng/dL).

Conclusion The results of this study suggest that oxidative stress based on elevated urinary 8-hydroxydeoxyguanosine levels is related to diabetes mellitus and cancer, which is further boosted during chemotherapy administration.

References and/or acknowledgements Great thanks to Assistant Professor Dr Betul Okuyan (Department of Clinical Pharmacy, Faculty of Pharmacy, Marmara University) for guidance and support.

No conflict of interest