ABSTRACT

Objective: Oxidative stress has been implicated in the pathophysiology of various life threatening diseases namely cancer, cardiovascular disease and diabetes. This study aims to compare the severity of oxidative damage in cancer and some factors that may influence the levels of urinary oxidative biomarkers. The factors were sample collection period, cancer stages and lifestyle disease conditions (which are known to be associated with oxidative stress) such as diabetes with and without hypertension.

Methods: The effects of the above mentioned factors on the levels of urinary advanced oxidation protein product (AOPP) and other oxidative indices such as  hydrogen peroxide (H₂O₂), malondialdehyde (MDA) and ferric-reducing antioxidant power (FRAP) were evaluated according to well-established methods.

Results: The period of sample collection did not show any significant difference in the parameters tested. The levels of oxidative stress in breast and colorectal cancer patients that generally increased with the cancer stages showed that cancer progression correlates with high oxidative damage. Comparison between diabetes with and without hypertension did not give any significant difference in the parameters tested. Among all the four oxidative indices, the level of AOPP in breast, colorectal and other types of cancers were significantly higher compared to diabetes with or without hypertension.

Conclusions: The oxidative damage to protein is significantly higher in cancer and may potentially serve as non-invasive oxidative biomarker for this disease.