Avaliação de biomarcadores de estresse oxidativo em pacientes com câncer de próstata de acordo com a classificação do escore da ISUP e dos níveis de PSA

Abstract

Introduction: Prostate cancer (CaP) is recognized as one of the most important health problems faced by the male population and is responsible for the deaths of thousands of men every year. Worldwide, PCa is considered the second cancer that most affects men and, in the pathophysiological context of this disease, cellular oxidative processes directly influence prostate carcinogenesis and tumor progression. Antioxidant defenses, such as molecules that present thiol groups (-SH), are essential for the neutralization of reactive species, such as thiobarbituric acid reactive species (TBARS), which are substances associated with lipid peroxidation, capable of intensifying stress oxidative and contribute to the development of CaP. Objective: To evaluate serum levels of thiols and TBARS in patients with PCa, according to the ISUP score classification and serum PSA levels. Methodology: This is a quantitative, observational and cross-sectional study. To this end, 39 men diagnosed with PCa were selected, before the start of any therapeutic intervention, and 45 control individuals, of the same sex and with a similar age range to the group of patients. The levels of protein thiols (TSH), non- protein thiols (NPSH) and TBARS were evaluated. The patient sample was obtained from the collection of 10 mL of peripheral blood carried out at the Hospital Regional do Oeste, located in Chapecó/SC. For statistical analyses, first, the data were tested for normality using the Shapiro-Wilk test. Afterwards, the One-way ANOVA test was used. The significance level was 0.05 and the statistical program used was GraphPad Prism 8.0.1. Results: From the analysis of the results, the mean age of the patients was 66 ± 6.72 years, and 65.81±10.30 in the controls (p=0.8503). Of the group of patients with CaP, 21 (54%) had serum PSA levels between ≥ 4 and ≤ 10 ng/mL before therapeutic intervention. Regarding the ISUP score, 19 (48.8%) were classified as ISUP 2. Patients with ISUP 1 and 3 had decreased TSH levels, while those with ISUP 2, 3, 4 and 5 had NPSH levels lower than those. controls. Furthermore, patients with PSA levels ≥ 4 ng/mL and ≤ 10 ng/mL showed a decrease in both TSH and NPSH. Regarding TBARS levels, they were significantly higher in patients with ISUP 1 and 2, as well as being lower at any level of PSA change. Discussion: The reduced levels of TSH and NPSH suggest a high consumption of these antioxidants in an attempt to neutralize ROS, generated during the oxidative process. However, even if this organic response is occurring, it is not sufficient to control the formation of molecules related to lipid peroxidation, such as TBARS, which play an important role in the alteration of biomolecules and tumor development. Conclusion: We observed that elevated levels of serum PSA and oxidizing biomolecules are directly associated with increased oxidant activity and reduced antioxidant potential, correlating with the progression of prostate cancer.