Oxidative Stress, Antioxidant Status Remain High in Nigerian Patients With Prostate Cancer

Iya Eze Bassey, PhD

Nigerian patients with prostate cancer are noted as having higher levels of total plasma peroxide (TTP), malondialdehyde (MDA), and nitric oxide (NO), as well as lower levels of total antioxidant capacity (TAC), even while undergoing androgen-deprivation therapy (ADT) compared with Nigerian men who don't have prostate cancer, according to results of a study published in the JCO Global Oncology.¹

Overall, Nigerian patients with prostate cancer were observed as having significantly higher waist-hip-ratios and NO (P = .0001), TPP (P = .001), oxidative stress index (OSI; P = .003), and MDA values (P = .002) compared with a healthy control group. No other notable differences in the mean values of other parameters between the 2 groups were reported (P > .05). 

Additionally, treatment-naïve patients with prostate cancer had significantly higher levels of prostate-specific antigen (PSA; P = .0001), waist-hip ratios (P = .011), TPP (P = .013), MDA (P = .011), and NO (P = .0001), and lower TAC (P = .013) compared with the healthy control group. Moreover, patients who did receive ADT had higher PSA (P = .0001), waist-hip ratio (P = .0001), TPP (P = .005), OSI (P = .005), MDA (P = .011), and NO (P = .0001) compared with the control group, though there weren't notable differences in TAC levels between the 2 groups (P > .05).

“This study has shown that oxidative stress is increased and antioxidant status decreased in patients with prostate cancer irrespective of treatment status and that MDA levels increased with duration of treatment,” lead study author Iya Eze Bassey, PhD, and co-investigators wrote. “Because elevated oxidative stress markers are independently associated with poorer outcomes, this should be addressed in the management of patients with prostate cancer.”

Prostate cancer is known to disproportionately affect men of African ancestry.² The disease is the most prevalent cancer among Nigerian men and comprises approximately 6.1% to 19.5% of all cancer cases in Nigeria, with an increasing number of men being diagnosed.^3,4 

In the case-control study, investigators enrolled 220 patients between the ages of 40 to 90 years; among these, 120 had prostate cancer and 100 were enrolled onto the healthy control arm. Patients with prostate cancer were divided into 2 additional groups: those receiving ADT and treatment-naïve patients. Those who were younger than 40 years, had benign prostatic hyperplasia, and those who were smokers were excluded from the study. In the control group, patients with a PSA level greater than 4 ng/mL were excluded. 

A number of individuals from Nigerian tribes were included, such as the Ekoi tribe of which there were the most patients with prostate cancer enrolled (25.8%), and the Yoruba tribe who contributed the fewest healthy patients and patients with prostate cancer. The Ibibios tribe comprised the majority of the control group (31%). The majority of those overall with prostate cancer were retired (25.8%); on the control arm, most were civil or public servants (32%). Fifteen percent of patients with prostate cancer had a smoking history compared with 9% of those on the control arm. Ten percent of patients with prostate cancer had a family history of the disease.

When comparing the treatment-naive patients and patients who underwent ADT, however, investigators found comparable parameters, with the exception of PSA and NO (P = .05), which were higher in the treatment-naive population. A positive correlation was additionally found between MDA and duration of treatment in the patients who received ADT (r = 0.280; P = .018).

While there was significant variation noted in the mean values of PSA levels (P = .0001), waist-hip ratio (P = .0001), TAC (P = .041), TPP (P = .006), OSI (P = .011), MDA (P = .015), and NO (P = .0001), there were no significant variations in the mean values of the other parameters in the study's groups (P > .05).

References

1. Bassey IE,Emodi BA, Akpan UO, et al. Impact of androgen deprivation on oxidative stress and antioxidant status in Nigerian patients with prostate cancer undergoing androgen deprivation therapy. JCO Global Oncol. 2020;6:1481-1489. doi:10.1200/GO.20. 00290

2. Cancer facts & figures 2016. American Cancer Society. Accessed November 30, 2020. https://bit.ly/2KJsqzh

3. Abdulkareem F. Epidemiology & incidence of common cancers in Nigeria. Presented at: Cancer Reg & Epidemiology Workshop; July 12, 2009. Accessed November 30, 2020. https://bit.ly/2Vh0qFg