Association between PSA and age in Macuxi ethnic population of the Brazilian Amazon forest region.

Purpose: Prostate cancer is one of the most common cancers in men, with higher prevalence in developed countries. Nothing much is known regarding the incidence and mortality of prostate cancer in Brazilian population or among the indigenous groups in Brazil. Therefore, this study aimed to correlate prostate-specific antigen (PSA) level and age in the tribe with Macuxi ethnicity, from the jungles of Amazon (between Brazil and Venezuela).

Patients and methods: This was an epidemiological cross-sectional study aimed to find the correlation between age and PSA in the 110 Brazilian Indian tribal men of Macuxi ethnicity. Serum PSA levels (total and free PSA [tPSA and fPSA]) were screened and analyzed considering age groups.

Results: We found that there was a significant correlation between the age and either tPSA ( p =0.016) or fPSA ( p =0.036). Interestingly, there was no correlation between tPSA and fPSA with any of the age groups, but we found a significant correlation between fPSA and tPSA in only the age groups 60-69 years and 70-80 years ( p =0.008).

Conclusion: In this study, we found a significant correlation between tPSA, fPSA, and the age of patients. However, the age-specific correlation was insignificant. From our current findings, we found that the levels of PSA may be considered as an important determinant in determining this correlation and specificity, even though more work needs to be done to verify this. Although PSA screening is a valuable research tool for male patients, the low specificity of the screening might provide false-positive results leading to overtreatment.