Racial influence on the prevalence of prostate carcinoma in Brazilian volunteers

Abstract

Purpose: To investigate the prevalence of prostate carcinoma in a sample of volunteers known to have a large proportion of Bantu African ancestors, and the performance of total PSA (tPSA), PSA density (PSAD) and free-to-total PSA ratio (f/tPSA) on the diagnosis.Materials and Methods: A total of 473 volunteers (range: 40 -79 years) were screened for prostate carcinoma. Those with tPSA >2 ng/ml and/or abnormal digital rectal examination were submitted to a transrectal ultrasound-directed biopsy (10 cores). The volunteers were classified as White, Mulatto or Black according to physical characteristics and to ancestors race reference. The following variable number of tandem repeats (VNTR) were analyzed in the blood of 120 volunteers without cancer and in 27 patients with prostate cancer: D4S43, PAH, F13A1, APOB and vW-1.Results: The biopsies performed in 121 volunteers revealed cancer in 27 (5.7% of 473). The proportions of cancer in White, Mulatto and Black were respectively: 0.6% (1/148), 6.7% (6/90) and 8.5% (20/235) (p = 0.006). The VNTRs analysis revealed heterogeneity in White, Mulatto and Black anthropologic phenotypes with the following admixture of Caucasian, African and Amerindian gene lineages: 67.5 ± 8%, 20.8 ± 8%, 11.7 ± 7%; 54.8 ± 9%, 36.3 ± 5%, 8.9 ± 7%; and, 45.3 ± 3%, 45.9 ± 4%, 8.8 ± 7%. Such a mixture was 50.5 ± 9%, 49 ± 8% and 0.5 ± 4% in volunteers bearing cancer, and 59.1 ± 7%, 31.7 ± 8% and 9.2 ± 5% in those without cancer. The sensitivity and specificity of tPSA at cut-off levels of 2, 2.5 and 4 ng/ml for volunteers with tPSA ≤ 10 ng/ml were respectively: 100% and 6,6%, 100% and 36,6%, 69,2% and 62,2%. PSAD at a cut-off level of 0.08 or 0.10, and f/tPSA at a cut-off level of 20% were able to increase significantly tPSA specificity without loss on sensitivity.Conclusions: The tumor prevalence was higher in Non-White than in White phenotype. The association of tPSA at a cut-off level of 2.5 ng/ml with a PSAD of 0.08 or a f/tPSA of 20% for biopsy indication deserves further investigations as an alternative to tPSA cut-off level of 4 ng/ml.

Self-declared ethnicity and genomic ancestry in prostate cancer patients from Brazil

“…Thus, patients with low and intermediate Gleason scores had a greater degree of African ancestry, contrary to previous reports of faster PCa progression among black American men (Powell et al, 2010). Furthermore, our analysis showed that patients with rapid PCa growth had a higher European genetic contribution, although several studies have demonstrated that black men are at greater risk of PCa compared to white men, especially in North America (Bouchardy et al, 1991), and present with a more advanced stage at diagnosis (Paschoalin et al, 2003;Coleman et al, 2008;Rebbeck et al, 2013). Our results can be attributed to the high rate of admixture in the Brazilian population resulting from five centuries of interethnic unions between parental groups.…”

“…These findings are similar to those of Paschoalin et al (2003), who analyzed the influence of ethnicity on PCa prevalence in northeastern Brazil, demonstrating that patients anthropologically classified as white exhibited 67.5% European, 20.8% African, and 11.7% Amerindian contributions, while in the mixed group, these values were 54.8, 36.3, and 8.9%, and among black participants were 45.3, 45.9, and 8.8%, respectively. Despite the small number of individuals analyzed in our study, the ancestry estimates obtained were close to those reported in the 2010 census by the Brazilian Institute of Geography and Statistics (IBGE 2011).…”

Controversial predictors of biochemical recurrence after radical prostatectomy: a study from a Latin American (Brazilian) Institution

“…The prevalence of prostate cancer in Brazil is higher in Black men compared to White men (12)(13)(14)(15). We studied the influence of race in regard to biochemical recurrence after radical prostatectomy.…”

Association between Literacy, Compliance with Prostate Cancer Screening, and Cancer Aggressiveness: Results from a Brazilian Screening Study

“…It was not a randomized, prospective study, and although literate and illiterate men were contemporary and of similar age range, intrinsic differences in their characteristics cannot be fully ascertained. Additionally, data on ethnicity were not available, since such these classifications in the largely multiethnic Brazilian population are difficult to attribute, as previously shown in genetic studies in Brazilian volunteers for prostate screening (29)(30)(31). Another limitation is that income data is not available, but the screening program was targeted to an underprivileged, uninsured population living in rural areas, with all work up and treatment performed by the public health system.…”