Obese African-Americans with prostate cancer (T1c and a prostate-specific antigen, PSA, level of <10 ng/mL) have higher-risk pathological features and a greater risk of PSA recurrence than non-African-Americans.

OBJECTIVE

to analyse the relationship between African American (AA) race and obesity in men with prostate cancer.

PATIENTS AND METHODS

in all, 4196 patients who underwent radical prostatectomy from 1988 to 2008 were identified in the Duke Prostate Center database. A subset of 389 (AA 20.9% and non-AA 79.1%) patients with a body mass index (BMI) of ≥30 kg/m(2) , T1c disease and a prostate-specific antigen (PSA) level of <10 ng/mL were stratified by race and analysed. Age at surgery, race, surgical margin status, pathological tumour stage (pT2, pT3/4), pathological Gleason sum (<7, 3 + 4, 4 + 3, >7), extracapsular extension (ECE), seminal vesicle invasion and tumour percentage were assessed by univariate analysis followed by Cox regression analysis.

RESULTS

in the entire cohort, 143 (38.1%) AA men were obese, compared to 509 (25.0%) of the non-AA men. AA men had a significantly higher tumour percentage (15% vs 10%, P= 0.002), and a greater proportion of pT3/4 disease (45.1% vs 26.2%, P= 0.039), pathological Gleason sum ≥ 7 (70.7% vs 50.5%, P= 0.003), positive ECE (37.8% vs 23.1%, P= 0.007), and positive surgical margin (52.4% vs 36.8%, P= 0.010) than non-AA men. AA men had a greater risk of PSA recurrence on Kaplan Meier (P= 0.004) and Cox regression analysis (P= 0.040, hazard ratio 1.72)

CONCLUSION

a greater proportion of AA men was obese in this cohort. Obese AA with impalpable cancer and a PSA level of <10 ng/mL have a higher risk of pathological features than obese non-AA men, as well as a higher risk of PSA recurrence. Obesity might be responsible for the racial disparity seen in prostate cancer.