BACKGROUND: Global prostate cancer (PC) incidence rates are lower in Asian men than Caucasian men. Whether this is the result of less screening in Asian men remains to be determined. We examined whether Asian race was associated with PC diagnosis in the REDUCE study.
METHODS: REDUCE was a 4-year, multicenter, randomized trial of dutasteride vs. placebo for PC prevention among men who underwent PSA-independent biopsies at 2- and 4-years. Eligible men were aged 50-75 years, had PSA between 2.5-10 ng/mL, and a negative pre-study prostate biopsy. We tested the association between Asian and Caucasian race and PC diagnosis using logistic regression.
RESULTS: Of 8,122 men in REDUCE, 5,755 (71%) were Caucasian and 105 (1.8%) were Asian. Asians had lower body mass index (24.8 vs. 26.9 kg/m2, p<0.001), smaller prostate volume (35.0 vs. 43.5cc, p<0.001), and were less likely to have abnormal digital rectal exam (p=0.048), but were similar in baseline age, PSA, family history of PC, and smoking status compared to Caucasian men (all p≥0.164). Asian men were equally likely to receive any on-study biopsy compared to Caucasian men (p=0.634). After adjusting for potential confounders, Asian men were less likely to be diagnosed with PC during the 4-year study (OR=0.49, 95%CI 0.28-0.88, p=0.016), compared to Caucasian men.
CONCLUSIONS: In REDUCE, where all men underwent biopsies largely independent of PSA, Asian race was associated with lower PC diagnosis.
IMPACT: These findings suggest lower PC risk in Asian men may be due to biological, genetic, and/or lifestyle factors.
|Journal||Cancer epidemiology, biomarkers & prevention : a publication of the American Association for Cancer Research, cosponsored by the American Society of Preventive Oncology|
|Early online date||20 Aug 2020|
|Publication status||Early online date - 20 Aug 2020|