Comparison of the response to treatment between Asian and Caucasian men with benign prostatic hyperplasia: Long-term results from the combination of dutasteride and tamsulosin study

The Combination of Avodart and Tamsulosin study was a 4-year, randomized, double-blind study of the efficacy and safety of dutasteride and tamsulosin, alone or in combination, in men with moderate-to-severe benign prostatic hyperplasia. In this post-hoc investigation, we analyzed primary and secondary end-points from the Combination of Avodart and Tamsulosin study in Asian (n=325) and Caucasian men (n=4259). The incidence of acute urinary retention or benign prostatic hyperplasia-related surgery did not differ significantly between treatment groups in the Asian subpopulation. In Caucasian men, the incidence of acute urinary retention/benign prostatic hyperplasia-related surgery was significantly lower in the combination therapy group compared with the tamsulosin monotherapy group (P<0.001), but not compared with dutasteride monotherapy. Combination therapy significantly increased the time to benign prostatic hyperplasia clinical progression and resulted in improved International Prostate Symptom Score, maximum urinary flow rate, quality of life, and reduced prostate volume in Asian and Caucasian men who received combination therapy compared with tamsulosin monotherapy. Combination therapy also significantly improved (P<0.05) time to benign prostatic hyperplasia clinical progression, International Prostate Symptom Score, maximum urinary flow rate and quality of life versus dutasteride in the Caucasian subpopulation. The adverse-event profile was comparable between subpopulations. In conclusion, Asian and Caucasian men respond similarly to these treatments, despite apparent racial differences in 5α-reductase activity.