Response to Re: External beam radiotherapy and radical prostatectomy are associated with better survival in Asian prostate cancer patients

We would like to thank So et al. for the insightful comments and considerations regarding our analyses on racial/ethnic differences in prostate cancer-specific mortality (CSM) rates according to treatment type (radical prostatectomy and external beam radiotherapy). Our findings, which are indeed naturally limited by their retrospective and population-based design, still suggest potentially significant discrepancies in CSM, favoring Asian race/ethnicity to a large extent, both for radical prostatectomy and external beam radiotherapy, that deserve to be explored further. Indeed, So et al. call for more prospective trials focusing on a race-/ethnicity-specific background, which would receive our full support. In fact, these trials should not restrict themselves to prostate cancer, but should also incorporate different cancers and differentiations between localized and metastatic settings. For example, the more favorable CSM rates in Asian prostate cancer patients appear also to translate to the metastatic setting, and have been reported earlier by our group. Conversely, Asian race/ethnicity appears to be associated with worse CSM in upper tract urothelial carcinoma but no disadvantage was detected for localized kidney cancer, to mention a few. However, all these findings are naturally prone to misinterpretation and biases that are inherent in a large epidemiological database analysis. Although a certain degree of adjustment (i.e. propensity-score matching and multivariable competing risks analyses) may help to reduce these biases within the database, solid trials should further substantiate our preliminary associations.