LAUSR

We read the recent article by Gandaglia et al. [1] with great interest. We congratulate the authors for this valuable research and want to highlight some important issues. The authors evaluated cancer-specific mortality (CSM) and developed a model that included variables such as the pathological characteristics of prostate cancer and nodal status, and used multivariable Cox regression analysis to assess predictors of CSM. One of the main shortcomings of the study is the fact that administration of radiation therapy (RT) was based on the physician's preference according to postoperative patient characteristics, which were not precisely described (details were not given regarding positive surgery margins, prostate-specific antigen [PSA] recurrence over the follow-up period, PSA levels, or lymph node status). Postoperative RT may provide a survival benefit in patients with persistently elevated serum PSA after radical prostatectomy (RP) [2–4]. Therefore, inclusion of patients who received RT after RP might have affected the results. Instead, in a study aiming to develop a model for predicting CSM after RP, patients with no intervention should be included. Although the authors also developed multivariate Cox regression analysis for RT-naive patients, there is only one model calculating the risk of CSM, and it is unclear which coefficients were used to develop this model. The study highlighted that when the patients were subgrouped according to their predicted risk of CSM, increased PSA levels were only associated with lower survival among men with a predicted CSM risk of >10%. However, serum PSA may not be the only determinant of CSM among patients treated with RT. Now that it has been