Commentary on "The association between sexual function and prostate cancer risk in US veterans".

Dear Editor,

We read with interest the article by Zapata et al.1 published in Asian Journal of Andrology. With data from 448 veteran men and using logistic regression analysis, this study the first time demonstrated that higher sexual function was associated with a decreased risk of prostate cancer. This association was hypothesized on that sexual dysfunction is a harbinger of heart disease, and prostate cancer and heart disease share similar risk factors; however, the mediation effect of testosterone (T) activity on the association can never be ignored. Although it has been discussed as one alternative explanation of the association in the article, in my opinion, it is not enough. Sexual dysfunction was a well-established clinical symptom of low serum T,2 and usage of T replacement therapy (TRT) which can increase serum T concentration of hypogonadal men to normal level can remarkably improve the symptom.3 Thus, it is highly possible that the T-mediated pathway tells most of the story between sexual dysfunction and risk of prostate cancer. Second, although exclusion criterion taken in this study included many items, an extremely important one – TRT history was not considered, which would lead to a non-negligible confounding. Third, since the oncogenesis of prostate cancer is a long-term process, the examination of sexual function at one time point, especially just before prostate biopsy as conducted in this study, cannot be convictive enough to predict cancer risk. We would like to know authors’ interpretations for these.

COMPETING INTERESTS

Both authors have no competing interests.