Iris de Nie

140 C H A P T E R 9 Since the prostate is not removed during GAS, it is reassuring that we observed a 5-fold decrease in prostate cancer risk in trans women using GAHT ( chapter 8 ). Currently, European guideline advice against population-based PSA screening, since it does not increase survival and causes overtreatment, and to only perform PSA testing in people with an elevated risk of prostate cancer after counselling on the potential risks and benefits. 21,153 However, it still remains one of the most controversial topics in the urological literature. 155 Given the low incidence of prostate cancer and lack of PSA reference values in trans women, there seems even less reason to perform routine screening in this population. However, it remains important that trans women and their healthcare providers are aware that the prostate is not removed during GAS and there is still a possibility of development of prostate cancer despite low serum androgen levels. In our gender identity clinic, all trans women with an elevated risk for prostate cancer (e.g. positive family history) are referred to a urologist to discuss the benefits and harms of PSA-based screening, as well as the lack of PSA reference values under androgen deprivation therapy. Implications for future research As already mentioned in the paragraph on methodological considerations, we identified several limitations of the current studies. Longitudinal data about the perspectives of transgender adolescents on family building and the importance of genetic parenthood are needed. Since nowadays, all transgender adolescents in our gender identity clinic receive fertility counseling from a fertility specialist prior to the start with puberty suppression as well as before initiation of GAHT, they may have different experiences than the participants of our survey study. For future studies it would be worthwhile to evaluate how adolescents experience this fertility counseling and how it affects decisional conflict and regret regarding reproductive choices. In addition, studies should be conducted on how trans women would feel about fertility preservation options in orchiectomy specimens obtained during GAS and to identify facilitators and barriers for implementation of such techniques in clinical practice. Furthermore, it is important to assess howGAHT influences the quality of germ cells and the safety of using cells harvested from orchiectomy specimens for reproductive techniques, and to continue research on the feasibility of i n vitro spermatogenesis so that transgender adolescents, who are otherwise unable to have genetically-related children, will be able to retain this possibility by cryopreserving testicular tissue containing spermatogonial stem cells.When such techniques are actually implemented in clinical practice, it is important to asses live birth-rate, as well as long-term follow up of children born from these gametes. Besides, more research is needed on how prostate cancer develops in trans women using GAHT. Since these tumors developed under androgen deprived conditions, underlying pathological mechanism are perhaps similar to proposed mechanisms of the transition from hormone-sensitive to castration-resistant prostate cancer, which might have implications for the treatment options and outcomes in trans women. To gain more knowledge on this topic, it would be interesting to investigate the clinical symptoms in trans women leading to prostate cancer diagnosis, as well as the receptor status in prostate cancer tissue of trans women.