The first objective of this study is to examine prostate cancer risk and overall survival (OS) in trans women compared to cis men. We also evaluate differences in prostate cancer risk and overall survival in trans women receiving gender affirming interventions including HRT and orchiectomy. Finally, we explore prostate cancer screening rates in trans women compared to cis men.

A retrospective review was performed using the TriNetX database, which includes 120 million patients from 100+ healthcare organizations. Patients were divided into subgroups based on treatment received: trans women with no medical or surgical intervention (NI), trans women with HRT but no surgical intervention (HT), and trans women with HRT and orchiectomy (SX). Groups were matched based on race and age using propensity scores. Groups were compared to a control cis-male group. Groups and outcomes were defined using CPT codes and ICD-10 codes indicating transgender status, malignant neoplasm of the prostate, and prostate cancer screening.

33,081 trans women were identified. After age and race matching, no significant differences in the risk of prostate cancer or OS through 15 years post-diagnosis were identified between trans women who received hormonal or surgical intervention versus those who did not. Risk of prostate cancer between trans women without HRT and with HRT also did not differ. Additionally, we observed a decrease in risk of prostate cancer and OS among trans women without any medical or surgical intervention (NI) compared to cis men. When examining prostate cancer screening rates in NI compared to cis men, NI had significantly lower rates of screening compared to cis men (1.9% vs. 6%; p<0.0001).

Using real world data, we found that among trans women neither HRT nor orchiectomy were protective for prostate cancer development and OS. This directly conflicts with current literature that demonstrates a protective benefit of both HRT and orchiectomy.  To date, this appears to be the largest cohort of trans women assessed for prostate cancer. The previous largest cohort comes from a Netherlands study that found decreased levels of prostate cancer among 2,281 trans women (1). However, this study only reported 6 cases of prostate cancer. In our cohort, there were 45 cases of prostate cancer among trans women on HRT (n=14,173). This data suggests that the protective effect of HRT and orchiectomy on prostate cancer development may not be as strong as once believed. Additionally, we observed that trans women with no medical or surgical intervention (NI) had a lower risk of prostate cancer development despite being biologically and hormonally similar to cis-men. To further explore this, we examined rates of prostate cancer screening in these two groups and found that trans women, even those who had not received medical or surgical gender affirming care, had a significantly decreased rate of prostate cancer screening.

Our findings suggest that HRT and orchiectomy may not provide a protective effect in the development and overall survival of prostate cancer. Furthermore, we for the first time report that trans women, despite being biologically at the same risk for prostate cancer as cis men, are screened for prostate cancer at a significantly lower rate. Overall, findings from this study emphasize the need for the comprehensive screening of trans women for prostate cancer and that inclusive guidelines should be developed to ensure adequate care in this population.

de Nie, I., de Blok, C. J., van der Sluis, T. M., Barbé, E., Pigot, G. L., Wiepjes, C. M., ... & den Heijer, M. (2020). Prostate cancer incidence under androgen deprivation: nationwide cohort study in trans women receiving hormone treatment. The Journal of Clinical Endocrinology & Metabolism, 105(9), e3293-e3299.