PROSTATE-specific antigen (PSA) screening may miss early-stage prostate cancer in transgender women undergoing oestrogen therapy, according to new research.
Study author Stephen Freedland of Cedars-Sinai, Los Angeles, California, USA, explained: “Many transgender women take oestrogen as part of their gender-affirming care. This drastically lowers PSA levels, which could mean the threshold we are using as ‘normal’ is too high to detect early-stage cancer in these patients.” Because of the castrating effects of gender-affirming hormones, PSA, whose production is androgen-regulated, would be expected to be lowered.
The research team analysed data from 210 transgender women, aged 40–80 years, who were on oestrogen therapy and had undergone PSA testing (86% White; 2% Black). The data, sourced from Veterans Health Administration records, revealed a median PSA level of 0.02 ng/mL, fifty-fold lower than the median PSA values seen in similarly aged cisgender men. Furthermore, the 95th percentile PSA value was 0.6 ng/mL, with the highest PSA recorded being 2.21 ng/mL. These findings contrast with the current threshold of 4.0 ng/mL, which typically prompts further investigation for prostate cancer in cisgender men.
The study’s sensitivity analyses confirmed the lower PSA levels, with similar distributions observed when using different measures of PSA. Notably, 36% of patients had undetectable PSA levels, with a higher incidence in those who had undergone orchiectomy (49%) compared to those who had not (23%).
Freedland emphasised the importance of PSA screening for transgender women, despite the differences in typical PSA levels. While PSA screening reduces the risk that cisgender men aged 55–69 years will die of prostate cancer, it is still unknown whether this is the case for transgender women on oestrogen. However, he urged transgender women on oestrogen to remember their prostate health.
“Don’t forget that you have a prostate, and that prostates can become cancerous. The best way we know to find those cancers early and reduce the risk of death is a PSA test. And if you choose to do that, keep in mind that the test values are not calibrated for you. Bring your results, and possibly this study, to your urologist, so that your results will be interpreted by someone who understands what to do with that information.”
The study underscores the need for updated screening guidelines and inclusive research that is more representative of minority transgender women.
Ada Enesco, EMJ
Reference
Nik-Ahd F et al. Prostate-specific antigen values in transgender women receiving estrogen. JAMA. 2024;DOI:10.1001/jama.2024.9997.
