A recent study published in the Journal of the American Medical Association (JAMA) has shed new light on prostate-specific antigen (PSA) values among transgender women undergoing oestrogen therapy. This groundbreaking research suggests that transgender women receiving oestrogen are more likely to present with high-grade prostate cancer compared to cisgender men, indicating potential delays in diagnosis due to the lack of PSA reference ranges specific to this population.
PSA is a protein produced by cells of the prostate gland, often measured to screen for prostate cancer. However, its production is regulated by androgens, making the interpretation of PSA levels in transgender women receiving oestrogen therapy complex. Oestrogen has a castrating effect, significantly lowering PSA levels and complicating the detection of prostate abnormalities.
The study, led by Dr. Farnoosh Nik-Ahd and colleagues, analysed Veterans Health Administration (VHA) records from January 2000 to August 2023. Out of 14,915 patients identified, 1,000 randomly selected transgender women aged 40 and older were examined to establish the cohort. All participants were receiving oestrogen therapy and had undergone PSA testing between the ages of 40 and 80.
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Key Findings
- PSA Levels: The study found that the median PSA value among transgender women receiving oestrogen was 0.02 ng/mL, significantly lower than the median PSA value of 1 ng/mL observed in similarly aged cisgender men without known prostate cancer.
- Undetectable PSAs: 36% of transgender women had undetectable PSA levels, a stark contrast to the typical PSA levels seen in cisgender men.
- High PSA Threshold: The study suggests that the traditional PSA threshold of 4 ng/mL for further evaluation is likely too high for transgender women receiving oestrogen. This could lead to delays in diagnosis and treatment.
The findings underscore the need for new PSA reference ranges tailored specifically for transgender women on oestrogen therapy. The current thresholds may not be applicable, potentially causing high-grade prostate cancers to be diagnosed at more advanced stages.
The study’s authors emphasised the necessity for additional research to determine the optimal PSA screening practices for transgender women. This includes examining the experiences of minority transgender women, who were underrepresented in this study. The lack of a comparison group and potential biases from unknown PSA testing indications also highlight the need for further investigation.
Oestrogen therapyThis pivotal study calls attention to the unique challenges faced by transgender women in prostate cancer screening. By establishing appropriate PSA reference ranges and screening practices, healthcare providers can ensure timely and accurate diagnosis, ultimately improving outcomes for this population.
Paper: Nik-Ahd FDe Hoedt AMButler C, et al. Prostate-Specific Antigen Values in Transgender Women Receiving Estrogen. JAMA. Published online June 26, 2024. doi:10.1001/jama.2024.9997 Access online here.
