Investigators examine prostate cancer incidence in transgender women

In this video, Matthew Loria describes the background and notable findings for the recent Prostate Cancer and Prostatic Diseases paper, “Incidence of prostate cancer in transgender women in the US: a large database analysis.” Loria is an MD student at Case Western Reserve University in Cleveland, Ohio.

Transcription:

Please describe the background for this paper.

The background of this paper that my colleagues and I looked into was first, this idea of what is the underlying incidence of prostate cancer in trans women. A lot of the research that's currently out there is quite limited. Working with trans and gender-diverse individuals, there are not a lot of solidified data, because cohorts tend to be pretty small when you're working with them. Or if you're working with electronic health records, things may not be documented as clearly as we would like to really get a full good history and to run robust trials to look at things that may be affecting this population. So a lot of the data that we actually have here in United States that guides our practice comes from places outside the United States. One of the most cited studies for looking at the rates of prostate cancer in trans women actually comes from places like the Netherlands, that have more robust data behind them and more national standardized information that allows really good keeping of information. So when we looked at some of their studies, we found that, in general, they reported that the rate of prostate cancer in trans women was about 5 times lower than cisgender folks, and this is for trans women who were on hormone therapy, or had undergone an orchiectomy. We used those as our base studies; we found that a lot of the papers in the United States have been citing this as their reason for examining the risk of prostate cancer in trans women. And so then we really tried to see, do these data hold up in the United States?...So when we started looking into the literature here, there are a couple studies that have been done, mainly by the VA, because they have the most standardized database of information. And one of the most recent studies...did a case series of 500 trans women at the VA and found that the rates were probably closer to only a 2 times lower rate of prostate cancer in trans women compared with cis men. That's what launched the platform for our study. We have access to a larger database that has pretty well-kept information about trans and gender-diverse individuals. And so using this database, we're then going to try and look at getting a large-scale cohort to see what does the rate of prostate cancer look like in trans women in the United States.

What were some of the notable findings? Were any of them surprising to you and your coauthors?

We're a group called the Group for LGBTQ medical research based out of University Hospitals Urology Institute, here in Cleveland. Our 2 principal investigators, Dr. Gupta and Dr. Mishra, are both gender-affirming surgeons here. For them, it was really important to figure out, how do I counsel my patients on this risk? How do I figure out what is the risk of prostate cancer on hormone therapy, not on hormone therapy, undergoing gender-affirming surgery, because obviously, the prostate still remains in situ after. So you're still at risk of developing prostate cancer. When we launched this project, we used TriNetX, which is an international database with about 125 million patients. We specifically looked at patients in the United States. And then from there, our first cohort creation was looking at those who had a diagnosis in their chart of transgender or gender diverse, which is like an F 64 specific code diagnosis for those who identify as transgender. That was our starting point to build this cohort. We looked at rates of prostate cancer among those who were on hormone therapy, and then those who had undergone an orchietcomy. And then we followed these cohorts till the end of their charts. TriNetX uses all claims-based data. And so we just followed them. And then at the end, we ultimately found that trans women from between the ages of 50 and 65 who were on hormone therapy had a 2.5-fold decreased risk of prostate cancer compared with cis men. So it was still a significant decrease compared with cis men. But a lot of the prior literature really suggest rates that are like 4, 5, 6 times lower than cis men. So really, this shows that while we think it's kind of a rare thing to happen, it really is not in this population. I think really the key takeaway from this is that, when we look at the age of our population that we are studying, the average person is 29 or 30 years old that's on hormone therapy and undergoing an orchiectomy, or some sort of gender-affirming surgery. So, when we think about this in the long term, this can become an increasing disease burden for this population, because prostate cancer is a disease of older age. And so you're not really going to start seeing this until people are in their 50s, 60s, 70s. And unfortunately, the trans population in the US is very heavily skewed toward the younger demographic currently. So as this population ages, it's going to become increasingly important to understand how this risk is modulated compared with cis men. And I think that's where a lot of people currently in the field of urology are maybe not placing a particular emphasis; it's just that this population is so young...And we highlight that as part of our potential reason for why this 2.5-fold lower risk was seen. It could just be that our population in general is a lot younger. So that age group between 50 to 65 was like a smaller chunk of our cohort as well comparatively. So we're very interested to see as this population ages, how does this risk change? But I think the main takeaway of this paper is that it is definitely not as rare as we once thought it was.

This transcription was edited for clarity.