Dr Jun Gong: Improved Access Closes the Gaps Between Black, White Men With Prostate Cancer

There are 2 sides to the equation when it comes to the disparities in prostate cancer between Black men and White men: socioeconomic disparities and biological differences, explained Jun Gong, MD, associate professor, medicine, and medical director, colorectal cancer medicine, Cedars Sinai.

Jun Gong, MD, associate professor, medicine, and medical director, colorectal cancer medicine, Cedars Sinai.

Image credit: Cedars Sinai.

In an interview with The American Journal of Managed Care^® (AJMC^®), Gong discussed recent research on the role socioeconomic status plays in disparities, identified biological differences that contribute to disparities, and how access to care has reduced the gap between Black men and White men.

This interview has been edited for clarity.

AJMC: In 2023, you published multiple pieces of research on disparities in cancer, particularly in Black men with prostate cancer. Can you first tell me a little about the documented disparities between Black men and White men with prostate cancer?

This has been a well-documented unmet need in the prostate cancer literature for a long time. What we do know from historical data is that Black men have a higher incidence of prostate cancer than White men.¹ But if you look at their mortality from prostate cancer, Black men almost have twice the rate of prostate cancer–related deaths than White men, overall.¹ So, we always knew that this disparity existed across all stages of prostate cancer to begin with.

AJMC: What role does socioeconomic status play in disparities?

This is a very important question that really highlights the 2 sides of the story here. One is biologic differences: Black men have biologically distinct tumors from White men with prostate cancer,² and is this contributing to the disparities in prostate cancer? The other side of the equation is the environment. Now, we call these barriers socioeconomic status,³ and we've done research on this.⁴ We've done research on both sides of the story,^2,4 and what we found is that they are both important, that just having access to timely care and life-prolonging therapies are very important variables that account for almost 80% of the differences in outcome based on the study.

AJMC: Your research identified biological differences among prostate cancers in Black and White men, can you explain that?

In a review that we recently published in Nature Reviews Urology,² we highlighted some of the evolving differences between the biology of Black men and White men with prostate cancer. And it really covers the spectrum from hereditary ancestral factors dating from the time and from the relationship to the African ancestry—there are actually differences in the chromosomes and genes that can be inherited that increase prostate cancer risk in Black men compared to White men.

But then there are also what we call somatic or sporadic mutations that develop—these are not related to germline or hereditary causes. These develop sporadically in the tumor types of Black men and White men. And when we've highlighted² that there are certain differences that exist. To give you a couple examples, DNA damage repair mutations have been definably found to be in higher incidence, both germline and sporadic, in Black men with prostate cancer compared to White men with prostate cancer. What does this mean, clinically?

We know that DNA damage repair mutations portend a poorer prognosis overall. But we have drugs that can target these mutations in the clinic that are FDA approved. So, how does this play out with Black men with metastatic prostate cancer if they have these DNA damage repair mutations? Do they just have a poorer prognosis, or because they have higher rates of these mutations, are they going to benefit more from these targeted therapies, such as PARP inhibitors, that are available, and how is it going to play out in context with White men with prostate cancer?

And just another last example, we've seen that SPOP mutations are of higher incidence in Black men with prostate cancer compared to White men with prostate cancer, and at least in the metastatic prostate cancer setting, SPOP mutations have a predicted benefit to hormone therapies compared to those that are SPOP wild-type. So again, how does this play out with the Black men with metastatic prostate cancer? Does this mean that they are more responsive to hormone therapies than White men with prostate cancer? And could this be contributing to why, in certain datasets, we've seen that Black men can do just as well, if not better, in terms of survival outcomes with systemic therapies to hormone therapies with White men?⁴

I think this is a very important topic to investigate. But on the flip side, you have all these options: how do we make sure that all Black men with prostate cancer get those options? And that's the access-related variable that comes to the equation.

AJMC: You mentioned that Black men tend to do better on systemic therapies. What does that mean or look like? Regarding treatment outcomes, specifically with systemic therapies, what have you found?

In our paper that we published in Journal of Clinical Oncology,⁴ recently, we first looked at national registry data. So, we looked at SEER [Surveillance, Epidemiology, and End Results Medicare] data, for example, over the past decade or so. We noticed, at least with the SEER database, that Black men did worse than White men with metastatic prostate cancer receiving systemic therapies. But then, as we kind of dug deeper into the evidence, we noticed that if you looked at prospective studies or randomized clinical trials, you actually saw the survival gaps disappear in the sense that White men and Black men receiving systemic therapy did just as well. And in certain cases, Black men did better than White men receiving systemic therapies with survival and treatment with systemic therapies.

This is where I think we tease out in the literature, what happens in SEER, real-world databases—these large databases—patients are subjected to socioeconomic barriers, you know, financial considerations, travel, access to clinic, access to medications. But in a clinical trial, what happens is that everybody is equalized. You enter the clinical trial, everybody is provided the same drug, and you are also monitored the same way. You have a research team, you have a doctor, you have clinical research coordinators checking on the patient to make sure, “Hey, did you take the drug? How are the pills going? How do you feel from a side effect potential?” And this balance is really important to highlight that this is why in an even playing field Black men probably do just as well as White men receiving systemic therapies.

AJMC: Going back to access to care, which is proving to be crucial to closing the gap between Black men and White men with prostate cancer. What are some of the steps that can be taken to help improve access to care for Black men so they’re almost getting the same access and care as they would in a structured, randomized controlled trial setting?

Well, that's a good point. I like the way that you hinted at real world because unfortunately, not all men are going to be candidates for clinical trials. But that is one point of contention that I would like to make. Right now, only about 3% of Black men are included in FDA-registered trials for prostate cancer over the past 2 decades. So, we can definitely do more with inclusion of more Black men in clinical trials. But what do we learn and how do we apply this to the real-world setting?

This is where we're hoping to advocate and inform our colleagues and our health care providers and patients, family members, and patient advocates. That knowledge: if you can get timely access to care, whether it's diagnostics or treatments, and if you can ensure that these patients are receiving the same standardized, FDA-approved life-prolonging therapies, the outcomes are comparable, and that Black men do not do worse.

I think this is very informative for community outreach, educational outreach, and patient advocacy groups, to kind of convey this information to implement systemic kind of changes in our health care system for this.

AJMC: You mentioned enrolling more Black men in trials and, in general, better representation in clinical trials. The FDA is pushing for that improved diversity. Are you seeing a difference?

It's a work in progress, which is an important work in progress. Just recently, there were 2 clinical trials that were led by Daniel George, MD, of Duke University School of Medicine, that actually were one of the first clinical trials comparing a strict Black man cohort with prostate cancer compared to a White man with prostate cancer cohort.⁵ As you can imagine, the times are changing, and this is very interesting and important to know that we are specifically designing trials for specific racial groups now in prostate cancer to really formally investigate and include patients of a variety of races into this.

References

1. Hinata N, Fujisawa M. Racial differences in prostate cancer characteristics and cancer-specific mortality: an overview. World J Mens Health. 2022;40(2):217-227. doi:10.5534/wjmh.210070

2. Gong J, Kim DM, Freeman MR, et al. Genetic and biological drivers of prostate cancer disparities in Black men. Nat Rev Urol. Published online November 14, 2023. doi:10.1038/s41585-023-00828-w

3. Lowder D, Rizwan K, McColl C, et al. Racial disparities in prostate cancer: A complex interplay between socioeconomic inequities and genomics. Cancer Lett. 2022;531:71-82. doi:10.1016/j.canlet.2022.01.028

4. Gong J, Kim DM, De Hoedt AM, et al. Disparities with systemic therapies for Black men having advanced prostate cancer: where do we stand? J Clin Oncol. 2024;42(2):228-236. doi:10.1200/JCO.23.00949

5. Exploring racial biases in clinical trials: the PANTHER study's findings on prostate cancer - Dan George. Uro Today website. June 15, 2023. Accessed February 16, 2023. https://www.urotoday.com/video-lectures/asco-2023/video/3468-exploring-racial-biases-in-clinical-trials-the-panther-study-s-findings-on-prostate-cancer-daniel-george.html