Disparities in RCC Trial Access Illuminate the Need for Global Scientific Collaboration

Expanding the access and variety of clinical trials—which are currently concentrated in high-income countries—to more underserved regions around the world is crucial to increasing care equity for all patients with renal cell carcinoma (RCC), according to Regina Barragan-Carrillo, MD.

Findings from an assessment of the global availability of RCC clinical trials, which were presented at the 2025 Genitourinary Cancers Symposium, showed that among 178 countries, at least 1 RCC clinical trial was available in 60.0%, 23.9%, 7.7%, and 0% of high-income, upper-middle-income, lower-middle-income, and low-income countries, respectively. Additionally, upper-middle-income, lower-middle-income, and low-income countries had significantly lower odds of having RCC clinical trials compared with high-income countries, with respective odds rations (ORs) of 0.215 (95% CI, 0.114-0.404; P < .001), 0.056 (95% CI, 0.018-0.176; P <.001), and 0.013 (95% CI, 0.001-0.228; P = .003).

“[Making change in this area will be an] important group effort that's not dependent on a single agency or a single nation,” Carrillo said in an interview with OncLive® during the meeting.

In the interview, Barragan-Carrillo discussed barriers to conducting RCC clinical trials in lower-income countries; findings from this analysis; and the need for international collaboration, government engagement, and decentralized trials to address these disparities and improve global data sharing, trial access, and treatment outcomes.

Barragan-Carrillo is a postdoctoral research fellow at City of Hope Comprehensive Cancer Center in Duarte, California.

OncLive: What are the main barriers to RCC trial availability in low- and middle-income countries?

Barragan-Carrillo: There are scarce data [about this topic], and the main barriers stem from cultural [differences]. For example, in certain types of social backgrounds, medical literacy levels are not the same as those we usually see, for example, in more high-income countries. Another important barrier is geographic locations. We have a problem, both in the United States [US] and in Europe and Latin America, that a lot of the big academic centers that have these trials available are only centered in the main cities. For example, I trained in Mexico, and most of the trials [in that country] are located exclusively in Mexico City and maybe a couple [other cities].

Finally, there's also what I would call a cultural barrier in the sense that there are not cultures in favor of clinical trial enrollment in many non-academic sites. An important message I would like to convey for community oncologists around the world is that clinical trials are also considered a first-line therapy. They are always a good choice to offer to patients, and [this decision] should be an active conversation [with the patient]; it should be a 2-way street.

What was the primary objective of this research, and what was the design of this study?

We wanted to determine whether there was a change in clinical trial availability for RCC depending on location—country wise—and other economic factors, such as health expenditure, each country's respective gross national income, and their overall location within the World Bank Ranking. [Using ClinicalTrials.gov], we analyzed all the clinical trials that were active from 2019 to 2022, and we included those that were made for adult patients that had occurred for at least 1 patient and had enough information available to determine the different sites that these trials were open in.

What proportion of RCC trials were found to be conducted in high- vs low-to-middle–income countries? How did the trial characteristics differ by region?

[In total, 60.0%] of all clinical trials in RCC were available in high-income countries. When we examined the respective proportions [of these trials] in upper-middle-income countries, lower-middle-income countries, and lower-income countries, [these countries had 31.6%] of all trials. In low-income countries in the 5-year [study period], we did not find a single clinical trial on RCC, which is impressive because [these countries have] such vast populations. To put this into perspective, [a large percentage] of all new cancer cases are diagnosed in low- and middle-income countries. This is a significant number of patients who are not accessing the most novel treatment studies and the most novel drugs.

A logical question to ask ourselves is: Why would we care? If you're not facing a problem, it's hard to understand. [However, beyond] social justice and trying to reach equity for all patients, even from a biological standpoint, when we achieve [better outcomes] in trials in populations that look like the real-world population, the evidence is much stronger. We have a better biological understanding of how certain compounds behave in different circumstances, [as they may not perform] the same in a patient with a genetic background from, for example, Latin America vs a patient from Europe vs a patient from Asia. All these differences make the evidence stronger, so it's helpful for everyone.

We were expecting to see a difference [in clinical trial availability between the higher-income and lower-income countries], but we were not prepared to see such a big difference. To put it into proportion, [regarding the] odds ratios [we used], for the high-income countries, we used the reference of an OR of 1. However, for the upper-middle-income countries, the OR decreased to 0.215. In the lower-middle-income countries, it decreased further to 0.056. Finally, for low-income countries, the possibility of accessing a clinical trial went much lower, [with an OR of] 0.013. That's a striking difference.

What economic factors were significantly associated with RCC trial availability?

The main factor was health expenditure. That's the strongest association we found. [This means not only] how much economic strength there is in every country, but how much money [the countries are] spending on health. Sometimes [these 2 factors do] correlate, but not many times, and not all the time.

What were some of the limitations of this study?

We used a single, US-based database. We are as good as the tools we have. There are other databases for clinical trials, but we wanted to at least show disparities in the biggest one and the one that's more widely available around the world. I would love to have a global database that is not dependent on a single country or a single institution, such as the National Institute of Health.

Other than that, I think the data [from this study are valid, and not only for RCC. We did the same analysis [focused on] bladder cancer [and led by Koral Shah, MD, of City of Hope Comprehensive Cancer Center] and the findings were similar. [These disparities are] not a problem we're seeing only for patients with RCC.

How do this study's findings underscore the need for greater clinical trial accessibility in low- and middle-income countries? What strategies could these countries implement to increase clinical trial participation in underserved regions?

That's the million-dollar question because it depends on many different factors and stakeholders. Pharmaceutical companies have an economic interest in doing these trials, but [oncologists] should partner with them. [Enacting change in this area] does not depend on a single group of people.

Governments should be actively engaging with pharmaceutical companies to have these types of trials available for their own populations. [We should also leverage] international agencies—like the World Health Organization, for example—that make specific efforts into making clinical trials available globally, to decentralize these trials. It's important to understand even the technical aspects of how a certain drug in a region that has certain weather or certain exposure to risk factors is going to affect patients. As oncologists, we play an important role in advocating for this, in showing the data and showing that [these outcomes are] not a personal perspective but are strongly proven by data.

What questions remain unanswered that you would like to explore further?

Even though approximately 70% to 75% of RCC cases are clear cell RCC [ccRCC], I would love to see [the global prevalence of clinical trials] in the non-ccRCC setting. We have observed that in certain populations, there's a higher prevalence of, for example papillary RCC. It's important that our trials reflect real-world problems. Frequently, as oncologists, we tend to see that the populations that are included in clinical trials tend to be younger, healthier, and more fit for these trials. Therefore, we rely on real-world data to understand whether specific interventions are going to benefit patients. We need to know, so we need to generate these data.

Are there any steps that individual institutions can take to help mitigate these disparities in clinical trial access?

To be completely honest, I do not think [this is an issue] that a single institution would be able to solve, because it is such an international problem. However, on the institutional level, it is important to trust the partners we have in other countries, to start building bridges and not gatekeep research efforts in a certain region. The Genitourinary Cancers Symposium, for example, is a great way to establish conversations and reach out to people from other nations to understand their needs and how we can start building these programs. If we don't talk about it, and if we don't make a statement and understand that this problem exists in many countries, it's going to be hard to start taking actions to solve it.

What is your main message to colleagues based on this research?

We need to rethink clinical trials and how we make them available. This is not only a conversation about being fair—which is an important point—but also about making patients live longer, [increasing access to] better treatments, and [helping the oncology field] better understand toxicity, so we can prepare ourselves. Now that the political landscape is changing, it's important to have a call to action for an international effort and not concentrate science in a single region.

Reference

Barragan-Carrillo R, Zugman M, Castro D, et al. Assessing global disparities in clinical trial availability for renal cell carcinoma (RCC). J Clin Oncol. 2025;43(suppl 5):449. doi:10.1200/JCO.2025.43.5_suppl.449