Two Decades of Global Cancer Clinical Trial Development Marked by Disparities

With the worldwide growth and expansion of cancer research programs in recent decades, a new 20-year analysis published in Cancer reports unequal development in cancer clinical research among low- and middle-income countries (LMICs), suggesting some influence of economic growth in the magnitude of development.¹

In the study, investigators examined temporal changes in the number of cancer clinical trials and analyzed correlations to changes in gross domestic product per capita in countries classified as LMICs in 2000 by the World Bank, amassing information on 16,977 trials between 2001 and 2020 from the National Institutes of Health’s ClinicalTrials.gov database.

Notably, East Asian countries experienced the greatest growth in cancer clinical trial volume. With a total of 5285 clinical trials over the 20-year period, China was the top performer of all countries analyzed; South Korea trailed with 2686 clinical trials. These countries’ clinical research development strongly correlated with economic growth, exhibiting correlation coefficients of 0.93 and 0.97, respectively. Conversely, South and Southeast Asian countries such as India, Indonesia, the Philippines, Thailand, and Vietnam saw limited growth in clinical trials but strong economic growth. However, such growth was associated with economic growth in only Thailand (0.76) and Vietnam (0.83).

A pronounced rise in clinical trial volume was likewise observed in Eastern European countries, including the Czech Republic, Romania, and Russia, with considerable economic growth found to strongly correlate with the increased volume (0.89, 0.97, and 0.90, respectively). In Africa, only Egypt showed sustained growth; South Africa experienced stagnation and a decline in clinical trial volume. In the Americas, sustained growth was observed in Argentina, Brazil, Chile, and Mexico.

As secondary objectives, investigators also broke down the number of clinical trials by phase and type of funding source or sponsor for each country, finding that China had the highest growth in the number of phase 1/2 studies. Additionally, pharmaceutical-sponsored trials were predominant in South American, South and Southeast Asian, North American, West Asian/Southeast European, and Eastern European countries. In contrast, the proportion of pharmaceutical-sponsored trials fell in China by 41% from 2001 to 2010 and 33% from 2011 to 2020, while the proportion of independently sponsored trials increased by 6%.

“These data reinforce the need for initiatives to support cancer research in LMICs,” the authors, Cascelli et al, said in the paper.¹

Scaling Up Research to Confront a Rising Cancer Burden

As the global burden of cancer rises along with increases in population, life expectancy, and urbanization, LMICs are projected to shoulder a disproportionate burden, currently representing over half of new cancer patients and deaths worldwide.²

Although the volume of cancer research has expanded and globalized to address this burden, challenges remain for LMICs in conducting and participating in clinical research, in part due to infrastructure and technology requirements, as well as overreliance on pharmaceutical industry–sponsored clinical research, which generally attempts to answer research questions that are more applicable and beneficial for high-income countries. Further, despite overall global improvements in research quality, LMIC participation in clinical trials has historically been concentrated in larger phase 3 studies, which may not be as relevant to LMICs to address local needs.

The findings from this study reinforce the importance of LMIC research participation and development of cancer clinical trials, underscoring the need for continued research efforts. Regarding the variable associations between clinical trial volume and economic growth observed in the study, while determining specific causes is beyond the study’s scope, these findings suggest that economic circumstances are not necessarily a determining factor of research output and that all LMICs have the potential to overcome barriers to become leaders in cancer research.

“Our data suggest that periods of economic woes—that are not unusual on the long road to economic development—should not be a deterrent to continued [clinical research] development. By unmasking the unequal [clinical research] development among LMICs, this study may serve as a roadmap for LMICs willing to match the top performers,” the authors concluded.

REFERENCES:

1. Cascelli FGA, Mitsuyuki MC, Werutsky G, et al. Disparities in cancer clinical trials among low‐ and middle‐income countries: a 20‐year analysis. Cancer. 2025;131(21). doi:10.1002/cncr.70067

2. Bamodu OA, Chung CC. Cancer care disparities: overcoming barriers to cancer control in low- and middle-income countries. JCO Glob Oncol. 2024;10:e2300439. doi:10.1200/go.23.00439