What is the extent of disparities in cancer clinical trials among low- and middle-income countries?

New research reveals that the number and complexity of cancer clinical trials since 2001 have varied across low- and middle-income countries (LMICs), with economic growth contributing to disparities, but only to a certain extent. The findings are published by Wiley online in CANCER, a peer-reviewed journal of the American Cancer Society.

Although LMICs are expected to experience the greatest global burden of cancer in the coming years, cancer clinical trials are disproportionally concentrated in high-income countries. Because evidence suggests that LMICs have increased the number of cancer clinical trials over the last few decades, researchers investigated disparities in the number and complexity of such trials among LMICs over time and according to economic changes.

Between 2001 and 2020, a total of 16,977 cancer clinical trials in LMICs were registered. The Asian countries of China and South Korea experienced strong economic growth and increases in clinical trials. Similar trends, though less impressive, were observed in East European countries and the West Asian/Southern European country of Turkey. Conversely, South and Southeast Asian countries like India, Thailand, and Vietnam—which also experienced strong economic growth—had mainly inconsistent growth in clinical trials. The North and South American countries of Argentina, Brazil, and Mexico were able to increase their number of clinical trials despite relative economic stagnation. Among African countries, Egypt showed strong economic growth with a corresponding increase in clinical trials, but no such correlation was seen in South Africa.

Taken together, the findings suggest that economic growth is a contributor but not the single determinant of cancer clinical trial growth among LMICs.

“We believe these data offer valuable insights for LMICs aiming to enhance clinical research,” said senior author Max S. Mano, MD, PhD, of the Latin American Cooperative Oncology Group and Einstein Hospital Israelita, in Brazil.

Additional information
NOTE: The information contained in this release is protected by copyright. Please include journal attribution in all coverage. A free abstract of this article will be available via the CANCER Newsroom upon online publication. For more information or to obtain a PDF of any study, please contact: Sara Henning-Stout, newsroom@wiley.com

Full Citation:
“Disparities in Cancer Clinical Trials Among Low- and Middle-income Countries: a 20-year Analysis.” Fanny G.A. Cascelli, Milene C. Mitsuyuki, Gustavo Werutsky, Carlos H.E. Barrios, Malu V.R. Barbosa, Michelle S. Almeida, and Max S. Mano. CANCER; Published Online: October 20, 2025 (DOI: 10.1002/cncr.70067).
URL Upon Publication: http://doi.wiley.com/10.1002/cncr.70067

Author Contact: Cauana Tavares, of the Latin American Cooperative Oncology Group, at cauana.tavares@lacog.group.

About the Journal
CANCER is a peer-reviewed publication of the American Cancer Society integrating scientific information from worldwide sources for all oncologic specialties. The objective of CANCER is to provide an interdisciplinary forum for the exchange of information among oncologic disciplines concerned with the etiology, course, and treatment of human cancer. CANCER is published on behalf of the American Cancer Society by Wiley and can be accessed online. Follow CANCER on X @JournalCancer and Instagram @ACSJournalCancer, and stay up to date with the American Cancer Society Journals on LinkedIn.

About Wiley      
Wiley is a global leader in authoritative content and research intelligence for the advancement of scientific discovery, innovation, and learning. With more than 200 years at the center of the scholarly ecosystem, Wiley combines trusted publishing heritage with AI-powered platforms to transform how knowledge is discovered, accessed, and applied. From individual researchers and students to Fortune 500 R&D teams, Wiley enables the transformation of scientific breakthroughs into real-world impact. From knowledge to impact—Wiley is redefining what's possible in science and learning. Visit us at Wiley.com and Investors.Wiley.com. Follow us on Facebook, X, LinkedIn and Instagram.