Inclusion of patients from Latin America in pivotal trials in genitourinary (GU) and cutaneous malignancies.

646 Background: Latin America bears an increasing burden of both genitourinary (GU) and cutaneous malignancies but remains underrepresented in trials shaping global standards of care. This gap raises ethical concerns and limits data generalizability. We assessed Latin American (LATAM) representation in landmark GU and skin cancer trials and explored ethical and strategic approaches to enhance equity. Methods: We reviewed practice-changing phase 2/3 trials in advanced GU and cutaneous skin cancers (melanoma, non-melanoma) published from 2015–2024. Data extracted included geographic origin, trial site distribution, and ethnicity reporting. Results: Overall, 46 pivotal trials (26 GU, 17 Skin) including a total of 38,900 patients were analyzed. LATAM sites appeared in 44 trials, but only 25 trials enrolled Hispanic/Latino patients (n = 2,459 patients; 6.3%). All GU trials referenced LATAM participation, though only a subset enrolled patients. Among melanoma studies, 15/17 (88%) mentioned LATAM participation, while 2 (12%) did not. Across the LATAM region, participation was unbalanced: Brazil (16 trials), Argentina (14), Chile (13), Mexico (12), and Colombia (6). Representation was higher in GU trials (Brazil 13, Mexico 10, Argentina 10, Chile 9, Colombia 4) versus skin cancer (Brazil 3, Mexico 2, Argentina 4, Chile 4, Colombia 2). Transparency was limited: only 2 trials reported Hispanic/Latino data in main tables, 5 in supplements, and 23 mentioned it in ClinicalTrials.gov. Conclusions: Only 6% of patients from Latin America were included in pivotal trials of genitourinary and cutaneous malignancies. Barriers likely included infrastructure gaps, regulatory delays, and limited funding. Policies mandating geographic representation, and context-adapted designs are urgently needed to move from intended participation to meaningful inclusion.