Assessing patient withdrawal in cancer clinical trials: A systematic evaluation of reasons and transparency in reporting.

• DOI: 10.1200/jco.2025.43.16_suppl.e23003
• Publication Date: 2025-05-28T17:31:48Z
• Authors: Anna Argulian; Alexander B Karol; Rodrigo Paredes; Kasopefoluwa Ogun...; Lexi S. Weintraub; Justin Miller; Yu Fujiwara; Himanshu Joshi; Deborah Blythe Do...; Matthew D. Galsky

e23003 Background: Patient withdrawal in oncology clinical trials ranges from 5% to 45%, posing significant threats trial integrity. High attrition rates can lead underpowered studies, selection bias, diminished generalizability, and wasted resources. Despite the importance of mitigating withdrawal, reasons extent are often poorly documented. The lack standardized practices for documenting reasons, coupled with infrequent use written consent forms, introduces ambiguity interpreting patient intentions limits on further participation (Cleland et al. 2004). To best our knowledge, this is first study systematically assess trial-reported cancer trials, aiming improve design data reliability. Methods: We reviewed all therapeutic phase III conducted between August 20th, 2014, 2024, ClinicalTrials.gov database. Supportive care without a consort diagram or descriptive equivalent were excluded. Withdrawal defined reason was considered investigator-initiated specified cause (e.g., noncompliance, request, loss follow up). Results: 300 165,674 patients across 14 primary types median follow-up 35.6 months (25th–75th percentile: 4.4–66.8 months) included, while 40 (11.8%) excluded due unavailable data. Included predominantly unblinded (185 61.6%) randomized (263 87.7%) designs, control arms utilizing placebo treatment alone (92 30.7%) standard (173 57.7%) therapies. Documented recorded Table. ranged 0-64.4% per (25th-75th 4.5-10.5%). Of who withdrew reason, 60.1% (N = 10,638) patient-initiated, 25.7% 4,435) investigator-initiated, 10.0% 1,769) labeled as lost follow-up. Conclusions: 14.9% discontinuations initiated by investigators reasons. enhance integrity transparency, future efforts should prioritize key stakeholders developing requiring documentation more clearly withdrawal. Reasons discontinuation. Reason # (% discontinuations) Progression disease 41,656 (36.8%) Death 30,620 (27.1%) 16,842 (14.9%) Treatment-related adverse effects 10,742 (9.5%) Sponsor termination 5,420 (4.8%) Other 4,008 (3.5%) Ineligibility 2,952 (2.6%) Max benefit 879 (0.8%)