139 - Characterization of Laboratory Eligibility Criteria In Phase III Oncology Trials: A Meta-Epidemiological Analysis
Presenter(s)
O. O. Pocha1, A. M. Miller2, N. Meimoun2, J. Liu2, R. Kouzy2, T. A. Lin3, P. Msaouel2, E. B. Ludmir2, and A. D. Sherry4; 1Tulane University School of Medicine, New Orleans, LA, 2The University of Texas MD Anderson Cancer Center, Houston, TX, 3Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX, 4Department of Radiation Oncology, Mayo Clinic, Rochester, MN
Purpose/Objective(s): Randomized clinical trials (RCTs) are crucial to improving cancer care, yet trial participation is exceedingly low. Eligibility criteria, specifically laboratory-based, may unnecessarily restrict patient participation in oncology RCTs and may be unrelated to the study question at hand, especially if copied over from previous protocols or templates. The goal of our study was to characterize the prevalence and specificity of laboratory-based eligibility criteria in phase III oncology RCTs and to explore trial characteristics associated with their use.
Materials/Methods: We conducted a meta-epidemiological study using phase III oncological RCTs published on ClinicalTrials.gov. RCTs were categorized by the presence of laboratory eligibility criteria and by whether criteria were defined using specific versus vague terminology. Multivariable logistic regression analysis was used to estimate the adjusted odds ratios (aOR) for relationships between trial characteristics and outcomes. Confounders were identified using directed acyclic graphs and statistical significance was defined as p <0.05.
Results: A total of 1,180 RCTs enrolling 889,541 patients were included in the study. Laboratory eligibility criteria were used in 63% (n=740) of trials. Renal (n=697) and hepatic (n=696) criteria were reported in 59% of the trials, hematologic (CBC) criteria in 52% (n=618), while electrolytes were reported in only 3% (n=38). Industry-sponsored trials were less likely to use laboratory eligibility criteria (aOR 0.53; 95% CI 0.38-0.73; p = 0.0001), whereas cooperative group trials were more likely to use them (aOR 3.11; 95% CI 2.17-4.44; p <0.0001). Among the trials using laboratory criteria, 54% (n=389) included specified values while 46% (n=351) used vague terminology. Industry-sponsored trials were less likely to report specific criteria (aOR 0.14; 95% CI 0.09-0.22; p <0.0001) as opposed to cooperative groups, which were more likely to include them (aOR 8.47; 95% CI 5.35-13.4; p <0.0001). Considerable heterogeneity was observed in hepatic and renal thresholds, especially estimated glomerular filtration rate (eGFR) and alkaline phosphatase values, while CBC and electrolyte parameters revealed greater consistency.
Conclusion: Our study demonstrated that over half of phase III oncology RCTs included laboratory thresholds in their eligibility criteria, with an additional half employing vague criteria. RCT laboratory criteria that lack specificity and/or relevance to the question or therapies at hand may inadvertently exclude patients who would otherwise be eligible for participation. Thoughtful use of eligibility criteria specific to each clinical trial may improve accrual and facilitate interpretation of future RCTs in oncology.