Thoracic Oncology Clinical Trial Eligibility Criteria and Requirements Continue to Increase in Number and Complexity

Introduction: Eligibility criteria and screening procedures are designed to optimize the scientific yield and maximize the safety of clinical trials. However, they may also heighten trial complexity, hinder enrollment, decrease generalizability, and increase costs. We analyzed the types and number of eligibility criteria and screening procedures among thoracic oncology clinical trials sponsored or endorsed by the Eastern Cooperative Oncology Group.

Methods: We identified trials and obtained protocols from the Eastern Cooperative Oncology Group website. Eligibility criteria were grouped and categorized as comorbidity (classified by organ system), administrative requirements, prior treatment, and measurable disease requirements. Associations between trial characteristics and eligibility criteria were analyzed by using the Kruskal-Wallis and Wilcoxon tests.

Results: A total of 74 lung cancer trials activated in 1986-2016 were identified. The total number of eligibility criteria was associated with trial principal therapy (a median of nine for surgical, 18 for radiation, and 20 for medical therapy [p = 0.02]), trial primary end point (a median of 20 for overall survival, 28 for progression-free survival, and 17 for other [p = 0.001]), number of therapies (p = 0.05), and year of activation (a median of 16 for 1986-1995, 19 for 1996-2005, and 27 for 2006-2016 [P < 0.001]). The increase in trial eligibility requirements over time was limited to medical therapy trials. Over time, there was also an increase in blood test screening procedures (p = 0.05) but not in imaging, cardiac assessment, or pulmonary function screening procedures.

Conclusions: The number of eligibility criteria and screening procedures in medical therapy lung cancer clinical trials continues to rise. Continued efforts to simplify protocol eligibility and procedures are warranted to promote trial adherence, enrollment, completion, and generalizability.