Brief Report: Should a prior cancer history be reevaluated as an exclusion for clinical trial participation?

Background: Clinical trials are designed to minimize factors capable of influencing patient outcomes beyond the specific diseases and treatments being studied; however, exclusion of prior cancer (PC) patients could potentially affect the generalizability of study results. We attempted to create a real-world proxy of recent immunotherapy trials in stage III and IV Non-Small Cell Lung Cancer (NSCLC) to understand the relevance of a PC history using the National Cancer Database.

Methods: Patients diagnosed between 2017 and 2020 were stratified by the presence of a prior cancer history and propensity matched to compare receipt of immunotherapy with those who did not. We analyzed overall survival using Kaplan Meier analysis and Cox proportional hazards models.

Results: The addition of immunotherapy to a regimen of chemotherapy and radiation was associated with superior survival whether stage III NSCLC patients had a PC history (HR): 0.65 (95% CI 0.59, 0.71) or had no PC history (HR:0.69 95% CI: 0.66, 0.72). The addition of immunotherapy was also associated with superior survival for stage IV patients with a PC history (HR) 0.78 95% CI 0.72, 0.85) or without PC history (HR:0.75 95% CI: 0.73, 0.78).

Discussion: Examination of real-world outcomes of two practice-changing trial regimens found the innovative treatment approach to be superior, regardless of patient PC history. Risk for a second malignancy is a reality of improving cancer treatment, thus, to individualize treatment for patients based on their personal and tumor attributes, cancer survivors will need to be included in trials.