Effect of distance to tertiary centre on enrolment of paediatric patients with relapsed or refractory cancer on early phase clinical trials in British Columbia

Objectives: Access to early phase trials for children with relapsed, refractory or progressive (RRPD) cancer is limited in Canada. Patients and families face barriers to access trials, which are poorly understood. The aims of this study were to assess availability of early phase trials and examine the impact of distance from home to study centre on trial enrolment among paediatric oncology patients with RRPD. Methods: Oncology patients <= 18 years at diagnosis who later had RRPD were identified retrospectively via registry at the only quaternary paediatric oncology centre in British Columbia (BC). We determined if distance to home, as calculated using geocoding software, was predictive of trial offer or enrolment. Results: Between January 2015 and July 2021, 266 patients experienced 396 RRPD events. Seventy-five patients (28.2%) were eligible for an early phase trial at least once. At first eligible event, 61 patients (22.9%) were offered trial (median age 11.8 years; 69.0% male; 46.0% with CNS tumour) and thirty patients (11.3%) enrolled. Distance was not associated with odds of offer (OR 1.01, CI 0.98 to 1.05) or enrolment (OR 0.99, CI 0.95 to 1.03) on univariate or multivariable analysis adjusted for sex and disease (OR 0.93, CI 0.86 to 1.00). For offered patients, 2-year event-free survival (EFS) and overall survival (OS) were 39.1% (CI 28.0% to 54.8%) and 51.8% (CI 39.9% to 67.2%), respectively. EFS/OS did not differ with distance or enrolment, but varied by disease (EFS P = 0.002, OS P < 0.0001). Conclusions: Children in BC with cancer and RRPD have limited access to early phase trials. Distance was not predictive of enrolment, suggesting that families travel to access therapy.