Analysis of socio-economic deprivation and cancer trial participation.

e13768 Background: Socio-economic deprivation is a determinant of inequities in cancer outcomes and might influence participation in clinical trials. We examine a zip code-based surrogate measure to assess participation in all phases of clinical trial at Europe's largest single site cancer centre. Methods: We identified 98,847 patients who attended The Christie Hospital NHS Foundation Trust in Manchester from 2018 to 2023. Level of deprivation was ascertained by matching patient’s current zip code to the English Indices of Multiple Deprivation (IMD) 2019 and assigning decile score (decile 1 representing the most deprived 10% of areas nationally). The deprivation deciles of the total population were compared with 4916 patients who consented to a clinical trial. Univariable analyses examined overall deprivation index, seven distinct deprivation dimensions, age, gender, ethnicity, cancer type, and distance to hospital. Multivariable analysis assessed dimension of deprivation adjusting for factors independently associated with consent. Results: Older patients (≥65 years) were underrepresented (OR, 0.629; 95% CI: 0.594–0.667; p < 0.0001), as were females (OR, 0.936; 95% CI: 0.884–0.991; p = 0.0238). Patients from out of region (≥50 km) were overrepresented (OR, 2.373; 95% CI: 2.210–2.547; p < 0.0001), as were patients with haematological malignancies in the trial cohort (vs. total population) (OR, 5.570; 95% CI: 4.556–6.878; p < 0.0001). There was no difference in representation between Chinese and White British, but Other White, Mixed, South Asian and Other Asian, and Black patients were underrepresented relative to White British. Patients from all deprivation deciles were represented in the trial cohort. Adjusting for age, gender, and distance to hospital, the most deprived patients (decile 1) remained underrepresented compared to the least deprived (decile 10). Income deprivation had the greatest impact, with 18.3% lower representation of the most deprived decile in the trial cohort (vs. total population), and 29.1% lower representation than the least deprived decile (OR, 0.817; 95% CI: 0.729–0.915; p = 0.0005; OR, 0.709; 95% CI: 0.627–0.801; p < 0.0001 respectively). In Phase 1 trials, this difference between most and least deprived increased to 34.8% (OR, 0.652; 95% CI: 0.498–0.852; p = 0.0017). The positive effects of being younger and living out of region were also significantly diminished among the most deprived. For example, in decile 1, the difference in representation between younger and older patients was 39.8% lower than in decile 10 (OR, 0.715; 95% CI: 0.559–0.915; p = 0.0075). Conclusions: At a large cancer centre in the public health sector in the UK patients from all deprivation levels participate in clinical trials but those from higher deprivation deciles are underrepresented. The strongest socioeconomic effect was observed for younger aged individuals, living out of region and in phase I trial participation.