Socio-economic Inequalities in the Utilisation of Novel Anti-Cancer Therapies

Abstract

Novel anti-cancer therapies use tumour biology to stratify patients on the likelihood of pharmacological response. Historically, conventional cancer treatment follows a socio economic gradient. It is unknown if novel therapies are subject to similar inequalities. This thesis aims to determine whether there are socio-economic inequalities in the utilisation of novel anti-cancer therapies. First, a systematic review and meta-analysis which synthesised evidence for socio-economic inequalities in novel therapy and predictive biomarker test utilisation was undertaken. Worldwide, low socio-economic status was associated with modestly low predictive biomarker test utilisation (OR 0.86, 95% CI 0.71, 1.05) and significantly lower precision medicine and biological therapy utilisation (OR 0.83, 95% CI 0.75, 0.91). Study data was primarily American, and inequalities varied by cancer type (larger in lung than breast cancers). Second, an observational study was conducted using English population-based cancer registry data linked with the Systemic Anti-Cancer Therapy (SACT) dataset on 40,179 women, diagnosed with HER2+ breast cancer between 01/01/2012 - 31/12/2017. Multivariable logistic regression determined likelihood of trastuzumab utilisation by deprivation (measured by IMD quintile). For women living in the most deprived areas compared to the least deprived, modest trastuzumab utilisation inequalities were found (mvOR 0.92, 95% CI 0.85, 0.99). Finally, a second observational study of the English population-based cancer registry data linked with the SACT dataset on 195,387 NSCLC cases diagnosed between 01/01/2012 - 31/12/2017 was performed. Multivariable logistic regression determined likelihood of any novel therapy utilisation by deprivation (measured by IMD quintile). For NSCLC patients living in the most deprived areas compared to the least deprived, significant novel therapy utilisation inequalities (mvOR 0.54, 95% CI 0.50, 0.58) were observed. Despite treatment advances and regardless of healthcare system or cancer type, a low socio economic status was associated with reduced novel anti-cancer therapy utilisation. Further work should explore why these inequalities occur to develop equitable approaches to therapy utilisation.