The topic of healthcare disparities has been receiving increased scrutiny lately, yet no studies have investigated the potential impact of the socioeconomic status of patients with cancer on their likelihood to enter an early-phase clinical trial. Ensuring access to clinical trials to all patients is important not only to ensure equal access to care but also to make sure that clinical trial results can be generalized to all patients in the real-world setting. For the first time, a team of British researchers has recently investigated this question, revealing important implications for healthcare stakeholders (Noor AM, et al. J Clin Oncol. 2012;31:224-230).
The study was conducted by researchers from King’s College, and from Guy’s and St Thomas’ NHS Foundation Trust, London, United Kingdom. The team reviewed referrals to phase 1 clinical trials at their center in southeast London during the 5 years between June 2007 and January 2012. Socioeconomic status was defined by the Index of Multiple Deprivation (IMD), with score 1 (IMD1) being the least deprived and IMD5 being the most deprived status. A multivariate analysis was used to compare incident cancer cases with patients who were referred and those who were eventually enrolled in a trial.
During the study period, 430 patients (median age, 62 years) were referred to the early-phase clinical trial unit at the center. A population of 10,784 patients with cancer and known IMD status was used as a comparator cohort. A univariate analysis showed that those with IMD5 (most deprived status) were significantly less likely to be referred to an early-phase trial (odds ratio [OR], 0.66; 95% confidence interval [CI], 0.48-0.90). This difference was even greater after a multivariate analysis; the adjusted OR indicated a 50% reduced likelihood for a referral for a patient with IMD5 compared with IMD1 (OR, 0.53; 95% CI, 0.38-0.74; P for trend = .002). However, once patients were referred, IMD status no longer affected the actual enrollment in a trial. Of the 430 patients referred to the unit, 174 (40.4%) were enrolled in a clinical trial.
Age <72 years did not affect trial enrollment, but older age did: all patients aged >72 years were less likely to be referred to the early-phase trial unit than patients aged <72 years. In addition, ethnicity was found to be a factor in unequal referral practices, with nonwhite patients being less likely to be referred to the unit than white patients (OR, 0.48; 95% CI, 0.26-0.88), but this difference was lost when adjusting for age, sex, cancer type, and deprivation index.
