Persistent Disparity: Socioeconomic Deprivation and Cancer Outcomes in Patients Treated in Clinical Trials.

PURPOSE: Patients with cancer living in socioeconomically disadvantaged areas have worse cancer outcomes. The association between socioeconomic deprivation and outcomes among patients with cancer participating in clinical trials has not been systematically examined. METHODS: We examined survival outcomes for patients enrolled in phase III and large phase II clinical trials for major cancers conducted by the SWOG Cancer Research Network from 1985 to 2012. Socioeconomic deprivation was measured using trial participants' residential zip codes linked to the Area Deprivation Index (ADI). Five-year overall survival, progression-free survival, and cancer-specific survival were examined using Cox regression frailty models, adjusting for age, sex, and race, and separately for insurance status, prognostic risk, and rural or urban residency. RESULTS: We examined 41,109 patients from 55 trials comprising 24 cancer histology and stage-specific cohorts. Compared with trial participants in the most affluent areas (ADI, 0%-20%), trial participants from areas with the highest socioeconomic deprivation (ADI, 80%-100%) had worse overall (hazard ratio [HR] = 1.28, 95% CI, 1.20 to 1.37, P < .001), progression-free (HR = 1.20, 95% CI, 1.13 to 1.28, P < .001), and cancer-specific survival (HR = 1.27, 95% CI, 1.18 to 1.37, P < .001). The results were similar after adjusting for insurance status, prognostic risk, and rural or urban residency. There was a continuous increase in risk of all outcomes as the ADI quintile increased. CONCLUSION: In patients with cancer with access to protocol-directed care in clinical trials, high area-level socioeconomic deprivation was associated with worse survival. Future research should examine whether the etiology of this residual disparity is related to reduced access to supportive care or postprotocol therapy and/or to differences in health status not reflected by protocol selection criteria.

A phase 2 study of ATRA, arsenic trioxide, and gemtuzumab ozogamicin in patients with high-risk APL (SWOG 0535).

High-risk acute promyelocytic leukemia (APL) remains a therapeutic challenge, with higher associated rates of early mortality and relapse than standard-risk APL. All-trans retinoic acid (ATRA) plus arsenic trioxide (ATO) is a well-established treatment for patients with standard-risk APL, but it is not well defined for those with high-risk APL. In a prior study of patients with high-risk APL, the addition of gemtuzumab ozogamicin (GO) to ATO plus ATRA suggested benefit. The SWOG Cancer Research Network conducted a phase 2 study to confirm the efficacy and safety of the combination of ATRA plus ATO plus GO in treating high-risk APL patients. The primary end points were 3-year event-free survival (EFS) and early (6-week) death rates associated with this combination. Seventy patients were treated. With a median follow-up of 3.4 years, the 3-year EFS and overall survival estimates were 78% (95% confidence interval [CI], 67%-86%) and 86% (95% CI, 75%-92%), respectively. Overall, 86% of patients achieved complete response. The 6-week mortality rate was 11%. The most common treatment-emergent toxicities during the induction phase included febrile neutropenia, aspartate aminotransferase/alanine aminotransferase elevation, hyperglycemia, hypoxia, headache, and prolonged QT interval corrected for heart rate. Retinoic acid syndrome occurred in 9% of patients. Approximately 37% of patients did not complete all planned courses of postremission therapy. The combination of ATRA plus ATO plus GO in high-risk APL patients was effective and generally well tolerated, suggesting an opportunity to offer a chemotherapy-free induction platform for patients with this disease. This trial was registered at www.clinicaltrials.gov as #NCT00551460.