Low Income Patients See Fewer Trial Benefits

Cancer patients who enroll in a clinical trial and have no health insurance, or are enrolled in Medicaid, the insurance program for low-income Americans, may not get the same benefits of successful trial treatments that other cancer patients do. Results from a separate study show that patients from socioeconomically deprived areas appear to have worse outcomes than their counterparts, even when treated on clinical trials with access to guideline-based cancer care.

Both studies were conducted by SWOG Cancer Research Network, a publicly-supported cancer clinical trials network funded by the National Cancer Institute (NCI) through the National Institutes of Health.  Both studies were also led by Joseph Unger, PhD, a health services researcher and biostatistician for SWOG at the Fred Hutchinson Cancer Research Center, and an expert on health disparities in cancer clinical trials.

One study, the subject of a September 6 oral presentation at the ASCO meeting, is the first to show a connection between insurance status and patient benefit in cancer clinical trials.

Gauging the influence of insurance status can be difficult because of the size of any given trial. So Unger analyzed data from 19 SWOG trials – large randomized phase III trials that enrolled a total of 11,026 patients. Treatments tested in the trials targeted a variety of cancers, from breast to lung to prostate, and proved to have a statistically significant overall survival benefit to participants. SWOG sites in both the NCI’s Community Oncology Research Program and its National Clinical Trials Network enrolled participants in the trials.

In cancer trials, overall survival is defined as how long a participant lives after they receive treatment, a measure of the efficacy of new interventions using drugs, surgery, or radiation. Unger wanted to determine whether the treatment effects on overall survival differed by age, sex, race and ethnicity, and insurance status. His results showed a discrepancy only for insurance status. Patients with no insurance or those enrolled in Medicaid had a smaller treatment benefit.

“We tend to assume that the relative benefit of a new therapy will be largely consistent across patient groups, so these results are concerning,” Unger said. “We may need to think about how we design our cancer trials so we’re accounting for these differences, and not misidentifying the benefits of the treatments we’re testing for important patient groups.”

In a separate poster presented on September 6, Unger will share research results that drive home the idea that disparities in clinical outcomes exist even after cancer patients receive high-quality treatment. Findings are highlighted in an ASCO media tip sheet distributed for the meeting.

In the poster, Unger and his SWOG team show that cancer patients living in socioeconomically deprived areas have worse cancer outcomes. The role of socioeconomic deprivation has not been systematically examined before in clinical trial patients.  

To conduct the research, the team examined survival for patients enrolled in all phase III clinical trials for all major cancers conducted by SWOG between 1985 and 2012. Using participant zip codes, and the Area Deprivation Index, a measure of 17 demographic indictators based on work by the federal Health Resources & Services Administration, the team found that trial participants living in the most socioeconomically deprived areas in the U.S. had worse cancer survival rates – even after adjusting for race and insurance status.

Unger said more research would need to be done to explain why cancer trial participants with no or low insurance, or who are from socioeconomically deprived areas, appear to have worse outcomes in clinical trials. However, he said that both analyses suggest that low income patients may have more difficulty accessing proper supportive care after their initial cancer treatment.

Both SWOG studies were supported by the National Institutes of Health through the National Cancer Institute under grant UG1CA189974.

Unger’s SWOG research team for the oral presentation includes Charles D. Blanke, MD, of Oregon Health & Science University; Michael LeBlanc, PhD, of the SWOG Statistics and Data Management Center and Fred Hutch; William Barlow, PhD, of the SWOG Statistics and Data Management Center and Fred Hutch; and Dawn L. Hershman, MD, of NewYork-Presbyterian/Columbia University Irving Medical Center.

Unger’s SWOG research team for the poster presentation includes Anna Moseley, MS, of the SWOG Statistics and Data Management Center and Fred Hutch; Scott D. Ramsey, MD, PhD, of SWOG and Fred Hutch; Ray Osarogiagbon, MD, of Baptist Memorial Health Care; Banu Symington, MD, of Sweetwater Regional Cancer Center; and Dawn L. Hershman, MD, of NewYork-Presbyterian/Columbia University Irving Medical Center.