Socioeconomic Factors, Not Race, Influenced Myeloma Survival in Younger Patients

August 23, 2016

Socioeconomic factors affected the care and survival of younger patients with multiple myeloma, but race/ethnicity itself did not influence survival.

Socioeconomic factors affected the care and survival of younger patients with multiple myeloma, but race/ethnicity itself did not influence survival, according to the results of a study published in Cancer.

Although there have been advances in the treatment of multiple myeloma in the last few years, improved survival has been seen predominantly among young and white patients.

“This finding strongly suggests that there is a huge disparity in outcomes that could potentially be overcome by improving access and affordability of treatments,” said study researcher Luciano J. Costa, MD, PhD, of the University of Alabama at Birmingham, in a prepared statement. “With the recent emphasis on comparative effectiveness in oncology, it also becomes crucial that all variables affecting outcomes-including sociodemographic factors-are accounted for when comparisons between different therapeutic approaches and health care systems are made.”

Costa and colleagues used data from the Surveillance, Epidemiology, and End Results (SEER)-18 program to identify patients with myeloma diagnosed prior to age 65 between 2007 and 2012. They found 10,161 cases of myeloma and looked at socioeconomic variables among these patients to see what factors might be causing this gap in survival. The median follow-up of patients was 27 months.

In an adjusted analysis of the SEER data, the researchers found that marital status, insurance status, and county-level income, but not race/ethnicity, significantly influenced overall survival. Specifically, shorter survival was associated with not being married, being uninsured, and residence in a county in the lowest two quartiles of income.

“The treatment of multiple myeloma has become prolonged, expensive, and complex. It is conceivable that patients who are not married and have low income have a more fragile support network with which to cope with the challenges of multiple myeloma treatment, which ultimately may influence access to novel therapies, hematopoietic stem cell transplantation, and the adequate management of recurrent disease,” the researchers wrote. “Yet another possibility is that patients with unfavorable sociodemographic factors also have more serious comorbidities affecting their ability to fully benefit from therapy.”

Patients with none of these socioeconomic factors had a 4-year estimated overall survival rate of 71.1%. In contrast, patients with one of these factors had a 4-year estimated overall survival rate of 63.2%; two factors, 53.4%; and three factors, 46.5%. The researchers’ analysis showed that patients with one socioeconomic factor had a 42% increased risk for death (hazard ratio [HR], 1.42 [95% CI, 1.28–1.57]), patients with two factors had more than twice the risk for death (HR, 2.15 [95% CI, 1.91–2.41]), and patients with three of these factors had almost three times the risk for death (HR, 2.81 [95% CI, 2.42–3.26]).

“Subsequently, we wanted to exclude the theory that competing causes of death were biasing the main analysis by estimating the relative survival for the main groups of interest,” the researchers wrote. “We verified that marital status, insurance status, and county-level income also were predictive of relative survival.”

Costa and colleagues then stratified patients by the number of adverse socioeconomic factors identified in the main analysis. Looking at the data this way, there was no consistent trend associating race/ethnicity with overall survival.